texts: Is the phraseology in the early portion of the movie The Net realistic?

texts:
Bear with me for a moment; I know that this is based on a movie scene, but there's a real question at the end.

Early in the 1995 movie The Net, there's a scene where a programmer is flying their Cessna at or near dawn, approaching the destination airport. This is a night flight, so it would presumably be an IFR flight with all of what that means, or rather meant in the mid-90s. We get to hear some communication between the pilot and ATC:

  (pilot) Burbank tower, Cessna seven-three-nine-Mike-Bravo, intercepting approach course, ILS runway eight.

  (ATC) 39 Mike Bravo, we've lost radar contact. Say your position and altitude.

  (pilot) Just passing the middle marker at 1300 feet.

  (ATC) 39 Mike Bravo, that's a negative. Verify your position and check your instruments.

  (pilot) All normal, for crying out loud, you must be able to see my lights.

  (ATC) That's a negative. Execute a missed approach immediately. Contact approach control on one-two-four point five.

A moment later,

   the airplane crashes into what appears like it could be power station chimneys, and turns into a fireball, killing the pilot.

That ATC exchange has always bothered me. I can see a few things that feel obviously wrong:

It seems awfully late, especially in IFR towards a big airport (assuming that's Hollywood-Burbank, which goes nicely with a later in-movie statement that this happened "outside L.A."), to contact ATC only by the time you are well into the final approach.
If this is an IFR flight, shouldn't the pilot be following a filed flightplan, and wouldn't someone notice if the aircraft strays too far from its intended course and at least ask the pilot what's going on then rather than wait until it is well into populated or industrial areas? (Note: I can't tell from the movie if the plane supposedly has a transponder or not.)
By the time of passing the middle marker, shouldn't the pilot have the runway clearly in sight and at the very least be lining up with it, if not already be fully lined up with it? This is in moderate darkness, but it doesn't appear to be in otherwise difficult conditions; no visible fog, for instance, even in aircraft-exterior shots.

If someone wants to comment on the above as well, feel free to. However, my main question is this: if this situation were to somehow develop in real life, then is the phraseology realistic? Would ATC say that they have "lost" radar contact? Since the aircraft is obviously in the wrong place by that time, it would seem like they should never have had radar contact in the first place. In such a situation, I (as a non-pilot) would expect ATC to request an ident, possibly verifying the transponder code as well.


texts: How are different parts of airliners handled after the end of life-cycle?

texts:
When I was young my father opened a ship equipment shop. He purchased the broken airliners wheel and resell to the ship operators as anti-crash barrier on ship or in the pier like in the picture.

How does the other parts in airliners be used after life cycle?


texts: Why did water come into USAirways Flight 1549 if an airplane is sealed and pressurized?

texts:
Airplanes are supposed to be air-tight and pressurized.
However, when USAirways Flight 1549 landed on the Hudson river; water started to come into the airplane.

How is this possible if the airplane is sealed? Was there a crack in the fuselage?


texts: What are the rules in UK law on carrying dangerous goods on drones?

texts:
If I wanted to use an unmanned drone for carrying potentially dangerous cargo like car fuel, what would be the legal requirements of this in the UK? For example, lets say I wanted to carry fuel in jerry cans for use by drivers who have run out of fuel.

What are the rules on commercial drone flights where the drone will be flying autonomously and out of visual sight of the operator?

What are the rules on carrying cargo like fuel in said drones?


texts: What is the rationale behind very short distance flights?

texts:
I was impressed to read here that some passenger airline routes are even below 60 km in length.

Even assuming that the passengers are already in the airport past the security check, probably a good bus could depart from the same gate and arrive to the destination gate in a very comparable time, as the plane still needs to taxi before and after the flight.

Why these short haul flights are reasonable?


texts: How does the lift coefficient of an A380 change when flaps are extended?

texts: I would like to know the lift coefficient with 10 degrees of flaps extended.


texts: What is the problem if the temperature of the  oil and heads of cylinders is too high? What's the fault in piston engines?


texts: Brace position - does it really save lives?

texts:
There are some people say the brace position was invented so that passengers don't experience pain when they die in a crash. The brace is designed so that you die quicker (by breaking your neck).

One source: Here

Is that true? If not, how does it provide better protection during a crash?


texts: What percentage of airliner flights globally are freight flights?

texts: So we have N airliner flights in the world each day. What percentage of them are "purely" cargo flights versus passenger flights (that may carry cargo as well)? We can exclude Combi aircraft and other intermediate cases for the sake of simplicity. Thank you.


texts: Which pilot (pilot flying, pilot monitoring) handles CPDLC (operates CPDLC interface)?

texts:
This question relates to commercial flights, typical two-pilot crew: In some airspaces, e.g. North Atlantic, pilots and Air Traffic Control use Controller Pilot Data Link Communication (CPDLC, datalink) to communicate instead of VHF or HF.
Voice communication is ususally handled by the Pilot Monitoring (PM, or pilot non-flying PNF) - meaning the PM does the communication, and the PF executes instructions from ATC. With regards to CPDLC, which pilot handles datalink communication, is this also the PM as per standard operations? Are there standard operations for this?


texts: How do you indicate whether the supply of power to the gyroscopic instruments is adequate?

texts: Is there an instrument to indicate this?


texts: What would have happened if the jet engine on my aircraft had ingested caulk from the pavement?

texts:
I was recently on a flight - the aircraft was a 737-800 - where I had a good view of the front of the left engine. The situation in the title did not occur, but it seemed awfully close.

After pushback, while the plane was waiting to start taxiing under its own power, I looked at the tiny waterspouts sporadically forming in front of the engine (it'd been raining all morning). And then I noticed a piece of caulk (or tar or whatever it is) was being lifted from between two concrete slabs of pavement.

The strip of caulk looked like it might have been 30cm long and 2cm in "diameter" (it had a more rectangular cross-section, but you get the idea). It was still attached at one end, but it was directly in front of the engine, and its free end was being "tugged" up toward the intake in fits and starts, sometimes standing straight up.

Thankfully, it never went further than that. I considered alerting the cabin crew, but everyone was already buckled in, and I really didn't want to cry wolf on a airplane (so to speak). Still, I was very much considering it just as the plane started moving without any further drama.

As soon as we were in the air, I discreetly told a flight attendant, and she told the pilots. She came back a little later asking for a few specifics, so I imagine the pilots were radioing the airport we'd just left.

And I got a free cup of coffee (yay...)

My question is: What might have happened if that piece of debris had come loose and been ingested by the engine?

I wouldn't expect it to be catastrophic or anything (which is also why I hesitated in informing anyone while it was going on), but I would expect it to be expensive. I.e. it might ground the plane, at least for a short while. Probably some flames out the back. Maybe it'd even mess up the engine by gumming up the works.

I was never worried for my safety or anyone else's. I know engines are tough, and can eat all manner of crap. And even if they tear themselves apart in the process, they contain it. Not that I'd expect something like that happening at low power anyway.

But really: I don't know for sure what would happen. I'm not a pilot or mechanic, just a nerd with a nerd's interest in engines and airplanes.

Edit: Checking the airline's website, it seems the engine would be a CFM 56-7B26, if that's at all relevant.


texts: Why do some airplanes fly at a very low speed (like this one) at a speed of 433 km/h (234 knots) at a whopping high altitude of 26,500 ft?

texts:
Okay. So I'am just having a doubt on this flight (BA359) flying from Lyon, France en-route to London Heathrow. It is flying at a way low speed of 433 km/h (234 knots) in which i think is a bit weird. It is quite far from London Heathrow before landing. But come on, the head wind is not way too much. I mean if it is way too much, the airplane will fly at TAS 700 km/h ( GS 950 km/h) corrected for a 250 km/h head wind/jet stream.

Or maybe there is an altitude restriction or instruction to fly at holding speed to finally hold at Biggin or Ockham holding stacks due to heavy inboud traffic? I'am just curious.


texts: How are military aircraft directed to targets?

texts:
How would a controller, say, AWACS or ground radar, direct via voice an aircraft to the location of an airborne target?

I've seen it in movies, but don't know if they where right, nor did I understand it.


texts: Is there a standard time zone for flight schedules?

texts:
I was reading a question on Travel.SE. The asker was asking whether the time on his ticket was in Daylight Savings Time or in standard time. I would imagine flight schedules are supposed to be time-zone/DST agnostic so as to avoid any potential confusion and timezone conversions.

A commenter mentioned UTC time, which makes sense to me.

So my question is: is there a standard time zone or other time standard used for tickets and/or flight schedules?


texts: What is the peak of coffin corner called?

texts: The converging point of Vx and Vy is the absolute ceiling. Can I call the peak of the coffin corner an absolute ceiling as well?


texts: Can general aviation use UHF to contact ATC?

texts:
In the US, if a civil aircraft has a UHF radio are there any regulations against it performing ATC communication on the UHF bands?

Pointers to the appropriate CFR's would be appreciated.

This question does not concern operating under an emergency state of any kind. The aircraft is assumed to be in compliance with all regulations otherwise at the time.

The reason for excluding emergency status, is that in an emergency the FCC states you can use whatever methods available to obtain help.


texts: What is the maximum legal flight time for single pilots under Part 91/135 operations?

texts: I'm referring to FAA Part 91 and 135 operations (or similar,  EASA) and the maximum duration of one single flight (not the maximum duty time per day / week / month). If any, what are the legal flight time limitations for single pilots? In other words, which flight time requires more than one pilot?


texts: How big a risk is to abort take-off before V1 with uncontained engine fire and side-wind?

texts:
The Blue Panorama flight 1504 had uncontained engine fire just before V1 during take-off. The pilot continued the take-off and succesfully landed the plane with one engine. In the TEDx talk the pilot Maurizio Guzzetti explained that he thought that if he had followed the official protocol he would have aborted the take-off and the heavy sidewind would have pushed the heat from engine fire to the cabin and caused the cabin to catch fire and result in casualties. Instead he decided to take the plane to air, turn the plane around and land with the other side to the wind before stopping the plane. Note that the plane was over the maximum landing weight and no ability to dump fuel.
Do you think that this was a real threat and if so, what should a pilot do with similar fire starting with slower speed? Assuming the fire cannot be contained and heavy side-wind is there a reason no believe the cabin will not burn, too? However, if you're a lot before V1, it really wouldn't make sense to try to complete take-off with only one engine.
The TEDx talk: Collaborating with machines at high altitude and speed | Maurizio Guzzetti | TEDxModenaSalon

A well made animation about the accident:
Bursting into Flames Just Before Takeoff in Rome | Season Finale [Real Audio]


texts: How to calculate camber for a balsa glider?

texts:
I am making a rubber powered balsa glider for a competition. I want to make the glider fly as long as possible. I've heard that a high camber means slower speed means more airtime. I want to make sure that the camber isn't too high, and I need to know what type of camber I should use. Also, I need to know if the horizontal and vertical stabilizer size is fine.

