texts: Which aircraft had the shortest operational life?

texts:
I read in Wikipedia that the operational life of Consolidated B-32 was limited to just a handful of months (January to August 1945).

Please note that B-32 wasn’t an experimental model, but an aircraft which was industrially produced in relatively large scale, was issued to some operative wings and was engaged in some actual combat events, showing even several appreciated features.

Was it the most short-lived aircraft type, all that considered?

I mean, is there another military aircraft type, assigned for combat mission to operative units, which was discontinued earlier than the B-32 (only seven months after the beginning of service)?


texts: How can an F-22 Raptor reach supersonic speeds without having supersonic inlets?

texts: The F-22 Raptor and some other jets do not have inlet spikes, yet they are able to achieve supersonic speeds. How is that possible?


texts: How do high-wing and low-wing aircraft compare in terms of structural damage in a crash?

texts:
Which type of aircraft is more likely to avoid damage to the aircraft structure: high-winged aircraft or low-winged aircraft?

What factors influence the type of damage usually sustained during a crash?


texts: Why do some fighter jets have movable horizontal stabilizer instead of elevators installed on the stabilizers?

texts: I have noticed that the horizontal stabilizers on some fighter jets move up and down to increase and decrease the angle of attack, but on some airliners they use elevators to adjust the angle of attack. Why isn't this kind of system used on airliners?


texts: Is there a practical carbon-free jet fuel?

texts:
For example, when I want to use a small turbojet or low bypass turbofan as both the APU and bleed air supplier for blown flaps, ailerons, elevators, (like the ShinMaywa US-2 amphibious plane) and rudders, (and hot wing deicing) there's a lot of internal ducting, and a large number of them are quite narrow, so having soot in them is like having thrombus in capillaries, so it's best that it doesn't contain so much as a single carbon atom in it.

EDIT: OK, the small engine mentioned above is used as a gas generator, not for thrust, that's the main engines' job. For the sake of the argument, let us assume the main engines are not available for bleed air like in real-life large airliners because they are say mounted on gimbals in a tilt-turboprop. If this sounds artificial, how about having a complete set of blown surfaces so the tilt-turboprop can have control authorities in pitch, roll, and yaw at airspeed 0 knots, i.e. when it's taking off vertically. Being a tilt-turboprop means it can not have helicopter-like variable pitch propellers like the V22 Osprey and has to rely on external measures for attitude control.

EDIT: It doesn't matter how weak the alternative fuel is as long as it can support the small jet engine's N1 RPM. It is only for the small engine.


texts: Why can airliners not fly as fast as fighter jets?

texts: Why do passenger aircraft not fly at the speed of fighter jets? What factors stop them from achieving such speed?


texts: What is the difference between "sensitive" and "non-sensitive" altimeters?

texts:
In this answer reference was made to "sensitive" and "non-sensitive" altimeters.

What is the definition of each, what are the differences, and why would one be used in preference to the other?

And why isn't it called an "insensitive" altimeter?


texts: Why are the airport pressure values for "altitude" (inHg) and "sea level" (mb) slightly different on the NOAA web sites?

texts:
If one looks, for example, at the NOAA web site for Denver International Airport we see (at the time of posting this question) the Pressure/Altimeter is 29.78 inHg, the Pressure/sea level is 1006.1 mb and the temperature is 54F.  If we assume 1 inHg is equal to 33.8639 mb, then I would have expected 29.78 * 33.8639 = 1008.4 mb for the sea level value.  But the NOAA web page lists 1006.1 mb.  Why is there (always) a slight difference?
-thanks


texts:
Maybe this isn't the right forum for this question but anyway:

WHY does a jet engine work?

I know how it works: compress Air -> inject fuel -> ignite -> expand -> thrust

But why does this work? Some energy from the expansion is used to turn the turbine which powers the compressor. Why is this self sustaining?

btw: It seems to be tricky to keep a jet engine running. There are examples that airliner engines sometime stall (Loss of airflow/compression in the engine)


texts: How much computing power is needed to keep commercial and military planes flying?

texts:
I've always wondered, what sort of computing power is needed to keep modern commercial and military planes in the air?

There are many systems of a modern commercial plane (e.g an Airbus A350), that would need to be automated and controlled by computer, one example that springs to mind is autopilot, another is flight instruments.

Similarly I'm assuming that there'd be many systems (e.g fly-by-wire) that need to be controlled by computer in a modern military jet (e.g F-22 Raptor).

What sort of computing power is needed to run commercial planes and military jets, and how do they compare to each other, and how does their computing power compare to the computing power of modern commercial CPU's? (Could my 2nd-gen Intel i7 CPU, with the appropriate hardware to make it into a PC, hypothetically be able to control all the automated systems on a modern commercial plane or military jet?)


texts:
What would happen if I perform an emergency landing at an Air Force airfield?

Would they send fighters planes to intercept me?

Would they arrest me?

Would they detain my aircraft?


texts: What does happen when a supersonic aircraft passes another supersonic aircraft, regarding sonic booms?

texts:
I wonder about sonic boom existence and effects when two fast aircraft interact, for example:

When supersonic aircraft flying opposite routes cross each other, do pilots hear a sonic boom?
If they fly in the same direction, with the appropriate offset, does one hear a permanent sonic boom?
If two aircraft fly in opposite directions at Mach 0.6, can they create a sonic boom by adding their individual shockwave speeds?

Two Sukhoi Su-30MKI maneuvering, Wikipedia

Further than the sound aspect:

What are the effects on the aircraft?
Is there a distance after which the effects become insignificant?


texts: How can an airplane land if a hail storm damages the windshield?

texts:
I understand hail can be very damaging to an aircraft, in particular to the engines and windshield.

In the event that a windshield becomes cracked so that visibility is impossible, can pilots pop out the windows when at a lower enough altitude in order to see the runway?


texts: FAA Standards for oral examinations on Practical Tests

texts:
What level of detail should be expected from an FAA examiner when administering the oral portion of a Practical Test for adding an additional rating on a CFI Certificate in an Area Of Operation marked as NONE, or not required, on the Required Area of Operation Grid at the beginning of the Practical Test Standards?

Specifically, In adding a Multi-Engine Land rating to my CFII, columns I, IV, and XII in the table are annotated as None, indicating that they are not required to be evaluated on the examination. I realize that at the bottom, in the Note, it states that "At the discretion of the examiner, the applicant's competence in any Area of Operation may be evaluated". My question, however, is in what detail should I expect oral examination in these areas?

In particular, the source material for Area of Operation I, (Fundamentals of Instruction) is the FAA handbook FAA-H-8083-9A, (Aviation Instructor's Handbook), which I had to study extensively to take my Knowledge test 2 years ago, (which I passed), contains 228 pages of academic material sufficient for at least one full semester of undergraduate course in psychology, maybe two semesters, and, for all practical purposes, is of little or no value to an instructor's day-to-day activities. 80-90% of the material is academic analyses of what are common-sense concepts which the average instructor with any experience understands intuitively, but in all likelihood, cannot regurgitate from memory in the organization or structure as presented in this handbook.

I was told by my instructor that the oral portion of practical test are now defined as to be "Open Book", i.e., if you don't know for sure, you must simply know where to find it. So, for details from this Instructor's handbook, like for example, Maslow's Hierarchy of Needs, or the differences between Thorndike's Laws of Learning and Bloom's Domains of Learning, etc. etc., is a examinee on a practical test responsible to have this knowledge at his recall by memory without aid of the handbook, or is it sufficient that he/she be aware of it and know where to look it up when necessary?

Again, I am asking about an Area of Operation marked as Not required (although optional) on the Areas of Operation matrix for a specific Practical Test.


texts: “, remain VFR” — may I enter Class C airspace?

texts:
During a flight yesterday, the approach frequency for a local Class C was unusually busy. I was heading back to an underlying Class D and the frequency finally quieted down enough for me to poke in a call of Huntsville Approach, Cessna 123AB, VFR with request.

ATC responded with <identifier>, remain VFR. I am not positive whether he gave the full callsign or just Tree Alpha Bravo — either way, definitely not Aircraft calling. He did not instruct me to remain clear.

I understand that radar advisories are workload permitting for VFR traffic, and clearly ATC had all the workload they could handle. Does that reply establish two-way radio communication and thus permit entry into their Class C airspace, just without flight following? What if the reply had been Tree Alpha Bravo, remain VFR? Assuming it does establish two-way communication, is it good Aeronautical Decision Making to fly into known busy airspace without advisories?

Rather than requesting confirmation on a busy frequency, I descended below the shelf feeling like a scud runner. Approach and landing at the Class D were otherwise uneventful.


texts: What are the hinged(?) structures in front of the F-4 Phantom's intakes?

texts: What are the large flat structures on the sides of the F-4 Phantom directly in front of the engine air intakes? They are more or less square, and may be hinged vertically.


texts: Why the lack of faster piston-powered planes?

texts:
There aren't very many fast piston airplanes in production. By "fast" I mean, if you look back in the early to mid 20th century, before turbines won out, there were lots of piston airplanes in production that pushed the practical velocity limit of propeller-driven aircraft, cruising 360+ knots in military planes, sometimes as fast as 330 knots in commercial airliners. And this was with a terrible understanding of aerodynamics and piston engines compared to today.

Today, for both singles and twins, the fastest speeds around aren't much higher than 200 knots. ~240 knots in the case of the very fastest couple available airplanes like the Cessna 400 and fastest Mooney.

There are indications that with modern materials and engineering, much faster speeds can be achieved using piston engines already available. The Cobalt CO50 Valkyrie design claims to push a spacious 4 person cabin up to 260 knots with a single 350hp engine. The recently-certified Diamond DA-62 can move a spacious 7 passenger cabin at ~200 knots using only a pair of 180hp engines.

Why aren't there more faster piston airplanes available? Would the market not be interested in piston powered planes that could do 300 knots? Shouldn't you be able to make almost those speeds for a very small plane powered by a single commonplace 350hp engine? Shouldn't you be able to make those speeds in a more spacious plane with a pair of commonplace 350hp engines?

My understanding of the marketplace is that the #1 reason people choose piston is cost. And isn't the cost of operating piston engines, even two piston engines versus a single turboprop, much much lower? How much does a 350hp turbocharged piston engine cost brand new, 50k-60k dollars? So even buying a pair of them is 100k-120k dollars. And then how much does a single comparable turbine engine cost? ~800k dollars with proportionately higher rebuild costs per flight hour? Plus 20%+ higher SFC than a piston?

