texts: if center of pressure moves forward with angle of attack, then does it move forward of center of gravity also at a particular angle?

texts:
Consider an aircraft where-

Center of gravity lies forward of Center of Pressure in CRUISE.

Now as angle of attack increases,

CP moves forward,

then for particular angle, it must move forward of CG.

In that case, wouldn't longitudinal stability be lost?
As , now the CP would be making nose pitch up moment, the tail plane will also make nose pitch up moment ( as it acts downwards)


texts: On an IFR Low Altitude Chart what does this symbol mean?

texts:
I read the information below in the aeronautical chart user's guide. I have several questions.

On the third line - Why is there an ICAO identifier for a U.S. & Alaska low altitude chart? I thought ICAO was for international flying?
On the fourth line it says '0' and '*' but there is no explanation. What do these two symbols mean?
On the fifth line it says there is a part time frequency, I assume because the tower is part time based on line three. So if this is the case, why does it need to say part time twice?

CITY - City

Airport Name - Airport Name

(APT) (ICAO) [D]* - Airport Identifier, ICAO Location Identifier, Class D airspace with far 93 special requirements operating part time

280 0* 43s - Airport elevation, unknown symbol, runway length (soft field)

(A) *109.8 - ATIS, Part Time Frequency


texts: Out of sight planes during final approach

texts: Does it ever happen that planes descending on a descent path (glide slope) block each other so that one (or more) plane is not visible from the tower (at the airport) or localizer? I want to know if that can cause technical issues. For example, how does a plane track a localizer if it's being blocked by the plane(s) in the front?


texts: What is the meaning of 'stall' in this sentence?

texts:
I have no knowledge about aviation. Can somebody tell me what is the meaning of "he ran through a series of stalls" in:

  He ran through a series of stalls, killed the engine, and brought the
  plane down to a safe and quiet landing.

Source: Blended Coaching: Skills and Strategies to Support Principal Development


texts:
I read that pilots often use printed checklists.

Is this a legal requirement, or are there also electronic versions available?


texts:
As in previous question I am trying to transpose a geospatial data format from within a EUROCONTROL application into something I understand, like decimal lat-lon.

An answer to my previous question Reference Map of EUROCONTROL charging zones got me a long way forward. I now understand that the data references this map:

This is the result of plotting the data in the file directly onto the screen. In the case of EG (UK airspace) I've added little circles to show the coordinates.

What I now need to do is to take some of the points within my file and have the actual coordinates in lat-lon (or indeed any commonly used format).

It seems to me that the boundaries of the map might be set by waypoints (or perhaps vice versa). I grabbed this image from aeroresource.co.uk and annotated it to illustrate my theory.

My assumption

It looks to me like the boundary of north east boundary of EG matches with the line of waypoints indicated by the annotated green line. So the north boundary starts with RATSU to the east and GUNPA to the west.

The easternmost boundary runs from RATSU to the north to NIBOG to the south.

And finally, to my questions

Is that assumption correct? Is the boundary of the various airspace zones delimited by waypoints?

If yes - is there an authoritative source of that information?

If no - is there an authoritative source of whatever points are being used to draw the bounds of the airspace?


texts: Aircraft lightning: What are the requirements for airworthiness?

texts:
Can you enlighten me about the airworthiness requirements in the field of lightning, for commercial aviation:

Which voltage or intensity is the aircraft required to sustain?
How is it demonstrated in practical?

Any major certification agency will be good.


texts: How close is this Su-27 to the aircraft recording the pass?

texts:
There is footage of an intercept of a US Nay recon aircraft being intercepted by a Russian Su-27:

(still from the BBC video article, who look like they got it from the US Navy directly)

which was reported on the BBC, CNN and elswehere.

I am not familiar with the proportions of the intercepting plane, but it looks like it passed very close to the recording aircraft!

Is there a good way to estimate how close it was, to within a rough ballpark? Tens of meters, a hundred meters, three hundred meters?

The CNN article reports that

  Officials so far, have not been able to estimate how close the Russian aircraft came to the US plane, but described the flight behavior of the Russians as the key factor in making the determination the encounter was unsafe.

but

  The US crew reported turbulence following that initial interaction in which the direct pass occurred. [During the second pass the Su-27] applied its afterburner while conducting a banking maneuver, which is believed to have caused a vibration that was experienced by the American crew.

On a related note, there was also a report of an Su-27 coming within 5 feet (!) of another aircraft earlier in the year; so it seems that this is not a one-off occurrence.


texts: Should the aircraft logbook be with the aircraft, or should it be on the ground?

texts: Should an aircraft logbook stay inside of the airplane, or on the ground with maintenance?


texts: Do fly-by-wire fighter aircraft automatically reverse the direction of control surface deflections during a tailslide?

texts:
During a tailslide (a flight regime where the relative airflow over the aircraft is from the tail towards the nose; i.e., an attack angle between 90º and 270º; i.e., the airplane is moving tail-first), the airflow over the aircraft’s control surfaces is in the opposite of the usual direction, causing deflections of the aircraft’s flight control surfaces to produce motions opposite those that would be produced in forward flight (for instance, in a tailslide, applying up elevator will cause the nose to pitch down, and left rudder will yaw the nose right).

Given that:

modern fighter aircraft use computerised fly-by-wire control systems instead of the mechanical linkages used in pre-21st-century fighters;
fighters are optimised for extreme maneuverability to the extent that a tailslide would be very easy to enter;
intentional tailslides could easily occur during combat maneuvering, or - even more likely - during an airshow;
and the control reversal inherent in a tailslide, like all types of flight control reversal, could easily kill an unwary pilot;

do modern fighters, during a tailslide, automatically reverse the commanded direction of flight control surface deflections relative to the direction that would be used in normal flight (for instance, applying down elevator rather than up if the pilot pulls back on the yoke in a tailslide)?


texts: What is the name of this vintage helicopter trainer?

texts:
I am curious about the tiny training helicopters that can be seen from the second 0:10 in this vintage video about the Cuatro Vientos helicopter school, near Madrid.

Were they "real" helicopters, capable of flying?

Were they a mass-produced model or an artisan solution? Who made them?


texts: Can you become FAA/TC commercial pilot with metal implants in hand?

texts:
I have a friend who wants to be a pilot and he has metal implant in his hand. It doesn’t affect his hand movement at all. I know that he will need to check it out with a Civil Aviation medical examiner first before it can certainly be okay. The problem is he is going to have to travel to Canada or USA to study aviation and do his medical. He just wants to know if in general metal implants are a no go in aviation before he travels to start his process of becoming a pilot.
( yes it’s not a question for me it’s really for a friend... I am already a pilot)


texts: How to land a sports plane with tailwind?

texts:
Let's say we have a Cessna 150 or some other lightweight two seater and no chance to land with head wind for whatever reason.
We're trying to land with a constant tailwind of 7 knots.
I would try to land as close to stall speed as possible to compensate the tailwind. So much for the theory. In reality, the wind is not constant. If I'm close to stall, dying wind will give me trouble. What's a general good approach for such situations? What configuration would you choose?
If the runway is very long, one can just go faster. But often, runways are rather short.


texts: Are there certain areas where a pilot can jettison his/her external fuel tanks?

texts: When a pilot feels the need to jettison their external fuel tanks, do they have to wait until they are above a certain area, or can they just drop them wherever they please?


texts: Why doesn't temperature affect Pressure Altitude?

texts:
In this picture:

it states the tops and bottoms of the 3 columns of air have the same pressure.
This explains the error in altitude indications given in a non-standard temperature.
Pressure only drops 1 inHg per 1000 ft. when temperature is standard.
Assuming that the bottoms of the column of air are at sea level, why aren't pressure altitude readings (setting altimeter to 29.92) affected by the True altitude formula, TA = IA + (4ft. x (1000s of ft) x (OAT - ISA))?
I was always told temperature does not affect pressure altitude readings because the atmosphere is not a fixed volume of air. If temperature increases, it will also expand in volume, like how the picture explains.
I could see how pressure altitude wouldn't be affected by 4ft. per 1000ft per (delta°C ISA) only if the picture assumed the bottoms of the pressure started at ground level.
Or does it affect pressure altitude, just very slightly and non-significant? Not as much as if you were in a fixed volume of air...


texts: How do I keep coordinated on a windy day?

texts:
I've noticed on windy days that keeping the aircraft coordinated can be difficult -- the ball will tend to bounce back and forth in the turn coordinator, and I will find myself "chasing" it with the rudder pedals.

Any advice for managing this situation?  At cruise it doesn't worry me as much as setting up for approach to land. I think I've read too many stall/spin in the pattern stories lately...


texts: How do planes receive their flight plan?

texts: When planes land, do they receive a hardline connection to ATC in order to receive the next flight plan, or do they receive their flight planes wirelessly from ATC?


texts: Do autopilot headings consider the earth's shape?

texts:
How do you set correct heading while cruising across latitudes?

On a flat map, point A might be to point B at, say, heading 060 (intentionally no cardinal headings taken for example, as they don't create this situation). But on a curved surface, like spherical earth, the heading doesn't remain constant- it keeps changing as you move away from or toward the equator, sending aircraft miles off-target over long distances, as a result of pole-bound spiraling of the path.

Is there a formula to determine the optimum heading at the outset (even though it may not 'seem' correct), thereby, reaching the desired point B on the globe at the end of the cruise?


texts: What is the reason for changing the speed reference (IAS or Mach number) with altitude?

texts:
Inspired by that question: How is the airspeed-Mach number transition handled in modern airliners?

When pressure and density decrease IAS also decreases. When temperature and pressure/density decrease speed of sound also decreases. As air pressure, density and temperature all decrease with altitude, if one fly a constant IAS or a constant Mach number while constantly climbing or descending, the aircraft actually constantly accelerates or slows relative to the air mass.

But at lower cruise altitude an aircraft will be piloted to maintain a constant IAS, while at upper cruise altitude a constant Mach will be flown.

Machmeter combined with airspeed indicator, source

What is the reason for changing the speed reference (IAS or Mach number)?


texts: If the aircraft is not trimmed correctly and either the pilot or autopilot is having to use constant pressure on the elevator does this increase drag?


texts: Why was a Lockheed L-1011 chosen by Orbital ATK for its Pegasus launches?

texts:
Not sure whether this fits better here in Aviation, or would be better suited for Space, but since the question is about a terrestrial aircraft, I'll start it out here.

