texts: How fast can a large passenger jet descend and slow from cruise to emergency land?

texts:
On 17th April 2018, Southwest 1380, a Boeing 737-700, was cruising about FL320 when it suffered a catastrophic failure to engine 1.  It then took 5 minutes to descend to 10,000 feet, and I noted from the ATC recordings that the pilot said it would require a long approach to land at PHL.

Is this because the airplane could not bleed off airspeed fast enough for a short/straight-in approach? Is this the fastest that a large commercial airplane can descend and slow for an emergency landing?

I assume that, to achieve maximum descent and deceleration the remaining engine would be pulled to idle, and that landing gear would be extended at maximum safe speed, which IIRC is 250 knots?

Would it be reasonable to fly cross-controlled with an aircraft in this condition?  With no engine thrust requiring rudder input, is that safe at all speeds?  How much can it increase drag?

What are the speed limits for extending flaps, and how much do those affect drag?

(I can appreciate that in the case of Southwest 1380 the pilot in command, not knowing the extent of damage, may have been hesitant to do anything that would strain the airframe or controls.  So I'm curious as to how long an "unstressed" descent would take, and then how much faster one could descend by using the most aggressive techniques that a pilot would reasonably use in an uncompromised passenger flight in the same model.)


texts: In what manner was the Vympel R-73 (AA-11 Archer) a game-changer in comparison with NATO's missiles?

texts:
I have heard that when the Vympel R-73 air-to-air missile was introduced it was a game-changer.

I have also heard that after the collapse of the Soviet block it was tested by NATO (via re-united Germany) and NATO was quite impressed by it. According to one source, in close combat the MiG-29 was better than the F-16 by 2:1 and better than the F/A-18 by 1.5:1.

What was so special about it? How did they make it? Did they have better experiences? Or ideas?


texts: Do Airbus pilots have to practice flying in alternate law?

texts:
I am sure when getting their type rating for Airbus FBW aircraft, pilots learn how to fly in alternate and direct law. After that, how much opportunity do they get to practice this skill?
On Air France 447 and Indonesia AirAsia flight 8501, the A/P switched off unexpectedly and the control law degraded to alternate 2. It appears in both situations that the PF had trouble stabilizing the aircraft roll attitude. It's difficult to determine whether this contributed to the pitch up and eventual stall but the original pitch up command may have been inadvertent while struggling to level the wings.
Under normal law, which pilots are accustomed to flying, the FAC calculates the amount of aileron deflection required to turn the amount of lateral sidestick deflection into a rate of roll with a maximum of 15° per second. In alternate 2 law the computer cannot make these calculations so it becomes direct stick-to-aileron control.
This can mean that the aircraft responds very differently than what the pilot is used to. Sometimes the difference may be slight but at high speed and high altitude the same stick deflections can result in a significantly higher roll rate.
Additionally the stick does not provide tactile feedback as to how much force is required to move the control surfaces. With conventional flight controls "roll or pitch rate would more directly correlate with the force applied on the control wheel, and not the amount of deflection required."1
These things combined can result in the pilot over-controlling. The control inputs can get out of phase with aircraft movements resulting in pilot induced oscillation in the roll axis. This occurred in both of the above accidents.
It must be terribly disconcerting for a pilot when the A/P disconnects and they are handed control of an aircraft they fly every day, but doesn't respond the way they are used to. I'm wondering how much practice they get at flying in this configuration, either in a simulator or in the aircraft itself. Do most airlines flying FBW aircraft require this regularly? Does Airbus - or anyone else - recommend any amount of further training or practice? Have these recommendations changed in light of the accidents?

1Bill Palmer, Understanding Air France 447


texts: Can surface roughing effects on an airfoil Reynolds number be quantified?

texts:
I am building balsa free flight gliders with a chord of 0.10 meters and a velocity of around 3 meters per second.  This works out to a Reynolds number of around 15,000.

The wings are around 1 meter in span, and are made with the wood grain running lengthwise.  They are thin undercambered (no bottom covering) with maximum thickness of 7 mm at 30% of chord from leading edge.

Because of the roughness of the unfinished grain, is my Reynolds more like 50,000, or am I still down in the range where a flat plate might be better?


texts: Effect of Low Vitamine B12 on Class 1 Medical

texts: Does anyone know what the effect of LOW Vitamin B12 is on an aviation medical class 1? My doctor did a blood test recently and put me on Vitamin B12 pills. Is this an issue for Aviation Medical doctors when they do a class 1 medical? i have to do mine shortly.


texts: Why don't flights fly towards their landing approach path sooner?

texts: For example shown here, the flight is heading to the centre of the airport, until it gets close when it then moves into it's landing path. This is an inefficient use of time, fuel and emmissions, why can't the airport tell the aeroplane exactly which runway and direction it will land earlier so it can more efficiently head towards the approach.


texts: During instrument approach, is an abbreviated racetrack course reversal allowed?

texts:
I was flying the RNAV (GPS) RWY 33 approach into KFNL during instrument meteorological conditions.  The plate identifies a non-standard 6 NM racetrack reversal at IMOMY:

Denver approach cleared me direct to IMOMY.  I was approaching from the Southwest, but NOT from HYGEN. Thus, I began a circuit around the depicted procedural track. I was cleared for the approach and approved to change to advisory frequency.

At about 4 NM outbound, ATC contacted me* and asked when I planned to turn inbound.  I advised that I could begin inbound immediately, which they then asked (not cleared) me to do, in order to avoid encroaching on departing traffic from KDEN.

During VFR practice approaches (not under ATC), we always shortened the course reversal on this particular approach to save time. When doing the real thing, it was always my understanding that the depicted track had to be flown EXACTLY as published.  Per the FAA Instrument Procedures Handbook:

  A holding pattern in lieu of procedure turn may be specified for course reversal in some procedures. In such cases, the holding pattern is established over an intermediate fix or a [final approach fix]. The holding pattern distance or time specified in the profile view must be observed. For a hold-in-lieu-of PT, the holding pattern direction must be flown as depicted and the specified leg length/timing must not be exceeded. (Page 4-53)

Now, I was also taught that if you have to perform a teardrop or parallel entry, that completed your reversal and no circuits are necessary:

  The holding pattern maneuver is completed when the aircraft is
  established on the inbound course after executing the appropriate
  entry. (Ibid.)

Question 1: Was it appropriate for me to attempt to fly the 6NM circuit?

Question 2: Am I allowed to choose an arbitrary leg distance (or time), as long as the 6NM limit is not exceeded?

*I was already switched over to the CTAF, but still monitoring approach control on the second radio which I always do just in case. Something I picked up from my flight instructor who flew larger planes for a living...


texts: Do all Class B and Class C towers operate 24/7?

texts: For Class B airports, I think the answer is realistically yes, due to traffic flows. How about Class C airports? Are there any legal requirements that it has to operate in 24/7, or is a convention?


texts: Why does the FAA require special authorization to act as PIC in the North American T-28 Trojan?

texts:
This airplane doesn't have a max gross takeoff weight of more than 12,500 pounds nor does it have a turbine engine.

The FAA requires special authorization to act as PIC in order to fly it.  What is the reason?


texts: When did the Tu95 first use its armament in combat? I know they can carry both missiles and bombs, I'm looking for the earliest date of either one being used in a combat situation.


texts: How is the moment due to pressure distribution calculated?

texts:
Consider the airfoil shown, with a co-ordinate system set up from the leading edge $O$:

I want to find the moment of force about point $O$ due to pressure on an infinitesimal piece of the airfoil at point Q.

A text book I'm referring to(Fundamentals of Aerodynamics by John D Anderson) says that the moment is:
$$ dM= (p dS) cos \theta ~ x_Q $$ (where $x_Q$ is the x co-ordinate of Q)

Is this expression an approximation that assumes thickness of the airfoil to be negligible compared to the chord length?

Because, the moment should be length $OQ$ multiplied by component of $pdS$ perpendicular to $ \vec{OQ}$ ... or have I made a mistake with the physics?


texts: How much fuel does an airliner consume at various stages of operation?

texts:
I used to think that almost all of an airliner's fuel consumption was during actual flight; but it seems that even while on the tarmac or at a gate it consumes a non-negligible amount.

So, in general for modern passenger airliners (say, produced over the past 20 years) and without regard to a specific manufacturer or model:

Let 1.0 be the normalized rate of fuel consumption at typical cruising speed. How much fuel is consumed, on average / typically, when...

Loading passengers?
Taxiing?
Waiting on the tarmac for clearance to take off?
Accelerating and taking off?
Climbing?
Descending?
Touching down and breaking?

Again, rough typical figures please. Or - you could give a concrete example which you believe is representative of the general case.


texts: How do foreigners (international students) work as airline pilots in the USA?

texts:
I am planning to study in the USA/Canada (whichever is easier to work afterwards) to get my pilot licenses from 0 to CFII or CFI-MEI, so my best bet is to apply for an F-1 visa program (since it grants 1 year working permit upon completion of my study).

So my question is how can I apply for an airline first officer position after getting 1500 flying hours? What else do I need? (I assume its working permit aside from the one granted by F-1 visa since it's only valid for on-campus jobs and it would be already consumed in getting my 1500 flying hours).

Any correction for the info stated would be much appreciated.


texts: How to announce in an ATIS message that two parallel runways are in use?

texts:
Suppose an airport has two parallel runways and aircraft can use any of them.

How would I announce in the ATIS message that both runways are in use?


texts: Can the big "X" sign be used for purposes other than runway closure?

texts:
About last Sunday night in the dark I was departing LAX on a redeye.  We pulled away from the terminals (maybe 500m?), made a right. Looking back out the window I saw a BIG lighted X (maybe 20? 30? foot high - really bright!) flashing. I guess it was one of THESE but it had four rather than five per arm and REALLY bright.  (I grabbed a completely hopeless video; I'll try to add it later.)

Now, just the previous day there was that incident at LAX where an airliner hit a supply truck, and toppled over the truck (some people in the truck were hurt even I believe).

Can the sign be used on situations other than runway closure? For example:

almost certainly some drama, such as the mentioned truck-jumbo incident, or
is it actually just a normal control sign that goes on an off?  (Perhaps, to indicate "don't cross here, someone else is crossing" - or whatever.)