Basically, I see the Piper M600 listed at 2.8M USD, or the TBM930 listed at 3.9M USD, and I don't understand why it would be hard to achieve nearly the same performance for a fraction of the price using a pair of cheap piston engines. For example the Piper M350 has the same 6 passenger cabin as the M600 and also includes pressurization, and with a single 350hp engine makes over 210 knots on a very old airframe with a list price of under 1.2M USD. If you basically built the same airplane but reoptimized for twin engines and using modern materials and aerodynamics, shouldn't you be able to achieve near 300 knots by adding another piston engine? And shouldn't you be able to sell the resulting airplane for well under 2M USD and with a significantly advantaged SFC and therefore range and payload than the M600?


texts: What’s the purpose of the small “hole” in front of wing root on A320-214?

texts: Someone knows what’s the purpose of this little “hole”?


texts:
Ok, so I'm a student pilot, and I'm going over the Vx, Vy, Vne, ... etc., and I see that "maneuvering speed" (the speed at which you can safely apply full flight controls) "changes with weight".

Which airspeeds don't change with weight? I can pretty much guarantee the the takeoff speed changes with weight, as would flap operating speeds, never exceed speed, and cautionary zone, because that is just the basic application of physics (inertia).

Why do we treat maneuvering speed as the only variable airspeed?


texts: Why do some military aircraft carry two datalink pods?

texts:
I was taking a look at pictures of the SLAM-ER when I noticed an F/A-18C carrying two AWW-13 datalink pods on its left wing. Why carry a second one? Does it increase signal strength or something?

Source: https://commons.wikimedia.org/wiki/File:F-18C_with_SLAM-ER_missile_and_AWW-13_pods_in_flight.jpg


texts: How do I get a copy of a Pilot Operating Handbook?

texts:
I need the POH for a Cassutt Plus or any variation for a University Project but I can't seem to find anything on the plane.
Any other information (flight capabilities etc) would be helpful - with references if possible!
Thanks


texts: Is a VHF NAV receiver inherently capable of processing a LOC signal?

texts:
These last few weeks I have been flying a couple of different aircraft that had inoperative glideslope capabilities, but I was able to fly LOC approaches without trouble. In my career as a pilot and mechanic, I have always had the—possibly inaccurate—understanding that a VHF NAV receiver had the capability of receiving and processing both VOR and LOC signals.

My question is prompted by this answer to a question regarding flight plan equipment codes—and particularly the comment section of that answer. In the comments of that answer it was stated that an ILS capable VHF NAV receiver is necessary to fly a LOC approach. For the purpose of this question let's overlook the inaccuracy of the ILS part of that statement and instead consider the LOC capabilities of a VHF NAV receiver.

I understand that the additional requirements needed for ILS capability include a glideslope antenna (possibly included in the existing NAV antenna), equipment to process the frequency pairing, and a glideslope display. I know that all LOC frequencies fall within the range of VOR frequencies (108.10–111.95 MHz and 108.0–117.95 MHz respectively) and the frequency spacing is compatible. I also understand that the circuitry required for VOR signal processing includes circuitry not required for LOC signal processing (that circuitry which can deteriorate over time requiring the periodic VOR accuracy checks).

Given all this, my questions are:

Is LOC signal processing an inherent capability of a NAV receiver: Will any given VHF NAV radio receiver be inherently capable of processing a LOC signal, or is there additional circuitry required for that capability beyond that required for VOR signal processing?

And if not,

Are there NAV receivers incapable of LOC signal processing: If LOC signal processing is not an inherent capability of a VHF NAV receiver, are there NAV receivers that were built without the LOC signal processing capability? In other words, is it possible that a pilot or mechanic would encounter a NAV receiver that did not have LOC signal processing capability? More precisely—from a pilot's standpoint—might I encounter a NAV radio that I could use to navigate tuned to a VOR station but not a LOC station?


texts: Who controls airspace and time in my area on helicopters?

texts:
I live in Newport Beach which is located in Orange County, California. I recently moved to an area where helicopters fly once in a while at 2-3 am above my house. Since I live on a hill, the sound is pretty loud and it wakes me up at night.

I was wondering where can I find more information about who controls the airspace in my area in regards to helicopters and how I look up the rules. I've googled a few things but can't find any answers. I'm not sure if it is the FAA or the county or the city or the state. Any pointers in the right direction would be appreciated.


texts: How much simulator training for general-aviation?

texts:
How much training/refreshing is necessary/desirable for instructing general aviation pilots? All I see is commercial pilots been trained in simulators.

A real general aviation airplane might be not much more expensive than a realistic flight simulator (full-motion  simulators with hydraulics), but wouldn't training specific scenarios (like engines-off, bad weather) in a simulator be a significant enhancement in their education?


texts: Will two blades or three blades last longer on a hobby drone?

texts: Will it be better to run a lighter 2 blade prop vs a heavier 3 blade prop for longevity and battery life? they are the same length. I am curious if the extra weight of the third blade will inhibit the time..


texts: What are the standard ATC light signals and emergency messages?

texts:
Apart from 'mayday' which other common emergency messages are used? Is there any regulation regarding them?

Any other light are used by ATC than these? : https://learntofly.ca/wp-content/uploads/2010/11/ATC-Light-Gun-Signals.gif

Is it the same Emergency messages and  Light signals used worldwide or are they different US-Europe ?


texts: Why do the elliptical and the rectangular wing show different aerodynamic efficiency?

texts:
I understand the elliptical planform is aerodynamically the most efficient type of wing planform and generates the greatest L/Dmax, but it's difficult for me to understand why.

What makes the elliptical shape of a wing aerodynamically more efficient, say, compared to the rectangular type of a wing?


texts: Is/why isn't the Antonov 124 to 225 wing upgrade method common?

texts:
I'm told that wing redesigns (edit: for tapered, swept wings) are difficult, so variants of a model often do with a common wing optimized for the middle member.
But then I read the following:

Based on Antonov's earlier An-124, the An-225 has fuselage barrel extensions added fore and aft of the wings. The wings also received root extensions to increase span.

That doesn't look so difficult. Of course, the wing root would be a new design, but we still get to keep the rest of the wing. Perhaps the flutter modes are less favorable......but wouldn't that be more or less inherent to higher spans?
So: Is/why isn't this method used to design variants or derivatives of large airliners?


texts: Who assigns an arriving aircraft a runway and runway exit to use?

texts:
I recently bought a simulator for tower controllers (Tower! 2011) and have some questions about the responsibilities of the tower controller:

When an aircraft wants to land at 'my' airport I get contacted once they are established on the approach path and already have a runway assigned ("Tower, N1234 with you runway 26L").Unfortunately sometimes it happens that aircrafts are assigned a runway that is actually to short form them to land - which I found out the hard way by getting punished because the plane was not able to stop on the runway.Who is responsible to assign the correct runway in real-life, the tower controller or the approach controller? If if were up to the approach controller that would basically be a bug in the simulator.
Who decides which runway exit an aircraft will use after landing?Again in the simulator I can advise the aircraft to taxi to the terminal via a certain route ("N1234 taxi to terminal via L4 M4 N4") with L4 being the exit from the runway I want this aircraft to take. Unfortunately the aircrafts - in the simulator - decide which exit they are going to use on their own. So it might happen that the aircraft I assigned the route to exits the runway at exit L5 and therefore cannot comply with my assignment.How is that handled in real-life? Does the pilot land the plane and then report back where he is (if I queried the airplane for a position I get a "N1234 is on the ground") or does the tower controller assign an exit that the pilot needs to take - and therefore the simulator would have a bug?


texts: Are airliners' pilots trained to safely ditch an aircraft?

texts:
After reading this question and these two answers it is clear that ditching is taken into account, at least for biggest airliners (and with reasons as it occured several times in aviation history).

Pilots are trained to face many technical problems that may lead to an accident (engine flame-out, cabin fire, partial loss of hydraulic power, partial loss of flight computers,...).

But, many airlines pilots do not posses the qualification (nor the training) to pilot specific categories of aircraft such as fighters, gliders or seaplanes. Thus it makes sense to assume they are not trained to fly in formation or land on water.

Is an airliners' pilot trained to ditch as he is trained to deal with technical emergencies? If not, what is its knowledge of such situation (only theorical, practice once on simulator,...)? Is there differences between country's regulation?


texts: Why did Boeing keep using yokes while Airbus moved on to sidestick?

texts:
The first Airbus had yokes but they changed to the sidesticks after a while But Boeing is still stuck with yokes even with 777-300ER decades later.

The sole purpose of the yokes are seemingly for the Cessna students to stick their charts and for some instructions on the airliners which I think isnt worth blocking the screenes.

One more thing. Is it true that its impossible to manual reversion an sidestick aircraft?

Why though? Boeing simply wants to keep R&D low or there are some other reasons? They are known for using the same design to keep costs down but didn't they ever tried to innovate the mechanics?

Perhaps just another example of design philosophy between the west and the east?


texts: What will the 737 MAX 7, 8, and 9 ICAO IDs be?

texts: Since the ICAO identifiers B737, B738, and B739 are already taken, what will the ICAO identifier for the 737 MAX 7, 8, and 9 be? Would it possibly be B73M7 etc?


texts: Why are some ATP CTP providers not on the FAA's approved list?

texts:
The FAA has published a list of ATP CTP provider schools. But I can still find other schools not listed in this list, like "ATP flight school".

I'm sure that only approved facilities can provide an ATP CTP course. What's happening here?


texts: What is the difference between high altitude vs low altitude approach?

texts:
Is there any factor that influences the decision of whether to take a high or low instrument  approach (e.g. Hi Tacan or Low Tacan)?

What are the differences between these two approaches?


texts: How much of an airplane's forward energy is lost to lift?

texts:
An airplane needs to move forward to generate lift, and because energy isn't created from nothing, all the kinetic energy of lift comes in the form of drag, where air (air resistance) turns forward motion into upward motion.

Some of the drag on an airplane is therefore "productive" in that it produces lift, and some is "unproductive" in that it takes forward motion from the plane without providing lift.

What percentage of an airplane's forward kinetic energy loss due to drag is productive as opposed to unproductive?


texts: What is the pressure on the pressure side in relation to the freestream?

texts:
The following [edited] images are from a network post:

The top image states on the pressure side, the pressure is greater than the freestream.

On the bottom image, the $C_p$ varies.