The topic of my question is why was the Lockheed L-1011 chosen by Orbital ATK as its aircraft launch platform for its Pegasus spacecraft launches?  On the surface, choosing an L-1011 seems odd because it's no longer being manufactured (not a big deal, probably), but also with so few airworthy L-1011 aircraft still in existence, it seems like an odd choice, being such an unusual aircraft from a maintenance and spare-parts standpoint.

Is there some performance reason that they chose to use an L-1011 that makes it a better aircraft for their launch purposes than other aircraft of similar size that have higher numbers of still-flying airframes?


texts: In a full-rudder sideslip in a Schweizer 2-22 or 2-33 glider, is the descent rate higher at 50 mph airspeed than at 60 mph airspeed?

texts:
Is it really true that in a full-rudder sideslip in a Schweizer 2-22 or 2-33 glider, the descent rate is higher at 50 mph airspeed than at 60 mph airspeed?
Likewise, is it really true that in a full-rudder sideslip in a Schweizer 2-22 or 2-33 glider, the no-wind glide path is steeper at 50 mph airspeed than at 60 mph airspeed?
I've heard several instructors in my glider club assert these things.  Some allege that at higher airspeeds the fin overpowers the rudder and reduces the obtainable slip angle (as measured by the yaw string).
I've logged plenty of time in these types of gliders but never have attempted to explore this issue experimentally.  But my intuition is that the slip angle (as measured at the yaw string) is not significantly larger at a lower airspeed than a higher airspeed, and that a given slip angle (as measured at the yaw string) produces much more drag (and also much more sideforce, requiring a larger bank angle to compensate) at a higher airspeed than at a lower airspeed.  Therefore I would expect the descent rate to be higher at a higher airspeed, and I would also expect the glide path to be steeper at a higher airspeed.
The minimum sink rate airspeed and the best L/D airspeed in these gliders are both in the neighborhood of 40 mph.
Bear in mind that the no-wind glide path is determined by the ratio of Lift to Drag, which is very nearly equal to the ratio of Weight to Drag.  So the question about the glide path is simply a question about which configuration creates more Drag.  Also, it is clear that if the glide path in the full-rudder sideslip is in fact steeper at 60 mph than at 50 mph, then the sink rate cannot be higher at 50 mph than at 60 mph.
Since the purpose of the full-rudder slip is to steepen the glide path and get the glider on the ground closer to the beginning of the runway, the glide angle is actually the parameter of greatest interest, but for whatever reason, in discussions between instructors and students I've heard the assertion phrased in terms of sink rate just as often as in terms of the actual glide path or glide angle.


texts: Reading the Wikipedia page, I see that the F-16 began production in 1973. That seems pretty old to me. So I ask, why is the F-16 still in service in many countries around the world? Is it that a superior fighter has been not been designed yet, or are there other reasons?


texts: What is a compounding wing and how does it increase helicopter performance?

texts:
The US Army is developing a list of enhancements for the next generation Apache attack helicopter. Among them this was mentioned:

  Topping the list of major changes is re-engining with the 3,000-shp Improved Turbine Engine, but the array of potential upgrades includes adding a propulsor and compounding wing to increase the helicopter’s performance. Aviation Week

What is a compounding wing and how does it increase a helicopter's performance?


texts:
So I know that altitude affects the speed of sound because of temperature differentials in the atmosphere, but I am curious what else affects how we hear planes overhead?

When a plane flies overhead, you dont hear a very constant filter at all frequency bands. It seems that lower frequencies are more consistent, where high frequencies seems to fade in and out, sounding much like a low pass filter.

Is this the product of the temperature differentials between you and the plane changing as the plane moves, or are there other factors? Does moving air affect the sound in any way?


texts: Who performs repossessions of airplanes?

texts:
When the owner of an aircraft defaults on their loan, their lender can send repo men to take the aircraft back, often against the owner’s will. However, unlike cars, which can be driven by anyone with a license, there are so many expensive type ratings for aircraft.
Do they specifically hire a pilot with the needed rating for each given job, or are there dedicate aviation repo men with scores of type ratings to cover any eventuality? It seems like the skill set to fly the plane doesn’t necessarily qualify you to slip in quietly and take it back from a belligerent owner.
Also, my friend Bianfable got me thinking of another issue. Who repossesses aircraft when the owner has fled with it to a foreign country?


texts: I would assume that buzzing the tower and general hot dogging around the airport is prohibited, so how do airshow pilots get practice? Do they practice at high altitudes? If that is the case, how do they practice stunts that by nature require low altitude, like Bob Hoover's waltzing landing?


texts: What is the working principle of anti-explosion fuel tanks?

texts: I recently read a question about Anti Explosion fuel tanks which are self sealing. But the technology seemed to be too old after a bit of research, and that it was difficult to apply this age old technique to pressurized fuel tanks at high altitudes. What are the modern technologies being used for auto - sealing of fuel tanks after being hit by enemy fire to avoid detonation?


texts: In a jet, are Vy and Vx achieved at a constant AOA at all altitudes?

texts:
It is known that in terms of IAS, Vx (best climb angle speed) rises with altitude, and Vy (best climb rate speed) decreases with altitude, until they converge at the plane's absolute ceiling. http://cospilot.com/documents/Why%20Vx%20and%20Vy%20Change%20with%20Altitude.pdf

In a jet powered aircraft, is this achieved at a constant angle of attack (AOA) regardless of altitude and other conditions (temperature, pressure, etc.)?


texts:
Some countries (e.g. Russia) develop fighter aircraft (e.g. Sukhoi) with 2 engines.

Is it for maneuverability, or is it because they can't build an engine that would meet the power requirement?


texts:
I know that BLU is military code and means "Ceiling at or above 2,500 feet; Visibility at or above 8,000 meters".

ETSH 241320Z 19007KT 9999 SCT048 SCT160 BKN200 08/03 Q1008 BLU+

ETSH 241220Z 20005KT 9999 FEW050 SCT160 BKN240 08/03 Q1009 BLU+

But what does + at the end signify?


texts: How can a plane be cheaply owned by multiple people?

texts: How can multiple owners save on the cost of a plane that sits 1-4 people. If each nonprofessional person contributes equally in money, how would it contracted up to share all the costs are divided fairly. With at least 1 pilot and 1 A&P mechanic to contribute in labor, how many others could "time-share" on one plane before it too much to be worth it? Is there a method or scheme cost efficient and fair?


texts: Where can I find official information about a recent crash in Mexico?

texts:
I have heard about a helicopter crash involving an Agusta A 109 in Mexico, that seems to be causing some turmoil due to the deaths of a newly-elected governor and her husband. Is there any info about what happened, metars, logs or something?

Aviation herald does not have any info about it.


texts: Does the coriolis force have an effect on the direction in which an aircraft travels?

texts: Suppose an aircraft is flying from Kenya (which lies on the equator) to UK (which lies in the northern hemisphere). Does the Coriolis force veer the aircraft to the right? Do pilots have to correct their flight route because of this?


texts: Can a bird strike destroy the stealth capability of F-35?

texts:
There is a video according to which a F-35 aircraft has been struck by a bird in Israel. This, allegedly, disabled its stealth capability.

More than a year earlier, two storks allegedly damaged another F-35 and made "maintenance work" necessary.

Can a bird that lives in Israel and surroundings actually make a F-35 lose its stealth abilities?


texts: Are there any aircraft with a nose wheel braking system?

texts:
I'm pretty sure that there are no aircraft equipped with a brake on its nose wheel, however two of my colleagues think there might have been.  Are there?

Aircraft with retractable gear of course have devices to stop the wheels from spinning when retracted,  but I'm asking about brakes used to stop or slow down the aircraft. Please don't consider aircraft with a tail wheel, gliders, experimental aircraft, or aircraft used for flight testing (certified aircraft only).


texts: How can civil ATC maintain safety with military aircraft around?

texts:
I've been asking myself for a while how ATC can maintain air traffic safety with regard to military aircraft - or if they just don't.

As I understand it, all bigger planes (let's for now focus on commercial airliners) have mandatory transponders and warning systems like TCAS and similar. By usage of such systems, ATC knows their position, altitude, heading etc. which is used for planning of take-offs and landings just as well as air traffic safety. Also, systems like TCAS allow pilots to directly respond to unsafe situations even if ATC "didn't see it coming". In short, lots of regulations and techniques to make flying safe.

Now I know even less about military aircraft, but I do know they have transponders, too. I suppose, since enemies would have it a bit easy, those transponders don't operate the same way civil transponders do; or at least they use different frequencies, encryption and what-not. I don't know if they have TCAS but, I suppose, even that could possibly be exploited by enemies.

If I assume correctly, civil ATC cannot necessarily see military aircraft. I've read in another question that FAA doesn't have much power over military but that's just the US anyways. Also, the answer in yet another question suggests that military aircraft do not have to maintain separation.

So, what's the verdict? Do military aircraft assume civil regulations while not in "combat mode"? Or are civil ATC indeed oblivious of military air movements and the military has to provide safety by regulating military and watching civil traffic?


texts: How to calculate the velocity gradient at the wall normal to the wall (Boundary layers)?

texts:
This problem is from "Fundamentals of aerodynamics" by John D. Anderson, Jr (Fifth edition, page 101):

Consider a flat plate at zero angle of attack in a hypersonic flow at Mach
10 at standard sea level conditions. At a point 0.5 m downstream from the
leading edge, the local shear stress at the wall is 282 N/m^2. The gas
temperature at the wall is equal to standard sea level temperature. At this
point, calculate the velocity gradient at the wall normal to the wall.

I already know: $\tau_w = \mu\left(\frac{dV}{dy}\right)_{y=0} = 282$
but how to get $\mu$ ??

Also I don’t know what this is for: “The gas temperature at the wall is equal to standard sea level temperature”


texts: Why are they called type I, II, III doors?

texts: Is there any functional reason? or are they just in numerical order? I am talking about A320 here.


texts: For jetliners, how is a swept wing justified over a thin wing?

texts:
For a given speed, a swept wing is a fatter alternative to a straight, thin wing. But why? Does not the sweep lengthen the wing and make it heavier? Is the swept wing chosen for the extra fuel tank volume?
Edit
Could you quantify the justification? Like, let's say we have this beam of depth x............


texts: Is there a method for calculating change in V-speeds with a change in weight for a Cessna 172?

texts: For example, what would the rotation speed (Vr) and stall speed (Vs) be at maximum takeoff weight versus flying with a single occupant? (2297 lb vs 1807 lb)


texts: What is the minimum number of engines required for taxiing an airliner?

texts:
What is the minimum number of engines required for taxiing for jet airlines from a fuel savings perspective, for 4 engine configurations and 2 engine configurations?