The dimensions of my glider include: 32cm fuselage, 7.8cm wing chord, 28cm wingspan, 5.5cm horizontal stabilizer chord, 11.5cm horizontal stabilizer span, 5cm vertical stabilizer height, and 5.5cm vertical stab width.


texts: What property of a wing allows it to flex?

texts: Is it the material used that allows the wing to flex or is wing flex caused by the structure of the wing?


texts: In the US, is it customary to tip the line personnel?

texts:
The etiquette of interacting with the line personnel wasn't really taught to me during flight training, and I feel that every time I ask for line service, I'm doing something wrong by not tipping. I don't travel with groups or other pilots very often, so I don't see this in practice...

Do line workers in the United States expect tips for service (fuel/parking) from GA pilots?


texts: Does ETOPS apply to Part 125 operations?

texts: Does ETOPS apply to aircraft operated under Part 125? I see ETOPS mentioned in Part 121 Appendix P and Part 25 Appendix K, but it would appear that ETOPS wouldn't apply to Part 125 operated aircraft?


texts: What turn to intercept a radial and how to tune in B737ng sim?

texts:
Forgive my very amateur questions, I have been out of flying for years now and I am getting fit to fly again after slight setback.

I have an opportunity of doing some refresher flying in 737NG simulator soon. I was given a mock clearance for practice and would like your input. Take off is from runway 30, runway heading till 2000ft and then track and intercept radial 020. The VOR station is right behind the runway at the airport.

Does this clearance allow me to fly a reciprocal of 020 inbound to the station? Or will I just have to fly away from the station on 020 radial?
Will a left turn be more appropriate than a right turn to intercept radial 020?
In a Cessna 172, I would twist the OBS to get a from flag and then select 020, how do I ago about this in a 737 sim? Is it the same thing?
Do I select the radial before or after take off?
Finally, the b737 uses ADI with a movable pointer or "sky up"which is different from what single pistons and light twins use. I will appreciate any tips to help me nail the movable pointer ADI/attitude indicator on the sim.

I will really appreciate any tips to help me make the most of the sim session and sorry for the terribly novice questions.


texts: What are the takeoff and landing distances of motor gliders?

texts:
I'm doing some estimations of weight and thrust loading for a college project, and in the formula below the landing distance is not a variable, but should be estimated using similar aircraft and usual runways. (There is also a formula for landing with the same problem)

The similar aircrafts are 18-21 meter self-launching motor gliders like DG-505MB, DG-1001M or ASG 32 Mi (but with absolutely no data I have now, information about any other gliders would be appreciated as well).
The only thing I've found was that European Regulations CS-22 allow motor gliders a maximum takeoff distance of 500 metres.
Source; T.C.Cork, Design of Aircraft


texts: What do I do if I wish to move my software from DAL Level A to DAL Level C?

texts: If I wish to downgrade my software's design assurance level (DAL) from Level A to Level C, what do I need to do? What are the benefits and drawbacks of doing this?


texts: Are the functions of ailerons and rudder similar?

texts: The ailerons help the plane to bank left/right by increasing lift to one wing and decreasing in another. Likewise, the rudder also helps in turning the plane by yawing and deflecting the nose right/left. So their performances sound quite similar(i.e. to make a turn)? Then, why should we keep both of them?Like in a ship or motorboat there is a rudder only and no ailerons.Are ailerons present for quicker operation and rudder for extra support and stabilization only?


texts: Is there a generic formula to calculate fuel consumption for passenger jets?

texts:
I am working on a game that has to calculate the fuel burn of real life passenger jets. Input values would be roughly the following:

Route (like JFK-LAX, based on Great Circle Map distance, ideally including reserves, holding, alternates, following real life nav points)
Estimated flight time
Aircraft type (A320-200 with Winglets, possibly the MTOW, engine types)
Possibly the OEW (i.e. cabin configuration/crew/catering)
Payload (Number of passengers/cargo)

Based on these values I would need a generic formula that can estimate the fuel consumption for such a flight, and/or possibly the max payload in case the range is not enough.

The thing is it should be generic enough so that it's possible to provide the parameters from publicly available information about aircraft types. I am aware of JSBSim or Yasim FDM, although I believe those would be way too detailed and complex for this purpose.

I am not sure if there is something like this as I understand it is quite a complex task.

The current formulas are too simple and do not take into account the payload or other factors, making it too static.

Any help highly appreciated.


texts: Does the FAA dictate that bridges are closed for the Thunder Over Louisville airshow event?

texts:
A big tradition here in Louisville is "Thunder Over Louisville". This starts the celebration for the Kentucky Derby. 'Thunder' is an airshow, fireworks, fair, concerts, and a nice day out along the river. This event leads to the closure of bridges over the Ohio River. Some closures are brief, such as I-65. Others are days long because fireworks and other aspects of the theatrics are positioned there.

We have a new pedestrian bridge called "The Big Four Bridge" which was opened very recently. This bridge is closed despite being a very obvious attraction to attendees and it can ease car traffic by allowing foot traffic across the river. There are many notices that this bridge is closed, but none of them cite the authority that closed the bridge.

Does the FAA hold sufficient authority to close bridges, roadways, or other locations for an airshow?

If so, what resources should I use to locate these closure notices?

This question is simply a curiosity. There are many logical reasons for the 'Thunder' organizers, local police, state police, and the FAA to close the pedestrian bridge. I want to learn more about what authority the FAA specifically would have in this matter just for the sake of learning.


texts: Should the helicopter be washed after any sea mission?

texts:
I was seeing this image:

The caption of this image says (source):

Here a Belgian NH90 NFH returning after a flight over sea. The
helicopter is washed by the fire brigade to remove the salt water...

Should any helicopter be washed after any sea mission? Are those guys washing the engine? If so, should the engine of helicopters be washed after any sea mission?


texts:
I have seen a WW2 movie where the pilot of the Supermarine Spitfire has difficulties to extend the landing gear as the engine is no longer running.

This would be reasonable if the gear normally needs hydraulic or electric power to be extended, otherwise probably just an attempt to add more tension to the plot. Would running out of fuel (no engine power) make the extension of the Supermarine Spitfire landing gear more difficult or different from usual?


texts: What are the effects of an increase in altitude upon ESHP of a turboprop engine?

texts:
This is one of the questions in the ATP material:

  What effect will an increase in altitude have upon the available
  equivalent shaft horsepower (ESPH) of a turboprop engine?

  A) Lower air density and engine flow will cause a decrease in power
  B) Higher propeller efficiency will cause an increase in usable
  power (ESHP) and thrust
  C) Power will remain the same but propeller
  efficiency will decrease

I chose (C) but the correct answer was (A). Could anyone explain why? Isn't the whole purpose of a turbocharged engine to sustain engine power at high altitude (below critical altitude)? Why does lower density at high altitude cause a decrease in power?


texts: Does it matter in which country I obtain my EASA Part 66 AME licence?

texts:
I have completed EASA Part 66 B1.1 exam modules (some from the UK CAA and some from the German 147 organisation).
My queries are:

Can I apply to any member state (e.g., Belgium, The Netherlands, Germany, Ireland, UK, etc.) to get my initial Part 66 licence?
I have already emailed few country’s licensing departments; they declined and advised me to apply only to the UK CAA.

If I can apply to any member state, why did I get these replies? If I can’t, why not?

Does it affect job prospects in the UK if someone has a Part 66 license issued by another European country? (And vice versa?)

To which authority (country) can I apply to get my Part 66 licence as soon as possible if I am eligible to do so.

Does it affect aircraft type rating endorsement in future on a Part 66 licence? For example, if my license is issued from Belgium but I’m working in the UK.


texts: Why can’t air traffic control radars determine the altitudes of primary targets?

texts:
There are two types of returns that show up on an air traffic controller’s radar screen:

Secondary returns are not, strictly-speaking, radar “returns” at all, but, rather, signals automatically broadcast from an aircraft’s transponder, containing encoded location, altitude, airspeed, identification, flightplan, aircraft type, etc., data retrieved from the aircraft’s onboard instruments.  These are highly valuable, but, obviously, can only be used with aircraft equipped with a functional transponder which have said transponder turned on and transmitting non-bogus data.
Primary returns, in contrast, are true radar returns – direct reflections of the radar’s beam from the surface of an aircraft, bird, cloud, piece of debris, missile, tree, UFO, balloon, hailstone, or whatever else happens to be in the air at that moment.  As they merely require that an object be located where the radar beam can reach it, they are of great use in tracking aircraft with nonfunctional transponders (due to, for instance, a general electrical failure or simply a faulty transponder), aircraft in combat zones (for whom broadcasting an identification signal would be a great way to get shot down), pieces of aircraft, flocks of birds, or whatever other non-transponder-equipped objects one has a desire to track.

One common limitation given for primary radar returns is that they provide no altitude information, but only positional information.  But this makes no sense, as determining the position of a target requires knowing its elevation angle, azimuth, and distance relative to the radar installation (without knowing the target’s distance, it could be located anywhere along a line extending from the radar’s location out to infinity; without knowing its elevation angle, it could be located [within the altitude limitations of the object generating the target] anywhere along a circular arc extending from the horizon to the zenith at the specified distance from the radar; without knowing its azimuth, it could be located anywhere along a horizontal circle centered in the sky directly above the radar), and, if the elevation angle, azimuth, and distance of the target are all known, that also pins down the target’s altitude – not just its location.  Besides, military radars can and do provide altitude information for primary targets (they would be useless otherwise, as intercepting an enemy aircraft requires knowing both its position and its altitude, and enemy aircraft are unlikely to oblige a radar’s request to provide a transponder beacon signal that would aid immensely in shooting them down), which has proven valuable numerous times; for instance, the accident investigation that eventually produced the NTSB’s very first AAR used data from a military air-defence radar to determine that a 727 that crashed into Lake Michigan had descended steadily into the water without levelling off, instead of suffering an uncontrolled excursion from level flight, while, more recently, primary returns received at several military radar sites in Massachusetts showed that EgyptAir Flight 990 pulled out of its initial dive before making a second and final plunge.

