texts: How is a light plane's nose wheel straightened during retract?

texts: Assuming a light aircraft has direct cable linkage to the rudders, during taking off in a very strong crosswind with the pilot correcting with hard rudder, what keeps the nose wheel from remaining off center and jamming as it retracts?


texts: What plane is this instrument panel from?

texts: I came across this instrument panel being sold as a potential craft project. I instantly knew what I wanted to do with it. I am going to give it, filled with old pics to my father-in-law who used to be a pilot. It would, however, make for a better story if I can find out the type of aircraft this instrument panel came from. Can anyone identify it for me, please? Maybe even just a hint at where to look?


texts: What instrument can be used to check that constant attitude is maintained?

texts:
In Sporty’s training, the following question came:

One way to determine that you are maintaining a constant attitude
is to occasionally check:
A. The vertical speed indicator
B. The tachometer
C. The altimeter

My answer is A, but sporty’s app says I’m wrong and correct answer is C.
Could someone please confirm the right answer and explain why?


texts: Was the Jabara Dreamlifter incident the biggest difference between required and actual takeoff length?

texts: DCA14IA016: on November 20, 2013, a Boeing B747-400LCF (Dreamlifter) landed at Jabara airport. They took off the next day which was considered a major feat given the discrepancy between the size of the plane and the runway length. Was this the biggest such discrepancy?


texts:
Some  Boeing 737s have this exit indicator in the cabin, attached in a seemingly odd position, next to the overhead bins, instead of in the middle.

Why is it placed here?


texts: What is the reference length in calculating the friction coefficient?

texts:
I am building a ground effect vehicle and I want to calculate the parasite drag of it.
So I found this site to calculate the friction
But I don't know what the "reference length" is. Is it the chord, the wingspan or the mean aerodynamic chord? And in case that the reference length is the chord, is their a different way to measure it for an inverted delta wing?


texts: Why doesn't a full yoke deflection also change the stabilizer trim on the Boeing 737 MAX?

texts:
Various websites have stated that during the 737-MAX crash in Indonesia, the pilots could not pitch up because of a faulty AOA sensor pitching the plane down.

The stabilizer has a rear fulcrum and front jack screw. The elevator, positioned by yoke, is hinged to the stabilizer.
If the yoke is pulled back, the elevator moves up. Then the stabilizer must move down, either automatically or manually, to remove the yoke loading.
However, if the yoke is fully pulled back, why doesn’t this force the stabilizer down directly so that the pilot always has total control of pitch without checking the flight manual or pushing switches?


texts: I am a new private pilot. My parents want me to take them flying. I do work and have a bit of my own money, but compared to the cost of flying it is not much. My parents paid for most of my training. I am still in high school, so I live with them and they pay for most of my existence. Obviously I cannot be compensated for flying them, but I wonder if there is any legal way for this to happen. The same question can be extended to when I take friends flying. Would it be as simple as me using a card that draws from one of their accounts? Me paying but with their money. Any knowledge/advice is appreciated, I would rather not break FAA regulation on my first flight as a private pilot.


texts: Can a single engine on an A320 provide wing anti ice?

texts: Can a single engine on an A320 provide wing anti ice for both wings in the air ?


texts: An unmanned aerial vehicle (UAV) was shot down by Turkish aircraft, which made me wonder, whether the Turkish pilots faced any defending moves from the UAV, or once they found it, taking down was a piece of cake?


texts: Can autopilot track ILS without any internal heading reference?

texts:
I am asking about the internal design of the autopilot of a CRJ200 (no autoland).
I was flying an ILS approach when the AHRS heading started to drift rapidly by 30 degrees. The autopilot somehow was not able track the ILS and started to to fly an "S" turns. After this incident I had a discussion with TRE. He insisted that the ILS has nothing to do with heading. I think that it's impossible or very difficult to design an ILS tracking autopilot without internal heading reference.
How can an autopilot know that a plane is turning and how much without some internal heading reference? Can anybody provide any info on this topic and how the autopilot is implemented?


texts: What modifications are required for automotive fuel STC?

texts: What actual engine modifications are required to allow certificated piston engined general aviation aircraft to run automotive fuel under an FAA Supplemental Type Certificate (STC)?


texts: What is the efficiency of the turbine of a modern jet engine?

texts: What is the turbine efficiency of a modern jet engine? Just the turbine efficiency only. What percentage of fuel energy the turbine converts into mechanical energy.


texts: Is there an ideal air temperature for best performance in a light aircraft?

texts:
I know cold air is better for engine performance in general, colder air is also denser making lift components stronger(from what I understand).

I was just wondering if there is a temperature or a range of temperatures that offer the best performance overall?

Is there a temp that covers all areas such as takeoff/climb performance, cruise etc. or is it something where each performance area has its own "sweet" spot?

Let's use common flight trainers like the C172 as the example.


texts: Do airlines use a software to calculate center of gravity?

texts: How do airlines calculate center of gravity? I have read in several airlines websites that they optimize the center of gravity position, to improve aerodynamic performance and reduce fuel consumption. Do they use some kind of software to do this?


texts: How does the flyboard air get sufficient lift/thrust with such small form factor?

texts:
How does the flyboard air get so much thrust when it can't have more than an 6" disc area (if that) on each of its four lift engines?

Isn't the thrust of a rotor = CT * p * Area * tipSpeed^2?
(CT - coefficient of thrust, p = air density, tip speed = linear speed at tip of rotor).

Shouldn't this limit the thrust such small rotors can create without the tips exceeding mach (and causing all the associated problems with that)?

How much thrust could each of these really be generating? I'm assuming their ducted fans, but still shouldn't be enough, should it?

It's also clearly not ground effect as it reaches heights well above where that would be relevant (claimed height of 1000 feet, though the videos tend to show only up to around 50-75ft).

Source:
http://www.guinnessworldrecords.com/news/2016/4/confirmed-franky-zapata-sets-new-farthest-hoverboard-flight-record-in-france-427011


texts: How large are the pilot rest areas of the A380 and B747-8?

texts: How large are the pilot rest areas of an Airbus A380 and Boeing 747-8? What entertainment systems are found in them?


texts:
A recent news item mentioned that "black boxes" are typically stored in the tail section of an aircraft to maximize their odds of surviving a catastrophic incident.

If they're stored in the rear of the aircraft, presumably flight data and cockpit voice data is transmitted via wires which run the length of the aircraft.

Aren't these susceptible to damage during an incident? There have been incidents of explosions and fires which damage flight control cables - aren't the FDR and CVR susceptible in the same way?


texts: Why are bird strikes on approach or landing not as common as on takeoff?

texts: I've heard about lots of bird strike incidents that occured during a takeoff roll or the early phase of takeoff climb but hardly heard of bird strikes on approach or landing. Are bird strikes much less common on approach or landing than on takeoff or initial takeoff climb? If they are, why is it?


texts: Why do some pilots misuse (troll) the GUARD frequency?

texts:
When flying I almost always monitor GUARD, VHF 121.5 on my second communications radio. It's almost a daily occurrence that I hear someone transmit the words "work work work" or a long, theatrical "GUUARRDDD!" as a response to someone calling for a ramp taxi clearance on the wrong frequency.

It is interesting that these particular responses are so prevalent.

Has anyone studied this misuse of the guard frequency to determine if there might be a cultural source?

At least in my experience with the last decade of aviation, there hasn't until fairly recently but such common use of the guard frequency for communications which aren't pertinent to its purpose. Has the FAA taken any actions on pilots for misusing the guard frequency in the way mentioned in the first paragraph?


texts: How do I achieve a lower stall speed, and capture potential CLmax without enough elevator control authority?

texts:
I am running some analysis on a uav, and the results I have found show that with proposed modifications I am unable to trim at my previous $c_{L\:max}$ and thus originally designed stall speed (experimentally determined).  Ideally I want to decrease my stall speed as much as possible (for obvious reasons).  Theoretically with a new flap design I can achieve higher lift coefficients however the elevator does not have enough control authority to obtain steady level flight at these conditions.  Varying my cg location somewhat will allow me to capture my original $c_{L\:max}$ but it doesn't have enough range to reach the new potential $c_{L\:max}$.

What am I over looking that can help me achieve a lower stall speed?  How does the propeller/power, glide slope etc effect this problem?


texts:
Can anyone identify this jet?
I took the picture in 2011 at McCarran.


texts: What are these fins on the Beechcraft 1900?

texts:
Here's an image for you to see these little fins. What are they used for?

Source (image has been modified to indicate location of fins).


texts: What is the difference between SSR and ADS-B?

texts: Can someone explain what is the difference between SSR transponder and ADS-B. From what I know ADS-B is a capability that can be incorporated into a transponder, but I do not understand the difference between them, I mean that from my point of view its' function and working principle is almost identical (both broadcast information that can be collected by ATC (and ADS-B info can be collected by other aircraft) and its like one device doing two identical things. Please help me out.


texts: Rotation direction for adjacent propellers, how do different arrangements compare?

texts:
(YouTube)

The Airbus A400M uses counter-rotating pairs where the blades meet moving downward (if there is a better description, tell me please).

I played the video frame-by-frame to make sure it wasn't a tricky stroboscopic effect; use <> if you're using the HTML5 player.

How do the different arrangements compare aerodynamically? I think for the three arrangements below, the propeller blade interference will have different characteristics.


texts: What is the RNP requirement within the KZAK FIR?

texts:
What's the RNP requirement with KZAK FIR?
I thought it is RNP 10 operating in NOPAC AND PACOTS, but I am not sure.


texts: Do any gliders come with a ground proximity warning system (GPWS)?  I realise that, for a glider, a GPWS probably wouldn't be able to help quite as much as in a powered aircraft, since a glider, by definition, doesn't have any engines which it can apply TOGA power on (unless, of course, it's a motorglider), but it could still warn the pilot if they were descending too rapidly for their altitude or were about to land with the glider in an unsafe configuration, thus allowing the pilot to take the necessary actions for avoiding a crash (for instance, by pulling back on the yoke, jettisoning ballast, lowering the flaps and landing gear if the glider in question is so equipped, etc.).


texts: Is repeatedly pitching an aircraft up and down to help it lose its energy quicker a viable landing technique?

texts: Say a pilot "bobs" his aircraft's nose up and down. The rapidly changing AOA should generate more drag than if the aircraft were to fly straight at a constant pitch where the AOA shouldn't be significantly large, right? Is the extra drag significant enough for this technique to be used in a practical landing approach?


texts: What's that in front of the overhead panel?

texts: There is that thing I have see a few pilot using it. it can be pulled outside and then inside. what's that and what's the use of it?


texts: Why do some fighter jets have double wheels in the front gear whereas some other aircraft have a single wheel?

texts: The Typhoon has a single wheel in the front gear, but the Rafale or Gripen have double wheels in the front gear. What is the reason for this difference?


texts: Is it possible to get the QNH value in Austria using a web service?

texts:
I got a altimeter sensor which can be connected to a computer and can be adjusted by the QNH!