Is using fewer engines counter productive, given that if fewer engines are used more throttle would be required and hence more fuel?

Finally can jumbos like the boeing 747-800 and the airbus A380 taxi with just one engine?


texts: Straight Wings VS Delta Wings, Variable wing with Forward swept capability

texts: What are the Pros and Cons (Advantages and Disadvantages) of a Delta wing and a Straight wing against each other, and if a Variable wing with a capability to become a Forward Swept wing is even possible to create.


texts: What may cause a pitot tube and Honeywell pressure sensor calibration inconsistency?

texts:
It is possible that my issue is specific to my setup, but I thought I'd try here if someone has experienced a similar issue. I will try to explain this clearly as possible, but it may be slightly confusing:

I place two pitot tubes in a wind tunnel in order to calibrate the sensors they were connected to. The sensors are identical differential pressure sensors from Honeywell (model# 004NDAA5). For each point in the calibration data, I took the average voltage from a sensor over 25 seconds (without changing the windspeed). I matched this with the measurement taken by a manometer. I did this for both sensors at the same time, and for a total of 15 points each. I did not include low windspeed measurements (below 5 m/s) due to the sensors low accuracy at that range.

Next I plotted the voltage data against the pressure data. This gave a linear relationship for difference in pressure (stagnation - static). I then used the following equation:

velocity = sqrt(2*diff_pressure/density)

After I did this, the two tube/sensor pairs agreed on the windspeed. The next day, they disagreed consistently by 3-4 m/s. I'm rather stumped as to what might cause this. To add, neither agree with a hotwire anemometer connected to the tunnel.

Things I've done to troubleshoot:

I swapped the tubes with each other to see if they affected the sensor reading, they do not.
I swapped the sensors pin on my Data acquisition (DAQ) setup. This swapped the voltages as expected.
I've confirmed with a multimeter that the voltage I am reading with the DAQ is the correct voltage output by the sensor.
Confirmed that the tubes were not within the boundary layer of the tunnel

Any suggestions?


texts: How does a commercial flight pilot handle turbulence?

texts:
In general, passengers dislike turbulence. Avoiding all turbulence sometimes is not viable, as it would make the flight too long, too expensive (fuel consumed), or simply not having alternatives.

How does the pilot deal with turbulence? Does he or she keep the same altitude? The same speed (relative to the wind)? Increase power?  AoA?


texts: Cross Country Planning: What do I put in the NavLog for the GPS route?

texts:
I'm a student pilot. My homework this week is to plan a cross country flight from point A->B using dead reckoning and on the way back B->A using GPS and flight following.

So the question is, do I put on my NavLog the dead reckoning (course heading, estimate time established, estimated fuel burn, etc... for each leg) only for the A->B route? What do I put in for B->A (GPS flight). I assume: basic estimation of fuel burn for the whole flight, straight line distance; how about take off and top of climb, things like that...? How do you usually do this?


texts: Are there differences in tool standards between aircraft manufacturers?

texts:
As a follow up to "What is the measurement system used in the aviation industry?" which specified about measurement units during operations, another question that comes to my mind is: are there differences used in tools for maintenance and repairs for aircraft produced in different countries?

Although things have been standardized these days, in the automotive industry you still get differences in the types of tools that are required for repairs. For example, the old British cars such as Land Rover or MG used imperial spanners until not long ago (3/8, 5/16 etc) whereas other cars used more common metric spanners.

Does this apply also to aircraft? An example that comes into my mind would be the Avro RJ series.


texts: What is an example of a quantitative analysis for the lift using Newtonian mechanics?

texts:
There are several different ways of explaining how an airplane generates lift. The simpler qualitative explanation uses Newtonian mechanics (the third law is invoked to explain how the wing pushes air down and is in turn pushed up by the air) whereas the more quantitative explanation uses aerodynamics and fluid mechanics.

I have been looking to find a simple model of an airplane wing that uses Newtonian mechanics to come to an approximate quantitative description of airplane flight. Everything I have found so far (such as this article) is merely qualitative.


texts: to whom are PAN PAN PAN calls addressed?

texts:
Can a PAN PAN situation be adressed directly to an ATC or must it be at adressed only at large?

This is a situation wereby the ATC was the destination before the situation of the pilote got worse.


texts: Does clearance delivery assign VOR or GPS-A approaches?

texts: I've listened to clearance delivery feeds on LiveATC. Is it possible for clearance delivery to assign VOR or GPS-A approaches instead of standard terminal arrivals (STARs)? Or would they just give you routing to a VOR or another waypoint near the arrival airport, and say "direct" afterwards to indicate that the TRACON for the arrival airport will assign the specific approach?


texts:
For the question What's up with the “What's Up at Wallops” app? I was reviewing the What's up at Wallops website and drifted to the launch photos page where I saw this aircraft. I did not find a caption, and a quick reverse image search in google did not return any helpful results.

I am fairly confident that it is not a "spaceplane".

What is this NASA UAV, and what is its function?


texts: What constrains a paraglider vertically?

texts:
I recently flew on a tandem paraglider for the first time. Since then I keep asking myself a question I have no clear answers to.

While flying I clearly perceived the lift generated by the airfoil, but the strongest feeling I had was as if the paraglider hung to a rail, like a suspension railway, or to a cable, like a cable-car. In other words, I perceived a very strong vertical constraint. I know the airfoil generates lift, but I understand the amount of lift is not enough to give you a stability feeling like when driving a truck! To be similar to the constraint produced by a rail, this vertical constraint should be in the order of thousands of kg, IMHO.

Any suggestions on how to estimate this amount, and its origins?


texts: Why should the centre of mass be ahead of the centre of pressure?

texts: Why is the centre of mass located ahead of the centre of pressure? And what would happen if centre of mass would be too close or too far away from the centre of pressure?


texts: Are carbonated drinks considered dangerous goods for air freight?

texts: I understand carbonated drinks in allowed in cabin, but, is it allowed in air cargo transportation, when you ship in bulk?


texts: How are turbine blades overhauled? What techniques are commonly used and how does it affect the integrity of the blade?


texts: Why does the US Marine Corps fly the Harrier, a VTOL or operationally STOVL aircraft?

texts: The UK flies the Harrier because they have STOBAR carriers, but why does the United States Marine Corps fly the Harrier?


texts: Why do ELT panel switches have batteries in them?

texts:
Does anybody know why ELT remotes (the panel mounted switches with LEDs) have batteries in them?
The ELT itself has a big battery and there's a wire between them that the ELT could use to supply power to the remote.
So - why do ELT remotes have their own, separate, battery (in a place that's often hard to access for replacement)?
Is it some kind of regulatory requirement? Why?


texts:
I have watched many aircraft takeoffs now where the flight deck announce 'Thrust Set', just after the engines are set to full.

Forgive the dumb question, but why does one announce that the thrust is set, perhaps more importantly, why is it necessary in the takeoff procedure?

I did attempt some research before posting, but the closest article I got did not make much sense to me I am afraid.

  For the GE CF6 engines, N1  should be stable at 70% before the TO/GA switch is pushed to set the armed thrust limit. If TO/GA is not pushed by 50 knots, thrust must be set manually and when VNAV goes active at 400', the A/T will automatically go active in THR REF, so you don't need to select anything if the A/T is armed.


texts: What is the difference between "Standard Metric Level" and "Altitude" in ICAO flight plans?

texts:
What is the difference between "S" and "M" in flight plan altitudes?

The FAA's ICAO flight plan documentation says:

  Standard Metric Level in tens of meters, expressed as S followed by 4
  figures (for example, S1130), or

  [...]

  Altitude in tens of meters, expressed as M followed by 4 figures (for
  example, M0840)

I don't know what "Standard Metric Level in tens of meters" means exactly? How is that different from "Altitude"?


texts: Where is the only Aerostar 800 ever built?

texts: The Ted Smith Aerostar has a very interesting history. Wikipedia has a list of all the models that were built. There's a note there about an Aerostar 800, only one of which was ever built. Does anyone know where that 800 is today?


texts: What is the meaning of sub-paragraph 3-9-6 j. in FAA JO 7110.65X?

texts:
In JO 7110.65X, section 3-9-6(j) says in reference to the 3 minute rule:

  j. Separate an aircraft behind another aircraft that has departed or
  made a low/missed approach when utilizing opposite direction takeoffs
  or landings on the same or parallel runways separated by less than
  2,500 feet by the following minima:

  Heavy, large, or small behind super − 4 minutes.
  Heavy, large, or small behind heavy − 3 minutes

Do you think this applies to an aircraft in the pattern making approaches to the runway in use after a heavy departs opposite direction?


texts: How to determine the direction of rotation of components inside a gas turbine engine using the blade profile?

texts:
I am new to Gas turbine Engines.
As of now,I am trying to understand the gas turbine engine DGEN 380 by the manufacturer Price Induction.
So I have identified the components such as Intake fan,Planetary gearbox, Centrifugal Compressor,HP and LP turbine.
However,I am not sure of identifying the correct direction of rotation for each of these rotating components based on blade profile. So if someone could explain it in a simple way,I shall be thankful.

https://minijets.org/fr/300-500/price-induction-dgen-380-390/


texts: Are there any softwares that can integrate with desktop sims that accurately simulate third party EFIS retrofits?

texts: So, are there any softwares out there that can integrate into desktop simulators, that can accurately emulate third party EFIS instruments for example, Dynon EFIS or Aspen Avionics Evolution?


texts: What are the aerodynamic design principles behind the "supersonic" propeller of Luigi Colani's C-309 racing plane?

texts:
One of Luigi Colani's designs that is particularly confusing to me is the second design iteration of the C-309 propeller racing airplane. Allegedly, its two propellers are designed to be supersonic and they have a very peculiar shape, as shown in the photo below.