So what prevents civilian ATC radars from displaying altitude information for primary targets?


texts: Where can I find the transition altitude in different countries/regions?

texts:
Where can I find the transition altitude in different countries or regions?

Hoping to cover as many places as possible. Links to the applicable regulations would be nice.

See also:

What is the difference between "flight level" and "altitude"?

Where can I find regulations in different countries for flight level rules based on direction of flight?

EDIT: Instead of request a list, now the question asks for how to find in general. A few examples should still be given though.


texts: What are the drawbacks of being a helicopter and fixed-wing pilot at the same time?

texts:
Are there any drawbacks if someone who is a fixed-wing pilot, learns to fly a helicopter, or vice-versa? Specifically, are there instinct actions in one category that are dangerous in the other?

Does this differ if someone is experienced in one category (e.g. 1000+ hours), versus a student learning both within a short period of time (e.g. less than 6 months in between)?


texts: There aren't exactly an abundance of stealth planes, but most highly developed countries own one. Why are there no stealth helicopters? If there are, why are they so obscure?


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

texts:
This is a followup to What is the measurement system used in the aviation industry? and related to this question from History.

I can understand the arguments as to why adoption of SI units would not make sense for the general population, but aviation is a specialised business. All professionals are highly trained, and would (should) be well versed in both systems anyways, so the transition would be much simpler from the point of view of human factors. The technology would probably be much harder to shift but again, with more and more displays and documentation going digital in cockpits, this again seems to be a not so huge problem. Maintenance and manufacturing is again fairly specialised and restricted to a smaller number of companies as compared to the general case.

What are the historical factors that lead up to the adoption of imperial units in the industry? Why are they still being used when widely accepted scientific standards exist?


texts: What process do I follow to land a civilian aircraft on a military base?

texts: Let's say I have business on a US military base (e.g. JBLM), and I'd like to fly a privately owned aircraft there. What is the process I follow before the flight to get approval to land, and once I'm enroute to ensure everything goes smoothly?


texts: Am I correct about what AC/DC BAT BUS does?

texts: The purpose of the AC/DC BAT BUS is to distribute either A/C electrical power and D/C electrical to the things in the aircraft that need them. For example, I think he whole ECAM system and displays use A/C electrical power. There are 2 of each BAT BUS (AC and DC). Do they work together so AC BAT BUS 1 and 2 work together and both distribute randomly or for example does AC BAT BUS 1 supply certain systems and AC BAT BUS 2 supplies the others. Do they have assignments of which systems to power, or do they work together?


texts: How can the glide ratio in a balanced turn be estimated?

texts:
I am trying to estimate the bank angle/turn radius required to lose a given amount of altitude during a full orbit. This has led me to trying to estimate glide ratio in proportion to $L/D_{MAX}$ of an aircraft in a balanced gliding turn, knowing only $V_{MD}$ and $L/D_{1g}$ for $V_{MD}$.

My approach is to use the following relationships:

$D = D_0 + D_I$

$D_{0} = C_{D_0} 0.5{\rho}v^2 S$

$D_I = C_{D_I} 0.5{\rho}v^2 S$

$C_{D_I} {\alpha} {C_L}^2 $

$C_L {\alpha} L $

$L {\alpha} n $

$n = \frac{1}{cos({\phi})}$ (${\phi}$ = bank angle)

Assuming $D_0 = D_I$ at $V_{MD}$ I think I should be able to calculate:

$L/D_{n_g} = \frac{L/D_{1g}}{0.5 + 0.5(1/cos^2({\phi})}$

Since altitude lost in a full orbit becomes $\frac{2{\pi}r}{L/D}$ where r = turn radius and

$r = \frac{v^2}{g tan(\phi)}$

Altitude lost in a full orbit should ${\alpha} \frac{1}{cos^2({\phi}) tan({\phi})}$ which looks like this. Does my method look alright, or have I made any incorrect assumptions or errors?


texts: Propeller Efficiency calculation different by two methods

texts:
Please refer to this MIT page which I used for my calculations:
https://web.mit.edu/16.unified/www/FALL/thermodynamics/notes/node86.html

I calculated my aircraft propeller's prop, thrust, and torque curves, and subsequently the efficiency at a certain operating point (given the input thrust requirements and airspeed), by dividing the useful power (=Tu_0) by the input power (torqueRPS), where u_0 is the flight speed.

Now, in the propeller plane, the airspeed is u_disk according to Actuator Disk Theory, and can be calculated using the formulas and the known info. When I calculate the input propeller power according to another formula on that page [Power in = Thrust * u_disk], I get an answer not equal to the one using the torque*RPS formula. Where did this extra power go? I was expecting them to be the same, and the aerodynamic losses to be factored into the useful power being lower.

In my example, the flight speed is 3 m/s. Due to the conditions of the aircraft and environment, this requires 42N of thrust, which requires 4.5N-m of torque at 1503 RPM. This is all due to the propeller characteristics. Now, the useful work is T * airspeed = 42 x 3 = 126W.

Using the calculations on that page, we can get the accelerated speed at the disk is 11 m/s. So the input power (According to the page) is 42 x 11 = 464 W. This is different from the conventionally calculated input power of Torque * RPS = 4.5 * (1500/60) = 700 W.


texts: Can lift occur if air is flowing over an object, but not under it?

texts: Can lift occur if air is flowing over a fixed-shape object, but no air is flowing under any part of the object? Maybe the object is the top half of a wing that's glued to the ground, or the object is dome-shaped, or some other shape. Maybe the object doesn’t actually rise or move, but when air flows over it, it exerts less weight on the ground.


texts: How to do the base turn course reversal?

texts: Can anyone tell me how to do the base turn course reversal? Please. I'm afraid it might be asked of me in my Checkride and my instructors haven't taught me that. Please.


texts: Before a flight, what are the most important things to check in an aircraft (walkaround)?

texts: During the pre flight inspection, usually the copilot checks many parts of the aircraft. Which are the parts and Why do they check them?


texts: When a paraglider pilot applies brake on one side and maintains the brake pressure, why does the roll rate eventually come to zero?

texts:
I recently started to study paragliding and I am confused about the rolling movement created when a brake is maintained.

I was reading this answer How do paraglider controls work? and I am not clear which force should balance the rolling created by the side force on the levered arm during the initial phase of the turn and stop the rolling motion.


texts: How to become pilot in India with lack of money

texts: Hello I am from India currently I am in class 12 pursuing PCM and want to become a commercial pilot but belong to a middle class family how can I pursue my dream. I can't afford course of 60 - 80lacs.


texts: I thought the shape of the wing gave an airplane upward lift. How can it fly if it's upside down?


texts: Why don't bypass ducts in jet engines narrow down the flow to accelerate it?

texts: Since decreasing the flow area increases flow velocity, why don't turbofan bypass ducts narrow down to produce more thrust?


texts: What is the occasional crackling sound on an A330?

texts:
On a recent long-haul flight on an A330, at various points during the flight a strange crackling-type noise could be heard through the aircraft. It first happened whilst taxiing for takeoff and then subsequently every two hours or so.

If I had to guess, I'd say it sounded like ice-crystals or something being blown down the air-conditioning ducts. I'm no aviation expert (by a long shot) but I've never head this sound before and wondered what it could be?!


texts: Why is a higher bypass ratio more efficient at lower speeds?

texts: Why is it that a larger volume of air moving slower is a more efficient means of propulsion than a smaller volume of air moving faster?  (This is true up to a given speed, obviously, as supersonic aircraft use lower BPR engines).


texts: Do all Bombardier jets have manual reversion?

texts:
Whatever CRJ 700 or Learjet 35A/45XR.

Do these aircraft have full manual reversion? Can you operate the flying surfaces in a hydraulic failure?

These aircraft are very small – even smaller than a 737 – so I guess they all do.


texts: What training is required to become an air traffic controller?

texts:
I'm curious as to what it takes to be an Air Traffic Controller. I sat in a preliminary online test after I got accepted in, but it was mindbogglingly difficult. One of the questions I had to do was to add two 8-digit numbers in less then 5 seconds. With such difficult questions in mind, there must be on the job training in addition to class room training as well.

Q: What sort of training is done in becoming an ATC, and what sets the difference between a good ATC and an average ATC?


texts: Why were the speed records set by seaplanes in the early thirties?

texts:
For nearly all of the 1930'ies, the fastest aeroplanes were all of the seaplane category (as opposed to landplanes, to use the terminology of FAI).

Presumably, the designers of the two categories had access to more or less the same technology (engines, materials, aerodynamics, etc.) given the large interest in the subject and funding available.

If we for a second rely on Wikipedia for the record listing, we see that the speed record for a seaplane set in 1931 is 655.8 km/h (Supermarine S.6B), while the record for a landplane set in 1935 (4 years later) is "only" 567.1 km/h (Hughes H-1 Racer).

Seeing how fast aviation technology developed in that period, it is remarkable that four years after the Supermarine record, the fastest landplane was still significantly slower than the fastest seaplane.

I would expect the large pontoons on the seaplanes to provide more drag compared to a simple landing gear, and hence by logic the seaplane should be penalised and achieve lower maximum speeds. All things being equal.

However, since the speed differences are so pronounced, all things obviously are not equal. So what are the differences between the two categories (or their designers and manufacturers) that can explain the gap in maximum speed?


texts: Could wing tilting be a mechanism for VTOL and high angle of attack for jetliners?

texts: My question is about turbofan airliners, could an airplane tilt its wings 90 degrees so that the fuselage horizontal axis is perpendicular to the longitudinal axis of the turbo fan. This way an airliner could be VTOL and at the same time it could have even 90 degrees angle of attack. Am I missing something?


texts: What's required for the ADS-B to function? A GPS or Mode S Transponder?

texts: Jeppesen defines the ADS-B as a surveillance system broadcasting GPS-derived positions and other information such as velocity over the data link. Yet, the Wiki article on ADS-B relates it to the Mode S transponder system. So the ADS-B operates either on a GPS or on Mode S. Is my understanding correct?


texts: Minix wingtip vortices mitigation - How does it work?

texts:
I stumbled upon this article: Minix wing tip device promises 6% gain in fuel efficiency for airliners.

Such an economy is appealing and I must confess the design is "sexy".