My impression was that it was at the "side" of a runway  or taxiway, that is to say, as if crossing it.  (Of course, my impression could be totally wrong.)  Would these Xs be used in that way, or, only at one end of a runway?


texts: Is there a brightness switch for the AOA gauge on the F-16? Please share a picture with the panel if you can.


texts: Do wingtip vortices cause a decrease in the lift component of aerodynamic force, and do planes need to pull more AoA to compensate?

texts: So, from what I know about wingtip vortices, they shift the angle of the relative airflow to where the effective angle of attack of the airfoil is lowered. Since the aerodynamic force is always perpendicular to the relative airflow, the aerodynamic force is also shifted and now has a backwards-facing component to it, which we call induced drag. Now, my question is, just looking at the way the vectors point, the tilting of the aerodynamic force backwards means that, while there is a greater backwards facing component, the upwards facing component (what we call lift) is decreased, right? So we can say that the vortices shift the aerodynamic force in a way so that the induced drag increases, but the lift decreases, right? And, if that is the case, then wouldn't the aircraft then need to pull an even greater AoA to compensate for that lost lift, which in turn would create even more pressure differential, which would then increase vortices even more? Then even more AoA would be needed, and so on... Then this cycle would go on until the aircraft bled all its speed... Obviously, that isn't the case and there isn't a snowball effect in real life? So is my fundamental understanding of vortices and induced drag off?


texts: What is the validity of doing 2D airfoil simulation for axisymmetric bodies?

texts:
I am currently working on axisymmetric bodies like fuselages/droplets etc. For this, I am interested in the point of flow separation (if there is) and velocity components at a certain point in space.

I know that XFoil is capable of doing this in a short fraction of time/effort compared to CFD for 2D sections.

What is the validity of taking this approach towards axisymmetric bodies?
With this I mean: using the cross section of the axisymmetric body and simulating this 2D cross section in XFoil, or any other 2D airfoil simulation programme.

Or: can I change the software in some way such that it can represent the physics better?


texts: What are good alternatives to sunglasses for flying?

texts: I'm a student pilot and I won't be able to wear sunglasses for 5 months... Now, how am I going to fly? I know you don't have to wear them but it's easier (brightness etc. etc.). Are there any alternatives you can give for flying? I've never tried a hat, is that a good option for the moment? Maybe it's a silly question but do sunglass contact lenses exist?


texts: What's the difference between the Multi Engine Instrument Rating and Instrument Rating in Canada?

texts:
Are the requirements for the Multi Engine Instrument Rating the same as Instrument Rating in Canada or is there a separate exam for each of them?

Thanks!


texts: Do aerodynamic forces and moments change aircraft pitch and yaw in the same way?

texts:
Several questions on the Aviation SE site have dealt with the question: can the rudder alone turn the aircraft:

This one, which was marked a duplicate of
this one, which was itself marked as a duplicate of
this question, with a skilful and detailed answer.

So we know in triplicate that the rudder alone can turn an aircraft. Not very comfortably due to the side forces, wrong way lean, different airspeeds on inside & outside wing etc, that is why the normal way to turn is to bank.
However, the following has been posted in the comments (partial quotes only due to length):

Yaw does not cause aircraft turn. It only causes yaw. Yaw is not turn.
Lift, pointed in a direction other than perpendicular to the horizon, is what creates turn. Nothing else.
With no other yaw force on the aircraft, if you have right rudder, that does create a leftwards force, but it also creates a right yaw (sideslip) which itself creates a rightwards force that opposes the leftwards force from the rudder.
It works in exactly the same way as it does in pitch. The elevator pulls the tail down and, because it's behind the CG, creates a nose up pitching moment (torque). Lift on the wings lifts the aircraft up, and because it's also (generally) behind the CG it produces a Nose down pitching moment. Because the moment arm of the elevator is so much longer the torques balance, but the Up force from wings is much larger than the down force from the elevator and the aircraft is able to fly. The force from the rudder, and the force from the sideslip angle of the fuselage act in the same way.
The nose of the aircraft does not "turn" away from the "direction the pilot ... " it only "yaws" away, and it only yaws away until the sideslip angle reaches the point where equilibrium occurs.

The gist of all this is that the aircraft would behave in yaw in the same way as in pitch: rudder deflection only causes an angle of sideslip, not a continuous turn in heading. That would conflict with the earlier questions posted above.
So the question is: does yaw really behave exactly like pitch? Does deflecting the rudder only cause a greater angle of sideslip but no flight path change?


texts: How did ATC procedures and airspace structure change after San Diego PSA collision?

texts:
In 1978, a Pacific Southwest Airlines aircraft collided with a Cessna 172 while approaching the San Diego airport in California. The GA aircraft was piloted by a student, and crossed the approach trajectory of the B727, killing 144 people.

Source

To my understanding, ATC was not aware of the Cessna actual location, The airliner crew didn't see the Cessna, and the Cessna was not wrong being in this airspace near a busy regional airport.

What changed after this accident to make such situation impossible?


texts: Can a GA magneto-spark plug ignition survive an EMP?

texts: Can the coil and capacitor (condenser) magneto/spark plug ignition system as exists on most general aviation aircraft survive an EMP? Let's talk about a standard Lycoming or Continental engine. How about most turbine engines? I'll use a PT-6 as an example. I assume the FADEC would be toast? How about other parts of the electrical system such as the battery? Is there any data or research on this?


texts: How is the synchronization of multiple engines managed in twin engined aircraft?

texts:
If one of the two engines of an aircraft is running at slightly less RPM then the other, how the synchronization is being managed?

Also, if there are more than 2 engines in the aircraft, how that will effect?


texts: Why are some item numbers missing in ICAO flight plans?

texts:
I was looking at an ICAO flight plan and observed that there are only specific ITEMS mentioned in it (see example below)? What is the reason behind excluding the item numbers 1, 2, 3, 4, 5, 6, 11, 12, 14 and 17?

(source: FAA)


texts: Has a commercial airliner ever crash-landed in an ocean?

texts: They have rafts and life jackets on board and before takeoff, passengers are explained how to use that equipment, but have any evacuations ever happened successfully?


texts: What Kind of airfoil configuration is preferred for an hyper sonic plane?

texts: I am trying to design a hyper sonic aircraft in line with X-15 for my Aircraft design project. This requires me to figure out the preferred airfoil shape for the wing.


texts: What are the hurdles to overcome before purely electric commercial aircraft can fly?

texts:
What are currently the largest issues with purely electric commercial aircraft (large scale ones like the size of a Boeing 737)?

Are there any organizations right now that are trying to solve those issues?


texts: Is there an issue with an acceleration followed by a deceleration when flying a SID?

texts:
Sometimes I see SIDs with a long straight climb segment (say 10 nm), followed by a wide turn with an IAS constraint (e.g. MAX 210 KIAS).

Is there any issue in accelerating to 250 KIAS and then decelerating shortly before the turn? Is that ever done?

EDIT
Fictitious example:

EDIT #2
Here's the actual chart (I hope no copyright infringement):


texts: What is the difference between staged and unstaged fuel manifolds?

texts: Also, I would like to know the difference between pilot, primary and secondary fuel flow.


texts: What is the maximum crosswind limit for a C150/2 aircraft?

texts:
What is the maximum crosswind limit for a C150 or C152 aircraft?

Does this change depending on the class of licence?

Are there exceptions for emergencies?


texts:
I am trying to understand the derivation of some simple equations to calculate the neccecary takeoff speed for an airplane (under ideal conditions).

Which is taken from 15. Takeoff and Landing. My main issue is the derivation of the horizontal equation

To get from the first to the second line my guess is that we use

R = W - L   and    m = W / g

My main problem is understanding the details between what happens from line 2-3 and 3-4. I would love if someone could give me a brief explenation of the symbols used, what does S denote?


texts: In what conditions do airline pilots favor crabbing over de-crabbing for crosswind landings?

texts:
There are several crosswind landing techniques described on Wikipedia, including crabbing (straightening out after touchdown) and de-crabbing (straightening out just before touchdown).

For airline pilots, are there specific conditions that favor the use of the crab method over the de-crab method for crosswind landings, despite the excessive side load the crab method may incur? When airline pilots use crabbing for crosswind landings, what are the reasons?

(This question is not about the general crosswind landing techniques dealt with in this great post but more about airline pilots' crosswind landing techniques. More specifically, my question addresses some possible conditions where the airline pilots would prefer the crab technique to the de-crab technique.)


texts: Why does Boeing use two different door-types (B757 hinge vs. B767 slide)?

texts:
Why did Boeing use a sliding door for the B767?

And why wasn't it used in later Boeing planes?

Edit:
Looking up other airframe manufacturers I realised that the B767 was introduced prior to the B757. And that other airplanes featured slide-up doors as well but the B767 was the last one featuring them. Could it mean it was some kind of fashion of the airplane design until the late 70s?


texts: How to arrive and depart surface class E airspace

texts: I fly VFR. I found all the information about the airspaces and I believe I understood everything. What I'm still struggling to find is how to properly arrive and depart surface class E airspace surrounding certain airports. I never practiced that before and non of my instructors ever mentioned how to do that. What I understood from class E descriptions, I have to get authorization to enter surface class E airspace. How to do that? What frequency to use? Where to find it? What exactly should I say? What to expect in reply? Can I do touch an goes there? Is it possible that my request will be declined? Does anybody have a youtube URL showing an example how to do that?


texts: Modern airliners are designed to be able to withstand the worst (vertical) turbulence. But what about the rarer lateral (horizontal) turbulence?

texts:
'Extreme' turbulence is a derived vertical gust velocity of >3,000 fpm (50 fps) that causes a vertical G-load of >3. The limit turbulence intensity for a modern day airliner is 90 fps. (there is likely a 50% safety factor, so the plane is capable of withstanding more).
Lateral turbulence is the type that puts most stress on things like engine pylons and the vertical tail, rather than the wings. An accident involving lateral turbulence is BOAC Flight 911 and the B-52 crashes (Savage Mountain and Elephant Mountain).


texts:
Which method is used to measure the runway conditions?
Is it impossible to land on a contaminated runway?


texts:
There are some circles below the wings of these two aircraft. Look:

Source: Airliners.net (modified)

Source: Airliners.net

On the second picture the circles are clearly visible on the wing. What are they? What is their purpose?


texts: Why does Thrust Reverser need to be operative during the cargo door operation?

texts:
It is stated that when the Electric Pump push button is depressed, the electric pump is automatically running as long as the cargo door selector valve is set to either OPEN or CLOSE position.