The leading edge of the C-309 propellers is both forward-swept and twisted in a circular fashion, given the propeller blades a helical appearance.
This is a very different approach from real-world supersonic propellers found in e.g. the Republic XF-84H Thunderscreech.

Assuming the propeller material to be indestructible for a moment, and that the propeller design is not guided by aesthetics alone, what would be the aerodynamic reasoning behind creating a propeller of such an absurd shape? Is it equivalent to a forward-swept wing that takes into account the relative velocity from the propeller rotation?


texts: What is the drag induced by a high bypass jet engine on an airliner?

texts:
What is the drag induced by a turbo bypass jet engine in a typical most modern airliner like the 777, the Jumbo Jet (Boeing 747-8) and the Airbus A380?

Given that the jet is travelling faster than the replacement of the air displaced by the engine suction, do parts in close proximity to this area where suction is largest cause less drag to the aircraft because of this micro second vaccum period occuring at all times when the aircraft is in cruise mid air?
I refer to turbo bypass engines because they are the ones most used because of fuel efficiency, noise, etc., in airliners, I do not ask about bypass ratio. I ask about the displaced air outside the engine, and the overall effect on drag caused by the engine as a physical component attached to the plane colliding with air.

Does the fact that it is sucking a very large amount of air around it reduce this drag and by how much compared to if it were not sucking any air at all?


texts: Why aren't AMA certified radio-control club sites shown on aeronautical charts?

texts:
All this drone business wound up affecting us R/C fliers that fly only at local verified club sites. I wrote (told) the FAA that our local AMA R/C flying fields are constantly having "our" flight areas intruded on by full-scale aircraft that unknowingly fly over our field.

Why are permanent R/C airfields not shown on aeronautical charts?

In response to comments:

We are not near an airport.
We take note when overflown by 2500' or less
Drones with FPV can easily stay under 400' AGL as suggested by the FAA but they will very likely not be aware of the location of manned aircraft
Other RC aircraft have no way of knowing where the 400' limit is and can easily go much higher, and manned aircraft would not be aware of this


texts:
(Not company call-signs)

Wikipedia gives the following guidelines

  Eastbound and northbound flights are traditionally assigned even numbers, while westbound and southbound flights have odd numbers.
  Other airlines will use an odd number for an outbound flight and use the next even number for the reverse inbound flight.
  For destinations served by multiple flights per day, numbers tend to increase during the day.
  Flight numbers of less than three digits are often assigned to long-haul or otherwise premium flights.
  Flight number 1 is often used for an airline's "flagship" service.
  Four-digit numbers in the range 1000 to 4999 typically represent regional affiliate flights.

but doesn't give any references (anybody have any?).

Assuming these are (generally) true, are there common strategies for how airlines number flights in a 'class'? For example, is there any significance between DAL310 and DAL342? AAL4569 and AAL4135?

Or is the standard method generating a (bounded) random number?


texts: How do I tell if class E airspace extends to surface or starts at 700'?

texts: I am confused about where class E airspace starts in the USA. If it has dotted magenta lines does it start at the surface? If small airport has round magenta circle but no dotted lines does class E start at 700'?


texts: What are the implications of no longer requiring a complex aircraft for the commercial/CFI checkride?

texts:
Are there any other implications for flying Complex Airplane (getting endorsements, etc.) now that the CFI and Commercial Pilot Practical tests no longer require the applicant to provide a Complex Airplane for the exam (As of April 24, 2018)?

The official FAA Notice says

  There is no change to the complex airplane training and endorsement requirements of § 61.31(e) or to the commercial pilot aeronautical experience requirements of § 61.129(a)(3)(ii) or part 141 appendix D.

So the requirements haven't changed but how about becoming an authorized instructor in a complex airplane now that you could technically become an instructor without ever flying in a complex airplane?

Even though I am supportive of this change, a fundamental change like this usually means there are some unforeseen circumstances, and I'm wondering if there are any far-reaching changes that aren't immediately obvious.


texts: How much weight does removing a vacuum system really save?

texts:
For a small GA aircraft (e.g. Piper, Cessna, Mooney), does anyone have a before and after weight savings example from removing a vacuum system?  E.g. calculated weight of component removal during W&B?

The context is replacing a standby attitude indicator with an electronic standby (e.g. MidContinent, Sandia SAI 340, etc)..

This question specifically refers to the vacuum system only, not the instruments themselves.  E.g. vacuum pump, hoses, fittings, etc.  Thanks!!


texts: How effective was WWII bombers self defense anti-air armament?

texts:
Bigger WWII bombers like e.g. the B-17 Flying Fortress were equipped with lots of machine guns for self-defense against single-seat fighter aircraft.

Wikipedia says:

  Defensive armament increased from four 0.50 in (12.7 mm) machine guns
  and one 0.30 in (7.62 mm) nose machine gun in the B-17C, to thirteen
  0.50 in (12.7 mm) machine guns in the B-17G. But because the bombers could not maneuver when attacked by fighters, and needed to be flown
  straight and level during their final bomb run, individual aircraft
  struggled to fend off a direct attack.

The last sentence and the fact that fighter escort was developed and also personal impression from live footage etc. indicates that the self-defense armament wasn't very effective.
Is this true?

I can understand that bombers cannot do evasive maneuvers, but so does the attacking fighter plane when it is homing in on the bomber and aiming, isnt it?
In that moment the bomber actually should have the advantage of being able to point the (several) mobile guns, while the fighter must use the entire airframe to aim its guns and thus has a very predictable flight path.

And in case it really wasn't effective, why did they carry it then? Must have added a lot of additional weight.

Are there any figures to illustrate the effectiveness of bomber self defense?


texts: Can a missile retarget to the heat from the firing aircraft's engines?

texts:
I have heard that modern war planes utilize missiles which are directed to the heat of the enemy aircraft's engines.

Can a missile, shot by a fighter helicopter or jet, target the heat of the engines of the aircraft which fired it?


texts: What is this four-engine propeller airplane?

texts:
I came across this print at a bargain store a couple weeks ago. At first I thought it might be a variant of a Lockheed L-188 Electra; then I noticed that it has at least 6 engines, as the print extends around the edge of the canvas and you can see a couple of propeller tips there. I haven't had any luck finding a 6- or 8-engine aircraft that matches it.

Edit: after looking at it a little closer, I think the edge might be a printing effect, an imprecise mirroring around the edge line (for example, some of the splotches look very similar to those in the front). So maybe it is only four engines?


texts: Do horizontal stabilizers on airliners have varying angle of incidence in the span-wise direction (washout or negative twist)?

texts:
Reading this question and answers, I was wondering if modern airliners with cruciform tail have some noticalbe washout or negative twist along the horizontal stabilizer's span.

During cruise, if wing's downwash angle is larger near the center of the aircraft, shouldn't horizontal stabiliser be slightly twisted according to this particular value, in order to reduce induced drag?


texts:
I have flight test data where the IMU is junk. The roll and yaw are obviously wrong, while the pitch seems to be correct. [I know the yaw is wrong because it doesn't match the changes in headings, and I know the roll is wrong because the it stays near 0° during horizontal loops where it should be closer to 20°.] The pitch seems ok because it is stays near 5° most of the time, which was the angle of attack for most of the flight.

I also have GPS data that gives me position at a high update rate.
I was able to use the position to compute the yaw values. With the position updates I can also estimate speed. With the position I can get a turn radius, and the change in position gives a velocity which can lead to a linear and/or angular momentum.

Now, I'd like to get an estimate of the roll (I say estimate because I figure the computation will require some simplifying assumptions).
The resolution for roll that I need is much less than the position data (by a factor of about 1000).

My question is this: given the position of the aircraft, how can I estimate the roll?

The purpose of this is for analysis of flight test data for a product that was tested on the aircraft. The product had (what turned out to be) a poor IMU, and we cannot do another flight test. I need the attitude and position to complete my analysis.


texts:
this is about converging subsonic nozzles.
Are they fully expanded? meaning exit pressure=ambient pressure?

What about diverging subsonic nozzle?
Are they fully expanded? what would happen if the exit pressure was greater than ambient? shock formations?


texts: Where to find a 1983 NTSB report of a R-22 clutch failure?

texts:
Why can't I find the incident report I had to file after my death defying landing at John Wayne Airport in Costa Mesa Ca. around 1983?
They found the clutch with 4 belts to have malfunctioned and grounded all Robinsons in service, until a better configuration was developed.


texts: Ailerons deflection of the F16 in take off and landing gain?

texts: Let's say you are at a safe altitude and landing gear is down and the aircraft is in To/L gains and you want to do aileron roll and apply full  left (or right ) stick to do the rolling maneuver.The F16 doesn't have any ailerons only flaps moving up and down  .But because is in the  take off /landing gain's with the flaps deployed at maximum angle only one moves other stand still at 20 degrees down .Will the raised flaperon go above the wing cord or not , meaning will  rise up above the cord line of that wing or not passing the wing line ?


texts: Where are the fuel tank sumps on an Aquila A210?

texts:
When I drain the fuel I have to do it three times:

  In addition to the drainer openings on both undersides of the wing and under the front fuselage (3 times in total).

Can you tell or show me where the third drainer (under the front fuselage) is located. Do you have a picture of it?


texts: What is the correct procedure for opening the cockpit escape hatch on an ATR-72?

texts:
I’m hoping someone can help me understand the correct procedure for opening the cockpit escape hatch on an ATR-72.

As I understand it, the operator must hold the rear handle, and pull the forward handle to open the hatch, is this correct?

Does the hatch pivot open, or does it come off completely?

How would one climb out after opening the hatch?

How is the emergency rope used?

Thanks in advance.


texts: What are the certification requirements for software used at airports?

texts:
If you develop software that is used at the airport and integrates into a departure control system (DCS), is it required to undergo some IATA certification processes?

When I search for IATA regulation on software used at airports, I can not find much. Actually I haven't found anything that states that, for example, a departure control system (DCS) must undergo some certification process.

I therefore ask, are there any certifications or validation requirements for software used at airports? For example if you develop a new DCS, would you be required to undergo IATA certification? What other hurdles (FAA, EASA, ...) are their for software used at airports?