I need the QNH for Austria, I figured out that the current QNH of the airports are streamed via radio.

Are QNH provided as text format or even better web service, so I can fetch mine automatically for transparent altimeter setting?


texts:
I've gone through the following questions on Stack Exchange and other few questions too:

Why is managing CG (centre of gravity) important?

How are the limits of the center of gravity chart established?

I still do have 2 questions in mind:

How do they adjust the fuel quantity/weight based on the passengers' weight on the plane? (was there any situation where few fat guys have been asked to move to front or back because I never saw any airliner weighing their passengers before boarding)
As the fuel starts burning, the pilot will fill/empty/exchange it from wing to wing or other storage location to balance CG, Will this cause imbalance (moving out of defined tolerances) in CG based on the passengers' weight?


texts: define the difference between a USAF Leg vs a USAF Sortie

texts: What is the definition of a Sortie versus a Leg according to the US Air Force?


texts: A320/321 FMA indications with Both Flight Director Channel Failed

texts:
I hope that someone can answer my question. My friend had “FD 1+2 Failure” in simulator during the low visibility approach. Flight Directors on PFD disappeared, but no FMA change and no approach capability downgrade. When a go-around was executed, lateral and vertical guidances of FMA went blank (SPD/ / ).
On the next approach, he captured G/S and LOC with both FDs failed, but no ROLLOUT indication after touch down.
Anybody can explain the logic behind this?
Thank you.


texts: What is this fighter aircraft parked in the South African desert?

texts: What aircraft is parked at 27°50'24.0"S 21°35'54.4"E in the South African desert?


texts: What are the data elements shown on the GE235 flight data recorder (FDR) plot?

texts:
The Aviation Herald already has an image of the Flight Data Recorder information from the crash of TransAsia GE235:

(click to enlarge)

I have determined that the green lines are for engine 1 and the blue lines are for engine 2, but beyond that, I'm a bit lost. Can someone translate the abbreviations and describe what information each graph is indicating for non-pilots.


texts: Why is "NoPT" indicated on this KYKM approach?

texts:
For LOC-DME approach (back course) at Yakima Air Terminal (KYKM), NoPT was mentioned at different locations on this 2008 plate:

Click for full plate. Source.

However there is no procedure turn at all. Why is NoPT mentioned?


texts: What type of BITE is involved after installing a new display on an aircraft?

texts:
There are 3 types of BITE (Built-In Test Equipment):

power up
interruptive
continues

which one of these is being used after installation of a new display on an aircraft?


texts: Can I log any PIC time if my medical certificate is out of date and I haven't flown in 20 years?

texts: I haven't flown in 20 years. My medical certificate is not up to date. Can I log a fam flight with a local instructor?


texts: Are aircraft still guided by ground marshals?

texts:
Are ground marshalling operations still conducted by personnel on the ground? Are there any airports that still do this procedure?

From Wikipedia.


texts: Why was the 737 main rudder servo valve’s vulnerability to causing uncommanded reversals never discovered in testing?

texts:
As was discovered during the NTSB investigation into the crash of USAir Flight 427, the design of the servo valve inside the main rudder power control unit (PCU) formerly used on 737 Original- and Classic-series aircraft was vulnerable to causing uncommanded rudder reversals if the valve’s secondary slide jammed to the valve housing at a position sufficiently far from neutral (the precise threshold varies depending on the valve and whether the secondary slide jammed in the extend or the retract position).

The valve was designed so that a secondary-slide-to-valve-housing jam would not cause a reversal:

(Image source, page 83 of report/page 107 of PDF file)

However, if the pilot applied a sufficiently fast, abrupt rudder input, this would cause the valve’s primary slide to overtravel past the secondary slide, porting hydraulic fluid in the wrong direction and causing the rudder to move in the direction opposite from that commanded, all the way to its blowdown limit:

(Image source, page 84/108)

Given the potential catastrophic results of an unexpected rudder reversal (especially at lower airspeeds), why wasn’t the valve tested to make sure that it would, in fact, react to a jam in the manner in which it was designed to do so, and, if so, why wasn’t this failure mode discovered in testing?


texts: Can i use diverter less intake in design based on MiG-29?

texts:
Which type of boundary layer diverter has been used in MiG-29?
Also, can I use diverterless inlet in my design that is based on the reference aircraft MiG-29?


texts: Is there a special way to calculate the (parasitic) drag produced by the propeller?

texts:
Is there a special way to calculate the drag produced by the propeller? Can I compute it with the standard formula for parasitic drag, with the circular area of the propeller as the wetted area?

To be more specific. I have a graph of the thrust vs. the incoming speed of my propeller


texts: Where to find information about number of seats knowing the aircraft Registration ID?

texts: Let's say I have an aircraft registration id (not sure about exact name) like LN-DYO. Where can I find an information about configuration of the aircraft - i.e. number of first class seats, business class and economy class seats? I would like to have some automated solution (API? parsing of web-pages?) to get this data for a number of aircraft.


texts: How does radius of a propeller affect its performance?

texts: Let's say we have a conventional two-bladed fixed-pitch propeller. All things being equal, would the same propeller but with half the size -- 50% radius, have 50% of the performance of the first propeller?


texts: Why do ATC instructions to change level include the words "climb" or "descend"?

texts:
ATC instructions to change level include the words "climb" or "descend" depending on the direction of the vertical maneuver. For example, "Descend to 2500 feet" or "Climb to FL70".

For comparison, instructions to turn to a specific heading often, but not always, include the words "right" or "left". We can say "Turn right heading 120" or "Turn left heading 360", but in some situations we may simply say "Fly heading 180". When using "Fly heading", it is implied that the turn should made in the direction that requires the smallest change of direction. A pilot heading east instructed to "Fly heading 360" will always perform a left turn, even if the word "left" was not included in the original instruction.

Similarly, for speed control, we have phrases such as "Reduce speed to 220 knots" and "Increase speed to 280 knots", while we can also simply use "Maintain 240 knots", in which case the pilot will then speed up or slow down as appropriate.

Radio phraseology is designed to be as short as possible, and radio calls should include no excessive words. This makes me wonder, why do we always include "Climb" or "Descend" in level instructions? If a flight is at FL320 and we need to instruct it to get up to FL340, it is self-evident that the pilot must climb, not descend. Using this logic, a phrase such as "Maintain FL340" or even just "FL340" (Example: "[callsign], FL340") should suffice.

I can think of reasons who we do use climb and descend. It most likely improves situational awareness for both controllers and pilots (including other flights on the frequency). It could also enable pilots to identify situations where they mishear a level instruction (Example: for a flight on FL320, instructed to "Maintain FL240", the crew might mishear this and think they are cleared to FL340. If the phrase "Descend to FL240" is used, this is less likely to happen). Finally, "Climb to" and "Descend to" is not much longer than "Maintain".

However, this leaves the question of why we have such "neutral" phrases for heading and speed restrictions. Wouldn't enforcing the use of "Right", "Left", "Increase" and "Reduce" introduce the same benefits we get from using "Climb" and "Descend"?

Is there a historical reason the phraseology concerning level changes is designed the way it is - perhaps an incident or accident where another phraseology was used? Or is it a coincidence that level instructions are different compared to heading or speed restrictions?

I can come up with "qualified guesses" myself, so I am hoping someone with actual knowledge on the topic can provide a factual answer.


texts: How does a horizontal situation indicator (HSI) work?

texts: I am trying to understand the Horizontal Situation Indicator. To my understanding there is a slaving transmitter, usually in a wing (the left wing in the Piper Archer and Seminole), which sends information to a flux gate, which then sends information to the compass card in a slaved HSI. Is any of that correct? Are the slaving transmitter and the flux gate separate components?


texts: Are there any 'smart' ejection seats that eject automatically when an engine failure occurs or the aircraft gets into to a stall that can't be gotten out of, to save the pilot the decision of whether s/he should try and save the aircraft?


texts: Would a two-seat light fixed-wing aircraft with a landing speed of 20 knots and a top speed of 180 knots be technically possible?

texts:
Watching helicopters come in to land, on occasion, I have noticed that they approach with a forward speed of a few knots, never land straight down. If there is sufficient landing space, would it be possible in some cases to replace the helicopter with a small fixed wing aircraft with low stalling speed?

The Helio Courier is an aircraft which is capable of flying slowly:

With a minimum-control speed of around 28 mph, the Courier is perfectly suited for confined off-airport operations. The first one was certified in July 1954 and powered by the 260 hp Lycoming GO-435-C2B2. - Wikipedia

I want to design (on paper at least), a tricycle retractable aircraft which is capable of the 20-200 knot speed range. Why has no one developed such an aircraft, and can the helicopter be replaced in certain situations by such an aircraft? Will it be technically feasible but commercially infeasible?  (Edit: can I do this with increasing wing area and power only?)

EDIT: What I am looking for is an aircraft that can meet these helipad specifications, see page 25 in the document : https://www.faa.gov/airports/resources/advisory_circulars/index.cfm/go/document.current/documentNumber/150_5390-2  and the image titled "Figure 2–7. VFR Heliport Approach/Departure and Transitional Surfaces: General Aviation". 4000 ft approach and 500 ft obstacles outside that. I can fire up my favorite flight sim and try the approach. Stopping within the helipad could be a problem.


texts: Which is the airliner with the most passengers per lavatory?

texts:
When flying long distances in large airliners like the B777 or the A380, there always seem to be long queues in front of the lavatories, generating longer waiting times than in the past. Kinda looks as if there are fewer and fewer toilets per passenger on board.