During this period, the operation of other systems powered by the Yellow Hydraulic system is inhibited except Alternate Brake and Thrust Reverser of ENG #2.

The Alternate Braking is understandably essential as it stops aircraft from moving, and cargo door operation is considered that aircraft is in parking, not landing phase when the thrust reversers are only being used.

My question here is why thrust reverser ENG#2 needs to be operative during cargo door operation.

Thanks for your answers.

(Source: Training Manual A320 Family)


texts: Is there an ARINC label/data that can be associated with a gyroscope's precession?

texts:
I am looking to read the precession of a gyroscope off of an ARINC bus, is there an ARINC label that can be associated with the gyroscope's precession value?

My thoughts are, that it might have something to do with the drift angle, flight path angle, and/or the magnetic heading. Am I in the ball-park? Or is there no way to measure the precession values?


texts: Why is full carb heat recommended when reducing power below normal setting?

texts:
In my first flight lesson today, my instructor asked me to apply full carburetor heat when we had to reduce power to 1900 RPM in our Cessna 152.

I was surprised by this as I didn't remember learning this in ground school, and I later checked the Jeppesen textbook I am using, and referring to the section on carburetor icing, I saw that when power is reduced below normal operating limits, full carb heat is recommended (must have missed it when studying the ground material).

My understanding is that the cause of carb icing is the sudden drop in temperature in the venturi due to drop in pressure as the fuel speeds up. If I am reducing power, I am reducing fuel flow, so shouldn't this reduce the chances of icing? So my question is why is full carb heat recommended when decreasing power below normal operation?


texts: Would it be safer if Drones carried transponders?

texts:
The current FAA regulations don’t permit UAS above 400’ AGL, but that doesn’t mean that the machines are not capable of flying higher than that.

Since a Mode-C (at the minimum) transponder is required in various airspaces, is it a good time to start considering the fact Drones should start carrying some sort of altitude-reporting transponders?


texts: How is a prevailing wind/average temperature study conducted to determine the runway direction and length for an airport?

texts:
A popular airport near me (KMYF) has two parallel runways, 28/10 R/L and a crosswind runway, 5/23. Almost always, 28R/L is in use. I'm sure they knew that there was generally a sea breeze in the area, and the wind typically will be right down the runway or within 10-20 degrees of centerline.

I'm sure they do prevailing wind study for the area, and my questions are about the study: What are the specifications for the study? Does the study vary in length depending on location? Is there a standard study battery of tests that they use, and do they test things like average temperature during the study to determine runway length (to maximize utility during high density altitude operations)?


texts: Why are listed times of useful consciousness so low?

texts:
I've been reading about Time of Useful Consciousness (TUC), and it says that at FL 180, the time of useful consciousness is 20 to 30 minutes at rest.

But I've been to a trip to Tibet, and we went on a bus trip around the places, and at one point the bus came to a mountain pass around 18,500 feet, and we all got off the bus, walked around, took pictures, and even ate lunch, so it was definitely not at rest. It was about 40 minutes to 1 hour, and I only felt slightly uncomfortable/out of breath.

According to the chart, I should have passed out, or at least become "useless". Why didn't this happen? Are the charts simply very conservative and apply to, say, unfit, crumbling, old pilots?


texts:
I was reading ASRS report when I found something I don’t understand. What would be the hazard of raising flaps on the ground? What bad thing can happen?

However, with all the activity around the aircraft, including refueling, it was not safe to raise the flaps. I elected…not to raise the flaps until the area cleared.

https://asrs.arc.nasa.gov/publications/callback/cb_482.html


texts: Can a pulse jet be used on a light GA aircraft?

texts:
I have an idea for designing a light, cheap and fast 2-seated private airplane... I was thinking about using a pulse jet engine which is simple to design and build, and is cheap too.

Noise is not an important concern in my region. The only things that I'm wondering about are efficiency, fuel consumption (range), vibrations and cooling.

Is it feasible to use pulse jet instead of regular engines?
Is the pulse jet functional and operational?


texts: How will the alpha lock function intervene when performing a takeoff at heavy weights on the A320?

texts:
In the FCTM for the A320 family of aircraft's under the SOP Takeoff chapter it is mentioned that the alpha lock function can intervene when performing a takeoff at heavy weights.

Can someone please explain the logic behind this ?


texts: I remember hearing a quote about aviation that was something along the lines of “asking a pilot why he loves flight is like asking an artist (or a painter?).....”. For the life of me, I cannot remember what this quote is; however, once I saw or heard it, I fell in love with it. I wish I had wrote it down but I didn’t. I could have sworn that I saw this quote on the film “One Six Right” but after going through it multiple times, I have yet to see it written on the screen or heard a person on the film mention it. This question has been bugging me for a couple years and I cannot seem to find any help googling it. Thank you for your help!!


texts: Why does the NASA X-57 need a "gust control system"?

texts:
Why are NASA's engineers concerned about gusts affecting the X-57?
I understand that NASA is recommending automatic torque based prop speed control to be used in flight but also in gusty conditions.
Source: https://en.wikipedia.org/wiki/NASA_X-57_Maxwell

The speed of each propeller can be controlled independently, offering
the ability to change the over-wing airflow pattern to cope with
flying conditions, such as wind gusts.

I understand:

The original airplane being used had a wing loading of about 17lbs/sq ft.

The X-57 has a wing loading of 45 lbs/sq ft with its new smaller wings.

The higher the wing loading, the less an airplane is affected by wind gusts as it needs much more wind velocity to generate lift. E.g. frontal wind gust hitting one wing, then the other on a lower wing loading would create much more roll.

Source: https://www.nasa.gov/centers/armstrong/news/FactSheets/FS-109.html

High-Aspect Ratio Experimental Wing
Perhaps the most noticeable difference from the X-57’s Modification II
configuration is the development and integration of an experimental,
high-aspect ratio wing. Designed by Xperimental of San Luis Obispo,
California, the wing features a large reduction in area, with wing
loading increasing from 17 pounds per square foot to 45 pounds per
square foot.
The reduction in wing area also contributes to more efficient cruise
flight through decreasing friction drag. The final Modification IV
effort will demonstrate that the high aspect ratio wing with the
integrated high lift motor system will allow the X-57 to take off and
land at the same speed as the baseline P2006T. The aircraft will also
be less sensitive to gusts and turbulence, leading to a smoother
flight.

If the X-57 is less sensitive to gusts, why does it need a "gust control system"?
One possible answer is that the X57 needs that flow over the wings to generate lift.
I understand that the X57:

has 14 x 24" 5 bladed props
props spin at about 4,500 rpm
motors generate about 14,000W of power
stalls at about 60mph.

Entering that into java foil, the programs generates a prop exit speed multiplier of 1.6 or roughly 100mph.
See pics below
<img src="https://i.stack.imgur.com/VgvjO.png" alt="X57 prop specs
" />

Example:
10 mph headwind, gusting to 20 mph, increase is 10mph, which is only a 10% of 100mph airflow over the wings at a stall speed of 60mph, with wings that should be 300% less affected by wind due to 300% higher wing loading.
So why does it need a "gust control system"?


texts: Does Karman line depend on the wing area, and if not, why?

texts:
The Karman line is the altitude at that the airspeed required to generate the sufficient lift to support itself exceeds the orbital speed. Looks like the Karman line is defined as some fixed value, equal to 100 Km. How this could possibly be?

In a usual flight, "the airspeed required to support itself" depends dramatically on the wing and can vary I think from 29 km/h for Gossamer Albatross till 389 km/h for X-15.


texts:
By David Monniaux (Own work) [GFDL, CC-BY-SA-3.0 or CC BY-SA 2.0 fr], via Wikimedia Commons

Many larger airplanes have gas turbine APUs (auxiliary power units). It seems that their exhaust is oriented to the rear and might provide some thrust.

How much thrust does an APU provide and would it be enough to keep flying an airplane if the main engines went out?


texts: Has the FAA moved to change its use of gender-specific words like airman?

texts:
Last year, the United States Navy was ordered to review all of its job titles related to gender reference, e.g. yeoman, fireman and seaman.  The Air Force has initiatives to fully integrate women in all jobs, and has also been pressured to review job names: Air Force Times Story, Jan 14, 2016

Has the FAA taken any action to review or change gender-specific titles like "airman"?  Is there a non-gender specific title like "airperson" coming into use?  Terms like stewardess and cockpit have been dropped from parlance.

Is there anything official or brewing at the FAA on this subject?

I'd be interested in your comments if using flight crewmember would be a valid substitute for the term airman.


texts: Is recurrent simulator training required every 12 months whilst acting as SIC under Part 91?

texts:
What are the regulations on recurrent training for a crew member who is type rated as PIC but is acting as SIC, flying internationally on a Bombardier Global Express Part 91 operation (not subpart K)? The last recurrent training for the crew member was 18 months ago.

Part 61.55 stipulates SIC qualifications but i would like to know if recurrent simulator training is required every 12 months whilst acting as SIC? If not, then what 'currency' values are required to maintain your privileges as SIC?


texts: What is the maximum pitch for the Boeing 787 Dreamliner?

texts: I recently watched a video of the Boeing 787 training before Farnborough.  This aircraft climbed very fast; does someone know the maximum pitch of this aircraft?


texts: How Realistic (or not) was the crash scene in Flight?

texts:
In the movie Flight, Denzel Washington's plane loses one engine and some other controls. To keep the plane gliding, he inverts the plane until it reaches a very low altitude. At the last second he flips it back right side up so that the belly of the aircraft takes the grunt of the crash landing.

Obviously this is all hollywood and takes a lot of creative license, but I'm a bit curious as to how realistic it was. Would you actually be able to fly a large jet upside down like that?


texts: What is the primary means of IFR navigation for private pilots?

texts:
I have been doing a lot of reading into IFR navigation, and have been looking at the various instruments and systems that are used.  I am going to exclude GPS here, as I have been focussing on some of the more 'old-school' methods.