Could someone expand a little bit?


texts: Why does an aircraft have to be flying straight and level to facilitate a jump?

texts:
In the other questions about parachutes on this site, it has been stated that the aircraft would have to be flying straight and level to facilitate a jump. However, there were quite a few pilots during WWII whose planes were not flying straight and level and who still managed to escape.

Is there a difference between then and now that I am not catching?


texts: What happens if a commercial airplanes navigation system completely failed during a flight?

texts:
What would happen if all of the the navigation systems (such as GPS & INS) in a commercial aircraft completely failed?

Could the aircraft land safely without all the navigation aids?


texts: What are the disadvantages of having vortex generators?

texts: I know the advantages of vortex generators (VGs): lower stall speed, lower landing and takeoff speed according to www.stolspeed.com. So what are the major reasons most GA planes and low speed ultralights don't have VGs on their wings?


texts:
Do runways always handle traffic in the same direction? Another question asked how runways were labelled left and right (8L and 8R, for example). But of course "left" and "right" depend on your perspective. If you were approaching from the opposite direction, then left would be right and vice versa.

Does this mean that runways only handle traffic coming from the same direction all of the time? Are there no ambidextrous runways that flip depending on the prevailing winds or whims of ATC?


texts: Why is "LINING UP" used as the proper response to a "conditional" line-up instruction?

texts: This is a list of the ICAO's standard phraseologies used for preparation for takeoff. I don't understand why "lining up" is (recommended to be) used as a response to a conditional line-up instruction. It can be very confusing, because it sounds like the pilot is lining up (against the ATC's intention) when he has to wait until the condition is met, like in the situation where the pilot has to wait until the arriving airplane touches down before she can taxi onto the runway to line up. I'm not a native speaker, so it might be just me. Does it sound reasonable to native speakers?


texts: What is the equivalence of Meteksan MILDAR in US inventory?

texts:
This is called MILDAR radar.

This is manufactured by a Turkish company named Meteksan.

Is this Turkish equivalent of Longbow radar?

If yes, why is that radar pylon-mounted rather than mast-mounted?


texts: What is the relationship between ADS-B IN/OUT and different mode transponders？

texts: What is the relationship between ADS-B IN/OUT system and different mode transponders? Can a aircraft with mode A or C transponder have the ADS-B in/out capability, that is getting more detailed surrounding traffic information like ID, position, velocity and broadcasting its own ID, position, altitude etc.


texts:
This is a while ago but it has been bugging me now and then.

On September 11 2011 (yes exactly 10 years after 9/11!) I was flying Easyjet 3467 from London Stansted Airport (STN) to Copenhagen (CPH). Scheduled departure was 18:40 local time but the flight was heavily delayed (around 4 hours as I recall) due to another bizarre incident.

Anyway, as we were finally sitting in the plane and taxiing, suddenly the pilot announces that he just got info that another airplane had been heading to land just where we were and had only been some 60 seconds away! A lot of passengers seemed to gasp for air and the pilot sounded quite shocked as well. But there was no other explanation added.

Is there a database of such events so I could look up more about what happened?

I found the flight on FlightStats (sign in required) but there were no real info.


texts: Why are fighter pilots seated and not reclined?

texts:
I have always wondered about this one.

Pulling high G-forces is, I assume, the most physical challenge the pilot of a high performance fighter aircraft needs to be able to sustain without blacking out or worse. Indeed, in most countries in the world would-be fighter pilots cannot qualify for jet-jockey status without first passing the dreaded centrifuge test.

Further, modern jets can in fact pull much higher G-forces than the pilot without damage to the aircraft. Indeed, I read somewhere once that one of the issues with auto-missile-avoidance systems is that the aircraft is limited to performing maneuvers that the pilot can withstand.

As I understand it, the issue with high-G turns is that the blood is drained or driven from the body to the lower (and upper when undergoing high negative-G) extremities of the body resulting in starvation of the brain and consequent blackouts or even embolism in the negative-G case.

I realize pilots wear tight G-suits which have air pumped into them to restrict the amount of blood that can accumulate in their lower extremities, but that doesn't reduce the stress on the heart trying to pump blood up to the head.

It seams rather obvious to me that much of the issue with high-G is caused by the seated position of the pilot. It is an established fact that the more vertical you are the harder it is to withstand G-forces.

Why then are modern jets not designed with the pilot in a more reclined position? For example, the position used by Formula-1 race car drivers:

Don't get me wrong, I understand F-1 drivers do not need to withstand the same kind of sustained vertical forces that a fighter pilot does, however the legs-up reclined position seems to be far more practical for a high-G environment.

I do realize that the whole ejector-seat mechanism would need to be redesigned to eject the pilot differently, and that the pilot's ability to see behind himself would be compromised without technical aids, but surely the increased turn rates and lower profile cockpit would outweigh those issues.

NOTE: I have seen other posts on using the head first "prone" position, including this stack-exchange link but nothing on reclined.

ADDITION: Found this image of a Foka-5 glider pilot position too... note how wonderfully streamlined it is.


texts: How much does it cost the airline if an aircraft makes a missed approach?

texts:
aircraft go around due to variety of reasons viz. Bad weather (inevitable), unstable approach, ATC errors etc.
knowing the cost implications will help in educating the stakeholders.


texts: What is the cost of electricity generated in the E175-E1?

texts:
I'm comparing two types of cabin illumination, and I'm having a difficult time to estimate the cost that will be saved by utilizing lights with a lower power consumption.

What are the costs of electricity on board an airplane? Basically, I am looking for the cost of a kWh of electrical power generated by the engine, during an average travel of about two hours.

I edit to any kind of airplane, because some aircraft are easy to find data. Some information I found already:

In round numbers, a 737 will burn 5,000 pounds (750 gallons) an hour. (https://www.usatoday.com/story/travel/columnist/cox/2014/10/12/boeing-737/17036931/)
An A320's two alternators can produce 150 kilowatts (kW) and needs only 50 kW in total. (https://www.safran-electrical-power.com/media/20151109_more-electric-aircraft-how-does-electricity-work-plane)
The cost of fuel is approximately $1/gallon (https://www.airlines.org/argus-us-jet-fuel-index/)

If somebody have any idea, I would be very grateful.


texts: How much data is stored in the flight data recorder per hour in a typical flight of an A380?

texts:
One drawback or impediment to the storage of flight recorder data on the cloud is the amount of data that'd be transmitted and at cost.

How much data in GB or TB is stored in the flight data recorder per hour in a typical flight of an A380?


texts: What is the optimal sequence of departures and arrivals on a single runway?

texts:
When in a peak load scenario with plenty of departing & arriving aircraft to keep the ATC pipeline full, are there considerations that make a certain sequence of Departures / Arrivals that optimizes throughput?

For specificity, let us assume a single runway in use and no general aviation aircraft with predominantly jet traffic and multiple runway entry & exit taxiways available. Including high speed exit turnoffs.

I typically see a sequence something like:

 Dep-Dep-Arr-Dep-Dep-Arr

But an alternative optimum might turn out to be:

Dep-Arr-Dep-Arr-Dep-Arr

etc.

I realize that the specifics will depend on the exact aircraft etc. but just to use an idealized model what would result from typical operating constraints. e.g. You need to allow a certain separation during approach but you can have multiple aircraft lined up for take off. So is the potential to squeeze departures into the "holes" higher? Also, you can clear a second departure after a first far more rapidly, than the landing-to-landing interval right?

Just wondering, if you had to set up a formal optimization model what sort of parameters & constraints should go into the model as inputs.

A follow up question: Say you had two runways available in parallel & widely spaced apart. Does it make sense (for throughput) to dedicate one to landings & another to takeoffs or is it more efficient to mix landings & takeoffs on both runways?

R18L: Dep-Dep-Dep-Dep-Dep-Dep-Dep-Dep-Dep
R18R: Arr-Arr-Arr-Arr-Arr-Arr-Arr-Arr-Arr

vs

R18L: Dep-Dep-Arr-Dep-Dep-Arr-Dep-Dep-Arr
R18R: Dep-Dep-Arr-Dep-Dep-Arr-Dep-Dep-Arr

PS. If further simplifying assumptions are necessary, let's imagine a hypothetical airport serving a single aircraft type, say A320 only. Or assume any type you will to be representative of a wide class of aircraft just to get the modelling started.


texts: Does a windmilling propeller create more drag than a stopped propeller in an engine out scenario?

texts:
For this question lets assume that we are talking about a fixed pitch propeller and not a variable pitch propeller.  I do understand that variable pitch props should be feathered during an engine failure.

The main rationale for this question is this statement that I found in a pilot forum:

  I've been doing some research on something I hard from my old chief CFI a couple years back, but I'm not finding much on it. He is the only person I've heard this from, and any CFI, DPE, ect. I've talked about this to since have not heard of it. That being that when you have an engine failure more than several thousand ft. with a non-full-feathering prop, that you should pitch up and decrease airspeed, sometimes to an intentional stall, to stop the rotation of the prop/engine. (Of course, only after you have attempted to restart.) The reason being that you will see a greater gain in glide distance by reducing the drag created by forcing thee air to turn over the engine. He claimed that while you would most likely be off of Vl/d for a short amount of time, thus not gliding in the most efficient manner, that is outweighed by the decrease in drag. (As I said, do this only with several thousand feet and plenty of time.) He claimed that in the case of something such as a 172, doing this procedure at, say 10,000ft, you would gain several more miles of glide distance.

So what I am asking for is if indeed a windmilling prop has more drag than a stopped prop and if so would it be beneficial to follow the advice in the pilot forum?


texts: Why do we take off with maximum power settings?

texts:
In most GA prop airplanes, take-off is executed with full throttle and high rpm. The usual reasoning is that this way, we leave the first few hundred feet, where failures are most severe, behind as fast as possible.
Isn't this like driving a car, seeing ice/playing kids/any other hazard, and speed up to leave the danger behind? In other words: Shouldn't we be most careful and conservative near the ground, with as little stress to the engine as feasible?


texts: How did the Brazilian Civil Aviation Authority have MCAS on paper from Jan 2018?

texts: how could they know but nobody else did? Did they buy the extra sensor or something?


texts: Which commercial aircraft can stay in the air the longest?

texts:
Which commercial aircraft, when fully loaded with fuel (and passengers and luggage up to its max takeoff weight), could stay in the air the longest without landing, and how long could it stay in the air? What conditions would it need to have maximum possible endurance if the plane had no intended destination to land or particular flight path? (This is for a fictional story.)