Are modern aircraft designed with fewer lavatories per passenger on board? Which is the airliner (CFR 14 Part 25) still flying with the most passengers per toilet?


texts: What are the effects of different seasons on flight training?

texts:
What effect will the time of year a student starts their flight training have on the difficulty of their training?

What particular problems will each season cause a student pilot?
What advantages does each season have?
Are there any studies showing how the time of year effects the duration or success rate of training?

Different latitudes will have different, or at least more extreme, effects so please note if an effect is only valid for a specific geographic area.


texts: How does a higher temperature when programmed in the FMGC affect REC MAX FL?

texts:
While I was reading the FCTM I came across this line mentioned below.

  An increase in the Outside Air Temperature (OAT), that results in a decrease of the REC MAX FL.

I wanted to know if we enter a higher than normal temperature for a particular FL or we even forget to put the minus sign in front of the temperature value (our older A320s with Honeywell FMS accepts the temperature without the minus sign) how does this cause the FMGC to compute a lower REC MAX FL?


texts: How far back in time does FAA Institutional Authority for 61.160 (R-ATP) minimums go?

texts:
61.160 contains the requirements for an R-ATP certificate, and there is a list of FAA approved institutions that are eligible to graduate applicants to meet the R-ATP requirements.
There is a column with issue and revision dates:

The increased qualification requirements were enacted in August 2013, and therefore these schools' LOAs are all issued after that date.
If a pilot had graduated from one of these schools' programs prior to the issuance of the LOA, does it still grant them the eligibility for reduced minima?  Is the authority retroactive?  If so, by how much time?


texts: What should a pilot do if he does not know where he is and has no form of communication?

texts:
I know this is an almost impossible situation, but... Imagine that a pilot is kidnapped and placed inside a Cessna plane. At a certain point the kidnapper jumps out of the plane, destroying the radio and taking all the aeronautical charts with him.

My question is: what should the pilot do, since he does not know where he is (he does not even know which country), there are no signs of civilization where he's flying, and he has no aeronautical charts?


texts: Why do many ram air inlets have this shape?

texts:
I often see this particular shape for ram air inlets.

Here on an older 737

It's stretched on the newer 737's but still the same basic shape

A also see it a lot on cars.

1979 Camaro Z28

Lamborghini Countach

Is there some aerodynamic advantage to this shape, and if so why?


texts: What vintage aircraft was registered as NC7210?

texts: Can anyone help identify this vintage aircraft, origin, and possible flight history. Airplane has this number of its wing, NC 7210.


texts: What are "approved weather reporting services" and do they apply to part 91?

texts:
When I look up Torrance Zamperini (KTOA) alternate minimums, it states, "NA when control tower closed, except for operators with approved weather reporting services."

My main questions are:

Can Part 91 pilots file this airport as an alternate when the control tower is closed?
Do the "operators" restrictions apply to Part 91 pilots?
What is an "approved weather reporting service"?

While we are on the topic, what exactly does the word "appropriate" refer to in the text below? FAR 91.169(c) seems to indicate that almost any source of weather information is acceptable (emphasis mine):

  IFR alternate airport weather minima. Unless otherwise authorized by the Administrator, no person may include an alternate airport in an
  IFR flight plan unless appropriate weather reports or weather
  forecasts, or a combination of them, indicated that, at the estimated
  time of arrival at the alternate airport, the ceiling and visibility
  at the airport will be at or above the following weather minima:


texts: How much g-force is experienced in a 45° turn?

texts:
A 60° turn in an airplane doubles the g-force; how much g-force is experienced in a 15°, 30° and 45° turn?

Is it 0.5, 1 and 1.5g respectively?


texts:
I'm idly curious to know what type of physical storage medium (e.g. is it a "mini-CD", USB key, a little hard drive, maybe a tape) is used for delivering avionics updates, for an as-recent-as-possible aircraft?

For big (e.g. commercial airliner) and/or military?

I guess you're not downloading updates from the internet?

Could you (optionally) also paint a vague public-domain picture of how the "chain of trust" works? Or is the delivery route (media passing hand to hand) not especially secure, and instead all the chain of trust is in built-in digital signatures?


texts: Where to download NATs (North Atlantic Tracks) information?

texts:
I am reading about NATs (North Atlantic Tracks) and I found out they are created and regulated by the following entities:

westbound flow: Shanwick Oceanic Control
eastbound flow: Gander Oceanic Control Centre

Since I cannot find their information but from other sources (non official!), my questions are:

What are their websites?
Where can I download the NATs information they generate?

Note: the information should be official and possible machine-readable.


texts: If propeller-driven planes with electric engine became the norm, would descent for landing with the engines turned off become a routine procedure?

texts: To elaborate on the question: I know that in modern fossil fuel-driven aircraft turning the engines off during descent and/or landing approach isn't feasible for safety reasons (which makes total sense to me) - but, given that electric engines are quite easy/quick to turn on & off  compared to toboprops and turbofans, is it  likely that lowering altitude with the engines turned off for a big portion of the descent (let's say, untill an arbitrary altitude would be reached, e.g. 500m or something along those lines) would become a norm in the airline industry?


texts: Is it true that blowing cannot be used for laminar flow control? Why?

texts:
Aerospace Engineering Desk Reference, page 505

  Tangential blowing can only be applied to the prevention of separation...The flow caused by blowing tends to be very vulnerable to laminarturbulent transition...

Is this true? Why? Is it because of the high speed of the blowing jet? Is it not possible to use a slow-speed (but faster than the local flow) jet to circumvent this?


texts: How many crew members load and offload luggage on an Airbus A380?

texts:
What are the standard ground needs of a modern double-decker airline.
How many crew members load and offload luggage on a modern double-decker airliner on any typical trip?


texts: Is there a modern single-seat turboprop?

texts: There seem to be a number of tandem seat turboprop trainers like the PC-9/Texan and the Super Tucano. Are there any single-seat turboprops? I am asking about modern production planes.


texts: On the A320, why is it not recommended to use the HP ground unit when the APU Bleed is on?

texts: Can someone explain what the HP ground unit is used for? And what damage happens to the bleed system if it is used?


texts: Is it bad practice to say my callsign first in a transmission to ATC?

texts:
Usually ATC is saying the callsign of the plane he speaks with first and then starts with the actual transmission. Pilots usually say their transmission first and end it with their callsign.

However, I somehow started to say my callsign first before every transmission. For example:

Intended:

  Me: Cleared for take-off runway 33, OE-CNK

How I do it:

  Me: OE-CNK, cleared for take-off runway 33

Is this bad practice? Will it annoy the air traffic controller because he has to keep in mind my callsign for the whole transmission? Or is this not very relevant?


texts:
I just came across this article on LinkedIn, and I have a few questions about it.
Some of BAe's claims are things such as:

Aircraft set to become more human as engineers develop smart skins which can detect injury
The revolutionary ‘smart skin’ concept will enable aircraft to continually monitor their health, reporting back on potential problems before they become significant. This would reduce the need for regular check-ups on the ground and parts could be replaced in a timely manner, increasing the efficiency of aircraft maintenance, the availability of the plane and improving safety.

In the past I have seen some claims of a similar nature (such as skin that adapts its shape to be more aerodynamic based on phase of flight).  What I am wondering is:

Is this really technically feasible?
Can such a skin really do what BAE claims?
Will this have any adverse effects on the aviation industry? (Usually people are so enamored with new technology and the good it can do, I am more curious if anyone has thought of the downside.)


texts: Should landing on a runway that has been closed by NOTAM be a violation of the FARs?

texts: At an airport without an operating control tower, should it be a violation of the Federal Aviation Regulations to land an airplane during VMC daylight conditions on a runway that has been NOTAMed closed?


texts: How do pilots identify the taxi path to the runway?

texts:
When the aircraft is readying to taxi, the ATC asks them to proceed to some runway number, say runway 09. In big airports, how do the pilots identify the correct path to their runway?

Does the ATC guide them? Or do they get a map of an airport chart?


texts: Is there statistical evidence of the benefits of CRM?

texts: Seeing there's apparently now a consideration towards allowing single pilot commercial aircraft, I figured a fairly good counterpoint would be the benefits gained from crew resource management (which I've often seen pointed to as something that might have prevented earlier accidents).  Has any empirical evidence been published showing a clear reduction in accidents linked to the development of CRM?


texts: Where can i find aircraft blueprints for study purpose?

texts:
I'm a 3D artist and i want to start my new project. I'm going to create an exact model of the Embraer 190 aircraft. I need this for my graduation project at the university (I chose such a project, there is much more than just modeling, but this is the first step). But at the zero step, I was faced with the fact that there are simply no free blueprints in the public domain. There are all sorts of approximate schemes of the aircraft, but they can hardly be called accurate. Even in the manual from Embraer, only exemplary drawings.
Where can I find such things? I am ready to buy them, if necessary.


texts: Who activates the fasten seat belt warning on commercial flights?

texts:
Who activates (and de-activates) the "fasten seat belt" warning on commercial flights? I would guess it is either the pilot in command (normally the captain) or the first officer (co-pilot).

If the answer is airline specific, then answer for American Airlines.


texts: Does a VNAV PTH descent need the Forecast Descent winds?

texts:
If VNAV PTH, contrary to VNAV SPD, maintains a given path angle, depending on the CI chosen, and not a given Speed, then in my mind winds shouldn't affect it, since they would only cause the Vertical Speed to be adjusted accordingly in order to stay on that "fixed" path (since winds will alter the Ground Speed)
After all, VNAV PTH has a band of approx. +/- 12 kt (i.e. 24 kt in total) within which it does not "care" what your speed is. All it wants is to maintain the selected Path.
Hence my question: Does one need to fill in the Forecast Descent Winds for a VNAV PTH descent?
Though I can clearly see and understand how they will affect a VNAV SPD descent.
Because if your primary target is maintaining a given Indicated Airspeed, (be it Mach or IAS), then the winds definitely define where you are going to end up on the ground.


texts:
The AFM for DA40 states in 4A.3.9 CRUISE checklist:

  Electrical fuel pump . . . . . . . . . . . . . . . . . . . ON at high
  altitudes

  CAUTION Operation at high altitudes with the electrical fuel
  pump OFF may cause vapor bubbles, resulting in intermittent low fuel
  pressure indications, sometimes followed by high fuel flow
  indications.