According to the pressure coefficient equation:

$$C_p = {p - p_\infty \over \frac{1}{2} \rho_\infty V_{\infty}^2 } = {p - p_\infty \over p_0 - p_\infty }$$

The area marked in blue for the pressure side ($C_p$ in the negative), the pressure is lower than the freestream. In magenta (the leading and trailing areas) it's greater than freestream. (If I'm reading this correctly.)

When all areas are combined for straight-and-level flight, what would the overall pressure be in relation to the freestream? Is the top image still correct with an overall greater pressure?

The question came up in chat and I'm not sure anymore. Of course pressure distribution will vary with speed and airfoil shape, so it's a general question. Any extra information on how speed/shape affect the pressure side is welcome of course.


texts: Why don't airliners have rudders on the winglets?

texts: There are a couple airplanes out there that use the winglet as the rudder, but why doesn't the winglet have a rudder on it to increase the turn of the aircraft?


texts: Why does U.S. airspace revert to class E above flight level 600?

texts:
According to Wikipedia, airspace defaults to class E below 18,000 feet AMSL (that is, all airspace below 18,000 feet AMSL is class E unless otherwise specified), whereas all airspace from 18,000 feet AMSL through FL600 is class A... but, above FL600, U.S. airspace reverts to class E.

Why does U.S. airspace revert to class E above FL600, instead of simply staying class A all the way up?


texts: Is the airspeed for the minimum the same for the theoretical power required curve as for the shaft power required curve?

texts:
I am aware that the efficiency of the propeller implies a difference in the values of the theoretical power required curve and the corresponding shaft power required, but does that efficiency correction change the abscissae of the respective minima...?

In this diagram (taken from von Mises' 'Fluglehre') the power is specified as 'Zugleistung', i.e. as the theoretical power drag (thrust) x velocity. All usual power required diagrams use that 'theoretical power'. My question is: If we took instead the shaft power, would the airspeed for the minimum of shaft power be the same...?


texts:
I see a lot of planes using thrust reversers and stopping in the middle of the runway in plane spotting videos, but I don't understand why they do it when they can obviously not use the reversers and still stop safely.

Also, doesn't it waste fuel? Don't airlines prioritize fuel savings over stopping faster? Why are reversers used even when they don't need to be used?


texts: If stealth aircraft are invisible to radar, then how does their own Air Force manage them or see them in flight?

texts:
Air traffic controlling is a significant deal when it comes to air forces. If a stealth aircraft like the F22 is almost invisible as said, it has cross section of very small metal ball. Then, how does US Navy/Air Force see their own aircraft in the air.
Possibly GPS/datalink?
As often said, stealth are not invisible but harder to detect, even then it will create huge problems for operating airforce to effectively see thier own aircrafts in the air.


texts: Why is the Aerodynamic Centre not affected by changes in Angle of Attack?

texts:
I understand that the Aerodynamic Centre (AC) is the point in the aircraft where the pitching moment never changes with a change in Angle of Attack (AoA). My understanding of the Centre of Pressure (CoP) is that it is the resultant pressure point in the airfoil and it slides rearward when AoA decreases and vice-versa, i.e. it changes its position with regard to the AoA.

Now the point is, how does the pitching moment (the force arm, i.e. the distance between the CoP and the AC multiplied by the force) remain constant when the CoP itself moves with the change in AoA?


texts:
For a personal flight simulator project, I am creating my own custom Boeing 747 classic series. I have about 50% of the project complete at a level of detail nearly equivalent to study-level flight simulators. I hope this is the right place to ask this.
Currently I am writing an autopilot that utilizes PID controllers. PID's are new to me so I am still learning a lot. I will do my best to explain what I need. If I am incorrect somewhere, please correct me!
The first controller I am attempting to write is for Heading Select, which will cause the autopilot to bank the airplane such that it will obtain and then maintain a selected magnetic compass heading. I have a lovely NASA paper, formed by collaboration with NASA and Boeing, that gives excruciating detail of the gains used for all autopilot modes. I also am referencing David Allerton's Principles of Flight Simulation for some basic examples.
According to NASA, for all lateral (roll) autopilot modes, the following fixed attitude and rate gains are used:
$\frac{\delta_a}{\phi}=3.2\frac{deg}{deg}$ and $\frac{\delta_a}{\dot \phi}=3.6\frac{deg}{deg/sec}$
This part already has me a small bit confused, but according to a later page, these are the gain values for roll angle and roll rate, respectively. The autopilot is limited to 12 degrees of aileron and 26 degrees of aileron deflection per second.
Source: https://ntrs.nasa.gov/api/citations/19730001300/downloads/19730001300.pdf
Pages 543 and 553
My best guess as to what these were, were the P and D values for an aileron controller (P value of 3.2 * bank error, D value of 3.6 * roll rate) but I am not sure of this. Testing the PID controller with this method, the aircraft does indeed roll to assigned headings, but the roll rate can be very high and does not seem well controlled.
The whole controller looks like this. The gain value of 2.83 is directly from page 553 listed above for the gain value of Heading Select mode on bank angle calculation.
$0.0016175\mathit{V}+0.110375 $ minimum $0.353$ maximum $1.0$ - This is a multiplier on the gain for heading select mode, proportional to true air speed (V)
$2.83$ multiplied by that True Air Speed modifier is the gain for Heading select, $K_p$
$K_p$ * heading error = target bank angle, $\phi$, maximums $\pm 30$ degrees left or right
Target Bank angle - Current Bank = Bank error
Bank error * $0.1$ = Target Roll Rate, $\dot \phi$, maximums $3$ $deg/sec$
Target Roll Rate - Current Roll Rate = Roll Rate Error
Bank error * $3.2$ = Proportional aileron deflection $P$
Roll Rate * $3.6$ = Derivative aileron correction $D$
$P+D$ = Total aileron deflection, maximums $\pm 12$ degrees
So that leaves me with figuring out how to get the deflection rate (how quickly the autopilot moves the ailerons). I am not sure how to calculate that with what I have and I find that my autopilot is completely ignoring the maximum roll rate information, accelerating very quickly into a bank.


texts: What stops Germanwings 9525 happening again — a suicidal pilot crashing the plane?

texts:
I'm unpersuaded and still afraid, after reading What safety rule replaced the now-rescinded two-person rule (after Germanwings 9525)?. What's to stop or prevent another lone suicidal pilot from crashing the plane by suicide? Pilots and people can easily lie about whether they have psychiatric illness. They can readily fake and lie through medical exams and psychological evaluations. Psychiatrists’ experiences of suicide assessment

One of the respondents, however, argued that it was not up to the doctor to question the narrative of the patient.

” It is not the least difficult to lie to one’s psychiatrist, it is rather easy, it is very easy. It isn’t our job to unveil the patient’s untruths.”

The truth about lies

"It’s not just common, it’s ubiquitous," notes Barry Farber, PhD, a professor in the clinical psychology program at Columbia University’s Teachers College and the editor of the Journal of Clinical Psychology: In Session. "Lying is inevitable in psychotherapy," he says.

Farber isn’t just speculating—he’s studied this topic for decades. In a survey of 547 psychotherapy clients, 93 percent said they consciously lied at least once to their therapist (Counselling Psychology Quarterly, Vol. 29, No. 1, 2016). In a second survey, 84 percent said this dishonesty continued on a regular basis.
And while therapists might suspect that they can tell when patients are being less than truthful, research shows this is not the case. In Farber’s study, 73 percent of respondents reported that "the truth about their lies had never been acknowledged in therapy." Only 3.5 percent of patients owned up to the lies voluntarily, and in another 9 percent of cases the therapists uncovered the untruth, notes Farber, who reports on this and related research in a new book, "Secrets and Lies in Psychotherapy," with co-authors Matt Blanchard, PhD, and Melanie Love, MS. "It seems therapists aren’t particularly good at detecting lies," Farber says.

So, in other words, what measures are currently available to prevent unstable pilots from causing harm, given that the psychiatric tests are evidently unreliable?


texts: Why do buses at some airports differ from conventional ones?

texts:
Why do buses at airports differ from conventional ones?
Why do they have such wheels or cover wheels at all?

Source.


texts: What causes the nose landing gear knocking noise on a Boeing 777 while taxiing?

texts: The NLG knocking noise heard on taxi-in to stand, what could cause this knocking noise?


texts: Why is 0 ft a valid target altitude for an autopilot?

texts:
Inspired by this story;

  The pilot of a Flybe plane that dropped 500 ft (152m) in 18 seconds had
  selected the wrong autopilot setting shortly after take-off, an
  inquiry has found...

  ...The plane climbed to 1,500 ft, but then pitched and "descended
  rapidly" because the autopilot was set with a target altitude of 0 ft.

Why is 0 ft a valid target value for the autopilot? Is there any practical use for being able to set it so low and are there safety features that would prevent the plane just hitting the deck?


texts: When calculating lift, using the the NASA lift equation, can any value be increased, ie. velocity or surface area, for increased lift?

texts:
I am trying to understand the breakdown of the NASA lift formula, which is written as such

$L = C_L \frac{\rho v^2}{2}A$

If I take for example CL=0.87, v=20m/s, ρ=1.22kg/m3, and A=9.02m2, my equation looks like this so far: Lift = (1/2) * 0.87 * 1.22 * 20^2 * 9.02. Can any one of those values be increased for greater lift? If I doubled my velocity would I double the lift that the velocity provides? But if I added 25% to the surface area of the wing, my drag also increases. How does that factor into lift? By decreasing velocity?

Does this equation scale in that way? I apologize if it doesn't make sense, I am not sure how to word the question well.


texts: What's preventing aircraft manufacturers to record every single possible value in FDRs?

texts:
The preliminary report of the ET302 crash included some data from the Flight Data Recorder. However, the position of the trim cutoff switches is apparently not among the recorded values.

Given that storage is so incredibly cheap nowadays compared to the price range of an aircraft, why don't manufacturers decide to record every single possible sensor value (including all switches in the cockpit) into Flight Data Recorders? Is this a purely economic decision to not do too much more than required by regulations? Or is there some other reason for it?


texts: Can a short in instrumentation wiring create enough 'spark' to ignite unvented fuel fumes?

texts:
Although this question relates directly to the NTSB findings on TWA Flt800, I was always puzzled and dissatisfied with the reason that failure in the instrument wiring harness inside the center wing fuel tank(CWT) caused the unvented fumes(a failure in itself) to explode; given that instrument circuits use microamps at 28vdc, resulting in less than .02Joules at best to transmit signals. A probe heater of course would be different, but that wasn't given as the reason. Are there any other instances where wires 'shorted' in an instrumentation circuit could cause sufficient energy to create a spark?