My question is, if a private pilot decided to fly their GA aircraft from A to B, lets say a distance of 500nm, what IFR systems would they use to navigate?

My first answer myself would be VOR, but the range seems to be a limiting factor.  For example, high altitude VORs have a maximum range of roughly 130nm (http://flighttraining.aopa.org/magazine/2000/December/200012_Features_The_ABCs_Of_VORs.html).  If we were flying between two major cities, this wouldn't be an issue, as I would expect plenty of stations to track to on the way, but what if I was flying between two airports where the VOR stations were positioned 300nm apart?  Is this sort of IFR navigation only possible with GPS?

Thanks in advance.


texts: Can a VTOL jet such as the Harrier enter a Vortex Ring State?

texts:
I'm curious, because they obviously don't have those huge rotors pushing the air away, but they are still getting their upward thrust from somewhere.

My gut says, yes, but it is more difficult. Is this right?


texts:
Why local(section) lift coefficient(CLL) is higher near the wing tips compared to the root on untwisted tapered wings and untwisted swept(aft) wings?

I know that in an elliptical wing(untwisted) the absolute angle of attack is the same in all the wing span so, the reduction in lift is 'proportional' to the reduction in area/chord of the section and then the CLL is equal in all the wing span.
I also know that in a retangular wing(untwisted), the effective angle of attack(due to the tip vortex) causes a reduction in the CLL in the tips compared to the wing root.

Even that I understand the flow pattern over swept wings(Attachment line/Spanwise airflow and it's effects on lift and in the boundary layer, adverse pressure gradient and tip stall)I just can't figure out, intuitively, the relation between this flow pattern and the increase in the CLL in the direction of the wing tips.

[ CL = L / S.q ]  Seems to be too simplistic to analise this particular case.


texts: Why did the AvroCar fail to fly above 3 feet?

texts: I don’t quite understand why the AvroCar didn’t reach more than 3 feet? Was it a ground effect keeping it at that height and it didn’t have the capability to fly higher?


texts: Would an ASTERIX decoder be "radar data processing" or "surveillance data processing"?

texts:
I am not an air traffic controller, I am a software engineer. I developed an ASTERIX decoder, the application will just extract all the information and save it in a text file.
I am just wondering how we can make use of the application in a real system.

Is that what we call Radar Data Processing or Surveillance Data Processing?

Edit:
I know that my question was ambiguous.So, I will try to clarify it further.
Is the information extracted from the ASTERIX messages useful for the Controller to conduct his work ?


texts: What are good ways to gain experience and flying hours?

texts:
As a pilot who has just graduated, what are the ways to gain experience and flight hours?

The first thing airline look at is your flight hours, they usually require 1200 hours.

Is there any chance for a fresh graduated pilot to get hired in an airline with only 250 hours of flying?

I'm graduated in the Philippines.


texts: What is the best place to understand the details of drones?  Preferably something open source.  Books would also be helpful.


texts: Is the weather radar on and active during the whole flight?

texts:
The title says it all: Do airline pilots leave the aircraft's weather radar on at all times during the flight and display the data on one or both of the Navigation Displays, or only if clouds/ weather are visible / expected?
I know it should not be active on the ground due to possible radiation harm, so my question relates to the airborne phases climb, cruise, descent.


texts: What are some ways to decrease turbulence?

texts: I know there are ways turbulence can be reduced, but what are these ways that keep the ride comforting and also with better stability.


texts: Gage or Gauge? Which is correct in the aviation industry?

texts:
Gage or Gauge?

Some official aviation sources seem to use the spelling "gage" whether referencing cockpit instruments or aircraft maintenance tooling.

However, more broad English sources note that "gage" is either interchangeable with "guage," or flat out incorrect.

Is either spelling technically correct, or only one?

Do the different spellings hold different meanings or connotations in aviation?

Are there official examples that could make the argument "gage" could be correct in specific circumstances (patents, manuals, industry standards, trademarks)?

Is there a history in early aviation using "gage" that has been carried over unofficially to today (like how older aircraft operating today may have mph on their airspeed indicator)?


texts: What is the function of this fixed protrusion on the tail?

texts:
(wikimedia.org)

Above you can see a small fixed (?) part on the Embraer 190, just above the KLM logo. It is on both sides of the tail. What is the function of this part?


texts: Why is the input power of an ADS-B Transponder much lower than its rated transmission output power?

texts:
ADS-B Transponders are usually rated with 150W or 250W transmission power, however the electrical input at 14V is rated much lower, usually around 6 Watt. How can that be?
150 W transmission power with an efficiency of 70% would result in > 200 W input ~ 15 Ampere at 14V. Even if its not CW, there would still be a significant current peak.


texts: Where can I get flight departure change data?

texts:
On sites like flightstats.com, there is an "event timeline" view that shows changes made to the scheduled departure or equipment for a commercial flight. I assume this information is being pulled from some central system / API.

Here's an example, from today

Jul 26  05:00   1:00 AM 6:00 AM Gate Adjustment
TAIL Changed From N14106 To N14102

Jul 26  14:27   10:27 AM    3:27 PM Gate Adjustment
Departure Gate Changed From 125 To 128

Jul 26  20:23   4:23 PM 9:23 PM Gate Adjustment
TAIL Changed From N14102 To N34131

Jul 26  21:30   5:30 PM 10:30 PM    Time Adjustment
Estimated Gate Arrival Changed From 07/27/16 07:30 AM To 07/27/16 07:31 AM

Jul 26  21:31   5:31 PM 10:31 PM    Time Adjustment
Estimated Runway Departure Changed To 07/26/16 07:50 PM
Estimated Runway Arrival Changed To 07/27/16 06:54 AM

Is there a programmatic source for this data? Perhaps with additional metadata not exposed on flightstats.com? I understand they do have an API themselves, which does not seem suited to hobby uses, so I'm looking for another source. Are these departure changes submitted to FAA/ICAO? Are they airport-local only?


texts: Do new VHF radios need to be flight tested?

texts:
I'm in the process of upgrading all our VHF radios and the local regulator has asked us to follow the guidance/recommendations from ICAO, as we have more or less cancelled many of our local rules. The radios will be used for voice only (including Volmet and ATIS).

What do the ICAO recommendations/procedures say about installing new air-to-ground VHF radios? Do they need to be tested by a test flight? Is there a difference if it is a new installation with new radios and new antenna, versus new radio types but with the same antenna, same frequency and same power output?


texts: How does this vortex form inside a jet engine?

texts:
I have seen this in a picture once online and thought it was very strange and wondered about the formation of this vortex and how could it happen.

Source

Not everyday do you see this happening. So how does this happen, and why does it not happen very often?

Source

Another picture of this strange occurrence. This generally happens with thrust reversal.


texts: What type of aircraft is depicted in the Taylor Swift music video "Look What You Made Me Do"?

texts:
It looks like some sort of business jet or small regional airliner, but I can't tell anything more specific than that.  About the only thing I'm certain about is that it's a T-tailed twinjet with rear-mounted engines.

View of the starboard side of the aircraft in question:

Frontal view of the aircraft's empennage:

Apologies for the poor lighting and resolution (especially in the first image).


texts: What website(s) can I use to plan an IFR route along airways? WORLDWIDE

texts: I'm looking for a good website where I can create a IFR route including the airways. I tried route finder but it doesn't give me the airways.


texts: What are lateral, longitudinal and directional stability?

texts: When we talk about aircraft having a stable configuration, it refers to lateral, longitudinal and directional stability. Can someone give a practical explanation of what those are and how they work?


texts: About how many aborted takeoffs are there each year in commercial aviation?

texts:
Watching this sim of a 777 engine failure on takeoffs got me wondering about RTOs, and how often they occur.

The interest was further driven after reading a comment by N1755L that might underline jeopardy in the process:

  If anything is to go wrong with the engines at close to the
  "not-enough-runway-left-to-safely-stop" point, the pilots have only
  10s of thousands of seconds of time to assess the situation and decide
  which decision is the correct one (attempt a stop, or continue the
  takeoff and get into the air).

Perhaps that's exaggeration.  And surely the majority of rejected takeoffs occur at safer speeds.  There appears to be a few similar questions about emergency landings, but nothing on RTOs?

I did find this article from an Aero (Boeing) magazine indicating:

  Historically, the RTO maneuver occurs approximately once each 3,000 takeoffs. Because the industry now acknowledges that many RTOs are not reported, however, the actual number may be estimated at 1 in 2,000 takeoffs.

The article appears to rely on data a couple decades old.  But wondering if that would be a reasonable estimate today.  And, even better, if there's any data on the breakdown of RTOs by speed.

Whatever you've got will be of interest, whether the dataset is confined to specific countries or even airlines.


texts: Why the moment arms in x-direction are considered as -x?

texts:
Thanks for anyone reading this question. I am able to understand the signs of the forces, but I could not understand why a negative sign is added to the moment arm in x-direction (please check the last line in the picture).
Thank you!


texts: What cargo airplanes can transport fully assembled large turbofan engines?

texts: Is there a big demand for transporting overseas for turbofan engines with nacelles like TrentXWB or GEnx by cargo airplanes ? If yes, what planes are used?


texts: Does a high-pitching-moment symetrical airfoil exist?

texts:
I'm looking for a high-pitching-moment symmetrical airfoil.

I understand the Zenith 701 uses a reverse NACA4412 as it has a high pitching moment. This allows for a smaller horizontal tail.

What about a symmetrical high pitching airfoil for the vertical tail?
Wouldn't this reduce the size of the vertical tail?

Does a symmetrical airfoil with a pitching moment exist?

How about one with a high pitching moment?


texts: What is the different between an aircraft engine gearbox and an aircraft engine transmission?

texts:
For an aircraft engine, what is the difference between a gearbox and a transmission?

I was of the understanding that a transmission is a type of gearbox. For example, in a helicopter, a transmission is used in to convert horizontal rotation of the turbo-shaft to a vertical shaft rotation. Is an aircraft engine gearbox and aircraft engine transmission the same thing?