Note, I explicitly want to exclude software that is used for air traffic control.


texts: Do modern aircraft have sensors to determine weight of the aircraft?

texts: Do ALL modern aircraft, particulary airliners and private jets, have weight sensors on all landing gear to determine take off and landing weight in real time so as to determine take off speed and approximate landing distance?  If so were are they installed and if not why not? Are there any attempts to install these on older jet airliners?


texts: About how much drag does a non-operating engine create?

texts:
I think the drag of the engine is high, for most type of engine, e.g turbo fan, jet, ramjet... I guess the engine's drag is worse than a flat plate of the same area perpendicular to air stream because the engine slows the air and compress it, and also the engine has many components inside it that will interact with air.

A flat plate is very bad aerodynamically and so the engine. Even small landing wheel should be folded inside body for better drag. So an aircraft with engines turned off will have very high drag, but I can not find any estimation on this matter.

For example, an aircraft that has L/D about 15, how about its drag if engine is removed, e.g. for better glide ratio when engine failure?

Can you estimate this drag?


texts:
In
Fire-involved Accidents and Incidents Reviewed
, Rudolf Kapustin stated in 1993 that

  Nearly all aircraft accident fatalities that are not the result of
  crash/impact injuries are the result of post-crash fires and the
  inability to exit aircraft quickly, which in most cases is attributed
  to incapacitation from toxic smoke, fumes or injuries.

This makes me wonder why airlines don't provide smoke hoods for their passengers in case of a fire, the same way they provide life vests in case of a water landing. If flights crossing a body of water must have life vests available for all passengers in case of a water landing, why not make an equivalent law for smoke hoods in case of a cabin fire?

Protective breathing equipment, or smoke hoods are protective head coverings that prevent wearers from breathing the smoke, particulates and toxic gases generated in a fire. There are two main types of hoods: those that have a source of breathable air and those that just filter the particles out of the air.

The smoke hood for aircraft passengers wouldn't need to be a firefighting grade smoke hood, just enough to get everyone out of the plane before they get asphyxiated.

Today, the recommendation in case of a cabin fire is to stay near the ground where the air is more breathable. If passengers could be equipped with smoke hoods, they could walk out instead, which would likely make an evacuation faster.

Granted, the smoke hoods would be used on rare occasions, they have a cost, take up space, weigh something, and you have to explain to the passengers what to do with one in case an accident happens. So it is unlikely that an airline would spontaneously decide to equip all seats with an emergency smoke hood.

But life vests have all of those disadvantages as well. It seems to me that these hoods would not be any heavier or any more expensive than the life vests, and might be used on more occasions than the life vests. I've seen smoke hoods the size of a soda can, so finding a place to fit one on each seat can't be so hard.

So why aren't plane equipped with emergency smoke hoods for passengers?


texts: Controlling jet engine thrust on airliners

texts:
Passenger jet airliners seem to control thrust by just adjusting the amount of fuel going to the engine thus affecting the engine rpm. This means it takes a small amount of time to spool up from minimum to maximum throttle and vice versa.

Are there any attempts to allow faster thrust response than this? Are any in current or planned use?

It seems that one could control the compressor pitch, change the gear ratio, or adjust the bypass ratio -- but I'm not sure anyone is doing this. Afterburners and thrust reversers/vectoring don't count. Faster engine respond would help with situations such as loss of rudder control let alone other emergency situations.


texts: What is the top altitude of the class delta KEDC? It looks like it's not depicted on the VFR sectional chart

texts:
Can someone tell me what I'm missing? I usually see a [-#] that denotes the airspace above a class delta. I believe KEDC (Austin Executive) is a class delta based on the chart supplement.

Attached is the VFR sectional from vfrmap.com:


texts: How does an aircraft descend without its nose pointing down?

texts:
I have seen many cockpit videos of airplanes landing, and nearly none of them have their nose down for losing altitude. How does this happen? and how does an airplane, such as A320, descend without its nose pointing down?
And how does this happen in a controlled manner?


texts: Turbine blade manufacturing/assembly process

texts:
I want to know the process for manufacturing turbine blades and the companies that are involved.

Who makes the turbine blades? Who applies the thermal barrier coating? Who repairs the blades?

Let's take the General Electric GEnx as an example. Does GE make the blades themselves, or do they buy them from a supplier? Where do companies like MTU Aero Engines come in?


texts: What is the most commonly occurring fault with this type of electrically driven gyro?

texts: I have an examination tomorrow about advanced avionics systems (EASA module 13) and we are required to troubleshoot a fault with the compass system. What is the most commonly occurring fault with a gyro compass system and how is it detected or identified?


texts: What is significance of N1 and N2 in Jet engine?

texts:
Why N1 Low pressure compressor RPM and N2 High Pressure compressor RPM are monitored in jet engines ?
Why specifically compressor RPM rather than turbine RPM ?
What do N1 and N2 signify in terms of relation with any engine performance parameters?


texts: What are the risks in landing on a beach vs. shallow waters?

texts:
I recently read a story where a pilot of a light aircraft died having attempted to land on a beach.

Would it be potentially safer to try an emergency landing on a beach, or go for shallow waters of 6-10 feet depth, or deeper water? (In the absence of anything more suitable).


texts: Clearance limit of VFR practice IFR approach?

texts: When a VFR aircraft has been approved by atc to perform a practice approach, is the aircraft also cleared for a published missed approach procedure?


texts: Which military aircraft does this seem to be? [F-16 vs MiG-21]

texts:
Can someone identify the aircraft based on the components, riveting style, or other technical details visible in these crash pictures?

a) Based on publicly available details, the chief suspects are MiG21-Bis or F-16. Are there US vs Soviet construction details, materials, etc that can enable identification based on these images?

b) There is a drop-tank in the images, which is claimed to be only compatible with one of these two aircraft. I'm looking for someone familiar with the MiG-21 or F-16 to comment.

Background:

Three aircraft crashed in the Kashmir region during hostilities on 27th Feb 2019. One was an Indian MiG-21bis, whose pilot ejected and was apprehended by Pakistani locals. Another was a Mi-17 helicopter, which crashed "due to technical reasons" killing six persons onboard, within Indian territory.

No information is available about the third aircraft; Indian sources claim they hit an F-16 while Pakistani spokespersons said they did not have F-16s in the area.

These are purportedly pictures of the downed third aircraft. This could be part of an F-16, JF-17, MiG-21, SU-30MKI, or Mirage in Pakistani or Indian service.

source: Photo/ANI

source: Photo/ANI

There is also a low-resolution video available via twitter, showing the droptank recovered from the site being loaded into a truck.

Link to low-resolution video on Youtube

source: @MdShafiKhatana/Twitter

Edit:

This is a recent incident. Some sources claim the image shows a part of an F-16 engine. Is this plausible?

source: Photo/ANI

Edit 2:

Is it plausible that this number "J0269" (from the above picture) can be used to identify the aircraft as an F-16B Block 20 MLU with tail number J-269 using this link?


texts:
I have been wondering how the mass flow rate is determined by the area of the engine air intake surface and the incoming speed of the air.

In still air, it is understandable that a stationary engine takes in air at the same rate as it is exhausting based on the preservation of the momentum of the air. Then, the mass flow rate through the engine intake surface can be easily calculated.

However, in still atmosphere with the same engine solely mounted to an aircraft cruising straight, level, and at constant speed $v$, it is not obvious to me how to determine the mass flow rate.

In particular, keeping the air intake surface area unity, can we determine the mass flow rate based on $v$ alone?


texts: Why do Czech Airlines have the airline code (IATA airline designator) "OK"?

texts:
Is there any specific reason why Czech Airlines have OK as the IATA airline designator?

According to an urban legend:

  Urban legend says that when airline names were awarded -- I believe in 1946/46 -- the Czechoslovak delegation, not versed too much in English, just said OK to the questions asked. So the name stuck.

I do not much believe in the legend, but still the question remains.

I would expect that at the time when the (then) Czechoslovak Airlines were assigned the code, there were not so many airline operators as nowadays and that CS (or something similar) must have been available.


texts:
I know that helicopters blades are like rotating wings that generate lift in the same way, but how does this make a helicopter hover?

Other question; how does the tail rotor help with the balance of the helicopter and why does it have to be on the left side of the vertical stabilizer instead of in the center?


texts: What happens if the pilot tries to do a loop in a full-motion simulator?

texts: I know that full-motion simulators, typically used to train pilots on commercial aircraft, have limits to how much they can tilt. They can't go upside down, for example. What happens if the pilot goes outside those limits, by doing a loop for instance? Does the simulation continue with the loop and the just the physical tilt effect gets ignored, or does the whole simulation shutdown and reset?


texts: Who pays for Air Traffic Control services?

texts: I imagine certain fees from flight boarding sales are paid to the FAA, but who is responsible for paying fees for passenger flights?


texts: What is the belly pod on this Beech A200 Super King Air?

texts:
In this photo of N46L, a Beech A200 Super King Air owned by Dynamic Aviation, there is a large pod attached to the belly with what looks like two largish ports or windows on the underside.  What is it, exactly?  It looks similar to a synthetic aperture radar pod or video surveillance package, but I was curious if anyone could ID it precisely.