I (sort of) understand the reason for needing to compensate for lower ambient pressure with a mechanical fuel pump, but the problem is I can't find a clear reference to what is considered "high altitudes" for this purpose? It has a demonstrated operating limit of FL164, so we're obviously not talking crazy high.

Is it more of a "if you experience these symptoms, try turning on the fuel pump" type of caution? Or is there some specific altitude above which the pump should always be on?


texts: What is the benefit of spoilerons compared to ailerons?

texts: Some airplanes like the B-52 or the MU-2 use spoilerons instead of ailerons to control roll. What is the benefit of ailerons vs spoilerons and vice versa?


texts: What is the maximum distance for class C service?

texts:
Sectionals say to contact the approach center of a class C airspace within 20 miles. Is this a suggestion or a rule?

What is the maximum distance to contact them via radio, other than signal limitations, if one exists?

What is the maximum distance to receive radar service from class C?

Note that class C radar service and flight following from an ATC center are not the same thing as it pertains to my question.


texts: Are there any full-size airplanes flying with a Selig S1223 airfoil?


texts: In a flat spin, does the F-16 use its rudder deflection against the rotation for recovering?

texts:
If the H-tail is used in recovery from the flat spin, is the rudder used for stopping the yaw or beta of the F-16?

I know that it is surely used for inverted flat spin, but I believe that the rudder is blanked by the H-tails in upright spin and is not effective.


texts:
I know the 'TAA' usually used in RNAV chart, but sometimes it can be used in ILS chart as well. (When defining an IF, GPS is solely methods)

but While I'm studying, I can't find exact difference between TAA and MSA.

Can you let me know ?

BEST


texts: How do you find information about overnight parking at any airport that is not your home airport?

texts: As a private pilot, how do you find information and plan an overnight stay at an airport other than your home airport? For example, where to park, how to get out of the airport?


texts: How does aviation deal with satellite and Moon laser ranging, and other scientific lasers in the sky?

texts:
It seems there are many scientific laser ranging stations around the globe and some are mobile.

Scientists Bounce Laser Off Soviet Lunar Rover Lost On Moon Decades Ago. Source

Questions

How dangerous are those scientific laser beams for passengers and crew, and for the aircraft?
Is there a NOTAM or a temporary flight restriction associated with scientific laser activity?

Background

For satellite laser ranging:

  In satellite laser ranging (SLR) a global network of observation
  stations measures the round trip time of flight of ultrashort pulses
  of light to satellites equipped with retroreflectors. This provides
  instantaneous range measurements of millimeter level precision which
  can be accumulated to provide accurate measurement of orbits and a
  host of important scientific data.

International Laser Ranging Service - Map of stations. Source.

and for the Moon:

  Laser beams are used because they remain tightly focused for large
  distances. Nevertheless, there is enough dispersion of the beam that
  it is about 7 kilometers in diameter when it reaches the Moon and 20
  kilometers in diameter when it returns to Earth. Because of this very
  weak signal, observations are made for several hours at a time. By
  averaging the signal for this period, the distance to the Moon can be
  measured to an accuracy of about 3 centimeters.

For astrophysics purposes:

  Adaptive optics systems require a wavefront reference source in order
  to correct atmospheric distortion of light. Sufficiently bright stars
  are not available in all parts of the sky [...], one can create an
  artificial guide star by shining a laser into the atmosphere.

See also

Thanks to Federico, a very nice timelapse video of laser activity at Mauna Kea (by Sean Goebel).


texts: How is it possible for the MIG 21 to have full rudder to the left, but the nose wheel move freely to the right and then straight or to the left?

texts:
How is it possible that the MIG 21 has the rudder to the left, but the nose wheel moves freely to the right, and then straight or to the left on the runway?
See timestamp 1 min 11 sec in this video:


texts: Why don't B747s start takeoffs with full throttle?

texts:
Why does the 747 start takeoff with partial power and increase to full throttle later down the runway, when the A380 for example starts on full?

Source

This is not the same question as:

Is it possible that derated thrust takeoffs are safer than normal takeoffs?
Why don't airliners use full throttle on takeoff?


texts: How long is a METAR valid for after issuance?

texts: I was wondering how long is the METAR report valid for after issuance? I know some airports issue them every 30 minutes and some every hour. So I wanted to know if a METAR is issued at 8:30AM then will it be valid till next Metar report i.e. 9:00AM or is it just valid for 10-15 minutes after that ?


texts: During spin recovery, can you just release the yoke/stick to neutralize the ailerons?

texts:
I have been watching spin recovery videos on YouTube for the last few days. Scary stuff and I haven't even started flying yet :o haha

Anyway, the recovery seems to be commonly described as PARE:

Power idle
Ailerons neutral
Rudder opposite of spin
Elevator forward

Do you physically neutralize the ailerons or does releasing the yoke/stick do that? Is that specific to certain airplanes?


texts: What is required for transatlantic flight in a private plane?

texts: What equipment is required to fly a small plane across the Atlantic via Canada, Greenland, and Iceland? Is any additional training required beyond an ordinary pilot certificate? Can it be done in VFR flight?


texts: Can I find the minimum IFR altitude based only on a SID plate?

texts:
I noticed this question here on aviation stackexchange, and I was wondering if there is a way to deduce the minimum IFR altitude (either 1000ft or 2000ft above obstacles, depending on whether or not the aircraft flies over mountainous areas) based solely on the information provided on a SID plate? Take, for example, La Guardia Five Departure (here is its textual description and here its take-off minimums).

Could someone point me in the right direction?

EDIT:

I understand that it is not required for a pilot to be aware of the minimum IFR altitude if he is following a SID. Perhaps I am overthinking it, but I am asking because I would like to know if, theoretically, an aircraft would have the right to climb with a climb gradient less than the standard (200 FPNM) while following a SID, if

A: There is not any other minimum climb gradient assigned

B: He is above 1000ft or 2000 ft (the aforementioned "minimum IFR altitude")


texts: Efficiency of the Kuznetsov NK-88 or NK-89 engine burning hydrogen

texts:
It's tough to find data about turbofan efficiency running on hydrogen.
The Tupolev Tu-155 has been used as a test bed for exotic fuels right before the fall of the soviet union, without much follow-up.
Is there any spec available on these engines? (like:)

Rated power
How much hydrogen used per second
Durability
Thermal efficiency

Matthieu Thomas of Airbus wrote an article stating an hydrogen turbofan could be more efficient than current kerosene ones because of:

Wide flammability range of hydrogen
High auto-ignition temperature

But as the piece is oriented pro-hydrogen, the author is probably not willing to admit any performance-wise downside of hydrogen when used in a turbofan. So a subsidiary question would be: Is there any foreseeable decrease of turbofan performance when switching to hydrogen?


texts: What does "clear of clouds" mean in FAA FAR part 103?

texts:
In FAR part 103 when they are talking about visibility requirements for flying an ultralight, sometimes instead of giving exact distances, they will just say "clear of clouds".

For example:

                                   Minimum
                                  flight
                                visibility
      Flight altitudes             /1/       Minimum distance from clouds
1,200 feet or less above the
surface regardless of MSL
altitude:
(1) Within controlled airspace      3       500 feet below, 1,000 feet above, 2,000 feet horizontal.
(2) Outside controlled airspace     1       Clear of clouds.

Or here:

                                      Flight
          Airspace                visibility        Distance from clouds

Class G:
1,200 feet or less above the
surface (regardless of MSL
altitude)                       1 statute mile   Clear of clouds.
More than 1,200 feet above the
surface but less than 10,000
feet MSL                        1 statute mile   500 feet below.
                                                 1,000 feet above.
                                                 2,000 feet horizontal.

What does "Clear of Clouds" mean in this context?  Just that I should remain clear of the clouds, or does it mean that the sky must be clear of clouds in the defined space?

And if it does just mean I need to stay "clear of the clouds", how exactly is that defined?  1000ft?  100ft? 10ft?  What exactly?


texts: Why does an ADIRU 1 failure disable all functions of the A330/340’s GPWS - even those not requiring ADIRU data?

texts:
Among the many (many many) aircraft systems degraded or rendered unavailable to the flightcrew of QF72 as a result of a partial intermittent ADIRU 1 (Air Data / Inertial Reference Unit 1) failure, the aircraft’s GPWS was rendered totally inoperative (all emphasis mine):

0440 [. . . . .] NAV GPWS FAULT [. . . . .] The GPWS required ADIRU parameters such as true track angle, computed airspeed, true airspeed and roll attitude, and it was only connected to ADIRU 1. A problem with ADIRU 1 resulted in a loss of the GPWS function.  [ATSB Transport Safety Report AO-2008-070, page 48 (page 68 of the PDF file of the report).]
In addition to the potential for a pitch-down command, other known effects associated with the data-spike failure mode on the A330/A340 included:
[...]

unavailability of some other aircraft systems, depending on the ADIRU involved. For example, in cases where ADIRU 1 was affected, the ground proximity warning system (GPWS) was no longer available.  [Page 200/220.]

It makes sense that those GPWS functions requiring ADIRU input would be rendered inoperative by a loss of ADR/IR data;1 for instance, excessive-descent-rate protection and terrain-ahead avoidance both require pressure altitude (to calculate the aircraft’s descent rate, in the former’s case, and to determine whether the aircraft has enough altitude to safely clear rising terrain ahead, for the latter), an ADR parameter, while bank-angle protection requires roll attitude, an IR parameter.
However, not all GPWS functions require ADR or IR input; for instance, of the GPWS’s original functions, most (dangerously low height above terrain when not configured for landing; excessive terrain-closure rate; loss of height after takeoff) require only radioaltimeter data2 (plus, for the first, aircraft-configuration data), which is unaffected by even a complete loss of all air and inertial data.
So why does a loss of air-data and inertial inputs disable even the functions of the A330/340’s GPWS not requiring said inputs?