Are there other types of gearboxes used in aircraft engines besides the transmission design?


texts: A scenario question regarding meteorology

texts: In the image attached, I’m struggling to find out why the answer is the way it is; maybe is me not being able to visualise it, but some help would be greatly appreciated.


texts: Can self-study and FSX substitute for the majority of PPL training?

texts:
I am 16 and am very interested in becoming a private pilot, and fly flight simulators. I do not have enough money for the entire training. I can only afford 5 flying lessons.

Is it possible to learn majority of flight maneuvers using a flight simulator and just take a few lessons to get used to the feel of a real aircraft?

What are the list of topics that you need to learn when gaining your private pilot license?


texts: May an instrument instructor log instrument approaches that a student flies in simulated conditions as approaches for currency purposes?

texts:
There's rumor that a former DPE claimed that a CFII who is providing training to a student can log that student's simulated instrument approaches as the instructor's approaches for currency purposes.
That didn't sound like it could be true, so I asked him if he could provide a written source to back it, but he could not.

So, is it true?  If so, can you please provide a source to prove it in your answer.
Common sense would tell me this is not true because the instructor is neither flying the plane nor logging instrument time.
Does it make any difference if the approach is simulated instrument in a flight simulator or FTD in which neither the instructor nor student have reference to anything but instruments?


texts: I came across this diagram of the B2. I was wondering how it achieved yaw. If I'm correct usually the rudder on the tail would do this, but the B2 does not have a tail. Does it have no need for yaw, or does something else act as the tail?


texts: Why did "only" two Max 8 accidents occur? Before the grounding, there must have been at least dozens but surely 100s if not 1000s of flights with this model. How come the vast majority of those flights didn't experience any problems?


texts: Why does the Boeing 787 engine nacelle exhaust have such an unusual shape?

texts:
Why does the Boeing 787 nacelle have this unique shape at the exhaust:

I haven't seen it on any other airplanes, does it serve an aerodynamic purpose or help engine efficiency or is it just to look pretty?


texts: Is possible to access the ICAO IBIS aviation bird strike database?

texts: I have found only the reporting part of it and some summary reports at https://www.icao.int/safety/Pages/IBIS.aspx.


texts:
Taking easyJet as an example, they have a fleet of over 200 A319's and A320's. At a price tag of around \$90m per plane, that equates to about \$18bn.

Given that their turnover for 2012/13 was around \$7bn, and their net profit was only \$660m, how exactly do they own so many planes? Are they financed long-term? Are they leased?

How are the deals structured for the big airlines when purchasing new planes?


texts:
What is the purpose of runway grooving?
How does the airport drainage system work?
Why do airports remove rubber from the runway?


texts: What's the difference between EFVS and CVS? Is there any aircraft certified with EFVS?


texts: How do tyre pressure sensors in aircraft work?

texts: I am specifically interested in the sensors used on the B777 and B787.


texts: Why does IAS decrease with lower air density if power is constant?

texts:
TAS increases with less dense air, which is intuitive. What I don't understand is why IAS decreases.

This is assuming sub-transonic speeds where compressibility effects are negligible.

To phrase this in more practical terms, if you look at the climb table in a POH for a turbocharged airplane you will see full throttle climb rate drops with an increase in altitude/temp, even before the MP drops. EAS and propeller efficiency would not seem sufficient to explain the IAS drop seen.

I would think that given a TAS, pressure altitude, and temperature, one could derive the IAS but I have not seen any math to do this.

This is in reference to a turbocharged propeller driven airplane that is capable of maintaining power at higher altitudes.


texts: How do pilots of small planes know where to move people?

texts:
On a recent flight from Washington, DC to Toronto, the pilot gave very specific directions to rebalance the plane (a Dash-8 IIRC), something like "someone needs to move to seat 11E."

How did he know that putting someone in seat 11E would balance the plane properly? Does the plane weigh itself or is there a computer model somewhere that tells him what to do? Or would an experienced pilot be able to look at the seat chart and know what to do?


texts: What is the minimum separation between two A380's while taxing in-line?

texts: If you are tailing another A380 on the taxiway, how much separation do you need from your nose to the A380 that you are tailing?


texts: Can Instrument Approaches be carried out when RVR is not given for the full runway length? (Approach Ban)

texts:
Bristol Airport (EGGD) has the following NOTAM in place:

INSTRUMENTED RVR RWY 27 STOPEND OUT OF SERVICE

Would aircraft be allowed to continue approaches into Bristol? If so, would the touchdown and mid-point RVR values suffice to decide whether the approach is legal (see Approach Ban below).
For example, the listed RVR minima for the RNP Approach runway 27 is 1400m (LNAV) - if the touchdown point and mid point RVR values were above this, could someone legally proceed with the published approach.
The UK AIP describes the Approach Ban as follows.

AD 4.9  Approach Ban - All Aircraft
4.9.3 An aircraft may commence an instrument approach regardless of the reported RVR/Visibility but the approach shall not be continued
below 1,000 FT above the aerodrome if the relevant RVR/Visibility for
that runway is at the time less than the specified minimum for
landing.
...
4.9.6 The touchdown zone Runway Visual Range (RVR) shall always be controlling.


texts: Are fighter jets designed to be so inherently unstable that a human can't fly one unassisted?

texts:
I'm told that in order to be more maneuverable fighter jets are designed in a way that makes them impossible for a human to control without the help of a flight computer.  Is this actually true?  Would a modern fighter (like an F-22 or Su-35) crash if the stability computers died?

Further, if this is true, what design techniques are making them unstable and how do they help with maneuverability?


texts: Why don’t airliners use stabilizer movement to assist with large pitch control inputs?

texts:
Most large airliners not only have elevators for pitch control, but also moveable horizontal stabilizers.  The elevators are used for primary pitch control, with the stabilizers being used to trim the aircraft, and, for some airliners, as an alternate method of emergency pitch control in the event of a loss of elevator control (due to, for instance, a failure of the hydraulic systems powering the elevators, an elevator actuator hardover, or the physical separation of one or both elevators from the aircraft).  Due to their much larger size, the stabilizers have a vastly greater maximum control authority than the elevators (which is why large modern airliners can be trimmed throughout very wide center-of-mass longitudinal-position ranges without having to defair the elevators, and why a stabilizer trim failure is generally somewhat inconvenient); however, despite this, few, if any, large airliners use the stabilizers to assist the elevators when making large longitudinal control inputs (for instance, when taking evasive action to avoid a MAC, or when recovering the aircraft from an upset).

Why is this?  Airliners can and do use secondary flight controls to augment the primaries in other situations; with roll control, for instance, small inputs are handled by the ailerons alone on most aircraft, while the spoilerons1 jump in to help the ailerons with larger changes.  So why aren’t the horizontal stabilizers called on to assist the elevators when large, sudden changes in pitch are necessary?

1: A spoileron is the technical term for a spoiler that is also used for roll control in flight (these are usually the same spoilers as those that can be extended symmetrically in flight to slow the aircraft).  Essentially all large aircraft, and many smaller aircraft, have them to help with large roll inputs; a few aircraft, such as the Mitsubishi MU-2, have only spoilerons, with no conventional ailerons.


texts: What are the advantages of towbarless pushback tugs?

texts: After watching the video below I wondered the reason for towbarless tugs. Lifting the front wheel of a 575 ton aircraft seems like it requires an awful lot of expensive and complex hydraulics when the goal is just to move the aircraft around on the ramp. What benefit is there to doing this over just using a towbar?


texts: Why is there an altitude limitation on operating the slats/flaps on the A320?

texts:
As per the FCOM limitations chapter there is an altitude limitation of 20000 feet for operating the flaps/slats on the A320?
Why this specific altitude?


texts: Are there any situations in which drones may legaly fly higher than 400ft?

texts:
FAA FAR 107 states, "The maximum allowable altitude is 400 feet above
  the ground, and higher if your drone remains within 400 feet of a
  structure."

Are there any exceptions to this rule that would allow a drone to be flown at a much higher altitude than 400ft AGL or within 400ft proximity of a tall structure?

source


texts: How did the term 'Buttered the bread' originate?

texts: I've heard this term used a few times to describe an exceptionally smooth landing


texts: What type of mechanism is used to operate the Embraer EMB 120 front door?

texts:
I have never worked on this type of aircraft, but I usually come across it in several hangars. I've been wondering on which mechanism this bulk door is lowered and lifted.

Is it by pneumatic system, hydraulic system or by electrical motors?


texts: How can an ATC choose the right flight level and heading for airplanes?

texts: I don't understand how air traffic controllers can choose the right flight level and heading for airplane when they are in the sky or they're approaching the airport to land.


texts: What factors govern the placement of a helicopter's tail rotor (left or right)?

texts:
An image search for 'helicopter' indicates that there isn't a consensus on whether to place the tail rotor to the left or the right of the tail boom, although I'm believe there may be a bias for left.

There never seems to have been a consensus: taking two popular early helicopter designs, the Bell 47 has its rotor on the right; the Hughes 269 on the left.

Bell 47 source

Hughes 269 source

There are many left/right conventions in aviation, e.g. where the pilot sits, which side the passengers exit etc. So the question is, what governs the choice, and would it be beneficial if a 'right' side was generally agreed on?


texts: How would an airplane land if the on-board radio breaks down?

texts: Is there a special protocol for a situation where the on-board radio communication equipment suddenly breaks down? Would the pilot be able to land on a busy towered airfield or would they be forced to look for a small landing strip in the middle of nowhere?


texts: Why does the Boeing 737 have 5 x the passenger fatalities of the Airbus 320?

texts:
I thought I'd compare the accident rates of these two similar, competing, very successful aircraft.

                    737     A320

Introduced          1968    1988
Number Built        8104    6171
Accidents/Incidents  329      60
Hull Loss Accidents  154      23
Fatalities          4287     782

These figures are from the respective Wikipedia pages. I assume they have not been the subject of edit-war falsification by fanboys of planemakers.

I wondered what might be the reason for the 737 seeming a much less safe plane.

The 737 design is 20 years older?

But it's still in production, so 1988...current 737s can be built with many of the same safety features found in an A320 produced the same year. Were 3,500 of those fatalities in the first 20 years?

There are lots more older less-safe 737s being flown by corner-cutting budget airlines in third-world kleptocracies?