The full photo is available at http://www.jetphotos.net/viewphoto_new.php?id=7118680.


texts: Is the F-117 fleet at Tonopah Test Range being mothballed?

texts: Are the F-117s based at Tonopah Test Range still in service? I heard from some reputable sources they are still flying around and being maintained, but someone else told me they are going away permanently. Does anyone know what's up with the F-117s right now?


texts: How common is it for flight attendants to have pilot certificates?

texts:
When looking up some information for the recent question Have there been any solo flights on airliners?, I found this article that lists several incidents in which a pilot has become incapacitated in flight. One thing that I found particularly surprising was that, in two of the six specific incidents they mention, the person who helped the remaining pilot for the remainder of the flight was actually a flight attendant who had a pilot certificate. This then made me wonder:

How common is it for an airline flight attendant to also be a certificated pilot?


texts: What are reasonable values for the position of an airplane's center of gravity compared to that of its center of lift?

texts:
I understand that if the center of gravity is in front of neutral point, it is stable. If the center of gravity is behind the neutral point, it is unstable. Based on the diagram, is it implied that h (center of gravity) cannot be greater than 1? When h = 1, there will only be c (mean aerodynamic chord). What does it mean if h>1? Is it off the wing basically?

hnwb = 0.25 (typically)

When I solved a problem, my h value was greater than 1. Isn't that incorrect because it is off the wing?


texts: Is there a difference in landing fees for charter and scheduled flights?

texts: Is there a qualitative difference for landing fees/charges between charter and scheduled flights at a particular airport?


texts: Comparison of specific thrust vs. speed, for EDFs and propellers

texts:
I stumbled upon this graph showing the decrease in specific thrust (Thrust by Power) in relation to velocity, for a Schuebeler EDF:
https://www.researchgate.net/figure/Specific-thrust-T-P-vs-airspeed-graph-of-Schuebeler-DS51-EDF-unit-based-on-wind-tunnel_fig3_304115129

(Is this a good example for EDF thrust reduction with airspeed, in general?)
The main question I have is how would the decrease with speed for a fixed-pitch propeller compare to the EDF decrease? Any graphs to illustrate?
(ignoring the initial increase of thrust for cruise -fixed-pitch props)
Thanks


texts: I've written a legal thriller. One scene involves the antagonist lawyers hiring someone at O'Hare to sabotage some other lawyers' private jet so that it crashes. But I don't know enough about aviation to write a plausible scene, as in what could someone on the ground do to down a plane that the pilots wouldn't see. So far, I've heard about someone deliberately installing the wrong size screws in the windshield because the pilot could miss them in pre-flight checks. This could cause the windshield to fail at altitude, either crashing the plane or ending in an emergency landing at the closest field. But are the screws are visible from the cockpit? And if so, would the pilot detect a problem before takeoff? Any guidance would be great. Thanks!


texts: What is a "flare-out" and why does auto-thrust reduce thrust during flare-out?

texts: The functions of auto-thrust include thrust reduction during a flare-out. What is flare out and why during flare out will the auto-thrust reduce thrust?


texts: Is the Airbus A380 a viable shorthaul airliner?

texts: What is the technical, mechanical and economic feasibility of using the Airbus A380 for short haul flights of under 4 hours in its 800 plus seat configuration?  I'm talking about cost and economies of scale, frequency of repairs and service etc.


texts: What makes it so hard to land on an aircraft carrier?

texts:
I have heard it is very difficult for a pilot to land on a carrier deck.

I have read this question but it didn't really give me a sense of the challenges that pilots face.

This question lent me the insight that metal decks, themselves, have different properties (that I should have considered)... perhaps friction, changes due to thermal shifts (that asphalt does not exhibit), perhaps it 'gives' differently under touch-down pressure.

Can someone paint a more-complete picture?  I'm sure there are also other factors, besides that the deck is moving.... but even then - perhaps there are 'different kinds' of movements of the deck that I haven't considered.


texts: Is the "Red two standing by" dialog in Star Wars: A New Hope sensible for real fighter pilots?

texts:
This SFF.SE question: " Why did Red Squadron give their call signs in random order? " raises a good point: for some reason, the "Standing by" responses Red Squadron pilots give before attacking the Death Star in Star Wars Episode IV: A New Hope are out of order:

  Red Leader: All wings report in.
  Red Ten: Red Ten standing by.
  Red Seven: Red Seven standing by.
  Biggs Darklighter: Red Three standing by.
  Porkins: Red Six standing by.
  Red Nine: Red Nine standing by.
  Wedge Antilles: Red Two standing by.
  Red Eleven: Red Eleven standing by.
  Luke Skywalker: Red Five standing by.
  Red Leader: Lock S-foils in attack position.

(to top off the mis-ordering, Red Eight and Red Four never respond).

This was of course answered in-Star-Wars-Universe, but I'd like a perspective of real aviation experts on this:

Is this protocol (all fighters in a group should report in by their call signs) based on something real fighter pilots would do (either WWII era pilots - since Star Wars fighter combat was famously based by Lucas on WWII - or 1970s era).
What is the main purpose of such a protocol? Communications check? Verifying who's flying? Verifying if someone has an issue? Team morale?
In light of #2, does the real life protocol have a specific order of responses, or is it as "whoever responds whenever" as in the Star Wars example?


texts: If I were to build a J3 cub twice the size of the original using the same CG would it fly?

texts:
How big of an engine would I need, if the original is 65hp?
What would be the weight of the up-scaled plane? Simply twice the
weight?
What would be the stall speed?
How fast would it go?  75mph?
Is there a software program to test aircraft design?


texts: Flight Following into Class C Airport where I'm Landing

texts:
I want to fly into a Class C airport and do a full stop taxi back.  I'll be approaching the airport with flight following.  When ATC hands me off to approach control for the airport I'll be landing at, what do I need to tell approach control given that I'm already on flight following?  I'm guessing that I need to tell them I have the ATIS and that I want to do a full stop taxi back.  It would seem that I would not need to report my position.  Do I need to report my altitude?  It seems I would say, "So Cal Approach Cessna 1234R with information A, inbound for fullstop taxi back."
And on my full stop taxi back, I'll land and then exit the runway.  When I exit I'll be directed to ground, and I'll ask for return for takeoff.  At this point I would also like to ask for flight following to my next airport, but usually I would ask clearance delivery, not ground, for flight following at a Class C airport.  Will ground be able to give me flight following?  Also, I will not have told them that I'm flying a Cessna 172/G because this information was not required to obtain flight following for me because I didn't take off from an airport with clearance delivery.  Is that going to matter when asking for flight following from ground?


texts: Can a passenger realistically replace suddenly incapacitated pilots?

texts:
Yes, this is a question from the movies. Assume that the plane is in flight and in perfect mechanical conditions. However, all the pilots onboard are suddenly incapacitated.

Can a passenger without any previous flight experience realistically save the plane and take it to a safe landing only by remote radio help?


texts: Why aren't test planes remote controlled?

texts:
There was a recent accident where SpaceShip2 broke apart in mid-flight, killing one and injuring another.

Given that we can remotely control drones from the other side of the world, why couldn't we do the same with this test airplane?

Considering that it's all launched locally, it would not even have the lag that drones have.


texts: What does "S-ILS" signify in an FAA NOTAM?

texts:
Consider this NOTAM for LAX from the current list:

  FDC 5/0341 LAX IAP LOS ANGELES INTL LOS ANGELES CA. ILS OR LOC RWY 25L AMDT 12C... S-ILS 25L DA 395/ HAT 291 ALL CATS VISIBILITY ALL CATS RVR 2200. ADD NOTE FOR INOPERATIVE ALSF-2 INCREASE S-ILS 25L VISIBILITY ALL CATS TO RVR 4500. EXCEPT WHEN ADVISED BY ATC THAT EQUIPMENT IS DOWN. CONSTRUCTION EQUIPMENT 178 MSL BEGINNING 1399 FEET NORTHEAST OF RWY 25L. 1502052152-1508042152EST

What does S-ILS25L signify, how is it different than just ILS25L, and where can I find the source document?


texts: Why new jet aircraft have wider, larger cockpit windshield/windscreen?

texts:
If you compare aircraft in the same category Boeing 737 with newer Airbus 320 and more recently Comac C919 or Irkut MC-21, it is striking to observe the changes in the cockpit windscreen design.

The trend seems clearly to be wider, larger windscreens. What are the reasons for that?


texts: What is the optimal bank angle to accomplish a given turn in a glide?

texts:
For an aircraft in a glide, what—if any—is the optimal bank angle to make a given turn while maximizing glide distance and maintaining published best glide speed?

In other words, at a constant airspeed, which bank angle will produce the greatest turn rate with the smallest loss in altitude. Assume a constant airspeed turn that is already established. I am not asking which bank angle will produce the least reduction in the vertical component of lift.

In envisioning this scenario, I specifically have in mind a single engine aircraft experiencing an engine failure at low altitude. However, the aerodynamic theory may apply to any fixed wing scenario.

Edit: let me emphasize that this question assumes the pilot is maintaining the aircraft's nominal published best glide speed throughout the turn, not adjusting airspeed to some variable theoretical best glide speed. Airspeed should not be a variable.


texts: What are the effects of endplate on airfoil section?

texts:
A 3D wing cannot achieve the same high lift/drag ratio (more than a hundred sometimes) displayed by a 2D profile (airfoil section).
This is due to 3D effects like spanwise flow, wingtip losses(vortices) etc.

What is the lift-to-drag ratio on a wing between endplates? Can you achieve the same ratios as a 2D section?


texts: As far as I know, a big obstacle to attaining laminar flow in aircraft today is the so-called "bug layer", presumably a lower layer of the atmosphere where bugs are encountered. So, my question is simply this: how high up do insects stop becoming a serious issue for laminar flow?


texts: Is it possible to obtain a CPL without a PPL?

texts: I've overheard that trainee pilots hired by airlines are not required to pass the PPL exam before attempting the CPL exam. Is this allowed by regulation?


texts: Why do shockwaves progressively move aft as speed increses?

texts:
As an airfoil moves from subsonic to supersonic, the shocks that develop over the surface move progressively toward the trailing edge. What is the physical explanation for this behavior?

As a side question, what determines where the shock (and hence location of minimum pressure) is located?


texts: Are there any differences between turbofan and turbojet engines besides bypass air?

texts:
I think I understand both engine types, but I am just wondering am I right in saying that the only difference between the two types of engines is the bypass air (i.e. a turbofan is just a turbojet engine with bypassed air).

If not, what are the other differences between the engines apart from the bypassed air?

Any help on this matter would be much appreciated.


texts: What is the optimal time to get from ASEL to ASES certification?

texts:
I am currently a ASEL pilot, in process of studying for IR, and will then be proceeding to AMEL. I know that if one holds ASEL & IR, and takes AMEL with instrument maneuvers included in the checkride, at the end I will have IR privileges in both single and multi.

What is the most optimal (time & cost) route to get my ASES? Are there any efficiencies to be had by completing seaplane rating after IR and/or multi? Or if I was to complete ASES before IR, once IR is done, I could exercise IR privileges when operating a seaplane (unlikely scenario, just want to understand the rules). From my understanding, I will, because IR applies to the category of airplane. Is my understanding correct?


texts: Are modern commercial airliners flyable without operational computer systems?

texts: Do modern commercial airliners have manual control capability to fly and land if electric power remains on but all computer systems and digital communication/guidance fails?


texts: Is it possible to estimate airspeed on top and bottom sides of a wing at zero angle of attack?

texts:
Assuming a flat bottom wing moving through the air at say 50km/h and at zero degree angle of attack, what will be the likely airspeed above and below the wing?