1: Although this raises the obvious question as to why such a safety-critical system as the GPWS was connected to only a single ADIRU, with no ability to switch its inputs to a different source should ADIRU 1 fail.
2: The very factor that makes the radioaltimeter inferior to the baroaltimeter for most purposes (its measuring height above the variably-high ground, rather than altitude above mean sea level) makes it ideally-suited for the GPWS basic functions (as we are interested in not colliding with the ground, rather than with mean sea level; indeed, in some cases, the ground is located below mean sea level).


texts: Is it a flight violation to mishear ATC instructions for exiting the runway?

texts:
I was on landing rollout and misheard a tower "turn off at xxx switch ground" call. We read back the incorrect taxi way and turned off there and switched to the ground frequency. After our incorrect read back we were not contacted again until ground told us to call tower. I was under the impression that the landing aircraft had the right of way over any traffic behind them, even on roll out. I was also under the impression that a tower cannot stop you from using the whole runway.

Is missing a directed turn off a runway a flight violation? If so what FAR/AIM or regulation did it violate? Is the fault with us for mishearing or with the controller for not correcting us? Does this count as a runway incursion? Does the controller maintain responsibility for maintaining separation until we taxi clear?

To answer a few of the questions from below:
when we contacted the ground controller, they gave us a phone number to contact tower then gave us a taxi clearance. When they told us to call i became concerned with receiving a flight violation. We were not corrected to my knowledge, we only heard radio traffic once we had turned off the runway. This was also not a LAHS operation.

another question: From the AIM 4-3-20 it says : "the following procedures must be followed..." "exit the runway without delay"
" is that at the discretion of the pilot?

also if tower gives you a taxiway instruction to leave the runway is that an instruction or a clearance?

Is it a good idea to call the local FAA office and see if they have opened an investigation?


texts:
I've been Googling how many parts are in what air planes, but I didn't get a result on how many parts are in a Boeing 767.

Anyone got any ideas or know the answer?


texts: What will happen if we start the A320 engines but we don't wait for the amber crosses on the E/WD to disappear?

texts: My logic is that we should wait for the sensors to register the present indications so we have a proper idea of what state the engine is in particularly the EGT if we have to consider a manual start.


texts: With an EASA PPL, can I invoice my mother's company for airplane rental to fly her to a convention, with no other renumeration?

texts: My mother who owns a private company asked me if I could fly her to a convention. She asked if it was possible if the costs of the plane rental could be invoiced to her company. Since I only posses a PPL (EASA) I was wondering if I was allowed to perform this flight since you're not supposed to do commercial flights. I won't get paid anything for this flight so I don't think there would be a problem but just want to make sure.


texts: Does EASA require airliners to be fitted with autopilots?

texts: For EASA OPS requirements, must an airline transport airplane be fitted with an autopilot system?


texts: How do CH-47 pilots lower the tail during a pinnacle landing?

texts:
(thedrive.com)

Given the recent rescue of a climber on Mt. Hood by a Chinook, how are the pilots able to lower the tail in this situation? Is this just the natural angle during a hover, or are there some adjustments the pilots can make to the fore and aft collective individually?


texts: Is there a reason that commercial jets do not have a “dead man’s switch”?

texts:
Following high-profile cases of disappearances such as MH370, as well as the lower-profile but no doubt common radar infringement and level / airspace busts that we don’t hear about often, is there a reason that commercial aircraft do not have a dead man’s switch?
Although I have no personal experience in aviation, this would have seemed a very simple way to answer the question of “was it pilot incapacitation?” Either it was, in which case the dead man’s switch triggers some sort of alert to ATC / on the FDR, or it was a  case of outside interference in which case either they a) fake incapacitation by triggering a dead-man’s alert, which the scrambling of jets would soon disprove or b) they don’t trigger a dead-man’s, and so at least pilot incapacitation is ruled out in the subsequent investigation.
Of course there is the question of how a dead man’s switch could be implemented, however given the number of SOPs already taught, this hardly seems a limiting factor.


texts: What is the correct traffic pattern at a towered airport?

texts:
When flying into a towered airport in VFR, is the pilot expected to enter a standard traffic pattern, or should the plane be flown in the most direct route to final as practical?

For example, if westbound into a class D airport with a north-south runway landing on runway 18, should the pilot enter the pattern at a 45 midfield, fly parallel on downwind as usual, then start the descent normally when abeam the threshold, turning left base and final? Or should the pilot simply fly to the north of the field and start the descent and turn a left final approach?

The AIM 4-3-13 doesn't really explain towered airport operations, as far as how to enter the pattern. This is the most relevant explanation I can find:

  When necessary, the tower controller will issue clearances or other
  information for aircraft to generally follow the desired flight path
  (traffic patterns) when flying in Class B, Class C, and Class D
  surface areas and the proper taxi routes when operating on the ground.
  If not otherwise authorized or directed by the tower, pilots of
  fixed-wing aircraft approaching to land must circle the airport to the
  left. However, in all instances, an appropriate clearance must be
  received from the tower before landing.

I've only flown into a few class D airports (only 3 months since I got my license), and wasn't sure about how to approach the field in certain situations. Some were straight in approaches, but a couple were generally as I described above. The tower usually says to report at 3 miles, or when turning to final. "When necessary" ATC will issue clearances for traffic patterns, but what to do if they just tell you are clear to land? Does "circle the airport to the left" mean do the full pattern procedure?

During flight training I never experienced anything other than pretty much a straight in approach to class D.

Edit: I found this explanation on a flight instruction website: "Pilots do not fly a standard traffic pattern at a towered airport, with a 45-degree entry to the downwind leg. Instead, aircraft enter the airport vicinity as instructed by ATC, reporting arrival on an assigned pattern leg and then accepting further instructions or a clearance to land."

This seems to contradict the AIM explanation. And again, what if ATC doesn't instruct anything, what are they expecting the pilot to do? A standard pattern or a straight in approach as direct as possible?


texts: On which part of the descent does a pilot begin to flare?

texts: On which part of the landing process does the pilot begin to flare?


texts: co-pilot incapacitation: land alone or with a passenger-pilot?

texts:
Pilots are trained to safely fly the aircraft in case of co-pilot incapacitation:

  "A commercial aircraft can be landed with one pilot at the control and
  Delta pilots are fully trained to do so if the situation were to
  occur." (Delta representative)

  FAA AC 25.1523-1 requires all aircraft to be capable of operation
  by one pilot only from either seat, so just one pilot can safely fly
  the aircraft - albeit under increased workload. (source)

So why would a pilot in such a situation elect to ask over the PA system "are there any non-revenue pilots on board, please ring your call button" and then land the plane together with this unknown person (a military pilot in this case) ?

This happened on United Airlines Flight 1637. Sure, if it turns out right (which it did in this case), it's certainly pleasant to have a helping hand. But there are all sort of things which could go wrong (“At the beginning, I interrupted her flow of operations, but we figured everything out extremely quickly."). Personally, I'd much rather prefer not being interrupted and distracted when I have to concentrate in this critical moment. Why take any risk at all when one pilot should be able to safely land alone?


texts: Are there any examples of sustained human-powered flight above ground effect?

texts: Every video of human-powered flight has the plane or helicopter so close to the ground that it benefits from ground-effect. Is there any exception to this rule, i.e. a still-air-level-ground human powered altitude record that is high enough to leave ground effect?


texts: What is the highest a helicopter can fly?

texts: What is the highest theoretical and current flight a helicopter can achieve?


texts: What drives the compressor before the turbine provides power?

texts:
I understand that the power extracted from the turbine is used to drive the compressor which sucks and squeezes air sent to the combustion chamber, and the cycle continues.

But initially the compressor has to suck in air! What drives it at this stage before the turbine takes over?


texts: What are Altitude, Attitude and Heading Hold?

texts:
Can someone give a good and simple explanation about these three dynamics?

Altitude Hold
Attitude Hold
Heading Hold


texts: Would a lighter aircraft require the same amount of power than a heavier one to fly at the same speed?

texts:
I had a question come up:

  If aircraft A is identical to aircraft B, except that aircraft B weighs 200 kg more. Which of the following statements are true?

The answer I selected was wrong:

  Aircraft A would need less power to fly at the same speed as aircraft B

I pictured that with less weight, a reduced angle of attack would result in less drag and hence less power? Would anyone be able to “lighten” me with this?

Thanks for the feedback, it may have just been a typo..
The 4 multiple choices where:
1) Aircraft A would need less power to fly at the same speed as aircraft B
2) Aircraft A would need the same power to fly at the same speed as aircraft B
3) Aircraft B would have poorer climb performance
4) Aircraft B would require a longer runway for landing


texts: I was going through A320 FCOM and came across this term. Is bowed rotor bending if the spool due to unequal thermal cooling


texts: How do pilot and copilot operate and coordinate the radio?

texts:
How do the pilot and copilot of a large commercial jet operate the radio when talking to ATC? Is there a push-to-talk button, or some voice-triggered mechanism?

Also, how do they coordinate it? How do they decide which pilot should be talking to ATC?


texts: How is the camera positioned for these plane-to-plane Schlieren images of shock waves?

texts:
These two popular press articles discuss the use of schlieren photography to image shock waves of jets during flight using a special schlieren camera on a third plane.

Gizmodo: NASA Captures First-Ever Images of Intersecting Shockwaves From Two Supersonic Jets
Ars Technica: NASA visualizes supersonic shockwaves in a new, awe-inspiring way

NASA's Glenn Research Center page on Schlieren photography is instructive but doesn't give a clue how this is done. Where is the camera relative to these target aircraft, and what's behind them?

This NASA page shows a diagram of traditional Schlieren photography but in that case a special light source is behind the plane, and the present photos are "in the wild" rather than in a laboratory setting.


texts: After completing my A&P are you suppose to get a temporary license? After the exam my DME just gave me a copy of my airmen certificate application

texts: I passed my exams on 17DEC2020. Currently the FAA's web site shows that I have no certificates, and shows that they are processing applicants from 25JAN2021...... what should I do?


texts: Airbus A320 automatic speed mode protection in SRS vertical mode

texts:
According to the A320 FCOM, capter 22 auto flight, flight guidance, the "automatic speed mode protection" of the auto flight system of the A320 disengages the flight directors upon reaching current VMAX+4kt which will cause A/THR to revert to speed mode. But this protection is only active in climb modes: CLB, OP CLB and EXP CLB.