Are there that many 40-year old 737s in the hands of incompetent airlines?

The 8,104 737s have, on average, flown many times more cycles than the 6,171 A320s?

But they address the same market, why would their usage differ so markedly?

The 737s have, together, flown many times more passenger-miles than the A320s?

See above. Plus I imagine older 737s have mostly been retired.

My speculation doesn't seem very convincing to me. Is there a better explanation supported by reputable studies?


texts: What is the direction of the sideslip induced by roll on a conventional aircraft?

texts:
For the sake of this question let's assume that the considered aircraft is an A320. The question is what is the sign of the aerodynamic $C_{n_q}$ coefficient? In another word, when the aircraft starts rolling, will the aircraft experience sideslip and if yes in which direction (and most of all why) ?

Instinctively, I would say that if the right wing (seen from behind) goes down (positive roll rate), it will be delayed compared to the left one, however I already read somewhere that the coefficient tends to be zero (no sideslip induced). I even heard some aeronautical engineers say that it is the opposite...

If needed, we can set that the x-axis is pointing backward and z down.


texts: How does handover between Air Traffic Controllers work?

texts:
I have a questions about air traffic control.
I understand how the controllers monitor and direct aircraft on their intended routes while maintaining clearance distances to other aircraft and obviously recognizing and avoiding collision courses, or at least I think I do.
My question is about hand-offs and range.
Presumably traffic is handed over to the next area controller when it approaches or reaches the limit of the controllers radar scope. However, how can the controller know that there is not another aircraft approaching out of scope range that is on a collision course with the aircraft leaving or approaching or traversing the boundary of his scope range?
Wiki says...

As an aircraft reaches the boundary of a center's control area it is "handed off" or "handed over" to the next area control center. In some cases this "hand-off" process involves a transfer of identification and details between controllers so that air traffic control services can be provided in a seamless manner; in other cases local agreements may allow "silent handovers" such that the receiving center does not require any co-ordination if traffic is presented in an agreed manner. After the hand-off, the aircraft is given a frequency change and begins talking to the next controller. This process continues until the aircraft is handed off to a terminal controller ("approach").

From that I guess is some centres the controller is expecting an aircraft to appear from a particular bearing, though even then, the variance would be wide at radar ranges.
I also realize that aircraft normally follow set lanes and altitudes depending on direct etc, but an aircraft in transition could appear pretty much anywhere. No?
That got me thinking that there must be an overlap on the visible range and that an aircraft is, for some period of time, visible from both centers. I guess that would work, but then it got me wondering how each centre knows who has control over the aircraft and if situations could occur where nobody is...?
That all brought up another question. I have to assume there is more than one human at busier control centers all working together. How is that managed? Who controls what?


texts: Would it be possible to start a modern airliner from cold & dark during flight?

texts:
Imagine a suicidal pilot or disturbed passenger who gets access to cockpit, messes with the buttons. He shuts down engines, IRS, and battery, it's the middle of the night at cruise altitude.
Would it be possible to restart everything during flight and land safely ?


texts: Do some right-handed pilots fail to use the left stick of an Airbus?

texts:
After years of flying left-hand throttle and right-hand yoke (in the right seat), are there ever first officers who simply cannot transition to the opposite due to particular hand-dominance?

As a corollary, are there any pilots who simply cannot acquire the left-hand dexterity/sensitivity to use the Airbus joystick when transitioning to captain?

And in all cases, are there ever trainees who cannot get used to yoking or throttling with a non-dominant?


texts:
Safety through understanding of human factors

This question is based on https://aviation.stackexchange.com/questions/27814/ and related to:

How have deep-seated cultural human factors (particularly in east Asia) in the cockpit been successfully managed in the past 20 years?
To what extent have political (race, gender, social class) attitudes been implicated as human factors in the cockpit?

Aviation industry safety has improved as much through better understanding of human factors in the cockpit as it has through advances in science, technology and engineering, to the extent that practitioners in other sectors (from software development to surgery) are interested in how its principles might apply to their own disciplines.

Aviation practices of this kind that aim to manage or mitigate human factors include:

extensive use of checklists
strict rule-following
extensive cross-checking
health-checking
blameless incident analysis
eliminating authority gradients that make it hard for junior crew to question decisions

Aviation practices across different cultures

These practices and the ideas behind them have largely emerged from western social cultures, and largely in the civilian post-WWII industry, and to a certain extent exemplify aspects of western politics and culture.

Examples of incidents related to cultural human factors

There are many stories (and some are no doubt apocryphal) of how cultural human factors have been involved in incidents. In recent years:

steep cultural authority gradients:

a junior first officer reluctant to question an overbearing captain's decisions
a timid first officer who failed to realise his remote and taciturn captain had actually died

attitudes to regulation, and attitudes of family/VIP exceptionalism:

the pilot who allowed a teenaged family member to touch controls in the cockpit
the pilots who ignored ATC advice to divert in fog because the president and other VIPs were anxious to attend a ceremony

How does cultural difference impinge upon human factors in aviation industry safety?

For example:

How well have they worked (adoption, implementation, outcome) in very different cultures?
Has it been particularly hard for them to find acceptance in other cultures (this applies not just to non-western cultures, but also for example to military culture in the west, where levels of authority and hierarchy are very significant)?
Have different approaches been used or tried with better results, in different cultures?


texts: What's exactly meant by the "slippery when wet" report on ATIS?

texts: I read this discussion and discovered the definition of "slippery when wet" from this advisory circular but I'm still having a hard time understanding why the runway condition is expressed as "slippery when wet" rather than just as "slippery." My guess is that the wet runway normally doesn't bring a slippery runway condition but it sometimes does and in that case it's expressed as "slippery when wet" rather than just "slippery." Is my guess correct?


texts:
When did ATA introduce the ATA chapters and since when was it used by all manufacturers?

Thanks!


texts: Still using knots, nautical miles, inches of Hg. Is that impossible to switch to SI units?

texts:
Why doesn't the aviation industry use SI units?.

I believe only a few countries use meters and other SI units in air transportation, including India and China (please correct if wrong).

Using kts and NM in navy -- built from the length of the 1' arc on a meridian -- simplified nautical mental arithmetic, and likely also helped at the beginning of aviation.

Current ICAO recommendations

In Annex 5 - Units of Measurement to be Used in Air and Ground Operations, ICAO allows 3 non-SI units (knot, foot, nautical mile) to be used...

  as alternative units because of their widespread use and to avoid
  potential safety problems which could result from the lack of
  international coordination concerning the termination of their use.

... but overall states in the same document that only SI units should be used, the same units for all members. Nevertheless the termination dates for alternative units have not been specified:

  It is intended that the use of the non-SI alternative units [...]
  will eventually be discontinued in accordance with individual unit
  termination dates established by the Council. Termination dates, when
  established, will be given in Chapter 4.

Case of vertical measurements / altitude

Vertical measurement in meters may be the more complex due to the existence of flight levels in feet, with the full system of vertical separation based on FL.

This topic was discussed in Using feet vs meters for altitude?. The current question is not a duplicate of the latter.

Other non-SI units

Other non-SI measurements seem more easy to remove:

Horizontal distances in feet and nautical miles may be expressed in meters, as already done for runway lengths. It is not as important as it was to mentally translate a latitude offset in NM.
Atmospheric pressure expressed in Hg column height may be expressed in Pascal. Many pressure instruments can be already calibrated both in inHg and hPa.
Speeds expressed in knots (sometime in statute miles per hour) may be expressed in km/h.

Question

Wouldn't it be useful (and safer) in the long term if we could remove most of the imperial units from new aircraft instrumentation, procedures, ATC, documentation and maps (at least for anything other than altitudes)

Just asking what is the current view from the air transport community itself.


texts: How would a pilot apply the information found on a 500 Millibar Vorticity chart to a flight?

texts:
The U.S. Flight Service website has these weather products listed:

I have circled the 500 Millibar Vorticity Charts.  I've been a pilot for 10+ years and have never heard mention of this chart by anyone in aviation.  I am wondering why is it listed here, but no one seems to use it.

What purpose does the information it provides serve for pilots?


texts: What is the maximum weight on the main gear of a large aircraft at rotation and touchdown?

texts:
For a large aircraft like a B747 or A380, how much does the weight on the main gear increase when the nose gear is in the air? I mean, in these two cases:

What is the maximum extra weight on the main wheels when rotating at maximum takeoff weight, with the nose wheel off the ground?
What is the maximum extra weight on the main wheels when touching down at maximum landing weight, with the nose wheel off the ground?


texts: Do I need to be acting PIC when doing takeoffs and landings for my 90-day currency?

texts:
The 90-day currency requirement means that to act as PIC of an aircraft carrying passengers you must complete the three takeoffs and landings. Does this include an aircraft where you are logging PIC time but not the acting PIC?

Could you technically then log the landings/TO's if you've blown your 90 days if you have a friend as acting PIC? The FAR also states this is required if you're operating an aircraft certified for two or more crew operations. Does this mean even without passengers, if you are a required crew member on a two crew ship, you need the 90 day currency?


texts: How does the energy and weight efficiency compare between a battery/electrical propulsion and combustion engine?

texts:
For the same total energy and power output would a battery powered vehicle be lighter than one which uses a fuel burning engine (Currently)?

This question is intended for helicopters.


texts: Can an ICAO contracting state charge money for NOTAMS?

texts: does anyone know of any written icao rules where they state if a contracting state is allowed to charge money for the dissemination of NOTAMS? are products like notams and Local Aeronautical Circular messages supposed to be free for everyone? so that safety can be guaranteed ?


texts: Why does this calculation show Gustave Whitehead's propellers were more than 100% efficient?

texts:
I have tried to calculate the efficiency of Gustave Whitehead's propellers using the information he provided to the American Inventor Magazine in 1902 (see the citation below).
Number of propellers = 2
Engine power per propeller, $P$ = 20 hp
Propeller diameter, $D$ = 6 ft
Static thrust per propeller, $T$ = 254 lbf
Propeller efficiency, $\eta_{prop}$
Gear efficiency, $\eta_{gears}$ < 100%
Air density, $\rho=1.2 \frac{kg}{m^3}$
Doing the calculations: $\eta_{prop} > \sqrt{\frac{T^3}{(P^2 \cdot \pi \cdot \eta_{gears} \cdot \frac{D^2}{2} \cdot \rho )}} = 101.4\%$ which is impossible.
Is there a mistake? If yes, where?
Note: I used the formula that relates static thrust to efficiency, power and propeller diameter.