I know this will be affected by camber and maybe wing chord too. But is there like a proportional estimate for specific wing camber?

I haven't got much knowledge about wing maths, but a formula would be appreciated.

Applying Bernoulli's equation requires the relative airflow above and below the wing. The things is, I'm trying to experiment with the fact that given atmospheric pressure, the two different airflows, and the wing area, one can actually determine the pressure difference between the top and bottom surface using Bernoulli's equation and also the total force holding the plane up by getting the product of the pressure difference and the wing area. So what I'm trying to do is estimate the lift force on my theoretical airplane model at a particular wind speed. I want to use this to estimate the minimum airspeed required for normal flight 'without flaps'.


texts: How long can an aerobatic (or any) plane fly "on its side"?

texts:
This recent question Can a plane bank without turning? asked if a plane can sustain some amount of roll in straight flight, sure they can.
Consider an aerobatic plane (perhaps a Pitts?).
As far as I'm aware it's certainly seems possible for them to fly "on their side" ... roll of 90° or -90° ... at least for short times.
I guess, in a "four point roll" you are on your side (90° or -90°) for at least a short time.
In fact - Pitts owners or others! - how long can you actually do that for?
There would seem to be no (upwards) lift at all?
Are there videos of someone flying on their "side" for miles?
Or in fact is it just an artifact .. you can only actually do it for seconds and really just momentum is keeping you seemingly from losing inches of altitude?
How long can you fly on your side for?
What's the deal on this?
If the answer is "only for a tiny amount of time" in fact, can ALL aircraft do that, or is it really only possible for "aerobatic" aircraft, and if so what's the enabling difference?


texts: Freezing cold cabin housing just under a window

texts:
I flew on a Boeing 737 plane yesterday and was sitting next to 2 windows. When I tried to rest my arm on the inner housing of the cabin during the flight, I noticed that the inner cabin housing just below one of the two windows was very cold. It was almost like touching a surface in your freezer. I was under the impression that it is not a common thing and that it could only result from outside air being in contact with the inner cabin housing which I believe is not supposed to happen.

I spoke to a flight attendant about it and he came check the window, but I feel like his feeling all in all was that I was worried for nothing, and I’m not sure he actually shared the information with anyone - and he did not thank me in anyway for reporting a potential issue.

I’m curious of anyone views on this issue. My uneducated guess was that it was maybe not a critical issue now, but a defect that should be known by maintenance teams as it could be tied to a structural issue of the outside window.


texts: How autonomous are commercial passenger airliners?

texts:
Average layman here. Assuming the latest generation of planes/avionics rolling out of the factory today, how autonomous are commercial passenger jets? Obviously, autopilot has been around for decades, but what are the limits of its capabilities? Can it take off and land by itself? What can be done remotely, if anything?

Watching a typical airliner-crew-is-dead-what-can-we-do-now movie caused me to think of this question.


texts: Is there any advantage to having both wings integrated into a single wing unit, rather than being attached separately to the fuselage?

texts:
if I have a wing, which is split in the middle of it and attached at each side of the aircraft (like in any commercial aircraft today), I get a bending moment at the root of the wing.
What if I have an continuous wing (box) like an oblique wing on the top of the fuselage? A friend of mine says, that this way the wing itself would carry its bending moments. How can I imagine this? Is this just like a beam? Does anybody has some papers about this?


texts: Does laser eye surgery prevent me from getting an EASA pilot licence?

texts: I am a masters student in Germany and I am very much interested in pilot training. I had a laser eye surgery (LASIK) 3 years ago. I heard that people who got it are not eligible as a pilot. Is this true for a private licence too?


texts: Why don't all new GA planes include a parachute system?

texts:
When the Cirrus was first introduced, it included a Ballistic Recovery System, which shoots a parachute out the rear of the plane that can save a plane and its occupants when something goes wrong.

Seeing as how this technology has been honed over the past decades, why don't all new planes incorporate this feature?  I would think that any drawbacks outweigh the benefit of not losing one's life when something happens unexpectedly.


texts: Change of Roll moment with change of wing position (z-direction)

texts: If I compare two identical configurations, which only differ from each other in low wing and high wing position. We assume that the lift and drag remains constant. Will I get the same coefficients in moment for pitch, roll, and yaw? Because the force arms are the same?


texts: Seatbelts-on during taxi protocol: Risk assessment

texts:
Typical taxi speeds are less than 20 knots. These are speeds at which city-transport  buses regularly operate & even exceed. Buses don't mandate seat belts & in fact even allow standees.

Now my question is: Is the risk of collision higher in a taxing aircraft? Are decelerations higher? Or do we operate in aviation with a lower risk appetite.

Just curious.

As a counterexample, during flight even if the seatbelt light is turned on, toilet-visits seem allowed (mostly, unless its severe turbulence). On the other hand, the ground taxi period seems an absolute PAX movement prohibition period akin to takeoff & landing.

Is ground-taxi riskier than in-flight seat-belts-on periods?

PS. Don't interpret this as advocacy to get rid the seat-belts during-taxi rule. Just curious about the differential risk assessment.

In any case most safety prohibitions are a risk-vs-convenience tradeoff. Just evaluating that tradeoff in this particular case.


texts: What (if any) endorsement do I need to give a student who scored 100% on his knowledge test?

texts:
My student studied his empennage off and got a 100% on his knowledge test.  Usually, when I endorse students, there's a sentence that goes:

  I have given [name] X hours of instruction on the areas in which he/she was found to be deficient on his/her airman knowledge test.

In this case, my student wasn't deficient on any areas of the knowledge test.  Do I need to make that endorsement?


texts: Does the country of issue of an EASA medical certificate matter?

texts:
I am choosing the country where to do my initial for the EASA Class 1 medical. The choice is to either do it in the UK (let's ignore Brexit for now) or in Italy. In both countries I would get (if deemed fit) an EASA Class 1.

My question is: to fly and train in Europe, how important is the country of issue?
If I pass the medical, I am planning to go to an FTO in the UK.


texts: Why is the PIC position for helicopters the right seat, rather than the left seat as in airplanes?

texts:
So far as I am aware, in a fixed wing aircraft having side-by-side seating and  dual controls but only a single set of instruments, those instruments are always positioned in front of the left seat. Even when an aircraft (such as commercial air transport) is fitted with dual instruments, the left seat is designated as the "pilot-in-command" or "captain's" position. This "left-seat as principal" designation appears to hold true for any fixed wing aircraft from a Cessna 152 to a Boeing 747, in all jurisdictions of manufacture and operation.

For a helicopter, the situation appears to be reversed - the "pilot in command" appears to always occupy the right seat.

Is this true, always, or is it an observational bias? Is this simply convention or is it specified by regulation? What would account for exceptions, if any?


texts:
Is it legal to barrel roll a plane?
Are you allowed with any pilot license?
Are there any requirements for the plane to be allowed to barrel roll?


texts: High altitude turbine efficiency question

texts: The simple reason turbine engines are more efficient at high altitudes is because as the air becomes less dense it requires less fuel as the ratio has to remain constant.  This holds true up to isothermal temperature which is usually at 40,000 feet.  The turbine compresses the colder air with less fuel required and you have a much lower fuel burn.


texts: Do commercial passenger airplanes have cambered airfoils?

texts: It seems to me that they logically would, since they have no need to fly upside down like an aerobatic plane would (so they would not need a symmetric airfoil for any conceivable reason). That being said, is that correct, and does anyone have a link to a reliable source where that is stated?


texts: Why aren't airports built with future expansion in mind?

texts:
There are currently numerous controversies around the world in regards to airport expansion, where local residents are opposed to new runways or changes in the hours of operation. The most famous example is probably Heathrow airport, where it took decades to finally approve a plan to add a third runway.

But why aren't airports built in a way where future expansion is possible? E.g. why wasn't an area 5 kilometers around Heathrow reserved for new terminals and runways, even if it wasn't clear if they're ever going to be required?


texts: What does it mean when a runway's safety area is not standard?

texts:
If an airport has a NOTAM that states that a runway safety area is not standard, what does that mean? Here's an example.

!CRW 12/043 CRW RWY 05/23 SAFETY AREA NOT STD 1512221324-1708151600

Is it something to do with the area on the ground that must be clear for takeoff and landing or some other criteria?


texts: How does this IMU work and how to convert its output into meaningful information?

texts:
To understand more about IMUs and IRS, I have chosen the Honeywell 6DF-1N6-C2-HWL Inertial Measurement Unit as an example:

I don't see any mention of the output of the IMU in the linked datasheet - have I got it wrong? And how to convert the output into meaningful data? How do I convert raw accelerometer data into Speed in knots, for example? Is there a specific formula to calculate the speed (velocity might be apt) while also taking into account the movements in other directions as well?
Is the raw data from this specific IMU accurate enough for use in a GA aircraft / Light Sport Aircraft?
Am I right in saying that this IMU doesn't need Pitot / Static sources?

While most details might be about this specific IMU, please feel free to also give answers that apply to all IMUs as a whole.

EDIT: I do not want any positional data. I prefer an AHRS with Airspeed and Altitude sensing capabilities.


texts: What 's the difference between Angle of Attack and Pitch?

texts:
I am interested in knowing the theoretical and practical differences between the Angle of Attack (AoA) and Pitch:

Graphical definitions
How are they related?
In what circumstances these angles are equal?
While flying, do you need to consider both or only the Pitch?

Thanks in advance :)


texts: How is a plane with only ailerons and jet (no props) controlled?

texts:
I saw this video and was wondering how he is controlling the plane:

It looks like he only has ailerons. It does look like he is shifting his body weight. Is that the answer? If so, that's pretty surprising! But I guess it's like a hang glider?
Does anyone know how you should shift your body to increase/decrease pitch, and increase/decrease yaw?


texts: Is this one of the engines from the 9/11 aircraft?

texts:
I ran across an interesting set of post-9/11 photos and I noticed this picture in particular:

The closest item on the truck looks a bit like an airplane engine, but I can't tell for sure. Is it one of the engines from the 9/11 aircraft?


texts: How does a fighter “thump” an intercepted aircraft?

texts:
In P&E Never Again: A Thump on Final, commercial pilot Mike Mercer describes an encounter with an F–16 shortly before rounding out to land.

