texts: Is an Airbus A319 allowed to fly with a missing flap track fairing?

texts:
During a recent flight from Copenhagen to Milan in an Airbus A319, one of the flap track fairings were missing from the wing. I saw this during takeoff, and notified a flight attendent as soon as the "seatbelts on" sign was turned off.

She seemed slightly surprised and went to the cockpit (supposedly to tell the pilot). After some minutes she returned and told me that it was fine, the captain had seen it during inspection and it was noted in the log

Is it normal procedure to take off with knowledge of missing flap track fairings? What are the consequences of one missing?


texts: How can I calculate the fuel required for a specific route and aircraft?

texts:
Okay, I'm writing a online game. I've got two airports and the equipment. For example: Heathrow - LAX on a 744.

What I want to work out is the fuel required, as this will apply a cost to the airline. I know there are many many things such as wind, temperature, regulatory requirements like alternate airport etc but I want something simple.

How can I work out simply the fuel required? Are there charts I can use for working out takeoff, each hour in cruise and descent?


texts: Can pilots turn off warning alarms? Re: Aeroperu Flight 603

texts: I just watched the Mayday S1E4 episode concerning Aeroperu Flight 603.  Gut wretching to see the pilots in that situation.  On listening to the recording tape, alarms were blaring constantly, some for maybe as long as 15 minutes straight.  I can only imagine that that constant blaring adds stress and confusion to the cockpit.  So I wanted to ask if pilots have the ability to silence alarms after a certain period of time?


texts: What should pilots state initially when telephoning a weather briefing facility for preflight weather information?

texts:
I've gotten this question wrong multiple times on practice tests. Sporty's study buddy claims the information is sourced from AIM 7-1, but it's nowhere to be found.

Correct answers included:

The intended route of flight and destination
Tail number
Identify themselves as pilots

What is the actual authoritative language that covers this test question?


texts: How can I use a window for an emergency exit?

texts:
A survivor of US-Bangla Airlines Flight 211 crash reports exiting out of a broken window.

My question is, in case you need to break an airplane window, what is the best way to do that?


texts: Do pilots need a clearance to go around?

texts:
I have read about the missed-SFO-accident and watched the 2:22 movie. I want to ask about going-around (or canceling takeoff) when the pilot is fully aware of an emergency that the tower is not (or is late at acting).

According to the reconstruction of the real missed-accident done by the news:

Air Canada pilot was on final cleared to land, but instead heading to taxiway for reason that will be explained after FAA & TSB investigations
Tower did not notice and did not complain, clearance was still ok
Pilot double-checked with tower because he saw lights on the ground
Tower double-confirmed clear to land
Other pilot on queue said "where is this guy going?"
Tower requested go around
Air Canada flight crew initiated go around.

The order of the last two events is currently not clear and subject to investigation.

In the movie both ingoing and outgoing pilots are scared by the sight of each other but ATC Dylan doesn't command action until the last moment, while clearance to land and take off is still granted for both.

It is clear that in the movie ATC has failed and pilot(s) are aware of a real danger that affects the safety of flight operation.

Like a driver sighting an animal on the road and braking (or worse moosing) without calling the police first. I am no pilot, I understand that flight is definitely different from driving. And I also enjoyed my time on MSFS virtual flight school. I said the above because I know it could be disappointing for experienced pilots.

I want to ask for my culture/curiosity: when a pilot is cleared to takeoff/land but sees a legitimate reason to cancel the maneuver (e.g. stop/go around), can he simply advise the tower that he is doing that or must continue as earlier instructed? AFAIK when an indicator indicates failiure at < 80kt speed the pilot can immediately cancel takeoff, otherwise is required to continue.

My idea is that the Air Canada pilot could have told the tower something like "we are now fully thrusting and going around because I am not sure about the safety of this landing, please give me further instructions for looping" by his initiative.