Note: I was thinking commercial jetliners when I wrote that, and I still am, but I was accidentally unclear about it. That's preferably what I'm looking for, though.


texts: Is there a parameter that links the areas of the fuselage and control surfaces?

texts:
Do aircraft designers look at the ratio of how much fuselage surface area can be loaded onto a given unit of wing and tail surface area including elevator, aileron, rudder etc? (Possibly, the surfaces of propellers and internal parts of jets, may be excluded while making such calculations.)

Is there such a parameter, and if so, what are the normal values?

This question is for normal fixed-wing and rotary-wing aircraft, and mostly commercial aircraft.

This question is NOT about fighter jets, space-shuttles, canard-wing designs, flying wings, lifting body and other cutting-edge-technology stuff.


texts: What is the maximum temperature of engine bleed air for de-icing the wings?

texts: What is the maximum temperature of the air bled from the engines of a Boeing 747-800 and an Airbus A380 to the wings for de-icing?  If the air is too hot, how is it cooled?


texts:
Citing Wikipedia article on the Vertical Stabiliser:

  Rudder lock occurs when the force on a deflected rudder (in a steady
  sideslip) suddenly reverses as the vertical stabilizer stalls. This
  may leave the rudder stuck at full deflection with the pilot unable to
  recenter it.

But how does this phenomenon occur from an aerodynamics point of view? What does it mean that the force reverses on the rudder? Is pedal force meant here? Furthermore, how can the pilot recover from rudder lock?


texts: Why is the fuselage on an airliner circular-shaped?

texts: Consider the fuselage of an A300. I have noticed this not only with airliners, but also for private jets and turboprops: why is the fuselage circular-shaped? Why don't aircraft have square-shaped fuselage? Does it have to do with too much drag?


texts: Why does the Pressure ratio across the compressor increases when the mass flow rate is reduced?

texts:
I am learning about Rotating stall in Axial Flow Compressors. So, when we throttle the compressor then there is Pressure Rise and later after the peak pressure rise tip stall starts to appear.
But I am trying to figure out the relation between mass flow rate and pressure rise.


texts: What is the minimum power system required to fly a commercial aircraft?

texts: I heard of a A320 landing, no lights, both generators out, RAT deployed, and with only 28VDC(battery power),  made a successful landing. Is this possible?


texts: Is there any technical word to be used on Radio Telephony, to say that there is a "body air-shipped"?

texts:
A great number of dead bodies are transported by airplanes everyday.
How will pilots report to ATC they are transporting it/them?


texts: Why do Ryanair pilots get paid such a low wage?

texts:
As I‘m living in Europe and I‘m interested in a commercial pilot career, I looked up the wages on various websites. (I hope the German screenshots don‘t matter too much).

Example 1 (Source)

Example 2 (Source)

Were/Are there really Co-Pilots who paid for their training themselves (I suppose) and now only get about 2000€ per month?


texts:
Has there ever been a fully automated takeoff, cruise, and landing of a large aircraft similar to commercial airliners?

In fact, has there ever been a fully automatic flight of any pure aircraft whatsoever? This is gonna sound crazy, but the only thing I know that comes close is the Soviet Space Shuttle Buran. It launched unmanned and returned successfully under computer control, including its glide and landing.

So I'm interested in automatic aircraft similar to large commercial airlines. BTW, remote control toy planes wouldn't count because that is not automated (a person is manually controlling it).


texts: Is it possible to build a honeycombed vacuum balloon?

texts:
Is it possible to build a vacuum balloon with a near perfect void that can lift heavy objects and doesn't collapse and buckle under the atmosphere?

I expect perhaps a honeycombed or lorimerlite lattice infrastructure with toothpick-like filaments spanning across the honeycomb or lorimerlite voids in an alternating double helix pattern. These "toothpicks" would be slightly thicker in the center and thinner at their ends where they connect to the inside of the honeycombed or lorimerlite lattice. This would be made made of titanium. I would choose a toroidal (donut) balloon.

Would this design work, or is there another design that would?


texts: What is the meaning of these slang terms used in ATC?

texts:
I have heard some slang terms used mainly by ATCs:

follow the black holes
taxi not too deep
how is your ride

What do they actually mean and are there others?


texts: Why did LaMia flight 2933 plan a flight longer than its listed fuel range?

texts:
According to the wiki, the range of the airplane used in the LMI 2933 flight has a range of 1600 miles. The distance between the airports though is 1605 miles though. I presume the exact range varies on conditions, but why would a flight that is outside the listed range be planned? This seems like an amateur mistake that should have been quickly caught on pre-flight checks.

Also, the wiki states that before crashing the plane made 2 loops. If the flight was running out of fuel, why would they do this? It seems like the flight could have easily made it if they flew directly, and considering that they had declared an emergency the ATC wouldn't be able to say no.


texts: On a calm day, what determines the active runway?

texts: When the winds are "calm" or variable, and as such there is no wind direction on which to base the decision on what the active runway should be, how is that determination made?


texts: After seeing effect of speed and bank angle on rate of turn, how would one mathematicly calculate the effect of changing mass.  For example, in a 30 degree turn at 100 knots, how would the rate of turn be affected if identical planes, one at 10,000 lbs, one at 9000 lbs were compared.  Granted, the pitch and power settings may be slightly different, generating different amounts of lift.  Would the heavier plane turn faster due to its greater horizontal lift component, or would it's heavier mass keep it more in the same direction?


texts: What are the advantages of the Airbus New Engine Option (NEO) program?

texts:
Airbus is planning to roll out an Airbus A320neo to replace its current A320 model, and they will offer this option on other models too.

How does adding more options for engines for potential customers act as an advantage for the Aircraft Manufacturer? Why wouldn't the manufacturer optimize its plane for one engine specifically, to give best performance and roll out the plane like that?


texts:
It is a well known statistic that rear seats has higher survivability rates than front seats due to generally lower impact forces.

Double decks airplanes are not so common so statistics would probably be unreliable, especially since Boeing's only have a forward double deck.

Has any survivability study been made on that kind of aircraft, that include upper vs lower deck ?

I'm mostly interested in the a380 but other design are welcome as well.


texts: Could this "Wingless Dodo" fly in real life?

texts:
There is a wingless Cessna in GTA 3 that is so impossible to fly that the game counts how many seconds you manage to fly it.

Would that plane fly at least 1 second in real life?
The plane looks like a C152.

Here's a video where that plane appears.


texts: Would a 50 mph aircraft holding a ground pattern in a 20 mph cross wind risk stalling by abruptly rolling away from a crosswind?

texts:
This is another play on the "down wind turn myth".

We all know a plane flying in a "uniformly moving airmass" is not affected by wind direction and speed.

But a plane following a ground track must compensate for wind direction and speed.
In this scenario:

Pilot Bob could not wait to fly his ultralight and went out to practice take-offs and landings on runway 270 with a 20 knot westerly wind from 270.  In the pattern, flying heading 180 on the crosswind leg, a heavy crab into the wind had to be applied to hold the ground track.

Instead of adding power, Bob increased AOA to hold altitude (BAD MOVE).
Flying near stall, the pilot abruptly rolled and yawed the aircraft away from the crosswind and began to turn into the 090 "downwind" leg.

Could this maneuver significantly change the AOA of the wing, resulting in a stall?


texts: What would escorting an airliner which is the subject of a security threat by fighter jets achieve?

texts:
Today, a Ryanair flight from Lithuania to London Luton was the subject of a presumed hoax, and had some form of security alert. In the incident, it was diverted to Stansted, while being escorted by fighter jets.

What would the escort actually achieve? My best guess is to shoot it down in case of a hijacking, but this seems like a particularly grim prospect and perhaps maybe not one that would be so publicly on display. Is there another reason why it might have been escorted?


texts: Did the Space Shuttle really wait until 50 feet above the ground before they put the gear down?

texts:
I saw a sign at the Smithsonian about the Space Shuttle where it said that their gear was not extended until 50 feet above the ground.  I've searched and searched for something definitive that had the actual procedures used, but can't find anything.

To put this in perspective, the policy for every jet that I have flown has been to have the gear down and locked between 1,500 ft. and 500 ft. (at the very lowest).  50 feet seems very very low! What happens if it doesn't come down on the first try and they need time to troubleshoot?


texts: What does "Where AOC requirements are redundant to AAC requirements, or more detailed, the AOC requirements will be followed." on Part 7 of CAR

texts: Does it mean, The requirements for AOC are no longer useful to AAC, AOC will be used?


texts: Is an A&P certificate ever required to work on military aircraft?

texts: Are military aviation mechanics - including civilian contractors - ever required to obtain an A&P certificate to work on active military aircraft?


texts: Under what conditions do airliners retire aircraft and sell them to other airlines?

texts:
How often (and under what conditions) are airliners resold to another organization with...less stringent qualifications?  Is there a certain number of hours after which an airliner has to be retired or something?  Or is it just that airlines like to buy new and shinier airplanes on occasion?

Further, when an aircraft is being resold, are there any particular procedures that have to be followed?  And are there different levels of airworthiness involved (ie., you have a lower litmus test if you are just selling it off to be used as a cargo plane or private plane?)


texts:
While exploring open jet turbine designs, I've stumbled upon one CAD drawing which has made me wonder.

It is based on a famous Tesla turbine and its highly-efficient way of compressing the fluid.