The Whitehead Flying Machine
Has the End been Finally Attained, and is the Dirigible Balloon to Go?
Editor, American Inventor
Dear Sir: Replying to your recent letter, I take pleasure in sending you the following description of my flying machine No. 22, the latest that I have constructed:
This machine was built in four months with the aid of 14 skilled mechanics and cost about $1,700 to build. It is run by a 40 horse-power kerosene motor of my own design, especially constructed for strength, power and lightness, weighing but 120 pounds complete. It will run for a week at a time if required, without running hot, stopping, or in any possible manner troubling the operator. No electrical apparatus is required for ignition purposes. Ignition is accomplished by its own heat and compression; it runs about 800 revolutions per minute, has five cylinders and no fly-wheel is used. It requires a space 10 inches wide, 4 feet long and 10 inches high. ...
The propellers are 6 feet in diameter and have a projecting blade-surface of 4 square feet each. They are made of wood and are covered with very thin aluminum sheeting. The propellers run about 600 revolutions per minute under full power and turn in opposite directions. When running at full speed they will exert a thrust of 508 pounds. I measured this thrust by attaching the machine to a post by means of a dynamometer and running the engines at full speed. ...
I have no photographs taken yet of No. 22, but send you some of No. 21, as these machines are exactly alike, except the details mentioned. No. 21 has made four trips, the longest one and a half miles, on August 14, 1901.   The wings of both machines measure 30 feet from tip to tip, and the length of the entire machine is 32 feet.   It will run on the ground 50 miles an hour, and in air travel at about 70 miles.  I believe that if wanted it would fly 100 miles an hour. The power carried is considerably more than necessary. ...
Trusting this will interest your readers, I remain, Very truly yours,
GUSTAVE WHITEHEAD
Bridgeport, Conn.

Source: The American Inventor Magazine
, 1 April 1902
.


texts: Can you identify this unusual plane by its description?

texts:
I saw this plane many years ago:

Same shape and size as an commercial airliner.
No windows along the fuselage
Painted flat gray (like a naval ship)
Had a blue circle on its "nose" (Blue painted radome)
Rectangular "hump" with rounded corners on the bottom of the fuselage.

If you can identify this plane, could you please tell me the make and model and what it's used for?

UPDATE: the question has been put on hold so I will try to be more specific. I saw a plane fitting this description flying unusually low over the Chelsea neighborhood of New York City on the morning of September 11, 2001 shortly before 9:00 AM. It was flying south over 8th Avenue. I had just exited the subway station at the 23rd Street and 8th Avenue. I was walking west towards my office on 11th Avenue when I was startled by a very very loud sound directly overhead. I turned and looked up and saw this low flying plane. I have never ever seen an airplane fly that low except near an airport terminal. It was shocking and frightening. I literally thought the plane was going to land in the middle of 8th Avenue. I remember looking for smoke or visible signs of damage but it looked like it was okay. It was actually slowly and gradually descending, but then it climbed back up. There were no markings on the plane apart from the blue "bulls eye" on the "nose" (pardon my lack of knowledge about aviation. I don't know the proper terminology).

Several minutes later I was on the M23 bus when I heard an extremely loud bang, which I would assume was the first plane hitting the WTC. It was so loud that my ears were ringing for a while. I remember trying to convince myself that the sound had nothing to do with the plane because the thought was too awful. At the time, there was a lot of construction going up on west Chelsea (gentrification. high rise luxury condos being erected where transsexual prostitutes used to roam the streets). I tried to convince myself that it was from the construction. The image that came to mind was taking a steel garbage dumpster and throwing it off the top of a skyscraper.

I don't know what this plane was but it had something to do with what happened on 9/11. If only I had had a camera at the time and could have taken a picture. I need to know what this plane was and how it fits into what happened that day. This is not a joke. I realize that this is going to be controversial and some people may be upset. I want to reiterate that this is not a joke of any kind. Please do not flag this post. I need an answer to what has haunted me for 17 years. Thank you.


texts: Why did Air France flight 447 fail to recover from the stall?

texts:
I have read the wikipedia entry about the accident but I don't understand why did the stall happen and why the plane couldn't recover from the stall.

Correct me if I am wrong but I would think a plane would naturally recover from a stall situation by pitching down the noise by itself with no control inputs needed and gaining speed (due to the fall).  The AoA would be back to safe values to generate lift again and the plan would be stabilized.

I don't get how a plane like that would fall from 35,000 feet with its engines set at 100% thrust.


texts: Is 'cost sharing' different between jet and prop powered aircraft?

texts:
I half remember, sometime in the past, there were different costs in turbine powered aircraft that were allowed to be put into the bucket for cost sharing.

Do I remember correctly or incorrectly?

If this a correct memory, what are the additional shareable costs in a turbine powered aircraft?

addendum:  My ancient brain has come up with some vague answers.

IE, the hourly payments for engine and airframe maintenance.  This was comparable to rental cost, but because  it is a defined amount in a turbine totally owned by the pilot, it was quantifiable.


texts: Is the Beechcraft Bonanza Jaguar edition different from any other A36?

texts: I've seen a few Beechcraft A36 Bonanzas with special Jaguar marketing. Some have special paint or interiors. During some hangar talk I've heard it said that the Jaguar edition is faster. Does it actually have any differences that impact performance?


texts: I am not connected to airlines .I am just an aviation enthusiasts .while studying the 737 FCOM I realized to study AMM also .but in Google I cant find it anywhere .so can anyone tell me how to get access to AMM ?


texts: What might have been the reasons for this low flight altitude?

texts: I was flying from Heathrow to Miami last wednesday (AA 39) and for the first ⅔ of the flight we were flying at 28.000 feet, only afterwards did it go up to 33.000 feet. So far I was under the impression that for reasons of fuel efficiency, airliners would try to fly as high as possible, and looking at the same flight on different days, it seems like they do in fact usually fly higher. So what could have been the reason for such a low altitude? Was it just weight due to being fully loaded, or are there other reasons as well?


texts: How many actuators does the F-35 have for each primary control surface?

texts: How many actuators does the F-35 have for each primary control surface like rudder, stabilator or aileron? And is it active/active or active/standby?


texts: Why did the 707 and DC-8 continue to use the JT3D even after the JT8D became available?

texts:
Pratt & Whitney’s first-generation turbofan was the JT3D (a derivative of the company’s first-generation turbojet, the JT3C), which entered service in March 1961, and, due to its greater power and lesser noise and fuel consumption, quickly replaced the JT3C (and also P&W’s second-generation turbojet, the JT4A) on the aircraft that had previously relied on the JT3C and JT4A (two civilian [the 707 and DC-8]1 and two military [the B-52 and KC-135]).2

However, the JT3D, although a vast improvement over the loud, inefficient turbojets it replaced, was still very much a first-generation design, with problems not seen on newer turbofans, and still quite the screamer and kerosene-guzzler even by the standards of just two years eleven months later, when Pratt & Whitney came out with their second-generation turbofan, the JT8D (entered service February 1964 with the 727).  The JT8D was a vast step ahead of the JT3D, and is still practically the state of the art for civilian low-bypass turbofans;3 not coincidentally, it is also the best-selling low-bypass turbofan ever, and the second-best-selling jet engine of any kind in history.4

Yet, even as Boeing and (McDonnell) Douglas readily adopted the newer, better-designed, quieter, more efficient JT8D for their second-generation jetliners (the 727, DC-9-10-through-50,5 and 737-100/-200), they continued to use the old JT3D on their first-generation jetliners for as long as those aircraft remained in production; JT3D-powered DC-8s continued to spawn in Long Beach until 1972, and the guys and gals from Washington State kept on putting JT3Ds on new 707s all the way up until 1979.  Admittedly, the early models of the JT8D had somewhat less thrust than the JT3D, but they could easily have been upbeefed to JT3D-equivalent power levels - as was, indeed, done in the 1970s to create the JT8D-200!

Why did Boeing and (McDonnell) Douglas continue to use an old, outdated engine for the 707 and DC-8, even after the JT8D came along?

1: Technically, not all pre-JT3D 707s and DC-8s used a P&W turbojet (the 707-420 and DC-8-40 both used the Rolls-Royce Conway, the first turbofan ever to fly), but the vast majority did (as U.S. airlines were reluctant to buy airliners with foreign-made engines, meaning that most orders of Conway-equipped 707s and DC-8s were for the smaller European and Canadian markets).

2: The turbojet variants of these aircraft were the 707-120, DC-8-10, B-52A-G, and KC-135A (JT3C) and the 707-220/-320 and DC-8-20/-30 (JT4A); the JT3D powered the later 707-120B/-320B/-320C, DC-8-50/-60, B-52H, and KC-135E.

3: Not that that’s saying much, given that the market for civilian low-bypass turbofans has (with one notable exception) been essentially extinct since the first narrowbody-sized high-bypass turbofans broke into the market in the early 1980s.

4: ...behind only the engine that finally evicted the JT8D from its niche, the General Electric/SNECMA CFM56 high-bypass turbofan.

5: Along with the DC-9-80, when it came along (which happened, ironically, shortly before the JT8D was rendered obsolete by GE’s French connection).


texts: What is the proper procedure for participating with "flight following" when leaving a non-control towered airport?


texts: Is there a list of accidents due to poor communication in English?

texts:
I would like a list of accidents satisfying the following criteria:

Poor communication between ATC and pilots was judged to be a major factor in the accident;
English was the language of communication between ATC and the pilots; and
The native language of the pilots and controller was the same, but not English.

I am not looking for discussion of whether using English is a good idea or not in these situations, whether its use played a role in these accidents, or whether better training in communications is needed. I just want a list of accidents where these conditions are met.

The poor communication need not necessarily have been attributed to insufficient knowledge of English.


texts: How likely is it that there is someone knowledgeable about piloting in a flight control room?

texts:
I saw a reasonably looking video about a non-pilot trying to land a plane with the help of a flight control tower (in a simulator):

             (it is in French).