This question is not about "what really did happen" to TWA800; this is about whether or not the NTSB(National Transportation Safety Board) made a correct analysis in implicating Instrumentation Wiring.

Note

  A joule (J) is a unit of measurement of electrical work or energy; 1 J
  is the amount of work done by 1 watt of power in 1 second. The power
  supplied to the FQIS components through the cockpit fuel gauge (0.02
  mJ) is about 10 percent of the minimum ignition energy (MIE)
  requirement (0.25 mJ) for hydrocarbon fuels, referenced by the
  American Petroleum Institute Recommended Practice 2003 (API 2003),
  Protection Against Ignitions Arising out of Static, Lightning, and
  Stray Currents, fifth edition, December 1991 Taken from here


texts: How will a damaged logbook affect pursuing a career as a professional pilot?

texts: I recently damaged my log book by putting it in the washer machine. I have picked through all the pieces and saved what little legible logs are left. I have requested a copy of my 8710 from the FAA. With sudden funding I have decided to pursue a career as a professional pilot. I have contacted the owner of the previous aircraft flown and requested copies of the aircraft logs. With all the information, I plan on reconstructing my log book. My question is, with my 8710 proving that I did receive my license, I also had an additional 40-50 hours of flight time that I would like to put in my log book. Should I expect any future hiccups with additional ratings and employment as a pilot? What else could I do to make this process smoother?


texts:
On a fixed wing aircraft, if the aircraft's attitude is disrupted by a small angle and the controls are let go, it will slowly right itself to straight and level, due to built-in aerodynamic stability (on most aircraft).

If a helicopter is banked or pitched a small angle, will it right itself with the horizon if the controls are let go?


texts: Why did the CL-400 Suntan have engines on the ends of its wings?

texts: I've been reading more about the development of the A-12, which in turn referenced the CL-400 Suntan. I noticed that the engines are located at the end of the wing, rather than integrated with the fuselage or on the midpoint, which is not something I've seen (or at least noticed) on any other aircraft (the closest thing I'm aware of is tip jets on helicopters). What is the design rationale behind locating engines on the end of the wing, and indeed for other locations?


texts: Related to "How thermals are found" this question about "Gliding your plane to save fuel" details how to use thermals to save fuel. To use thermals to maximize range, can thermals be mapped in real-time using Doppler or sensors or a data base of some type to fly by?


texts: What does AO2 in the remarks of an ASOS/AWOS mean?

texts:
I occasionally see AO2 in the remarks of an automated weather report. What does the AO2 mean?

METAR KSLC 280453Z 00000KT 10SM FEW042 SCT055 BKN080 04/02 A2981 RMK AO2 CIG 037 NW RNWY SLP087 T00440022


texts: What causes spiral mode instability and how do you minimize it instead of trying to dampen it?

texts: What causes spiral mode instability in a GA plane and how do you minimize it in the first place, instead of trying to dampen it with dihedral (which is reducing efficiency by reducing vertical lift)?


texts: When a new plane is being tested, could it at some phase carry passengers (maybe for free).. Or does it have to be certified, before it can carry a single passenger. Could some one throw some light on any FAA regulation in this regard


texts: A Boeing 720 looked like a 707 but was the size of a 737. I flew in one in 1961. I did not travel regularly until 1970 but I do not remember ever seeing a 720 again. Was it intended to have limited production? Are there any 720's still flying?


texts: Where can fuel consumption data by aircraft type and route be found?

texts:
I am interested in building a data analytics platform for fuel consumption by aircraft type and route. I imagine this kind of information is readily available to airlines thanks to ACARS data. I need the data to build CO2 emissions models.

Are they any freely-available datasets or do I need to get this information from an airline directly?

Thanks!


texts: What is the function of ECS in airplane?


texts: What dictates the aspect ratio of an aircraft's wing?

texts: When designing an aircraft, there has to be a decision as to the aspect ratio of a wing. It's been said that having a higher aspect wing will reduce drag for the same wing area, however most of the time wings are shorter than they can be. So my question is, what exactly dictates the aspect ratio of a wing, and why don't they make them as long as possible?


texts:
I know that the IR - Instrument rating - is the full-blown option to be allowed to fly IFR. I also know that EIR - En-route Instrument rating - is an option to have a license that's restricted to fly IFR except for during takeoff and landing.

What is CBIR and what is Basic IR? I also heard that Basic IR will "come soon" and "replace EIR". What's the roadmap for EASA instrument ratings in the next years?


texts: Why was Air India flight AI101 diverted to SHJ 5 times in the past few days?

texts:
Air India flight AI101 using a 777-300ER on multiple westbound and eastbound routes was diverted to SHJ airport in Sharjah, UAE. I am curious if there is a specific reason. It cannot be a coincidence 5 times to the same airport.

Link to flight history: https://www.flightradar24.com/data/flights/ai101


texts: Why are AMRAAMs often mounted on the F-16's wingtip hardpoints?

texts:
If an F-16 is armed with AMRAAM and Sidewinder missiles, with regards to inertia and roll-rate, it would seem to make sense to mount the heavier AMRAAM closer to the fuselage, and the Sidewinder's IR sensor would have a smaller blind spot (created by the aircraft's fuselage) if the weapon were mounted farther away from the fuselage.
Why are AMRAAMs often mounted on the wingtip hardpoints (e.g. as in this picture), instead of the lighter and line-of-sight dependent Sidewinders?


texts: What makes the Air Force and Navy pilots different?

texts: As far as I know, aviation in both divisions are almost the same. They fly various aircrafts, they do dogfights, air to ground attacks, air transports, electronic attacks, and more. Can you say that Air Force and Navy pilots are different in some ways?


texts: How to choose the right ILS when the runway has more than one?

texts: I'm wondering how is the right choose when an runway has ILS x, Y, Z. What should I consider in order to pick one of those for landing?


texts: Is there a rule of thumb for aircraft design?

texts:
I'm wondering how to best scratch build an rc aircraft and what rough proportions the aircraft should be in.

I'm aware of the fineness ratio that determines the width to length ratio of a cross section of a wing should be around 1:3 or 1:4, but I can't seem to find similar rules for:

The distance between the wing and tailplane
The length of the wings

Am I just better off just making a scale model of an established aircraft instead of using these rules?


texts: Why don't most fighters have thrust reversers?

texts: With the exception of the Panavia Tornado, fighters do not have thrust reversers. Why is this? Why does the Panavia Tornado have them?


texts: What was enabling control to the pilot on the Snecma C-450 Coléoptère?

texts:
Looking at the Snecma C-450 Coléoptère, I was wondering about the (4?) fins towards its tail:

Source: Wikipedia

Were they able to pivot to help the pilot control the aircraft?
If not, what else was enabling control to the pilot ?


texts: Does a plane have more lift while flying in a cloud? (All other things equal...)

texts: Inside a cloud, the plane flies in a medium (air + water droplets) with a higher density than 'normal' air. If airspeed and AoA are the same, lift should be higher. It is really so...?


texts: What is the Effect of Unsynchronized Propellers?

texts:
A long time ago, I had the privilege of flying in 4 engine turboprop airplanes in which the props were 'synched'(blades rotating in same speed) which of course is necessary for smooth thrust.

However, one of the exercises we performed(as a military aircraft) was called a "crash and dash"; we dove as steep as we could until we could get as close as we could to the surface, then pull out of the dive and attempt to 'fly below' any surface radar that may be tracking us.

Every time we did this maneuver it threw the props out of 'synch' and cause the airframe to shudder violently. Anything that was literally not 'nailed down' was thrown through the cockpit or cabin.

My question is, what effect does this have on the airframe and does one of the events require an inspection, or shorten the check cycle?


texts: What is the highest number of airliners shown flying together in a single photo?

texts:
I was re-visiting this question about a timelapse photo of multiple airliners and started wondering about the maximum number of jetliners that could be photographed together while flying.  I have found cases of Airbus aircraft flying in formation for promotional purposes, (see 5 here  and 6 here) and I'm sure Boeing have done the same.  However I was thinking that a busy airport with a lot of aircraft in holding patterns waiting to land might provide an opportunity for more, even though they would be maintaining vertical separation.  Does anyone know of photos like that?
To be a little more precise in what I am asking for, I am looking for a non-edited photo showing the most airliners where the aircraft must be originally built to carry passengers commercially and must be flying (not one of the many reasons photos of planes in "storage" on the ground or stacked up for demolition)


texts: Why does a shrouded propeller have a lower downstream velocity than an unshouded propeller?

texts:
Why does a shrouded propeller have downstream velocity $V_3 = V_0 + w$, while the unshrouded propeller has a velocity $V_3 = V_0 + 2 w$?
What are the reasons of this difference?
$
\begin{align}
w &= \textrm{induced velocity of the propeller}\\
V_3 &= \textrm{exit velocity}\\
V_0 &= \textrm{free stream velocity}
\end{align}
$


texts: What radio frequency bands are associated with the long wire antennas, why do some aircraft have them and others don't?

texts:
On many older aircraft, and in vintage aircraft photos, you can often see long wire antennas strung from some point on the top of the fuselage to the top front of the vertical fin. On newer aircraft, it's either a rare find or not seen at all. The fact that some aircraft even today still have them leads me to wonder about their function - which radio frequency bands they are used for, whether those bands are no longer used, or whether the frequencies are still in use but the long wire has been superseded for most installations by a more compact antenna design.