At first glance the concept seems to make sense, but there should be a reason why it hasn't been explored by the industry? (the only alternative exploration I've found is a cold jet design, which is also a subject to a "scam" tag).


texts: Why are aircraft coloured in yellow during construction, repair or overhaul?

texts:
Why are aircraft usually coated with "yellow", while either during construction or repair and overhaul?
What exactly is the purpose of it?


texts: What exactly is considered "instrument time" for an instrument rating?

texts: I have read in several sources that you are supposed to log instrument time when you cannot orientate the airplane by outside, visual cues alone. This seems clear enough. But I've also read that roughly 10% of flight time should be on instruments. Now, the instrument rating requires 40 hrs on instruments or in poor visibility conditions, so can we infer that pilots would receive their rating after approximately 40x400 = 16,000 hrs? Is this estimate approximately correct? Also, does all of this time require an instructor?


texts: What are the experience requirements and process for becoming an FAA Designated Pilot Examiner?

texts: When it comes time to hire a new Designated Pilot Examiner (DPE), what does the FAA look for? What triggers new DPE job openings? How do the application and onboarding processes work? Are there more written tests? Is there a “checkride checkride”?


texts: What documentation do Airbus/Boeing supply at initial delivery of an aircraft?

texts: What are the Aircraft Documents supplied by Boeing and/or Airbus at first delivery? Do they supply Form 8130 or Certificates of Compliance for every part? Or is the AIR/ARL all that is supplied?


texts: What are the least powerful airplanes that ever flew?

texts: What manned airplanes have achieved flight with the least powerful engines (no gliders!), and what was their top speed? Im sure I've heard of an airplane with an 8hp engine capable of exceeding 120 MPH airspeed


texts: Do glider pilots have to wear parachute in countries where mandatory even if flying with a foreign glider?

texts:
Today I saw this video on Vimeo that shows a pilot flying a new solar glider (N- registered aircraft) in Italy without wearing a parachute (I believe in US is not mandatory).

Actually here in Italy it is mandatory to wear parachutes in gliders (at least I- registered). In our club we carry them also on our D- gliders but I don't know if it is also mandatory.

What is the scope of local regulations for foreign aircrafts? Do they have to comply also with this issue or is it up to the user, since it is a factor that only affects him?

Please feel free to edit my question with better words if my text is incomprehensible.


texts: It so occurs to me that commercial airliners cruise at altitudes of over 30,000 feet. But why do they fly so high if there are many dangers such as cabin de-pressurization when they can simply fly lower?


texts: Can anyone explain what are the apron taxiway and aircraft holding taxiway with an illustration, please?

texts:
Note: There are 3 types of taxiway

1) Apron taxiway

2) Aircraft holding taxiway

3) Rapid exit taxiway


texts:
Yesterday, I saw a strangely-shaped aircraft in the sky.

Searching for "aircraft silhouette" on the web, I found this picture within seconds on a vector graphics site. It describes perfectly what I saw, so there is nothing else I can say about the aircraft.

But I did not find any information what aircraft it is.

The wings are not swept and those stubs at their front look like propeller engines. But it seems as if there are fans at the rear of the fuselage...

So, does anybody know what aircraft this is?

EDIT:

@DeltaLima: Not bad. I'm pretty sure that this picture really shows an A-10. The picture is part of a larger one, and the other aircrafts were military ones, too.

I saw the aircraft it in Geneva, near GVA airport. Now, I doubt that I saw an A-10 there, as the last A-10 left Germany a while ago, and afaik there are none in Switzerland or France. If I neglect the stubs (which I may have noticed on the picture only), it could also have been  one of those at the GVA airfield, which have a comparable shape.

EDIT 2:

Meanwhile, I'm quite sure that it was one of those labelled A, B, C on this picture from google maps (though, B and C are pretty much the same):

The airfoils as well as the elevator were definitively not (significantly) swept and there was no gap between the airfoils and the fans in the silhouette.

Maybe, it was one of those, maybe, it was a similar aircraft. May be, it really was an A-10.

So, this are three 'maybes'. Lets add another:

Maybe, we put this question on hold as there will be no definitive answer.

But thanks a lot for your contributions!


texts: Can I take friends flying with a private pilot glider license?

texts: In the US, will glider clubs let you take up friends in a two-seater if you have a private license? Or do you need a commercial license?


texts: Can a plane turn around like on this photo?

texts:
I've never seen a plane do such a maneuver, have you?

Is this photo just a hoax?


texts: How does the battery master switch activate the battery contactor in Cessna 152?

texts:
I have trouble understanding how the battery master switch activates the battery contactor in this schematic from the Cessna 152 manual. This is the model from 1979 or later with an Alternator Control Unit.

Image source: Flight Literacy

I believe that the battery contactor is a relay that connects the top and right contacts (as in the image), when the left contact is powered.

Initially, all switches are off, the alternator is not turning, and there is no oil pressure:

The left contact of the battery contactor is connected to ground via the battery master switch in off position.
The battery contactor is not powered. It disconnects the battery from the connection through the Ammeter to the primary bus.
The battery voltage is distributed only to the clock and the oil pressure switch.
The two diodes close to the battery contactor are in reverse bias and therefore not conducting.

When I change the battery master switch to the on position, I expect that the battery contactor is closing the contact, and connects the battery via the Ammeter to the primary bus.

That requires power on the left contact of the battery contactor.
The battery master switch connects this contact (via "Alternator field circuit" breaker and "Pull off ALT" breaker) to the primary bus.
The primary bus is not powered yet.
In the way I read this schematic, the battery contactor cannot be activated. Nothing happens.

What am I missing?


texts: Do aircraft engineers take into consideration engine placement to avoid ground strikes in a cross-wind landing?

texts:
On a multi-engine airplane with wing-mounted engines, do aircraft designers have a standard way of ensuring that the banked landings associated with cross-wind's do not cause a prop or engine-housing strike on the ground if the pilot were to over-bank?

Is there some rule such as, "the wing tip would need to be the first part to strike if the wheel is in contact with the ground", or similar standard of practice in design?


texts: What policies, technologies, equipment, etc is used to mitigate liquid spills in the cockpit especially during turbulence?

texts:
While reading this stack exchange question about waterproofing cockpits, I wondered what common industry practices as well as personal practices are in place to mitigate spills and damage.

Type of cups, serving times, cupholder design and placement, length and altitude of flights, weather considerations and sterile cockpits for example.

Additionally, are reportable spill events so uncommon as to not warrant mitigating procedures and design practices?


texts: Why is it that T-tails want to climb like on a PA-44? It seems like it always wants to climb

texts: I'm having a little difficulty understanding the aerodynamics of a t-tail and how it affects climb.


texts: What's the difference of Vs from Vs0 or Vs1?

texts:
Vs: Stall speed or minimum steady flight speed for which the aircraft
  is still controllable

  Vs0: Stall speed or minimum flight speed in landing configuration.

  Vs1: Stall speed or minimum steady flight speed for which the aircraft
  is still controllable in a specific configuration]1

How is Vs different from Vso or Vs1? Is it safe to assume Vs is a generic term involving both Vso and Vs1?


texts: How did SR-71 spy, flying at 80,000 ft and 3500 km/h?

texts:
The SR-71 Blackbird is a famous supersonic reconnaissance/spy aircraft, undoubtedly one of the most amazing flying machines ever. Now, with the capabilities it had:

  Maximum speed: Mach 3.3 (2,200+ mph, 3,540+ km/h, 1,910+ knots) at
  80,000 ft (24,000 m)

How was it used for spying? It must have been difficult to focus on any object on the ground, from such a great height and then many problems are encountered with high speed photography. How were these and many other problems overcome?


texts: Can I use the private pilot written exam for sport pilot?

texts: I'm planning to first get my sport pilot license and then continue on to private pilot, to save on written exam costs is it possible to just take the private pilot written exam for the sport pilot license or will I have to take both?


texts: What is the outer kink on the airbus 340-600?

texts:
I was checking some information about the a340-600 and got this statement: "thickness/ chord ratios 15.25 per cent at root, 11.27 per cent at inner kink, 9.86 per cent at outer kink and 10.60 per cent at tip"
I know where the inner kink is but what is the outer kink and where is it located?


texts: Is it just commercial operating aircraft flying paying passengers that require an air operators certificate (AOC) or do cargo operators require one also?


texts: What is the significance of hover performance in helicopters (HIGE, HOGE)?

texts:
I was looking at a helicopter performance chart and it listed two values in feet, identified as "Hover in ground effect (HIGE)" and "Hover outside of ground effect (HOGE)."

What do these numbers mean, and why are they significant?


texts: Is GPS considered to be a navigational facility for the purposes of Ops Spec C055?

texts:
For 14 CFR 119 certificate holders, Alternate Airport IFR Weather Minimums are prescribed by Operations Specification (Ops Spec) C055, specifically Table 1 of that specification.

Below is a generic example of Table 1:

The wording in this table is understandable in the context of a traditional, ground-based navigational facilities such as NDB, VOR, or ILS providing an approach. For a simple example, if an airport has an operational VOR navigational facility providing an approach, that satisfies the requirements of the first row with the result that the 400 ft ceiling and 1 sm visibility minimums might apply.

However, some §119 certificate holders are authorized to conduct GPS approaches and to use GPS approaches in determining alternate airport weather minimums. For these operators, the table needs further clarification as it does not provide a framework to derive alternate airport weather minimums based on the GPS approaches that are otherwise authorized to be used for that purpose.

No such clarification seems to be given anywhere else in C055 or elsewhere in the Ops Specs.

How do GPS approaches fit into table 1? Does the Global Positioning System (GPS) constitute a navigational "facility" for the purposes of Table 1? If so, does it constitute a single navigational facility, thereby satisfying the requirements of the first row, just as if a single VOR provided an instrument approach?

Is there guidance provided elsewhere on this?


texts: Is part 141 ground school really supposed to be 35hours?

texts: I'm in a part 141 program and in ground school. My instructor dismisses class very early almost every day, but in the logbook he keeps for us he writes a lot more time than we actually meet on any given topic.  Is that okay?


texts:
Why is the fan in a turbofan different than a propeller in a small airplane? Why do propellers typically have 2 or 3 blades, but the fan has a lot more? And why is the fan shrouded but the propeller open?

I read that a ducted fan is more efficient at very slow speeds (it generates more static thrust than an open prop), but at high speeds the drag becomes too great and you're better off with an open propeller. Which is why they use a ducted fan in hovercrafts, for instance. But if that's true, shouldn't the fan in a turbofan be open (unshrouded), considering the high speeds (higher than a propeller)?

Also, how does the fan get away with supersonic tip speeds and the prop don't? Would the fan be more efficient if tip speeds were lower?


texts:
When I read through IFR materials online, or when I hear pilots talking about approaches, they often talk about using fixes to get to/through the approach.

Two questions (closely related):

Firstly, just to make sure I completely understand, what are fixes in this particular context?
Secondly, how are they used when a pilot is using a particular approach?


texts: Are all the Airbus A380's 16 exits designed for everyday use?

texts:
Are all the Airbus A380's 16 exits designed or everyday use for embarking and disembarking the aircraft, or are some specifically designed for use as emergency exits, such that opening any of those designated as emergency exits would require specialists to put them back in place?