Does anybody know why the "automatic speed mode protection" is not available in SRS vertical mode where A/THR is also in THR CLB mode?

Also does anybody know if this protection uses the VFE of the selected flap config or of the actual config? E.g. if you are in climb and inadvertently select flaps from UP to CONF ONE then the aircraft won't let you do that but does this (cruise lock) but as far as I know the speed tape on the PFD already shows the maximum airspeed for the selected flap 1 config. So does this already disengage the flight directors? Or do they use the actual flap position or overspeed warning from the flight warning computers?


texts: When was the first THS (Trimmable horizontal stabilizer) used and on what aircraft? Has any UL or GA trimmable stabilizer?


texts: How to calculate normal takeoff ground roll when the POH only has Short Field Takeoff tables?

texts:
The Cessna 172S POH only has Short Field Takeoff Distance tables.  How do pilots determine ground roll for a normal takeoff on a long field with hard surface?

The examples in the POH only deal with short field takeoff.  Similar thing with chapter 10 in the Pilot's Handbook of Aeronautical Knowledge.  It's either short field takeoff or referring to charts that don't exist in the Cessna 172S POH.

Do pilots look up the short field ground roll, apply the adjustment factor for headwind and apply another adjustment factor?

The POH says, on page 5-4 "...keeping in mind that the distances shown are based on the short field takeoff technique.  Conservative distances can be established by reading the chart at the next higher value for weight, altitude and temperature."

Does that mean to use the chart, but use the row for the next highest PA and the column for the next next highest temp when determining normal takeoff ground roll?

I've searched this forum and haven't found anything applicable.


texts: Which situations would cause a company to ground or recall a aircraft series?

texts: Which agencies or companies might decide to ground an aircraft series, and in which situations can this occurr?


texts: Is the airspeed different between above and under the wings?

texts: I heard that when an airplane is flying, air speed or air pressure is higher under the wings. Is it true?


texts: What angle are front rotors of tandem helicopters tilted and why this value?

texts:
I've read that the front rotor of tandem helicopters are tilted forward so that you can get a forward velocity with no nose-down pitching of the fuselage, but what angle is used for this tilt and why this value?

Is this angular value chosen such that you can have no nose-down pitching at the design-point operation of the helicopter? ie, if the helicopter is designed to cruise at 150ktas, is the forward rotor's angle set such that your forward force cancels the total drag at this velocity and maintain no fuselage pitching? And if you wanted to go faster than 150ktas, you would just have to pitch the whole helicopter to get the rear rotor's upward thrust to join in to accelerate forward?


texts: Is there a minimal approach speed for airliners during rush hour?

texts: For busy airport, sequencing can be complexe. If the ATC put all aircraft in front of each other with the correct separation (which can be really small for busy airports) in final, if the airliners' approach speed vary significantly, one plane could catch up the preceding one. Can the ATC ask for a pilot to increase its approach speed up to a minimum speed?


texts: How the stabilizer cutout switch functionality has changed from Boeing 737 NG to 737 MAX?

texts:
The Boeing 737 NG has stabilizer trim cutout switches marked as MAIN ELECT (left) and AUTOPILOT (right). Turning off the right switch disables automatic stabilizer trim in autopilot mode and automatic stabilizer trim by the STS in manual mode. The stabilizer can still be trimmed with electric trim switches on the control wheel or manually with the hand crank. Turning off the left switch disables the electric trim on the control wheel.

The Boeing 737 MAX has stabilizer cutout switches marked as PRI (left) and B/U (right).

With the MAX, Boeing added MCAS to the existing STS functionality. If Boeing kept the cutoff switches functionality intact, then turning off the right switch would disable both STS and MCAS, keeping the electric trim operable. Instead, in case of misbehaving MCAS Boeing requires to cut off BOTH switches without explaining what each of the switches does. With both switches turned off the only option to change stabilizer trim is to use a hand crank.

On the NG, if only the left switch is cut out, does it disable electric trim on the control wheel only, or it completely disables electric assist no matter where the command comes from, so in effect when the left switch is turned off it does not matter what is the position of the right switch?
What is the meaning of the new MAX labels?
What is the exact functionality of these switches individually?
Why the algorithm of turning off auto trim system has been changed?


texts: What means do airline ground staff have to converse with pilots in flight?

texts:
It seems that airline operational staff on the ground have the ability to initiate verbal communication with airline pilots on at least some airliners, in flight.

Obviously pilots can communicate with ATC using, for example, VHF radio.

Perhaps, even in aircraft where phone service is not available to passengers, pilots in the air and/or airline staff on the ground can

initiate a voice call using telephony equipment that is separate from any PSTN (public switched telephone network)?

using existing headset?
using aircraft internal intercom handsets?
some means of selecting the call recipient?

send text messages over the data links (e.g. via ACARS (Aircraft Communications Addressing and Reporting System) through VHF (very high frequency) or SATCOM (satellite communication))?
use private VHF frequencies to communicate with airline operations?

If any of this is true, how does this work from the perspective of a pilot, steward or an airline operational staff member on the ground?


texts: What are the FAA requirements for an aircraft to be IFR certified?

texts:
As I understand it, the FAA certifies certain aircraft types for IFR flight in general. All aircraft of that type are then certified, not something you have to do with each individual aircraft.

What are the minimum requirements for aircraft to be certified for IFR? Is it all location-sensing equipment?

And a bonus: can I get a single aircraft that is only VFR certified to be IFR certified if I add more equipment?


texts: What happens to a large plane after a successful gear-up landing?

texts:
There are plenty of videos of non-fatal gear-up landings - even of airliners. I can find none that show the recovery of the aircraft after safe evacuation of crew and passengers and completion of safety procedures.

How is the runway cleared? Is the plane towed away (scraping along the ground)? Are there cranes available in large airports? Can a single crane lift and move a large airliner?
Is the plane considered a write-off or can some be repaired and continue in service? Where would such repairs take place?


texts: Are Hybrid Airship pilot different from other aircraft or helicopter pilot?


texts: How useful is skyscrapers and high buildings lighting to get a visual reference for pilots by night? (not obstruction lights, just general lights)

texts: I would like to know how useful is skyscrapers and high buildings lighting to get a visual reference for helicopter and small planes pilots by night in cities like New York. This is different from obstruction lights. I'm talking about shapes and colors.


texts: Can I fly a paramotor after learning on a paraglider?

texts:
This video has inspired me to spend next week doing a 6 day paragliding course. The only downside is the school near me don't teach paramotoring.

Could I buy (and safely use/self-teach) a paramotor after learning to paraglide?


texts: In simple mechanical stick linkages, is there crosstalk between the aileron and the elevator movement?

texts:
The background story:

I'm an aviation enthusiast (who has played a lot of sim in his life and will play lots more :D) but I've never actually flown any plane myself, as in, actually used the controls (but I'm planning to make my PPL one day, I've always wanted to have wings :).
I also have an idea in my mind which involves a simply constructed stick control column.

While looking at some pictures of the mechanical construction of the linkages that translate stick movement to aileron/elevator movement, I've stumbled upon this design analysis of the Mitsubishi A6M3 Zero, a japanese WWII fighter plane.

The bewilderment:

Looking at this drawing of the linkages on the stick,

I was wondering:

If the stick is rotated exactly and only around the aileron axis (thus describing a pure 2D movement along the surface of a circle, basically, the stick does not rotate around the "bolt" (A) with which it is mounted to the bell crank), it looks to me as if this would inevitably lead to a change in angle on the elevator, since the distance between the point where the push pull rod is linked to the stick (B) and the point where it is linked to the "elevator hinge" (C) and the push pull rod would pull stronger on the elevator (leading to a higher AOA) the further the stick is rotated around the aileron axis.

The question(s):

Does this mean that in aircraft with similar stick mechanisms, the further you rotate the stick to the left or right, the more you would have to push it forward/the less you would have to pull it back in order to not change the pitch of your elevator?[1]

If this is the case, is it a problem or does one intuitively get used to compensating for this "crosstalk"?

[1]: I'm not talking about lowering your AOA the more you bank to avoid stalling. Just imagine you're in a steep bank and push the stick to the side quite far to level your wings. Would you have to push forward so you don't increase your AOA while levelling out?


texts: Would a homemade lawn chair balloon be visible on ATC and collision avoidance radar?

texts:
I am not a pilot, but have a question about radar detection of improvised lawn chair balloons that I thought might be on-topic here.

This BBC news article describes a marketing stunt gone awry involving a lawn chair, a large number of multicolored helium balloons, and the owner/operator/parachutist

According to the article, he was charged with "mischief causing danger to life".

A similar stunt by American truck driver Lawrence Richard Walters, nicknamed "Lawnchair Larry" or the "Lawn Chair Pilot"  also resulted in fines and legal action.  In that case, the government dropped the fine for "operating a civil aircraft for which there is not currently in effect an airworthiness certificate" because it was not applicable to that type of aircraft. The article also mentions some other attempts to fly lawn chair balloons, including a fatality from crashing at sea.

My question is whether such an improvised manned balloon would be visible on typical airport radar or the independent radar/collision-avoidance systems operated on board large modern passenger aircraft, and thus avoidable.