Knowing that modern aviation radio operates in the 108-137 MHz band, and that most modern aircraft use much shorter rigid antennas, the long wire would seem to be inappropriate or unnecessary for that purpose. So, why would aircraft of a more modern design still be equipped with one? What other radio communication (presumably much lower frequency) would call for such an antenna?


texts: Is there a fixed ratio between highest L/D and max endurance L/D?

texts:
It can be demonstrated that, for any airplane, there is a fixed ratio between the maximum range and maximum endurance speeds (1.31607...).
Does another, fixed ratio exist between highest L/D and L/D at maximum endurance speed...?


texts: Can air to air refueling can be done in the rocket engines as done in the Aircraft jet engines?

texts: Can air to air refuelling can be done with rocket engines as is done with conventional aircraft jet engines? If no then what are the possible hazards or conditions preventing this?


texts: How often do talk-down landings go wrong?

texts:
There are some well documented stories of non-pilots successfully landing airplanes after the pilot was incapacitated. Usually this involves radio assistance by ATC and/or flight instructors.
My question is whether there is any statistical data available about the success rate of such landings. I would judge success by the lives saved by the landing attempt.
I am aware that the term "non-pilot" is somewhat vague, in that it could refer to anything from a complete novice to a student pilot or even a GA pilot trying to land a commercial jet. Any kind of statistical data involving people punching above their weight trying to land an airplane in an emergency would qualify as an answer.


texts: How is a 436 seater A330 fuel efficient?

texts: Cebu Pacific is a Philippine low-cost airline , which has 6 A330 in its fleet. The capacity of each of them is 436 . As far as I know, one of the reasons why airlines introduce First Class cabins is because its impossible for them to fly with a huge number of passengers and their luggage. It makes the plane very heavy and less fuel efficient. That's why, we don't have any A380 with more than a capacity of 550 , against its maximum of 853. But, how does Cebu Pacific makes profits from operating a 436 seater A330( which commonly has a capacity of 300 people)?


texts: Has a passenger's consumer electronic device ever actually caused a crash?

texts:
Most of us are familiar with the standard warnings and regulations against passengers using electronic devices (at all during takeoff and landing, and in some cases throughout the flight). This is based on a concern that sensitive avionics or aircraft radio equipment could be affected by interference from devices being used by passengers.
Has a commercial flight ever crashed as a direct result of a passenger using an ordinary consumer-grade electronic device during the flight? More specifically, has there ever been a crash investigation where the conclusion was e.g. that the plane wouldn't have crashed if the passenger in seat 5-F had turned off his Game Boy before takeoff?
To be clear, I'm not asking about why there are electronic device regulations or safety guidelines. I'm asking if these guidelines are purely theoretical (we're pretty sure that using them could cause a crash, even though it's never happened) or if there have been actual crashes due to device usage.
Also to be clear, I'm asking only about ordinary, consumer grade electronics (e.g. phones, laptops, tablets, beepers, walkie-talkies, video game consoles, etc.), rather than military or industrial equipment.


texts: My grandfather in the back seat apparently.


texts: What are the lines of triangles on the DCA RWY 19 River Visual approach chart?

texts:
A recent update of a certain flight simulator made me revisit this chart and I had not noticed the lines of triangles (at the Chain Bridge / Roosevelt Bridge etc, but not at the Key Bridge) in a past version, years ago.

What are they?  I couldn't find the information in the FAA Chart User's Guide.


texts: Why does the UK CAA medical questionnaire need to know hair colour?

texts:
The CAA (UK Civil Aviation Authority) application for a medical certificate asks for hair colour. Why? Are there any diseases / conditions more prevalent to particular colours? Most of the questions are seem to be rooted in common sense, but is hair colour really relevant?

Update in response to comments. Height, weight, sex, eye colour and race ALL have a relevance to medical conditions. Height and weight can indicate BMI and possible eating disorders, many conditions are gender specific, and some medical conditions are more common in different races (Cystic fibrosis is more common amongst northern Europeans, Sickle-cell anaemia is mostly a problem for those with African ancestors). Even eye-colour can (according to google) indicate a increased likeliness of a particular condition.
If hair colour really is there just for general identification purposes, then it's the only question on the form (other than name and CAA reference number) that has no medical purpose.


texts: What is more environmentally friendly? An A320 or a car?

texts:
Presuming the A320 is at least 80% full (of passengers) and comparing it to a typical road car with 2 people inside, which one is more environmentally friendly, per passenger mile?

I have attempted to do some rudimentary calculations, but then was reading that because aircraft release their emissions at altitude, this offsets (?) some of the environmental impact.


texts: What are the most challenging taxi manoeuvres that a typical commercial airline pilot must execute?

texts:
I am currently involved in a University level modelling excercise which looks to investigate the handling qualities of a novel nose wheel steering system.

As part of this study, I am interested in understanding what are the most challenging taxi manoeuvres that a commercial airline pilot would typically execute, both regularly, or in special circumstances.

Some specifics for the question:

I am primarily interested in answers from pilots of Single Aisle
sized airliners (A320 family, 737 series, etc.), although general
cases are also welcome.
I am interested in the kinds of manoeuvres which place the highest demand on the NWS system in terms of responsiveness, max rate demand, etc.


texts: What are the length requirement for US aircraft N-Numbers / registrations?

texts:
Many small aircraft registered in the US seem to have a registration that follows the pattern of N, 4 numbers, and ending in a letter. Sometimes they only have 4 characters, or less. And then there's the FAA Gulfstream N1.

Who decides on what the N-Number will be, and are there requirements for how long it should be?


texts: Is there a disadvantage to the "fan in fin" design seen for the tailrotor on many Eurocopter helicopters?

texts:
A quick google search will show that a lot of Eurocopter models have their tail rotors contained within their tail booms, while a look at Bell or Sikorsky models (and I'm sure others: I'm using Bell and Sikorsky because they're major non-European manufacturers) shows out-of-boom tail rotors. I can see a couple of advantages to the Eurocopter design:

Less danger: the fan blades can be protected from harm and be further removed from people.
Less noise: I don't have empirical evidence for this, but drawing on knowledge of other ducted systems, this design probably produces less noise, at least in the directions perpendicular to airflow.
Pure symmetry: maybe I just like this from an aesthetic perspective, but unlike the unbalanced external tail rotor design, the in-boom design is perfectly balanced.

Is this design less efficient? Is it the space constraints placed on the rotor by the boom?


texts: How does one launch unmanned high-altitude balloons without posing a safety risk to aviation?

texts: How can people launch balloons privately (filled with helium or hydrogen) that reach the altitude of 30,000 feet? Isn't that a safety risk in the same way as geese?


texts: Why Consumer Drones don't use multi-blade (more than 2) propellers?

texts:
Maybe unusual question but it's related to Aviation world, even if is more directly related to Drones one.

Why almost all consumer drones like DJI's and Yuneec's ones (but it's true also for other manufacturers) uses two blade propellers only?

I'd think that tri-blade or quad-blade could spin slower and so quiter.

Exist 3rd party multi-blade propellers compatible with commercial drones, so is possible to use them but what advantages/disadvantages they have? and again... why default ones are only two-blade?


texts: Why does 14 CFR have skipped subparts as seen in the ASA 2019 FAR/AIM book?

texts:
As an example, part 91.101 skips every even number until 91.126.

Why are they not in sequence as 101, 102, 103, etc?


texts: What are the major drivers of cost/price differences between Cessna 172 and Piper Cherokee?

texts:
This may be closed as opinionated but I'm looking for answers with hard data if I can get them. The Cessna 172 and Piper Cherokee are touted as two of the most successful light aircraft designs in the world, and they are primary competitors, with Piper originally designing the PA-28 Cherokee to be a lower-cost version of the Comanche that would compete directly with the 172 of the day.

However, in today's new market, a 2015 Cessna costs about \$370k, while Piper Archers (the continuation of the PA-28 airframe after Piper's corporate restructure) made in the last 10 years or so are selling for about \$200k. Cessna also seems to hold more value; "classic" 172 airframes from the 70s and 80s hold about a \$100k value in classified ads, while flight-ready Cherokees from the same time can be had for \$30-40k and a few Cherokee airframes are being offered at prices I've only ever seen 150s sold for (though there's likely something wrong with those examples).

The aircraft, while different externally (the 172's overhead-wing versus the Cherokee's low-wing design is the biggest difference), seem to have many similar specs on paper; passenger count, horsepower variants (Piper's actually better here as the 180hp variant was most common compared to the standard 172 powerplant at 160hp), instrument capabilities, etc. Cockpit pictures indicate the interiors are comparable; a bit dated as you'd expect from aircraft made 30 years ago, but perfectly serviceable.

So the question is, where's the additional retained "street value" of the 172 coming from? Is the 172 more well-reputed for safety or reliability? Are its handling characteristics considered better for everyday flight (perhaps due to the parasol wing)? Is this a question of average age of airframes? Is it just the Cessna name (in other words, am I comparing a Toyota Camry to a BMW 5-series)?

Obviously some of this stuff will depend on a comparison of specific hulls, but there's a definite trend; the market in general seems to value the 172 more highly than the PA-28 with all other things being equal on paper. The question is why.


texts: Why can't blimps be economical for commuter / public transportation?

texts:
I dont know what the net load is for a blimp, but if they could somehow carry 100-400 people, why coudln't they be used like ferries in metro cities like SFO and NYC? Even if they could only scoot at 60-100mph, they can cut clean across waterways and save a ton of time for commuters while (seemingly) being more efficient than fixed-wing aircraft as well as safer (engine failure? gently float down and call for help).
A bonus would be if they could convert their balloon into a flying wing shape in flight via compressing the gas, reducing volume, and having it fold into a wing-shape allowing them to increase speed. If they could get near 200mph, that could open up decent commuter service between LAX <-> San Diego. But even 60mph could connect the greater Los Angeles area. If the weather were bad, a cable-tethering system could be used to guarantee smooth landings (fly into the tether, grab it, command the cable to retract, thus pulling the blimp into the station).


texts: Why offload bags for missing passengers when flights are allowed to carry unaccompanied non-PAX air-cargo in holds?

texts:
Several times, my flight has been delayed when passengers don't make it to the gate in time and then (after a long wait) the baggage-handlers have to go into the holds and manually find the bags to offload.

First, is this a legal requirement? Do all carriers follow this same practice?

If so, then why is this a security risk any greater than the same flight anyways carrying air-cargo in its hold? Flights do that, correct? Not all cargo space is filled with checked-in baggage?

Does anyone know the rationale behind this calculation? If the hold anyways contains unaccompanied cargo then why treat unaccompanied passenger baggage as a high risk?

Also, historically, is there a record of such offloaded bags (for missing passengers) actually turning out to be containing explosives?


texts: When may I change my transponder code to 1200 when being handled by ATC?

texts:
When am I allowed to change my transponder code to 1200?
Is it after clearing the boundary of regulatory airspace (ie. airspace requiring radio contact and an operating transponder)?


texts: What does it cost to get an ATP certificate from scratch?

texts:
If someone decides to become a professional pilot - meaning an airline or business jet pilot in the USA - what does it cost to get the certifications and ratings and build enough hours to become employable? Let's assume that the person is starting from scratch and works through private, instrument, commercial and ATP qualifications.