In other words do all have hinges for everyday use?


texts: Any FAA or other regulations prohibiting taxiing between parked aircraft?

texts:
So the other day I was getting checked out at a local FBO, after returning to the ramp, instructor told me to taxi between two parked (tied-down aircraft). It was a tight squeeze but I taxied at about 1 MPH and I looked at left wing while instructor kept an eye on right wing. I really didn't think anything of it. Note, access to the other side of the line was blocked off by some vehicles so we couldn't taxi in from the back, hence cutting between two parked aircraft. However, we could have shut down on the front and pushed the aircraft back into its parking spot.

However, about 5 minutes later, a car drove up to us as we were securing the aircraft. It was the owner of one of the aircraft that we taxied next to. He spoke to the instructor, I didn't hear exactly what he said, but it was something about not taxing so close to his aircraft. Personally, I have no problem, pushing the airplane back into its spot, but it got me thinking about what regulation if any is implicated here.

I looked, and didn't find anything. So my question is whether there are any FAA, airport or other regulations or rules that prevent a small aircraft from taxiing between two parked aircraft on the ramp? I don't think there is any legal authority prohibiting taxiing between aircraft, or how many feet you must keep from a parked aircraft.

This reminds me of the aviation joke:

Aircraft Squawk - Left main almost needs to be replaced.

A&P Response - Almost replaced left main.

In this case:

Aircraft owner - You almost hit my airplane.

Me - You're welcome.


texts: Sell 1/4 share or buy 3/4 share and leaseback?

texts:
I currently own a 1/4 share of an Archer, but due to relocating I have put it up for sale and was planning to find another partnership once its sold. It's been on the market for about 3 months and have not had many people contact me with interest (no one serious). The other option I am debating is to buy up the other 3 shares and make the plane available for leaseback down in my new area.

Anyone have any feedback if leaseback is a good option? If I can get 80hrs/month (which is what the FBO owner says he's getting on each of his 172s), then I'd earn enough to cover the loan for buying the 3/4 shares, but I'm very concerned of hidden pitfalls. I've seen the condition of most rental planes & I'd be appalled if my Archer ever looked like those. Does anyone have any advice/suggestions?


texts: Isn't lift inverted when flying upside down?

texts: How can an aircraft still continue to fly when it turns turtle or upside down in air? Is'nt it opposite of 'lift' principle?


texts: How can an all flying rudder be almost 100% more efficient than a vertical stabilator and rudder?

texts:
How can an all flying rudder be almost 100% more efficient than a vertical tail and rudder?

According to the Zenith school of aircraft design, a rule of thumb for the size of an all flying rudder is 7% of wing area. For a classic vertical tail and rudder, the rule is 12%.  That's an increase in area of almost 100%!!

A classic rudder foil, something like a NACA0012, has a max cL of roughly 1.5.

A vertical stabilator and rudder is like a wing and an unslotted flap, which adds cL of about 0.7. That's a total cL of about 2.2, which works out to an increase in efficiency of 50%.

So... why is an all flying rudder 100% more efficient, if a vertical stab and rudder produce 50% more lift?


texts: What will be the immediate action by the pilot and ATC if any plane blocks the runway while landing?

texts:
Suppose, if the Airport has only one runway and one plane is trying to take off at the end of the runway and other plane trying to land from the other end of the runway.

Due to any reason if the pilot decides to abort the take off.

In that situation that plane is blocking the runway and it is in the way where the other plane is trying to land at the same time.

What action will be taken by the pilot who is landing the plane and what action will be taken by ATC?

Is there any chance of collision?


texts: Does the TIS-B "hockey-puck" contain VFR mode-C targets with unconfirmed altitude?

texts:
When receiving TIS-B traffic via ADS-B In, I'm curious what mode-C targets are included.

Is it only mode-C traffic with confirmed altitude in contact with ATC services (presumably with a transponder code)?

Or does it include traffic with unconfirmed altitude that's probably squawking 1200? Does it leave off altitude in that case? How would it know if traffic is within +/- 3,500' of your aicraft to give you your "hockey-puck" of traffic?


texts: How does Bernoulli's principle contribute in lifting airplane?

texts:
I have searched if any explanation that bind Bernoulli's principle in lifting airplane. There is one here which receive many appreciations, but still did not answer the question. So far, it was taught, explained, or mentioned in any aerodynamic or airplane principle, but never bound the Bernoulli's formula to the lift formula. As we know, there are pressure conservation as below:
$$\mathrm{P}_{1}+\frac{1}{2} \rho \mathrm{V}_{1}^{2}+\rho \mathrm{gh}_{1}=\mathrm{P}_{2}+\frac{1}{2} \rho \mathrm{V}_{2}^{2}+\rho \mathrm{gh}_{2}$$

Due to height is considered are same below and above the wing (the different are very small), then the third part of the equation will cancel one each other. Then left only part one and part two of each side of the equation. As the velocity above (considered as V1) is said will be different below the wing which wind is faster in above, then pressure above the wing will be lower, which will lift the wing. Thats is commonly taught in every explanation. Then, the

$$V_{2}=\sqrt{\frac{2\left(P_{1}-P_{2}\right)-\rho V_{1}^{2}}{\rho}}$$
Meanwhile, lifting formula is expressed as below:
$$L=\frac{1}{2} \rho v^{2} S C_{L}$$
V here is the airplane velocity, which is the wind hit the airfoil. Thence, V=V2 of the Bernoulli's equation above. V1 that hit upper side of the airfoils/wing, which is said faster than below, is unknown.

So, where is the Bernoulli's principle contributes in this case? How actually we calculate the lift force of an airplane?


texts: Are winds that are not from the prevailing wind direction more often gusty, and why?

texts:
It seems to me that, looking at the ground weather forecasts (as opposed to, say, low level forecasts), it's far more common for the wind to be predicted to be significantly gusty when it is blowing across the runway direction of my local airport, than along with it.

Now, obviously, the wind doesn't particularly care about the direction of the slab of asphalt on the ground, but the slab of asphalt is normally aligned with the prevailing wind in the area.

Is a wind that blows at a significant angle to the prevailing wind direction more likely to be gusty, than a wind blowing in the prevailing wind direction in the area? If so, what's the mechanism behind that? Or is this just a case of me being more frustrated about gusty crosswind conditions, thereby noticing it more?

My area is relatively flat.

To clarify, since there seems to be some confusion about this; I'm referring to area ground-level weather forecasts intended for the general public (as those offer a longer-term outlook, typically with reduced resolution and accuracy up to ten days ahead), not METARs or TAFs (however presented) which are about weather conditions specifically at the airport now and in the next several hours.


texts: Say I have $x million to buy an F-14 Tomcat and am physically fit (I think) to be able to fly it. Is there a short pilot training course I can attend to get licensed to fly it?


texts: Why do Turkey and UAE limit the age of aircraft flying over their territory?

texts:
Why do the civil aviation authorities of Turkey (15 years civil, 25 years cargo) and United Arab Emirates (20 years) limit the age of aircraft flying over their territory? I think if an old plane receives good maintenance and doesn't have too many cycles, it's still a safe plane.

For reference, see this news article of a leased Kabo 747-200 that is being refused clearance by the UAE because it is older than 20 years.(German/English)


texts: Why does the temperature rise in the boundary layer after a shock wave?

texts:
Is it because the BL thickens after the shock so the drag increases, causing a increased friction? Here M=0.82 far from the airfoil, the picture represents the static temperature in Kelvins around the symetrical airfoil at angle of attack 0°.

This is the total temperature for a supposedly everywhere adiabatic flow.

This is not the static temperature but the Mach number, for $M_{\infty}=0.70$

Mach number for $M_{\infty}=0.80$

Mach number for $M_{\infty}=0.99$

Mach number for $M_{\infty}=1.20$

I understand that as velocity decreases, temperature rises, but I have another file that shows the evolution of static pressure and it does not increase as static temperature does, after the shock in the BL.

Thank you


texts: Anyone able to help identify what aerofoil this is?

texts: Firstly, apologies for the potato quality of the image below. I am attempting to determine the qualities of a VTOL and cannot find any data online. If anyone knows what aerofoil this could be that would help a bunch! (the green line is the upper edge and the yellow line is the lower edge)


texts: What's the difference between Holding Point and Hold Short?

texts: I heard some ATCos requesting pilots to report, on holding point, and also hold short. Is there any difference on them?


texts: How can a tug be referred to as company?

texts:
I was listening to some [REAL ATC] MD-80 DELTA CRASH at LaGuardia Airport and noticed something just after 8:41. My question isn't about the accident, but actually about a request to the LaGuardia Tower from Tug1 (or Truck1, it's not clear, although the CC calls it Tug1 it sounds like Truck1) where the tug asks "Tug1 at company, we can cross Papa?"

I understand that the term company is used during ATC communications to tell one plane of a company (such as American Airlines) that they are talking about another airplane from the same company.

But how can a Tug/Truck be referring to a place as company?


texts: Can someone identify this unusual plane at SeaTac airport?

texts: I saw this plane at the SeaTac Airport and thought it was very unusual. The wings look too small to even be functional to me. What kind of plane is this and what is it used for?


texts: Where's the A318 on the runway that caused a 747 to go around?

texts: I screenshot 1:00 of a 480p YouTube video. The autopilot proclaims Minimums at 1:01, and the pilot flying decides to go around at 1:02 because an A318 was still on the runway, but I can't spot it, or any airplane, on the runway in the video! Can anyone? Or does anyone possess this video at a higher resolution?


texts: What are the criteria that govern the choice between titanium, composites, and more common materials, like aluminum?

texts:
In the newest large commercial jets, composite materials seem to be all the rage. The first thing I wanted to know is why composites were chosen instead of titanium? If I'm not mistaken, titanium has even more specific tensile strength.

Let's also be clear about what exactly composites are. "Composite" just means a mix of two or more materials, and in aerospace, it is predominantly autoclave-cured carbon-epoxy.

Ultimately, it would be good to understand the criteria that govern any choice among titanium, composites, and aluminum. Specifically, which areas of the plane are candidates for an advanced material? and why? What factors dictate the decision?


texts: Is a wingtip vortex strongest at the critical angle of attack?

texts:
Generally, wingtip vortices increase in strength as the angle of attack increases.  Is the critical angle of attack/Cl Max the peak strength, or do the vortices generally continue to increase in intensity once the plane is in a stalled condition? For the purpose of this question, assume the stall is not an accelerated stall and is entered from straight-and-level flight in smooth air.
If taken to an extreme, such as a 90 degree angle of attack, there would no longer be wingtip vortices, just turbulent flow and drag.
If it doesn't peak at the critical AOA, where does it peak?


texts: Why are RVR values reported in good visibility?

texts:
I just pulled the METAR for KLAX. Why are they reporting an RVR value for runway 25L if visibility is 9 statute miles?