I believe that this was an ideal case where the plane was compatible with the airport so that the landing was almost automatic (they showed a short version of (successfully) trying to land without the automatic mode).

The person in the control tower was extremely knowledgeable about the plane, explaining exactly where to press, where to look etc.

Assuming that the whole exercise was realistic - how likely is it that there would be someone handy who could, by heart, explain via the radio what the exact steps to take are?

Note: I realize that the situation will be different between a large airport (where they could make an announcement "we are looking for a Boeing 747 pilot, please contact the reception desk if you are one") and smaller ones. In the video, they started from a cruising altitude and it took minutes to go from "there is nobody in the cockpit" to "listen to me carefully, I will guide you". It is more the realism of time which I am trying to assess.


texts: Why doesn't the black box also record video?

texts: Why does the black box still only record the cockpit's audio today, rather than also recording video of the cockpit? Wouldn't a video of the pilots' actions and what they were seeing outside the plane be very helpful in determining what caused an accident?


texts: Where can I find more details about how ornithopters work?

texts:
I learnt about the special helicopter-ornithopter which was put forward by Delft University. Its principle is different from a common helicopter and it doesn't need a tail rotor. But there is very little information about it on the Internet. I sincerely hope that someone can give more details about it, or tell me where to find them.

It operates like this:


texts: What is the maximum number of cabin crew members on an A320 load sheet?

texts: What is the maximum allowable number of cabin crew members to be mentioned on the load sheet for A320, with respect to weight and balance? And does the number of deadheading crew members add to this figure ?


texts: What is the fastest possible transatlantic flight today?

texts:
I'm working on a novel that, as part of the backstory, requires samples of a biological agent to be flown from Incirlik Air Base to labs across Europe, and then finally from the UK to the US.

In the context of the story, time is critical. Using any currently available aircraft (large or small, civil or military, US or allied etc.), what is the shortest flight time that could realistically be achieved?


texts: Which are the alternatives to EICAS or ECAM?

texts:
I know that ECAM and EICAS are the systems for Airbus and Boeing for the monitoring of the aircraft systems. So, on a A320 there is the ECAM and on a B737 there is the EICAS. I know the differences between them and how they work.
What I wonder is:

How do I know in a not Airbus/Boeing aircraft which is the system for the monitoring of aircraft alarms?

For example: what do I have in a AW139, or in a Gulfstream650? Is it still called ECAM or in some other ways? Is it built by the same manufacturer? Has it the same name?


texts: Can people who suffer from motion sickness become pilots?

texts:
Suppose a person suffers from motion sickness when flying, but wishes to become a pilot (let us say, with the eventual goal of flying for a major commercial airline).  Is this possible?

Is motion sickness a medical disqualification for a pilot's license, in many or most jurisdictions?
Most over-the-counter motion sickness medications cause drowsiness, so they are obviously not a good idea for a pilot to take.  Do pilots have access to other effective treatments that are safe to use while operating an aircraft?
Do pilots find that they get over motion sickness the more they fly, similar to the way sailors develop "sea legs"?
Are pilots taught techniques to remain focused on flying even if they are experiencing motion sickness symptoms (nausea, vomiting, dizziness, etc)?


texts:
A quick follow-up to Why do planes always land on rear wheels instead of the nose wheels?

What airframe designer/manufacturer is credited with the first retractable landing gear system? I ran past the article on retractable gear over in Wikipedia without really finding an answer


texts: May the tower use the runway while an emergency aircraft is inbound?

texts:
I have a question regarding an aircraft in emergency. Of course it will have  priority for landing but if the position of this aircraft is very far, like for example 20 minutes or more away,
would the tower be allowed to clear other aircraft to land or take off? Is it permissible for the tower to do so?

Is there any law or statement in the civil aviation regulation about such things?


texts: How much air does a 777-300ER's pressure cabin hold?

texts:
I've been wondering how much air a 777-300ER's pressurised cabin holds, but, while most of its specifications are fairly easy to find, the amount of air it contains is not.

Does anyone know what volume of air is held by the pressure cabin of an empty 777-300ER?


texts: Can the measured thrust of a propeller be greater than the max thrust predicted by Froude's theory?

texts:
Can the measured thrust of a propeller be greater than the maximum possible thrust predicted by Froude's Propeller Theory?

Is Froude's theory reliable in practice regarding the upper limit of the thrust delivered by a propeller of diameter, d, turned by an engine that absorbs the power, P?

I get the measured thrust of a 26 inch, 2 blades propeller, higher than what Froude's theory predicts.


texts:
I've seen on many airports a lot of vehicles transporting some "brown boxes".

Any idea of what is this?
 (I don't ask what's exactly inside this box, just in general)
Source: 123rf.com

What that may be?  Baggage? : in case that boxes contain baggage, why don't they put it as loose baggage or in ULD's. May that be other type of cargo?


texts: How does a dispatcher assign relative costs to trajectories in TOS?

texts:
In FAA's Combined Trajectory Options Program (CTOP) flight operators submit a set of possible routes (TOS—Trajectory Options Set) that the airline is willing to take for a given flight, if there is a flow constraint present in the air space. The airline tells the command center, which trajectectories it prefers by assigning a relative trajectory cost (RTC) to each route, which tells the command center how much ground delay the airline is willing to take to get a certain route.

My questions are - how do dispatchers determine how much RTC to assign to each route? What are the main things that they consider? Is there some kind of software that allows to calculate that, or is the process relatively informal and intuitive?


texts: Why did my instructor recommend that I fly a Piper Seminole down to the runway rather than trying to flare it like a Cessna?

texts:
I have flown as a student the Piper Seminole 3 or 4 times, it was so much fun grabbing a bunch of throttle levers and pushing them all like a real throttle quadrant in a large jet aircraft, but anyway my question is this:

When landing and just nearing the end of final, when I was just about to the chevrons my flight instructors always asked me to fly the plane right down to the runway, which is different from flying 172's where I could flare right at the chevrons and try my best to get a 'greaser' and chirp the tires enabling a nice transition where I momentarily heard the faintest stall horn just before landing, enabling a quick turn off to a taxiway...why did I have to fly the twin right down before cutting throttles?


texts: Are commercial aircraft required to have the model number painted on them?

texts: On a lot of aircraft, the model number / aircraft name is clearly marked somewhere on the fuselage, e.g. "Airbus A320". Is there any rule or mandate, that all aircraft must bear the model number at some designated place on its body, to help others identify them?


texts: Why are autorotations to a full touchdown not practised any more?

texts: What is the history behind a decision to discontinue helicopter autorotations all the way to ground contact? In the 1960s, our Army flight program directed full ground contact for any and all autorotations. I will never accept that 'simulations' are a substitute for actual practice. We were taught every possible aspect of autorotating a helicopter possible, including a vertical autorotation.


texts: What would be the power requirements and performance of a Scroggs-type delta-wing aircraft with a 250 cm span?

texts:
Roy Scroggs, a tailor, patented in 1917, US1250033, and in 1932 US1848578, a Delta Wing plan form machine 'Flying Dart', flight tested

              with an OX-5 engine, they say anything would fit an OX-5 powered airplane, as in Besler Steam Airplane, it had same Leading Edge swept, 60º, as Handley Page HP 115 of 1961, that tested the Concorde wing (

             )
The page of an study from the French ONERA about vortex over a Delta plan wing is an experiment conducted with the type of pointed wing in the description by Jones, and in the Langley tests on A Lippisch DM-1, but it's not sure if flow will be identical on a truncated point Delta, as used in first Saab 'Draken'.??

I wonder what the power requirements and performance would be of an Ultralight Airplane with a wing span of 250 cm, maximum width allowed on the road, and a total weight less than 299 kg. 115 kg empty weight is the class limit for Ultralight


texts: Do helicopters fly the same instrument approaches as fixed-wing aircraft? If so, which approach category and minimums do they use?


texts: Why is a straight-in approach not allowed to RWY 07 at Cluj (LRCL)?

texts:
Here's a VOR approach for runway 07 at Cluj (LRCL).

On the lower left side of the chart you will see the "Straight-in" OCA(H) as N/A and then a "Circling" OCA(H) of 2540 (for category C). There is only a 6 degree offset between the final approach course and the runway, and as far as I can tell below 30 degrees (or maybe 15?) the approach is considered straight-in.

So why are straight-in approaches not allowed but circling ones are?


texts: On airliners, are spoilers used in any part of flight other than landing?


texts: Are tritium runway lights widespread in remote areas?

texts:
There was some interest in the 80s and 90s in providing runways in remote areas with tritium lighting (which requires no external power, since the radioactive decay in a sample of tritium gas induces radioluminescence in a suitable material). However, apart from this failed trial in Alaska (pdf) and various vague mentions of it on the internet, I can't establish if this every became a viable technology.

Has it become widely-used (perhaps for military airstrips, if not for civilian ones)? And if so, how did the technology improve in the last couple of decades to make it work?


texts: What was the first Russian jet designed with the use of area rule? Also, how did the Russians acquire the knowledge of this design method? Was Whitcomb's discovery public?


texts: What benefit does a group get from being an FAA recognized flying club?

texts:
FAA defines a flying club in 5190.6b.ch10.6 and ends by saying:

  A flying club that violates the requirements for a flying club – or that permits
  one or more members to do so – may be required to terminate all operations as a flying club at all airports controlled by the airport sponsor.

So hypothetically if this were to occur, then you'd have an LLC that owns a plane that is not a flying club. Does this mean that they wouldn't be able to fly their plane or carry on like normal? Aside from being able to label themselves as a "Flying Club", what impact would this have?


texts: What is the approximate range of the Pelegrin Tarragon?

texts:
I recently read about the Pelegrin Tarragon ultralight aircraft made in my country, and got interested in it.

Is it possible to have a reasonable estimate of the average distance you could cover in such plane, taking into account that it has a cruising speed of 270km/h, a  96l fuel tank and the engine it uses (a single Rotax 912ULS) is listed as using 15l/h at 5500rpm (75% power)?

Unfortunately, the manufacturer's page doesn't list any max distance or indeed any technical specs, and Wikipedia entry doesn't list much more either