I'm thinking of a scenario where someone already has a career and income but decides to change to flying and is able to invest the necessary time and money. Of course this could include other commercial flying jobs along the way - like crop dusting or banner towing - but the idea would be to eventually reach a position that pays a decent salary. "Decent" isn't very precise but I mean something much higher than the low regional salaries mentioned in this question.


texts: Does high density altitude affect your landing speed?

texts:
So I had this question asked in my recent commercial-pilot checkride:

The DPE asked me about high-density-altitude airports; he specifically asked me if I should add airspeed when I'm on landing approach to a high-density-altitude airport.
 My total understanding is that the ground roll and landing roll would be affected, as well as the climb, but I've never heard about landing speed being affected; I've been looking in books and researched on the web but I can't get a solid answer.


texts: Which channels to listen to on liveatc concerning arriving flights?

texts:
For fun, I decided to watch arriving aircraft to airports on flightradar24.
Now, what I'd like to do also is simultaneously listen to ATC traffic concerning these incoming flights.
I've found Liveatc.net and, for example, there're plenty of choices of channels for JFK airport.
Which channel should i listen to if I'm interested in the radio exchanges concerning holding patterns and final descents? Is this handled from the tower?

(If JFK isn't a good example, feel free to recommend any other airport, European airports preferred. I tried LHR, FRA and CDG but it seems they aren't covered by liveatc.)

So, the more general question is: how are the channels labeled on liveatc that are about holding patterns and approaches?


texts: Spanwise flow and wingtip vortices in forward-swept wings

texts:
One of the benefits of forward-swept wing is that spanwise flow direction is from tip to root. However, in this answer an X-29 has quite significant sweep angle, at which drawbacks such as aeroelasticity effects dramatically increase.

What happens to the wingtip wake on a forward-swept wing?

Here are some points I'd like to touch:

Does sweeping wings forwarg completely eliminate it, and if it
depends on sweep angle?
How to estimate sweep angle, at which the
spanwise flow starts to flow to the root?
Considering a tampered wing with only trailing edges swept forward, is it enough to get wing characteristics (primarily spanwise flow) like (or close to) forward-swept one?


texts: Should I switch the transponder to STBY or not while changing codes?

texts:
I´m now reading Bob Gardner’s book “Say again, please” and there is this instruction on page 54:

  Do not turn the transponder function switch to STBY while changing codes.

What is the reason for this? I’m a PPL student and my instructor told me the opposite.


texts: With flight dynamic equations, how do I return to positive alpha if alpha is always negative with negative w?

texts:
I'm coding a flight dynamics simulation, but my simulation runs into a problem with negative angles of attack. Once alpha is negative, it is impossible to get back to a state where the plane is generating positive vertical velocity.
At the start of each frame of the simulation we have some forward velocity ($u$) and vertical velocity ($w$), and at the end of each frame we calculate new values for $u$ and $w$. To keep things simple, assume the plane generates 0 lift at 0 alpha, we're always in level flight with no change to pitch or roll, and the pilot only makes changes to $u$ with the throttle.
If $u$ decreases enough that we generate less lift force than gravity, $w$ becomes negative and the plane begins to descend. The usual formula for angle of attack ($$) is a function of $u$ and $w$:
$ = arctan(w / u)$
This means a negative $w$ and positive $u$ will always give a negative $$.
I calculate lift with this equation (simplified. $q$ is dynamic pressure):
$L = 2π *  * q$
This means a negative $$ will always give negative lift.
And finally, the next frame's $w$ is just a function of lift and gravity (in level flight):
$w_{next} = w + L / mass - g$
So it is possible to have positive $$ and lift but end up with a negative $w$ due to gravity.
If a frame of my simulation ends with negative $w$, the simulation is put in a state where it is impossible to ever return to positive $$, because negative $w$ always gives negative $$. Negative $$ always gives negative $L$. And negative $L$ always gives negative $w_{next}$ Negative $w_{next}$ always gives negative $$ on the next frame.
Increasing $u$ eventually should return me to positive $L$ and $w$ as $q$ increases, but doesn't - it only generates more negative lift. What factors am I missing to be able to get back to positive $w$ with just an increase in $u$?


texts: How do people smuggle stuff with private airplanes?

texts:
I get it, the question seems as if I'm reaching out for answers from experienced smugglers! But no. As a matter of fact, I'm trying to get answers on air surveillance & security.

Love it or hate it, these kind of smuggles are being done all over the world. However, recently I heard a story from a retired soldier stating that he used to know people who knew people who smuggled jewelries, hard drugs, guns and even people from middle eastern countries to Europe, specifically, Germany! Via planes!

In fact, he said some stuff was too valuable for them to "risk it" by land transports. He added that the pilots were experienced World War II pilots who specialized in flying at high speed in very low altitudes to make deliveries for infantry units on distress, making them unnoticed on radars and unstoppable for air defense systems.

So that's for World War II, which ended on 1945, so the question is, how can people still do this considering all the enhancements and improvements or even inventions (which some boldly have "foolproof" labels attached to their names) implemented on radar and satellite technologies? Especially on a country like Germany, with superb defense and military status?


texts: Are there any aircraft powered by tip jets in the propeller blade?

texts: I am familiar with tip jet powered helicopter experiments. Is there any aircraft that use/used this mode and would it be useful to use a tip jet driven prop on aircraft instead of piston or turbine power?


texts: Where can I find a free list of ICAO and IATA airport identifiers?

texts: Is there an open source or free comprehensive (or close to it) list of ICAO to IATA airport identifiers? The official list from ICAO costs hundreds of dollars. I suppose such a list could be scraped from Wikipedia.


texts: How does Pitot Heat influence airspeed indication (assuming no ice or moisture)?

texts: Should Pitot Heat ON (in dry weather conditions) decrease airspeed indication because warmer (so less dense) air flows through the tube?


texts: Where can I find flight plan records for a private flight in the 1970s?

texts: How would I find a record of a private plane flight from Canada to the US in the early to mid 1970's? I am researching records of my father.


texts: Why are the wings of most passenger jets on the bottom?

texts: I have always wondered why most manufacturers put the wings on the bottom of commercial jets. Help would be appreciated.


texts: Is there any kind of removable ELT on board an airliner?

texts: Is there any equipment similar to an ELT on board on airline airplanes as for GA aircraft? Something that can be removed from the wreck in the event of abandoning the site of the crash.


texts:
How much drag does a RAT deployment add?

I was watching a simulator video of an A320 dual engine failure at low height during climb out and one step in the protocol was the pilot manually deploying the RAT.

Simulator Video

Since he doesn't manage to make it back to the runway from his 2000 ft engine flameout run I was wondering if not deploying the RAT would make any difference due to reduced drag?

Would the on-board batteries and windmilling engines be able to provide sufficient power for control surfaces?

Also, are there real life incidents of a 2000 ft (or lower) dual engine failure that made a safe return to the runway? Sully Sullenberger's A320 had reached approx. 3,000 ft, yet he was forced to ditch rather than return.

Does the energy management differ drastically from type to type? i.e. Among dual engined aircraft would some be easier to land from a 2000 ft dual engine failure than others? For typical climb profiles, weights etc.


texts: How many four-engine commercial passenger jetliner types are currently in use?

texts:
Just heard following somewhere:

It is easy to distinguish four-engine passenger jetliner type, because there are only three of them:

if it has "hump" upper deck then it is Boeing 747,
if it has two decks then it is Airbus A380,
otherwise it is Airbus A340.

Is this statement true?
I'm asking about commercial passenger jetliners only. So no cargo, no military etc.


texts: How to advise others of imminent danger?

texts:
In a case such as United 326 - where an aircraft got cleared for takeoff while other planes at the same time get cleared to cross that runway - how would an outside party that picks up on the mistake inform the others that a disaster is about to happen and that people need to take immediate action?

Would they call mayday, or just shout out in "freeform", something along the lines of "Imminent collision, runway 19C!".


texts: How can coefficient of lift on the ground with flaps in the takeoff position be calculated using airfoil data?

texts:
In essence I'm working on a design project and I'm specifically looking at takeoff analysis at the moment. I already have access to great textbook resources, but I'm struggling to determine the coefficient of lift $(C_{L_G})$ on the ground with flaps in take-off position for the following equation taken from Appendix K-4 of Synthesis of Subsonic Airplane Design by Torenbeek:

$$\frac{a}{g} = \frac{T}{W} - \mu - \left(C_{D_G} - \mu C_{L_G}\right) \frac{\frac{1}{2}\rho V^2 S}{W}$$

Similar equations can be found in other textbooks, but I haven't found any reference to how $C_{L_G}$ can be determined from airfoil data. Currently I'm considering just using the zero geometric angle (ie compensating for the AoA the wing is mounted at) coefficient of lift for the airfoil, but how would I then account for the position of the flaps?


texts: Taxiing with one engine: Is engine #1 always used or do they switch?

texts:
I recently travelled with an A320 and an A321 from FRA (Frankfurt) to TXL (Berlin) and back again. On this and on previous flights I already noticed a whining sound, much louder than other sounds, while we were still at the gate or soon after leaving the gate and starting taxiing. I cannot remember exactly. My research showed that this was the PTU's sound (aka “barking dog”), typical for an A320 and its sisters.

One of my references was this post. The author said:

  [The PTU can be heard]
      At the gate, especially if we taxi in on one engine.
      During the taxi, the left engine is running and pressurizing
      the green system.

This led me to this question:

When taxiing with one only engine, do pilots always use the left-most one (#1)?
Or do they randomly choose one of the two (or four)? If they always use the port/port outer engine, doesn't it wear out sooner? Or are the engines swapped at regular intervals (like car tyres  are swapped from front to rear)?


texts: Which models of the Boeing 737 are still in production?

texts:
The BBC is reporting that the production of 737 aircraft has been reduced from 52 to 42 per month due to a loss of 737-Max orders.  It isn't clear in the report whether the Max is the only 737 being made now.

Does Boeing currently produce any other models of the 737 or is the Max the only one?


texts: What is the scratching sound produced by aircraft on the ground (taxi-in/taxi-out)?

texts:
Since I have flown in aicraft as a kid, there was a sound audible when the aircraft is on ground (before taking off or after landing) which is similar to the sound a DJ does when he scratches the disks.