KLAX 281553Z 00000KT 9SM R25L/2400VP6000FT FEW012 FEW045 18/08 A3000 RMK AO2 SLP157 FU FEW012 FU FEW045 T01780083 $


texts:
I have a few brushless motors and I am trying to get the best thrust out of each motor. I am busy doing some research but can't get a clear answer. What would be the best fan duct design to achieve maximum thrust?

Project: mini hover bike prototype with 2 or 3 motors. Duct size doesn't matter at this point.


texts: How do different RPM–MAP settings affect range?

texts:
For a cruise in constant-speed prop aircraft, you can choose different combinations of the manifold pressure and prop rpm to generate the same amount of power. For example, in order to generate 117 BHP (65% Rated Power) at sea level in the chart above, you can select either the combination of 24.5 for MAP and 2100 for rpm or that of 22.9 for MAP and 2400 for rpm. Here, what's the difference (if any) in selecting different combinations of rmp and MAP to generate the same power? Any benefits using the combination of low rpm and high MAP or vice versa?

This other post answers my original question, yet I have a follow-up question:

How does the combination of low rpm and high MAP extend the flight range?

To my knowledge, whatever combinations are chosen, as long as the combinations generate the same power, the same amount of fuel is consumed. The above chart supports that: The same 10.3 Gal/Hr is flowed into the engine regardless of the combinations in the box.

For your information, I asked the same question to my instructor, and he told me there's really no difference when it comes to power and fuel efficiency. But I was not persuaded at first, because I thought it was the MAP that controlled power output (BHP), and therefore, the less the MAP, the less fuel required. And a more efficient use of props could supplement this loss of power, resulting in the same thrust power. But the above chart just contradicts my reasoning. According to the chart, it's not the MAP alone but the combination of MAP and rpm that determines the BHP. But if it's the case, I don't understand how the range of flight could be extended by decreasing MAP and increasing rpm.


texts:
Here you can see two of them on the B747. What are they and what's their function?

Source: FAA's Pilot's Handbook of Aeronautical knowledge


texts: Is there a rule-of-thumb for estimating distance to an aeroplane?

texts:
It's generally hard for humans to estimate how far away an aircraft really is.
Question: Is there a standard rule for estimating the distance to an aircraft?
For example:

The entry/exit hatches are 2.4 metres high and your thumbnail at arms length translates to a 2.4 metre high door at 400 metres

Adults with normal 20/20 eyesight can make out an airliner's passenger windows in normal sunlight, so the plane is under 500 metres away, and over 500 metres if you can't make out individual windows.

Aircraft's registration code must be XX cm high and is therefore readable at up to 1000 metres.

Of course lighting and elevation differences, paint designs and model of plane, and even heading differences would mess it up a bit, but this is a rule of thumb in lieu of any other information.

For example, the popular fallout character is not giving a thumbs-up.  Instead he's comparing the size of a distant mushroom cloud to his thumb to see if he's outside the nuclear fallout zone.

Inspired by How close can planes fly to each other over the ocean?


texts: What plane has the widest range in speed in which it can operate?

texts: What propellor plane, other than planes with vertical takeoff capability, has the largest gap in speed between its slowest stall speed and its maximum airspeed? I am looking for a plane with a short take-off but also can go fast if needed or slow and fuel-efficient.


texts: How can a CFI renew their certificate with the FAA during the government shutdown?

texts: My CFI certificate expires at the end of the month. I have completed the required Flight Instructor Renewal Course ("FIRC"), but when I called my local FSDO to make an appointment to submit my renewal application for a new CFI certificate I discovered that the FAA is shut down. If the shutdown continues through my CFI expiration date, can I renew my certificate with the FAA after the expiration date?


texts: What can I do if I cancel IFR when I shouldn't have?

texts:
Standard procedure for T-38 training is to cancel IFR in the MOA and fly back to the base VFR.

A couple days ago I canceled in the MOA out of habit and instantly realized that I was above a broken layer between my and the base.

Luckily the other side of the MOA was clear, and I used the extra distance for a more shallow descent than I'd have otherwise done.

But it got me thinking, could I have asked ATC to get me back on my previous clearance?  Being a military training flight, and military controllers I'm sure they would have been super chill and helped me out regardless.  But in the civilian world what would be the best way to handle this situation (other than "don't cancel IFR")?


texts:
As is documented here among other places, a couple of the interceptors sent after United Flight 93 on September 11, 2001 were scrambled so hastily they did not have time for the ordies to visit and arm them up.  While not having live missiles on you at all times makes sense for a variety of reasons -- I can't understand why a fighter jet would be flying around with 0 rounds of ammo for their gun, considering how much of a W&B impact the ammo load has.

Furthermore, even if the media coverage was referring to them being loaded with training slugs instead of live ammunition -- you can seriously damage an airplane with 20mm slugs, as one Grumman test pilot (among other folks, it seems) found out the very hard way!  Sure, you'd have to use quite a bit of cannon fire to do it, but it'd still be preferable to a last-ditch ramming attack, no?

So, how could a fighter be scrambled into a situation where their only option was to ram their target?


texts: How could a Focke-Wulf 190 pilot see anything at all from his cockpit?

texts:
As one can see from the images below, the seat seems to be placed so low on the cabin, I cannot figure out how the pilot could see anything.

Can anyone explain how a Focke-Wulf 190 pilot would be able to see out of the cockpit?

Source

Source


texts: Why would a pilot use ailerons for countering asymmetric thrust in mid-flight?

texts:
A inexperienced 747-400 pilot used ailerons for counteracting asymmetric thrust in 1998 aboard United Airlines Flight 863 (YouTube recreation).

Why would an airline pilot do such a mistake? Why would a pilot disregard the counter yaw training he got from the Baron 58 to the 737?

Is he the only pilot that did this or are there other pilots that do the same mistake too?

Perhaps he simply forgot rudder.


texts: Does the PA-44's squat switch disable the stall warning?

texts:
I've read the AFM and looked online about the gear system for the PA-44 Seminole and there is apparently a squat switch on the right main gear that disables the stall warning whilst on the ground. However during my pre-flight I have tested the stall warning with the battery master and avionics master on and it worked.

Is the stall warning squat switch not a feature on the newer PA-44s any more? The one I train in is about a year old now.


texts: Could the vertical stabilizer be removed on the NASA X-57?

texts:
I was reading this article about how NASA will develop this new X-57 X-plane which has many tiny electric motors mounted on the wing.

Now, I wonder: How come this aircraft still has a vertical stabilizer? I thought that one of the points of having many tiny electric motors was that you needn’t worry about an engine failure (one engine fails, you shut down the one on the opposite side; you still have 12 working, no big deal). You probably don’t have to worry about lateral stability either, because those motors can probably easily stabilize sideslip oscillations (a bit like on a quadrotor, where you can maintain a stable hovering position thanks to accelerometers and fast control feedback).

Am I missing something?? If so, isn't there a way to downsize the stabilizer a little bit? How would you go about calculating that?

EDIT: I realize the problem of power failure, but couldn't it be just avoided by carrying lots of independant battery packs (instead of a central big one), so you can be sure that you statistically never lose control of all your engines?


texts: Would a headwind result in a faster propeller rpm?

texts:
A few weeks ago I did an experiment with a model aircraft that has a motorized propeller. I turned on the propeller and it turned at a constant speed. Then I turned on a desk fan and put it in front of the propeller (see the picture below) and I saw an increase in propeller rpm and an increase in noise.

Does this also happen to a propeller when a headwind hits it?


texts: Are radio channels used by airliners half-duplex channels?

texts:
Can a pilot transmit and receive information at the same time? Or can he either transmit or receive but not at the same time?

I thought communication channels were half-duplex because this reduced the chance of the information by trasmitter (say the ATC) being overlapped by information from the receiver (the pilot) in case he possibily accidentaly pressed the PTT button. Is that a right assumption or not?


texts: Do all flights with the exception of military show up on FlightAware?

texts: I ask because I just saw a B737 land at KCSG. I haven't seen one land here in a while and in my curiosity wanted to know who it was. I got on FlightAware and I don't see any B737 arrivals within the last week. Has anyone got a clue as to why this is? The B737 was all white and I didn't see any obvious ID marks on it.


texts: Why doesn't GE replace all 4 engines for on their flying test bed instead of just 1?

texts:
GE (General Electric) flies Boeing 747s equipped with new engines that are being tested. Why can't they equip the test airplane with all 4 of the new engines? Wouldn't the thrust be imbalanced by replacing only 1 engine? As you can see, it may have 1 big engine and 3 smaller ones:

Other times, smaller engines are being tested. Would the smaller engine provide enough thrust for a large, heavy airplane like the 747?


texts: How should a newly minted instructor sign an endorsement?

texts:
A newly issued flight instructor certificate often has the word "PENDING" in the certificate number field.

In 8900.1 Flight Standards, Volume 5, Section 1, Section 5, Paragraph 5-112(c)(2)(a) Instructions are given that the temporary airman certificate for a flight instructor should be filled in with the corresponding airman certificate number with "CFI" appended.

In the event that does not happen, and the certificate number shows "PENDING", how should the instructor format their signature to make an endorsement prior to the issuance of a permanent replacement?


texts: What are the structures on the sides of and aft of the canopy on Israeli F-16s?

texts:
I know Israel has highly modified F-16s, but just what are the structures on the sides and top, aft of the canopy? See this image of an Israeli F-16 compared to a normal one:

Vs


texts: Which are the advantages of low pressure levels during flight? (i.e during cruise flight in a commercial aircraft)

texts: I understand that due to health and security reasons, there must be a minimum in the pressure inside the cabin (75 kPa). But in class I have been told that maintaining low pressure levels has advantages, which ones?


texts: How does one test a stall warning during pre-flight?

texts:
As a pilot, if your preflight inspection includes testing the stall warning system, how is that done?

A recent question about ADs brought up AD 68-17-04, which requires pilots to test the stall warning system for proper function as part of the preflight inspection.

How would this test be done? How would other types of stall warning systems be tested?