  Without warning, the Baron abruptly yawed 15 degrees right, and there was a thunderous noise on the right side of the aircraft. I was standing on the rudder pedals to maintain directional control and managed to keep things more or less aimed at the runway … On the rollout I got a look at the F–16 in full afterburner climbing back to altitude and turning to circle the field. I concluded immediately that we had been “thumped,” a procedure we used in the military that was designed to rattle and harass the pilot of an intercepted aircraft.

For context according to the linked account, this incident took place inside a VIP TFR that the author flew into unwittingly. His hand plotting and ADS-B display on his EFB led him to believe the TFRs were well north of his destination. Shortly after departure, the author attempted to request but was unable to obtain flight following.

What maneuver does an intercepting fighter perform to “thump” its target? Other than the severe yaw that the author mentioned, what are other typical aerodynamic effects?


texts:
Lately I've been wondering if it's possible to interface an everyday computer with the ARINC buses (either 429 or AFDX).

This would be very useful for simulation, testing and prototyping purposes. For example, we could write a computer program that sends ARINC labels to the bus and see how the avionic systems react to it.

But I think that the greatest challenge would be in the physical layer.

The image on the left shows some connectors that we can typically find in everyday computers. The image on the right shows the connectors that we can find in the front panel of an avionic system.

At first glance making such a connection does not look straightforward.

Nevertheless I've done some research and I have found devices which seem capable of interfacing a computer with the ARINC bus via the USB port:

  These pocket-sized USB adapters are the easy and portable way to interface your computer to ARINC 429 and ARINC 717 Avionics
  databuses.

  Source: Astronics

So connecting a computer and avionics is possible in theory. Still, I don't see how I would be able to connect this USB-ARINC adapter to the avionics box, since the connectors are different.

So there must likely be an access point somewhere in the avionics where this adapter can be connected.

This is all I could find.

So again,

Is it possible to communicate an everyday computer with the ARINC bus?
If so, what is the access point where we would connect the wire?
Would there be any other challenges I didn't take into account?


texts: Why do Airbus sidesticks add their inputs?

texts:
There have been a couple of Airbus disasters where, in the confusion leading up to the crash, both pilots have attempted to control the aircraft with their sidesticks at the same time. In the absence of either pilot using the priority button, the effect of this is that both inputs are added, and the result clamped to the maximum single input.

On the face of it, this is a very curious design decision. Obvious alternatives include prioritising the left-seat stick (unless the priority button is used), or even averaging (instead of summing) the inputs.

Are the original reasons for this design decision documented? Is there an advantage to summing the inputs?


texts: Why do the wing tips on the Boeing 777X fold up instead of down?

texts:
The outer 11.4 feet (3.8 meters) of the wings of the Boeing 777X are designed to fold up when on the ground. Why aren't they designed to fold down?

It seems to me that folding down would be more "fail safe" if the locking mechanism failed in the air. The wings are generating lift, so they would hold themselves up and continue to contribute to keeping the plane aloft.

Up-folding wings could lift themselves if the locking mechanism failed in flight and destabilize the plane. The folding bit is less than 12 feet while the diameter of the engine nacelle is greater than 14 feet, so it doesn't seem like proximity to the ground is the issue.

What are the biggest reasons for folding up instead of down?


texts: Is potentially dangerous to select the take-off power on airliner lower that temperature at the moment on the airport?

texts: Is potentially dangerous to select the take-off power on airliner at lower settings  value due to the temperature that could be increased by the time the aircraft will go up?


texts: Are NDBs and VORs dying as a navigational method?

texts:
I am new to aviation, so bear with me on this question:

I have read in multiple places that the VOR/NDB navigational aids are dying out to GPS. Is this true? Are more modern aircraft being built with glass, digital instrument readouts that capitalize on GPS services instead of the traditional vacuum tube ADF and VOR Indicators?


texts: First airplane to use a flight simulator?

texts:
Icarus, Pegasus, da Vinci's flying machine and Wright brothers airplane probably didn't have a flight simulator, since computer science was not yet developed enough (Antikythera ancient analogue computer in 70BC, Wright brothes until 1948, ENIAC introduced in 1946).

So, which bird was the lucky one, to first be accompanied by a flight simulator?


texts: Why do T- tail airplanes have a shorter vertical stabilizer?

texts: Airplanes with a T-tail design have a shorter vertical stabilizer than the conventional design , what is the reason?


texts: Do airplanes have any kind of fire insulation?

texts: Commercial airplanes sometimes suffer from a bird strike or something else that could ignite a part of the engine. So apart from noise insulation, do airliners have fire insulation?


texts: Are there different configurations of cabin crew seating arrangement for one aircraft model?

texts:
In many airlines, cabin crew are shown to be sitting in different areas. Is it common for airlines to offer different seating configurations for a particular airline model? Also, are there any advantages of the same?

For example, in A320, you will find cabin crew seating in the aisle at the rear of the aircraft in some aircraft, near the toilet.


texts: Is a pilot responsible for CTAF announcements in this scenario?

texts:
A Cessna 525 Citation Jet is coming in to land and a single-engine Cessna 150 is taking off at a small airport with no ATC. The Cessna 150 stays in continued radio contact and the Cessna 525 Citation Jet does not.

An accident occurs where the Cessna 150 clips the Cessna 525 Citation Jet on the tail end. The Cessna 150 crashes and burns. The people in the Cessna 150 pass away and no one is injured on Cessna 525 Citation Jet.

Is this labeled as an accident although the Cessna 525 Citation Jet did not stay in radio contact after landing when the Cessna 150 attempted to take off?

https://www.cbsnews.com/news/marion-indiana-airport-planes-collide-2018-04-02/


texts: Do I need to obtain a student pilot certificate to transition from Glider to Sport Pilot?

texts:
I am a current Private Pilot Glider, and will soon begin training to obtain my Sport Pilot Licence. My question is about the requirement to obtain a student pilot certificate to solo in the training aircraft. I have heard that it is no longer the normal practice to record the solo endorsement on the student pilot certificate, but instead to record it in the logbook.

With that in mind and the fact that I already hold a Glider licence, do I need to obtain a student pilot certificate?


texts: How does the rotor blade material affect aircraft performance?

texts:
Helicopter rotor blades in newer helicopter designs are made from composite materials. This results in improved performance. Is this simply because they are lighter or is there another reason behind that?

For example, for the new CH-53K the blades are made from titanium fiberglass composite. The use composite rotor blades results in better "hot+high performance".

How can that be? Isn't performance simply weight/lift ratio?


texts: Are drones used in firefighting, agriculture and pest control?

texts:
Well, as the question says I am interested in the use of drones in agriculture.

Are there any drones designed to carry a tank of some chemical or water?

How large are those tanks?

I have seen that airplanes are used in agriculture and in extinguishing forest fires. They can carry tanks containing 500-2000 kg (or more) of chemicals/water.


texts: Do pilots make money from the airline they fly for (Delta, JetBlue, Southwest, Skywest), the company that makes the aircraft they fly (Boeing, Airbus, Lockheed Martin, Embraer, Bombardier), or just by the hours they fly?


texts: Which airfoil would be optimum for a glider?

texts:
The glider I am designing has a mission requirement to fly for as much time as possible. It will fly in the low Re range of about 150,000 to 250,000.

While comparing different airfoils I am looking for a high value of Cl^3/2/Cd to get as high endurance as possible and a high Cl/Cd ratio.

Any other parameters I should consider in selecting the airfoil?
I am currently considering Wortmann FX 63-137, E61, DAE-31 and Fx-74-c15-140.
Any other airfoil suggestions would be appreciated.


texts: Why are fast passenger airplanes no longer produced?

texts:
Concorde was a fast aircraft, but no comparable aircraft is designed today by manufacturers.

What are the main reasons for manufacturers to prefer larger planes carrying more passengers rather than planes flying faster with a less passengers?


texts: Why do most military aircraft use different engines than commercial aircraft?

texts:
Why do most military aircraft and helicopters use different engine technology (fighters, B52, U2, etc) than most commercial aircraft?
[I removed the use of axial terminology]


texts: What is "Block burn" and how is it calculated?

texts: I have heard a couple of times the term "block burn" in the aviation industry but I am not sure to what it exactly refers. My second question is how is it calculated? I have also heard it depends on seasonal data


texts: Question about congestion of the 1090MHz frequency

texts:
I'm no expert so there's likely to be a lot of mistakes in this post.
ADS-B - Automatic Dependent Surveillance - Broadcast, (out) transmits (in) receives position data from/to other aircraft and to ATC.
I've been trying to find out more about how congestion of the 1090MHz frequency will be addressed. It seems that ADS-B out is becoming fairly ubiquitous. Additionally, there will be more aircraft interrogating (on 1030MHz) and responding to interrogations on 1090MHz for transponder based systems (TCAS, SSR). From this post, it sounds like things are already congested in some areas.
Here are some of the things that I'm unable to google for so far:

On the wikipedia page for TCAS, there is mention of a bandwidth limitations of 1 megabit/second. What does this mean?:

a) Within an airspace only 1 megabit/second of data can be transmitted cumulatively.
b) Air traffic control can only receive 1 megabit/second.
c) Individual aircraft can only transmit 1 megabit/second.
d) The receiving equivalent of c.
e) Other

What is physically limiting bandwidth? Will there eventually just be too much interference between signals whilst using this frequency, or is it a hardware issue? I couldn't seem to google this issue, maybe I need some keywords.

Are the solutions to increasing capacity about being more clever with how the packets are sent (more efficient packet sizes, fewer packets, better/cleaner transmission), improving ground or air hardware, or is there a "add more lanes to the highway" solution? It seems 978MHz is equivalent to adding more lanes.

What is the consequence of congestion? Are packets corrupted as noise rises? What keywords should I google?

Also, thanks for all the useful info on this site, aced a Masters assignment recently because of the aircraft designers on here.


texts: Can multiple aircraft share the same logbook?

texts: If a private pilot owns 3 planes can he use 1 logbook for all 3 or does he need to use 3 logbooks?  Would the answer change if he also owns a helicopter?


texts: Would discharging a firearm in-flight cause an explosive decompression?

texts:
I was reading a BBC FAQ about Federal Air Marshals, which has this chilling quote in it:

  A gunfight on a passenger airliner is seen as an option only of last resort.

Presuming an air marshal has to discharge his weapon on-board, and it goes through the fuselage, would this be likely to cause an explosive decompression?