Sorry for the wird example, but I do not know how to explain it better. It is like the scratching of a disk and the sound starts at a higher pitch and it ends at a lower pitch. I am really interested in finding out what it is and why it happens, since I have never been able to find out how it is produced.


texts: How common are cancelled landing attempts?

texts:
I recently traveled from Stansted, UK to Skavsta, Sweden with Ryanair, and was informed that depending on the weather (it was very foggy), we might end up landing at Arlanda (~150 km from Skavsta) instead.

The pilot later decided to try landing, went down to what felt like 20–50 meters (I could see the airport as clearly as one can see an airport in thick fog...) and suddenly rose sharply and then leveled out, causing some serious roller-coaster-like ~0g feelings.

The pilot then tried a second time and landed without much trouble.

How often does this occur? Was it dangerous? Is it according to standard procedure when approaching an airport in bad weather conditions? What might have caused the pilot to actually land the second time but not the first?


texts: Does ICAO allow continued flight in RVSM airspace after a transponder failure?

texts:
If a civil aircraft's transponder fails in RVSM airspace, can it still be allowed to fly in RVSM according to ICAO?

And could it be allowed to fly in class A airspace, according to ICAO?


texts: Can an appropriately-fitted UAS (of any size category) be flown in Class B airspace?

texts:
If I fitted an Unmanned Aircraft System (UAS) with an operating Mode C transponder and maintained two-way radio contact with ATC, could my UAS be cleared into class B airspace in the USA?

(Inspired by:

What legal actions would be taken against a drone pilot if they flew a drone into class B airspace?
)


texts: Are steam gauges more reliable than glass panels?

texts:
I have always had a deep appreciation for technology and the future and I encourage that technology should move us forward whether that be in aviation terms or otherwise but one question has been on my mind for a very long time and that is why we have computerized gauges and not the old fashioned ones with the gauge hand behind glass. In the event that a plane loses power, wouldn't it be better to have physical gauges because if the plane loses power, those critical gauges on a screen will disappear. Is it just me or does it not make a huge difference? I suppose an old-fashioned glass gauge will stop too, just the same as a glass cockpit gauge?

Thanks. This is a question I have always wanted to ask someone who has the expertise to answer it.


texts: Would a 90 kg object jettisoned from an aircraft create a detectable movement?

texts:
I was reading the description of an old hijacking which has this snippet of interesting information:

  After takeoff Cooper told Mucklow to join the rest of the crew in the
  cockpit and remain there with the door closed..... At
  approximately 8:00 pm a warning light flashed in the cockpit,
  indicating that the aft airstair apparatus had been activated.... The crew soon noticed a subjective change of air
  pressure, indicating that the aft door was open. At approximately 8:13
  pm the aircraft's tail section sustained a sudden upward movement,
  significant enough to require trimming to bring the plane back to
  level flight. At approximately 10:15 pm Scott and Rataczak landed
  the 727, with the aft airstair still deployed, at Reno Airport....an armed search quickly confirmed that he
  was gone.

Would a 90 kg man jumping off the aft stairs of a B-727 in flight create a detectable "sudden upward moment". Not just a slight one but "significant enough to require re-trimming"?

Doesn't sound like a fluke or the product of a vivid imagination because we further know that:

  An experimental re-creation was conducted using the same aircraft
  hijacked by Cooper in the same flight configuration, piloted by Scott.
  FBI agents, pushing a 200-pound (91 kg) sled out of the open airstair,
  were able to reproduce the upward motion of the tail section described
  by the flight crew at 8:13 pm.

The full story is here:

https://en.wikipedia.org/wiki/D._B._Cooper

I'm estimating the mass of a fully-fueled B-727 as about 60,000 kg. A detectable perturbation by a 90 kg ejected body sounded a tad unlikely.

But I'd love to see a more accurate calculation. I suppose the center of gravity and the long lever arm for the aft stairs location will matter?

PS. It seems far more plausible to me that the movement detected was actually due to the aerodynamic forces on aft stairs and not the effect of the ejected 90 kg mass. The only reason I was rejecting this explanation was that the timing seems off if we are to believe the flight crew report:

They seem to have detected two events: A pressure change and later this reported sudden movement. So the movement does not seem correlated in time with the aft stair deployment.


texts: Where can I find a canonical list of sources for worldwide digital GA VFR maps?

texts:
Related question: Where can I find GA VFR maps for Australia?

For various areas of the world, where are authoritative General Aviation VFR maps, charts, and so on available on the web?


texts: Would a Chinook helicopter fly better with contra-rotating along with counter-rotating propellers?

texts: Would a Chinook perform better or have any advantage with dual contra-rotating propellers over a Chinook with just normal counter-rotating propellers?


texts: Has Airbus planned to build a larger version of the A380?

texts: The current Airbus A380-800 could carry over 800 people. Has Airbus planned to build a new, larger version that could carry 1000 or more passengers?


texts: Is it possible to design a helicopter with fixed rotor blades only (no blade angle/flap/pitch)?

texts:
I am not familiar with helicopter rotor design but I wonder if it is possible to build a working/flying helicopter with fixed rotors that cannot change the blade angle, flap, pitch or adjust blades otherwise?

I am curious whether the changes in rotation speed would suffice for controlling the aircraft. I guess the cheap RC helicopter models may use such simple design, but is it possible to scale that up to 1:1?

I mean propellers that are solid state and cannot be adjusted in any way except changing their rotation speed, like plastic props used in RC modelling. I do not mind if the whole helicopter design is a traditional main rotor + tail rotor or a coaxial rotor design.

I am interested in 1:1 scale size (at least the Mosquito personal helicopter size). Has anyone tried such simple design?

Also I consider electric propulsion where the RPM changes may be quicker that with internal combustion engines.


texts: Can a turbofan run without the fan to provide power without thrust?

texts: Is it possible for a turbofan jet - like on a 747 - to run without the fan, if for example you just want the thrust from the internal jet to use to heat up water, not to use as thrust?


texts: What's the point of having ILS on runway signs?

texts:
Runway signs show the ILS category next to the runway designation. But if you flew and didn't drive to the airport, you already know (hopefully). Either way, you are taking off, so you don't really much care. One might say that you will have to land again in case of emergency, but ATC might not give you the same runway. So what's the reason of showing ILS category on runway signs?

Note: I changed "markings" to "signs" in this question since markings are painted on the ground, signs are the red ones I am asking for.

EDIT: The linked question is not exactly the same:

What is the purpose of several mandatory stops (RWY AHEAD) at busy airports?

What are mandatory stops? How are they several? (I never noticed that). I didn't know all these until I asked about the "runway signs". The other question presumes that you are familiar with some terminology. And it doesn't mention ILS.

Also, it looks like a similar case. I vote for reopening.


texts: What are the bars protruding from this C-130?

texts:
This C-130 was photographed on approach to Ellington Field (EFD), Texas.

What are the protruding, truss-supported bars aft of and below the wing?

There's an airshow coming up in ~3 weeks at EFD, so it may have something to do with that, especially considering the fancy underwing paint job.


texts: Why do the flap maneuvering speed margins to stick shaker depend on altitude?

texts:
Why do the flap maneuvering margins to stick shaker reduce with increasing altitude?

Ref: It is written in FCTM of the Boeing 737-800:


texts: Can the debris pattern from a crash site confirm explosion as the cause of a crash?

texts:
Is there any precedent or can the debris pattern positively confirm the cause of a crash due to:

an internal explosion OR
strike from a missile or other military projectile?

If a particular flight path is necessary to facilitate the question, assume the 1988 Airbus flight.


texts: What were those two military helicopters that I recorded?

texts: I have recently recorded two military helicopters. Here is a screenshot of it:


texts: Why do we have to perform a normal APU shutdown if a fuel spillage occurs?

texts: I was reading in the limitations chapter of the A320 which stated that if a fuel spillage occurs we have to perform a normal APU shutdown what is the reason behind this?


texts: Why do older students take longer to learn to fly?

texts: I have heard or read many CFI’s say that older students take more time to learn to fly. I know that as we age our brains in general have more difficulty learning new things, but what part of flying is it that usually takes longer for older students? Do they have more trouble learning things like procedure, regulations and aerodynamics or is it the physical coordination of controlling the plane, judging distances, etc. that takes longer? Maybe it’s the multitasking involved?


texts: What's the name of this component of the turbofan engines?

texts: Almost many of turbofan engines that I've seen so far nowadays had a part like a small wing. what do you call them? here is some pictures of the thing I'm asking question about:


texts: What is the purpose of a fuse pin in a turbine engine?

texts:
what's the difference betweeen fuse pin and mounting bolts of an engine ? Are they the same ?
Any digram of a GE-90 engine showing those would be appreciated.


texts: Is it allowed to operate an aircraft when the Emergency Locator Transmitter has been removed?

texts: I purchased an aircraft from which the previous owner removed the ELT before I took possession; it was present during the test flight. I need to know what the minimum legal requirements are for a replacement. Can I use a personal unit which are sold everywhere or do I need a specific unit for general aviation?


texts: What is the difference between a tire deflation and a tire explosion?

texts:
In this question, our intrepid former 747 pilot Terry mentioned, in the accepted answer, that:

  As I understand it, tires that dangerously overheat will explode before melting, and that's why thermal plugs are used which melt and deflate the tire to prevent their exploding.

His understanding was confirmed by other comments and answers.

My question is what is the net difference between a tire deflating due to the plug melting and the tire deflating due to explosion? Either way, you're landing/taxiing with a flat tire.