A 1970s military research paper on radar supporting the need for secondary transponders in detecting light aircraft also mentions detecting doppler from propellers (p.4) in addition to the primary radar reflection, and I would expect the cross section of a lawn chair to perhaps be within an order of magnitude of that of a propeller.   A 2m x 0.5m x 0.5m sparsely filled aluminum chair frame is also still larger than typical microwave radar wavelengths (1Ghz = 30cm wavelength, most radars are going to be above 1Ghz), so it should reflect the radar but of course is a fairly small object compared to large aircraft and therefore the detection range could be lower.


texts: Do small aircraft have sockets for passenger headsets?

texts: I am currently training for my PPL. in the Cessna 182s we use I've only ever noticed two sets of ports for the headsets. If there were additional passengers in the back seats, how would they communicate?


texts: Why do pilot and GPWS approach callouts say “minimums” instead of “minima”?

texts:
A safe instrument approach requires a number of callouts along the way; two of the most important come fairly late in the approach, first to alert the pilot flying that the aircraft is approaching the minimum descent altitude (MDA) for that approach, and then when the aircraft actually reaches the MDA (these callouts were traditionally made by the pilot monitoring, but are now usually made by the aircraft’s GPWS).  At this point, if the pilots have the runway environment clearly and consistently in sight, they can continue and land; otherwise, an immediate missed approach is mandatory.

These callouts are typically annunciated in plural form, as, respectively, “approaching minimums” and “minimums”; however, the plural of “minimum” is not “minimums”, but, rather, “minima”, which is also shorter and takes less time to say than “minimums” (and good time management is one of the many many things that are critical during an instrument approach, especially one in low visibility or over or near obstructed terrain), so why do these pilot and GPWS callouts typically use the longer and ungrammatical “minimums”?


texts: What is the typical sink rate during a well-executed carrier landing at the moment the main wheels touch the deck?  And how has this changed over the decades?


texts: What do we hear, on the ground, from a helicopter in flight?

texts:
Last week I heard a helicopter approaching from a distance.

The sound it made was a very distinct and deep wop wop wop at a remarkably slow two beats per second, more or less.

As it came closer, the sound suddenly changed, to something more like six beats/second, with a quite different and more familiar chattering.

What were we hearing from the ground? What do the two different sounds represent?


texts: How to use wind currents for constant elevation in gliding?

texts:
I am using X-Plane learning some basics in aviation. Currently, I'm using the glider so I can focus on flying and not engines.

I've heard of gliders being able to catch drafts so as to keep continuous flight. Is there a rule to be able to do this? I thought by riding with the wind and occasionally intersecting I might keep up the energy, but it does not seem to work that way.


texts: Where can I find a video about making F-16 jet fighter canopies?

texts: I'm searching for a video of the manufacturing process for an F-16 jet fighter canopy. Can anybody help me?  Does anybody know where these canopies are manufactured?


texts: What documents/procedures I have to follow to fly my aircraft from the UK to Norway?

texts:
I'm planning a trip to Norway for when Covid restrictions here in the UK are lifted, and was wondering what documentation is needed to enter Norway. I've already emailed AVINOR, and they simply gave me a link to toll.no, which yields no helpful information.
I'll be flying myself in a British aircraft. I'll be departing from Wick in Scotland and arriving in Kristiansand Kjevik in Norway. I'd like the details as if it were normal, pre-covid times.


texts: Can a change in altimeter setting make you change the airspace?

texts:
If you are at 17999 MSL VFR, you twist in 29.92 into the altimeter, and it raises your altitude to above 18000, did you bust the class A?

Then theoretically, could you be in class A airspace with a local altimeter setting if there is a very low pressure?


texts: Who decides how fast commercial aircraft fly: the pilots or ATC?

texts:
Once a commercial aircraft is in the cruise phase, who determines the speed of the aircraft?
Do pilots have the authority to fly at up to the maximum permissible speed of that plane, or does ATC decide on that depending on the approximate time it will take to reach the destination? Is it stated in the flight plan that the pilot cannot go beyond some specific speed even if the aircraft is capable of it?


texts: What are the Requirements for the implimentation of Low Visibility Procedures at an airport?

texts:
So I was wondering if the RVR at an airport is reported above CAT I conditions for eg 1400 Meters etc but the Visibility is 50 to 100 Meters then would the pilots carry out non instrument approach or would the approach would be carry out as per Low Visibility conditions ?
And what are the conditions for an airport to impliment Low Visibility conditions ?


texts: Normal tendency of helicopter with counter clockwise rotating main rotors (top view) with force trim off and leaving controls?

texts:
Is it normal for the helicopter with CCW rotating main rotors to pitch down and roll left in forward flight, when force trim is turned off and hands off the cyclic?
Moreover, when we put the helicopter in right bank, would it tend to return to straight & level / left bank after a few seconds when hands off the cyclic (force trim off)?
By forward flight I mean 80 to 100 kts


texts: What level of information does a PIC have about a missile crossing their aircraft route?

texts:
Recently North Korea launched a missile out of its national airspace on a trajectory which crossed the route of an aircraft from Air France. The aircraft wasn't in danger at any time, the minimal distance between the missile and the aircraft was always higher than 100 km (7 minutes separation).

Source: CBS

ATC was not able to inform the aircraft, or any other aircraft in the vicinity. If the timing was such the missile could hit the aircraft it seems this would have made no difference.

From a pilot in command, responsible for on-board safety, stand point, what kind of information is available regarding such events? Is there some protection possible yet, or expected in the near future? If not, can (or must) a PIC asks for something to be put in place?


texts:
EC-ATQ was a Douglas DC-7C.
It was damaged beyond repair on 2.10.1970 in Madrid.
Does anyone have more information?

Was a piano dropped on top of it and nobody was willing to take the blame?


texts:
This Wikipedia page about biplanes says

  in a wing of aspect ratio 6, and a wing separation distance of one chord length, the biplane configuration will only produce about 20 percent more lift than a single wing of the same planform.

My question is, does the wing of  biplane share the lift load 50/50 ?
Secondly, what is the formula for calculating the interference drag of a biplane?


texts: How do large airport refuelling systems work?

texts:
As I am sitting on board my plane and have been informed that there may be a three-hour delay due to a pressure problem in the fuelling system at the destination, it seems like an appropriate moment to ask: how do these systems at large airports (in this case, Amsterdam Schiphol) work?

Apparently, it is an airport-wide problem affecting all flights that need refuelling.

How and where is fuel stored?
How is it delivered to the aircraft?
What sort of technical problem with pressure could affect an entire airport the size of Schiphol?


texts: Why are non-essential passenger flights still being flown?

texts:
I'm not asking about essential passenger flights like for "like food, supplies, and flying medical workers.

Oughtn't non-essential passenger flights have been shut down in North America, to curb the spread of COVID19? Have they truly not been grounded because

  The airlines wrote to Congress that they’d lose an additional \$7-$10 billion if there was a mandate airline shutdown.

and airlines are "afraid of losing routes and more money"?


texts: Is it possible to drop a payload via anchored parachute?

texts:
Apologies if this is not the proper forum for this question -

Here's my situation:

I'm trying to drop a payload via parachute with some accuracy.  I'm worried that in the above setup, the line will interfere with parachute deployment or - if not deployment - operation during flight (imagine wind pushing the chute into the line).

I haven't tested this yet but plan to.  Does anyone know how the payload <> anchor connection might be engineered to ensure full deployment throughout the descent?


texts: Why is the intake of the 757 (RR) engine slanted?

texts:
I'm sitting looking at a 757 with Rolls-Royce engines and just noticed that the intake is slanted forward by 5-10 degrees. Anyone know why?

(wikimedia.org)


texts:
Nowadays to avoid C.A.T. the crew checks the charts before, or receive pieces of information from the leading pilots or from the VOLMET stations.
Is there any weather radar able to spot Clear Air Turbulence?


texts: How did the 9/11 hijackers find their way to New York City?

texts:
It is quite well known that the airplane hijackers on 9/11 were not professional pilots. So, my question is how some people who didn't have any experience of navigating the airplanes could find their way, for example from Boston to New York City?

I read somewhere that some natural signs like the Hudson River (for example) helped them to find their way through New York City. But I'm still looking to find a more convincing answer if it is available.


texts: What is the legal altitude to fly through Yosemite Valley (US)?

texts:
I have a question regarding flying in the Yosemite Valley national park, which I flew over last weekend in an open-cockpit gyroplane.

The sectional states you must be a minimum of 2,000 ft about the highest point within 2,000 feet of you. The famous valley itself, containing El Capitan and Half Dome, has a highest point of 8,800ft or so, so when I flew it, I was at well over 10,000 ft.

However, it occurred to me afterwards, that if the valley is actually more than 4,000 ft wide (which it is), then all I needed to do was to be sure I was more than 2,000 ft above the valley floor, which is at 4,000ft.

So instead of flying over it at 10,000, I could do it at 6,000ft if I'm in the middle of the valley.

This would put me way below the peaks of El Cap and Half Dome, but provided I'm more than 2,000ft away from them, I'd be legal.

Is that correct?


texts: Why do the transponders introduce codes instead of using aircraft registration numbers?

texts:
(A non-pilot here, just a Aviation.SE reader, recently into listening to ATC. I am wondering...)

Why do the transponders use their own codes? (squawk) It seems to me, it would be safer and less of a burden, if each aircraft programmed their own registration number into the transponder and everyone used that?


texts: When are ATC frequencies preset in the radios?

texts:
I've noticed that sometimes pilots tend to present the next ATC frequency in the standby radio, and when required to switch frequencies, they can just push the frequency transfer switch to switch the preset frequency to the active radio.
When do pilots preset frequencies? I.e. tower or ground frequencies are known through the briefing material (i.e. Jeppesen charts), so they could be preselected to accelerate operations. Are there any rules as to when preselect the next frequency, is it also done during cruise flight or only in the terminal area?


texts: When do we use IATA codes and when do we use ICAO codes?

texts: I found on this website several questions speaking of IATA, ICAO and airports codes. The fact that two identification codes for the same airport exist means there are cases where you use one, and other cases where you use the other. I wonder what is the rule to know which code (IATA or ICAO) should be used.


texts: Will prior hospitalization for alcohol intoxication prevent the issuance of a first class medical cert.?

texts: I recently went to the hospital for alcohol intoxication, will that cause any issues getting my first class medical exam this week? I live in the US, I am a college student and I have rarely drank before; this was mostly a case of not eating and not drinking often. And trust me I don't even want to touch a bottle of alcohol for a very long time.


texts: How do larger aircraft compensate for reduced visibility from the cockpit, e.g. less visibility of the rear of the aircraft?

texts:
In smaller planes, pilots has apparently great visibility in front, on the sides and a good portion of the rear of the plane. But as the plane's size is increased, the visibility is also reduced. One obvious factor is height of the cockpit from ground, but it appears (from pictures) that pilots of bigger Boeing/Airbus planes have too many blind spots. However, I did notice that some bigger planes have a camera behind the nose gear to ease in taxiing etc.