The only thing that comes to mind is that once the plane is on the ground and stopped, an exploding tire might injure safety crews and/or pax evacuating.


texts: Why aren't Rogallo wings or parafoils used in aircraft with fuselages?

texts: I was wondering why no aircraft with a cockpit and fuselage use Rogallo wings or parafoils. I'm guessing they would have the advantage of low weight, collapsibility (storage), and low cost.


texts: What are the "panels" on the wingtips of the Panavia Tornado?

texts:
I am wondering about the purpose of the panel marked with the number 156 in this picture:

The same black panel can be seen on the wingtips here:

And also here:

What purpose does this panel serve? It could be just a construction technique, but in that case why would they cut a hole in the larger panel just to cover it up with the smaller black one?


texts: How do pilots manage their flight times?

texts: When flying double-digit hour flights, such as 13 hours from Chicago to South Korea or 18 hours from Singapore to Newark, New Jersey, everyone on the plane, including the pilots, will most likely experience jet lag, as the passengers will experience "nighttime" at some point and become sleepy. Since there are two pilots, the pilot and the copilot, how do they manage their time? Does the copilot start flying the plane when the pilot rests, or vice versa? Or do both stay awake for a grueling 18 hours? Or do they rely on autopilot?


texts: When to turn onto the initial heading on ODP

texts: I'm asking about the slight turn off of runway heading on Obstacle Departure Procedures (ODPs) that are sometimes textual or graphical and simply say "Climb heading 305 degrees...," but runway heading is like 311 degrees. I've looked at several ODPs and none say to climb to a certain altitude before making that initial heading change. I also read the FAA instrument flying manual and didn't find any guidance on this. The way its depicted on the graphical ODPs it appears that you make the adjustment when you are over the end of the runway, but I'd like to know if there is something official from FAA on when to change from runway heading to the initial heading of the ODP.


texts: How much power is needed by aircraft IFE systems during flight?

texts: How much power is needed by aircraft In Flight Entertainment systems during flight if they operate all the devices connected in the cabin?


texts: Is there a way, by which an airline or ATC would be alerted, if both pilots are asleep or incapacitated?

texts:
There are various questions around, which deals with what happens if both pilots are incapacitated, but my question is different.

I want to ask, is there a way by which an airline or ATC is alerted that both pilots are asleep or incapacitated, more like a camera which tracks eye movement, which would alert the pilots or cabin crew or ATC.


texts: Are you cleared to next altitude when you get "direct" while flying SID?

texts: Let's say you just took off from the TACOMA airport and were flying ATOME TWO DEP. ARRIE transition. The Seattle tower instructs you "direct to ZUMBI" and to contact Departure, and you contact Departure and report "Departure, N1234, passing 2000, direct ZUMBI." If departure just replies "N1234, Departure, Radar contact," are you cleared to the next altitude of KIMSH (at or above 10000ft) or should you maintain 9000 until Departure gives you higher?


texts: What could reasonably be done in case 7,500 airplanes must be landed quickly?

texts:
I read 5,000 to 10,000 aircraft are flying at a given time. There are several very unexpected but plausible reasons to land all planes quickly, e.g: a war / terrorism event; a giant volcano eruption); or a major meteorite impact

Whatever, in case there is a sudden need to stop flying, what would happen:

From an ATC standpoint, is there any impossibility to conduct such massive landing?
Is there enough runway throughput to allow planes to land quickly?
Is there enough room to park all aircraft?

Is there any preparation for this kind of operation in some countries?


texts: Is the true altitude always lower than the indicated altitude as long as a correct local altimeter (QNH) is set on the altimeter?

texts:
Given the fact that the altimeter setting is corrected for the temperature of the airport, on the condition that a correct local altimeter setting (QNH) has been made to the altimeter, is the true altitude always lower than the indicated altitude as the altitude increases above the airport elevation regardless of the temperature of the airport, since the temperature generally drops as the altitude goes up?
For example, even when the temperature in the airport is, say, above 30 degree Celsius, do we still fly lower than the indicated altitude of, say, 5000ft, just like when we do when the temperature is below 15 degree Celsius, standard ISA temperature?


texts: Why we don't see the "SkyRider" seats in action?

texts:
In 2010 nearly all newspaper reported on the new invention of the company Aviointeriors.
They created new airplane seats called "SkyRider" which you can "stand" in. This should increase Airlines profitability.
I'm not a big fan of the SkyRider seats but who can I thank, or why don't we see them in Action?


texts: Does ADS-B In receive track or heading angles?

texts:
I am reading this: https://mode-s.org/decode/ehs/bds50-track-n-turn.html

I am wondering the Track angle which ADS-B In recieve is really the track angle (derived from line joining the previous and current point) or the heading angle (or its body angle)?


texts: How, typically, do passengers and crew behave in a real-life airliner evacuation?

texts:
Two parts to this:

Do passengers tend to behave in ideal ways?
How do the cabin crew behave?

We know what's supposed to happen: the passengers are supposed to follow instructions, leave possessions behind not inflate their life-jackets inside the aircraft, and so on.

To what extent does this actually happen?

I know for example that passengers have inflated their life-jackets inside the aircraft (with tragic results, in the case of Ethiopian Airlines 961, where some passengers became trapped inside and drowned as a result). I can bet that some passengers will inevitably want to insist on gathering some tremendously important belongings.

I assume also for example that the management of the emergency exits isn't simply left in the hands of the passengers sitting next to them, but that the crew as far as possible take charge, and that generally they become ferociously assertive and intolerant of any nonsense from recalcitrant passengers.


texts: Is there any "instrument take-off system"?

texts: Flying close to the ground is really dangerous and yet needed to land and take off. ILS is designed to keep the adequate trajectory close to the ground with (almost) no visibility. Is there a similar system for take off, e.i. a system helping pilots to maintain the adequate trajectory near the ground with almost no visibility at take off?


texts: What kind of test is going on in this image?

texts:
Some times we see images of jet engines on the net that have strange colors. For example take a look at the bellow image. What the operator is doing? Why the color of blades are white with red on its borders? why are they numbered? why is the color of spinner yellow?

Source of image


texts: Why is this chart called a Short Field Effort Takeoff Ground Roll and not simply a Short Field Takeoff Ground Roll?

texts: What does the word 'effort' mean in this context?


texts: Is ILS secured from being hacked/overriden/disturbed?

texts: Since ILS uses radio frequency. Then is it possible that some one transmit a malicious signal on the same frequency ? Are there any measures to prevent that ?


texts: Instrument landing: why do all electronic devices need to be shut off?

texts:
A few days ago, I took a flight home. Towards the end of the journey, the captain asked us to shut down any electronic device that we had on board, including iPods, CD players, phones and so on, because there was very low visibility, and we were starting an instrument approach.

From what I could understand, an Instrument Landing  System (ILS) allows an aircraft to be centred on the approach path, assisted by radio signals delivered by an ILS (a localiser and a glide slope), without any visual reference. These signals are in the 110 MHz (LOC) and 330 MHz (GS) frequency range.

Given that for the take off, visual landing, and the journey itself, shutting off the devices is no longer required (even though there are radio signals being used for communications and navigation), why this extra precaution on a low-visibility ILS approach? What interference could a CD Player possibly produce with the instrumentation to an extent that it's more dangerous than with the normal take off,en route, and landing phases?

On a side note: as you probably understood, my level of expertise is very low, so forgive any dumb mistake or oversight.


texts: How many staff are needed to support aviation on an aircraft carrier?

texts:
An aircraft carrier is the largest type of warship and is used to transport, operate, and maintain military aircraft.

The staff which support aircraft in the carrier can be divided into 2 groups.

Some "variable" staff are directly related to the aircraft operation like Pilots, the number of those staff is proportion to the number of aircraft.

On the other hand the number of the "fixed" staff is fixed, regardless the number of aircraft, like Air Traffic Control.

How many of the 2 different types of staffs are employed? To simplify the answer, please use the biggest Nimitz-class as example.


texts: How is flight planning performed with short turnaround times?

texts: For low cost carrier short-haul flight such as Dortmund-London I have experienced multiple times that turnaround times are around 20-25 minutes. In such a short time what is included in the flight planning of the pilots. This time seems very short to perform flight planning, preparation etc. Is it generally the case that for repeating flight planning efforts and necessity are reduced by a significant amount?


texts: Is engine shp directly correlated with its payload capacity?

texts:
For a turboshaft engine, does increasing its shp also increase its payload capacity?
What are the other factors determining the payload capacity of a helicopter?


texts: How do large airliners de-ice in flight?

texts:
How do large airliners de-ice their surfaces in midair? In smaller planes like the ATR or the caravan there are deicing boots as per picture:

How is this achieved on bigger aircraft, as there seems to be no such mechanism?


texts: Is there anywhere one can buy or find plans to build a human powered aircraft?

texts: I was surprised to find that only two Gossamer Albatrosses were built. Is there any way to get or build an aircraft like that today? (I don't mean design your own).


texts: Do FAA sectional charts show all power/transmission lines?

texts:
The FAA's sectional aeronautical charts include some power/transmission lines. How complete is this?

I am specifically interested in using something like ForeFlight for aeronautical charts while hot air ballooning. Is this a fool's errand?

If it is an incomplete reference for power/transmission lines, does anyone know what criteria the FAA uses for inclusion in the charts?


texts: Is the Mach number shown by an Air Data Computer considered a "true" Mach number?

texts:
I am trying to find more information on "true" vs. "indicated" Mach number (not airspeed). I've found older fighter aircraft manuals online that have a conversion chart from one to the other, but the modern jets I've flown don't have such charts.

During a recent flight at 41000 feet, at a Mach number of 0.81, a true airspeed of 476 knots was displayed on the EFIS. In the standard atmosphere, 81% of the speed of sound is 464 knots at that altitude. Sure enough, the actual temperature was some 13 degrees C warmer than the "standard" -56.5 C, hence the true airspeed of 476 knots instead of 464.

But that leads me to believe that the Mach number I am flying is not really "true".

The relevant flight manuals do not use the words "indicated" or "true" to qualify the Mach number.


texts: Can glide ratio be increased with bi-wing configuration?

texts: We all know that increasing the wingspan of an aircraft tends to increase the glide ratio.  Instead of increasing the wingspan, could an extra wing of the same size or less as in a bi-wing configuration also increase the glide ratio?  Which bi-wing configuration would be most ideal for this purpose?


texts: Why is this 777 zig zagging over the Pacific (and delayed by 2.5 hours in air)?

texts: Why is this 777 (CX 806 on June 6 2017) zig zagging over the Pacific (and delayed by 2.5 hours in air)?


texts: Do Federal regulations compel airlines to avoid schedule disruptions?

texts:
I understand that airlines may classify certain passengers as "must-ride" and, at least as a matter of policy, bump regular passengers in order to accommodate "must-ride" passengers.  I also understand that it is common for airlines to classify crews riding deadhead as "must-ride" based upon whether or not they are urgently needed at their destination.

I was recently informed that federal regulations actually compel airlines to do everything they can to ensure that crew members successfully make it to their destination in order to crew a scheduled flight, but I was not given the specific regulation that applies.

Is there a DOT or FAA regulation that requires airlines to bump standard passengers in order to transport "must-fly" crew members?  Is "must-fly" status just a matter of airline policy, or is it some FAA- or DOT-defined status that airlines make use of?

If not, is there a more general regulation that compels airlines to avoid cascading cancellations at all costs wherever possible?