So the question is that how do pilots compensate for this lesser visibility? Do they always need external help (e.g. ground crew)? Is there some sophisticated technology helping them? I am sure they cannot just raise or lower a wing or some other maneuver to check nearby traffic.


texts: Will I have to redo flight time for switching to a new CFI?

texts: The CFI that I am flying with is experiencing health issues and may not be able to fly anymore.  If I switch to a different instructor will I have to redo flight time with the new instructor or is it perfectly OK to log flight instruction with different instructors.  So far I have only about 4 hours instruction and have not soloed.  My jurisdiction is the USA.


texts: Why are "counterweights" used in aircraft production?

texts:
From this question, manufacturers use "counterweight" or "ballast" when producing aircraft. Why is the use of weight necessary? Supposedly aircraft should be made as light as possible, and counterweight is just dead weight without any function.

I presume it is used to balance some centre of gravity, but why would that be necessary? With industrialized factories, components can be engineered to great accuracy, so a case-by-case adjustment to account for manufacturing errors should not be needed.


texts: Would a "fuel leak" at the gate be a reportable incident?

texts:
This news story shows video of fuel being expelled from a wingtip of a 767, while at the gate. The engines were apparently running during this event. After the cockpit crew learned of what was going on, the engines were shut down and fire equipment was brought in.

Since this happened on the ground, is this an incident that must be reported to the FAA? The article says that the airline hasn't given any details of the incident.

Perhaps this belongs in another question, but what could have happened here?


texts: Commercial aircraft minimum and maximum climb angle and rate?

texts: Is it possible for a commercial pilot to set a minimal rate of climb - for example, 350' NM climb rate, target heading of 200 degrees and target altitude of 2000 feet above MSL - before getting radar vectors from ATC when they hit the target altitude?


texts: What is the trend of gender distribution among pilots?

texts:
Are there any statistics on the distribution of pilots between the two genders? Specifically, has the ratio changed over the past decades (I'd expect female pilots to be getting more common)?

I'm aware that the number will vary between countries. I'm more interested in the trend of certain group(s) that are statistically significant to an area (e.g. all commercial carriers in the United Kingdom / all PPL holders in the United States).


texts:
The following section is from Instrument Procedures Handbook (FAA):

If a feeder route to an IAF begins at a fix located along the route of
flight prior to reaching the holding fix, and clearance for an
approach is issued, a pilot should commence the approach via the
published feeder route. For example, the aircraft would not be
expected to overfly the feeder route and return to it. The pilot is
expected to commence the approach in a similar manner at the IAF, if
the IAF for the procedure is located along the route of flight to the
holding fix.
If a route of flight directly to the IAF is desired, it should be so
stated by the controller with phraseology to include the words
“direct,” “proceed direct,” or a similar phrase that the pilot can
interpret without question. When a pilot is uncertain of the
clearance, ATC should be queried immediately as to what route of
flight is preferred.

Can you give examples to clarify it  a little bit more for each case. Pictures are appreciated.


texts: In an emergency situation just after take off, is fuel dumping useful?

texts: Imagine a hypothetical scenario where a jet heavily loaded with fuel experiences more than one engine failures after $V_{1}$. Then I suppose that losing some weight would be beneficial since the airplane is not designed to sustain climb with such limited thrust. In such a case a) how much would dumping fuel help in this emergency (i.e. is the rate of dumping fast enough?) and b) could the captain proceed to do it without ATC authorization if he/she considers it necessary?


texts: Why did the 777-9 leave landing gear down during first flight?

texts:
In Sam Chui's video covering the first 777-9 flight, there's a shot of the plane over the clouds with landing gear still down.

I thought maybe the shot was from another flight. I couldn't find another video with exactly that shot, but CNET's video shows the landing gear remaining down for a long time after takeoff.

Assuming I'm correct, that the gear remained down for the whole flight: why?


texts:
Does a plane have brakes to stop or slow down while flying?

For example, if the pilots see a large flock of birds at some distance in front of the airplane, and they want to reduce speed suddenly. What will happen if an airplane doesn't have such brake?


texts: Would the solid material inside an airship displace air and be counted towards lift?

texts:
The hydrogen inside an airship has a mass that is approximately 14 times lower than the mass of air and this difference results in lift.

However the solid material inside an airship including the frame, skin, walkways, gasbag material etc. would also displace air.  Would the air that these materials displace also be counted towards lift?  I'm not sure.
If the extra displacement is counted towards lift is there any reasonable estimate as to how much space the solid material might fill?  1%, 2%, 5%?
A U Class Zeppelin has an outside volume of approximately 59,000 cubic meters.  However if 2% of this volume was solid material that's 1,180 cubic meters of atmosphere displacement or an extra 1,445 Kg of lift.  Although not decisive I'm sure that any little bit helps.


texts: Why 360 degrees is in the top instead of 90 degrees in aviation?

texts:
Normally on 2D map, if there is point say A(0,0) in the center and there is point B in the 2nd quadrant . The angle is always in 90<=x<=180. But in aviation, it is 270<=x<=360 . Why ?

Treat this as a basic question.


texts: Is there an easy way to determine where a part goes on an airplane?

texts: In order to classify parts for export I need to determine where our parts go on the plane.  (Engine or structural/body)  Specifically looking at the canister, heat shield assy and lock support for the Boeing 767/777.


texts:
Just what the title states.

Since the Wright brothers, aviation technology for fixed-wing craft has advanced by an order or more. Rotary wing craft on the other hand (I know little about aviation; please correct me!) have advanced significantly by way of lift capacity, and maneuverability. Yet velocity has achieved nothing like the kind of advance seen in case of fixed-wing craft.

Is a rotary wing craft capable of supersonic flight?
How is it limited by contemporary technology?


texts: Am I allowed to replace my own Model A-30 Altitude Digitizer?

texts:
My Transponder Mode C (Altitude Reporting) function quit working.  The position reporting function is working fine.  I believe the failed component is the self contained Model A-30 Altitude Digitizer "box" that is bolted to the interior of the fire wall.  It has a connector cable to the transponder and a rubber pitot tube connection.  I am an Aerospace engineer with 32 years experience designing and testing Space Shuttle Main Engines and components.  I have done my own annuals and had my local FBO mechanic inspect the work and sign it off.  The replacement of the Altitude Digitizer box does not require the removal of the transponder - just bolt on the new box and re-connect the air tube and plug in the "D" connector to the transponder.

As the aircraft owner would that be approved for me to do as a non-complex assembly/maintenance?  I know the calibration would have to be done by my certified avionics shop personnel, but can I do the R & R of the box?  Having my avionics shop do it adds another \$200.00 to the calibration cost of $175.


texts: Why was a flight delayed because of a bird in the cockpit?

texts:
This Washington Post article is about a Delta Airlines flight that took off after an initial delay, before turning back again shortly after, because of a bird that managed to stowaway in the cockpit.

My questions,

Would it be dangerous having the bird in the cockpit?
Was the decision to turn back expected or over the top?
Do Delta regulations (or relevant regulations) actually cover something this specific, or would it have been under some catch-all? If so, what would that be?
Have there been any similar incidents?
Does this ever happen on small private aircraft?  (It's not unheard of to find a small bird sitting in your car for some reason - maybe it's the same?) Has it ever happened to anyone here, what's the outcome?

and mostly,

Why didn't they just kill it?

(Aircraft kill small birds by the thousands, I mean - chicken was probably served on board.)


texts: Is it a standard procedure to use emergency slides without imminent danger?

texts:
On 11 Jun 2017 Easyjet U23246 from Ljubljana to London Stansted diverted to Cologne-Bonn over a "suspicious conversation". All passengers were evacuated using the emergency slides, see BBC Video.

This made me wonder why this is appropriate at all:

There was no imminent danger. It's an international airport, so surely they have at least one set of mobile stairs that could have been used in a safer manner?
Apparently nine people (of 151) needed medical attention after using the emergency slides. That's 5%!
If it had been an incident and police needed to enter the aircraft, wouldn't they arrive on mobile stairs anyway?
Apparently the airplane sat for 30min before evacuation anyway, so it wasn't even faster to use the slides.

I'm just wondering what prompted them to deploy the slides in the first place. I'm under the impression that they need to be replaced upon use and hurried evacuation didn't seem to be necessary in the first place.

As a passenger, I think a lot of people might get argumentative over not having stairs. Especially when small kids and disabled people (e.g. dependent on a wheelchair) are on-board. Not to speak of the economic and public relations impact...


texts: Is there any flight school that uses jets as part of their training program?

texts: Is there any flying school out there that use "jets" as part of their training program? I mean like a Cessna Citation or Phenom.


texts: How do airplanes regulate the output frequency of AC generators?

texts: AC electrical buses are common in airplanes from light piston twins all the way up to the largest airliners. I usually see both a 115v and 36v AC bus with a 400 Hz output frequency. How do most airplanes regulate the output frequency coming from the AC generator?


texts: Why aren't cell phones allowed to be used in aircraft?

texts: What problems do cell phones cause? How is using a cell phone in the air different than using it from the ground?


texts: Why is it called "STBY RUD" on a Boeing 737?

texts:
(Source: b737.org.uk)

Anyone knows why "STBY RUD" is named "STBY RUD" when the selection of the switch position activates the standby hydraulic system as well as the standby rudder system (by opening  rudder shutoff valve)? Is it because the standby rudder is more important than the standby hydraulic system as a standby system?


texts: Is it allowed to use an ex-military aircraft overseas?

texts:
We are considering using an ex US military helicopter in our counter poaching operations in the Central African Republic, while keeping it registered as a US aircraft with the US "N" number. We are not exporting it to sell and we will and we will maintain ownership and the US "N" number.

What restrictions are there for taking an aircraft like this out of the US, if any?

I know of a good many former US military helicopters in private and commercial uses in some African countries. And I know that some ex US military helicopters are not "eligible" to export, and some are.

What is the difference?