This is allowed in the MSFS simulation (you can open virtual ATC radio and announce missed approach even a few feet above ground, they will tell you how to loop over the circuit asap). Is it allowed in reality, or do pilots need a clearance to go around?


texts: Can I still take the knowledge test with the US government shutdown?

texts: Non-Essential employees at the FAA are out of work due to the US Government shutdown.  I am nearing the end of my Private Pilot Training and am almost ready to take the Knowledge test.  With the US Government shutdown, can I still take the knowledge test or do I have to wait for the government to reopen?


texts: Why is the static margin expressed as percentage of the MAC?

texts:
Most textbooks use the static margin (the distance between the aircraft's centre of mass and its aerodynamic centre) to assess the longitudinal static stability.

Instead of using an absolute value for the allowable range of the static margin, it is expressed as a percentage of the Mean Aerodynamic Chord (MAC) - for example between 5 and 30%. Why is this so?

For a given aircraft, the higher its aspect ratio for a given wing area the shorter will the chord become. Hence the MAC will also be smaller. This will in turn reduce the absolute value of the allowable range for the static margin.

Is this simply a convention or is there an aerodynamic or flight mechanics reason why the allowable range for the centre of mass is smaller for smaller MACs or shorter wing chords?


texts: Is excess fuel leaking normal during take off of a B737?

texts:
When we look over this video

it's noted that some fuel is coming off from the left wing during the rotate. This is the position of the fuel vent within the wing, of course, 'leaking' due to new vertical and horizontal forces combined which, in turn, force fluids backwards and outwards in a swept wing, so not exactly a fuel dump procedure as published. My question is: is normal or correct for an airliner to have such an excess of fuel causing it to reach the fuel vent until it spills during take off? Shouldn't this wing carry less fuel?

EDIT: To help explain exactly what I am talking about, we are looking for a very thin trail of fuel coming from the fuel vent of the left wing. This vent is located under the wing and a little ahead the (left) aileron. We are not talking about a vortex from the engine vortex generators or from the flap edges. ;)

This:

This other video shows the same with much more detail:


texts:
The wikipedia page on G-forces, https://en.wikipedia.org/wiki/G-force, lists that WW1 aircraft encountered 4.5-7g during dogfights.

This made me wonder, how did pilots in the early days of aviation handle the g-forces? G-suits were not invented until 1940s.


texts: How does gross weight affect helicopter autorotation?

texts:
The factors which affect helicopter autorotational aerodynamics include airspeed, gross weight, rotor RPM, and density altitude. The effects of these factors can be examined during a few phases of the autorotation, including entry, steady state descent, flare, and touchdown. The effects of gross weight seem very unintuitive to me, so I would like clarification on how gross weight affects the steady state descent and the flare, in particular.
Steady State Descent
My helicopter aerodynamics book says the following:

Gross weight determines RPM at a given collective pitch. At high gross weight, more blade pitch is required to maintain a desired RPM, so higher gross weight results in a slower rate of descent, assuming all other variables remain the same.

So high gross weight decreases descent rate. That's unintuitive to me, so I'm trying to build a logical path. I know from experience that making tight turns during an auto causes RPM to increase. Tight turns increase positive Gs on the aircraft, which is equivalent to increasing weight. So higher gross weight will tend to increase RPM, requiring the pilot to raise the collective (blade pitch) to maintain RPM. There's question 1: why does increasing weight (or G loading) tend to increase rotor RPM?
The second logical step is how this required increase in blade pitch will decrease the rate of descent. I understand that increased blade pitch increases AOA, thus increasing the lift produced by the rotors. However, this increased lift is opposed by the increased weight that started this whole discussion. Here's question 2: for a given increase in weight, is the resulting increase in lift larger? This seems to be the only way to achieve a lower rate of descent.
Flare and Touchdown
My helicopter's flight manual includes the following diagram, titled "Minimum Height for Safe Landing after Engine Failure"

This chart indicates that at a given density altitude, it is unsafe to be too heavy during an auto. I assume that the danger is related to the flare and touchdown, since during the descent it seems safer to have a lower rate of descent. My intuition tells me something about how the rotors store energy as RPM during the descent, and the flare and touchdown dissipate that energy in order to slow the helicopter's forward and vertical speed. It seems intuitive that a heavier helicopter will require more energy to slow, which means at and above some threshold weight, the helicopter will not be able to flare enough to touch down gently. But, is there a more rigorous explanation for high gross weight being dangerous at the "bottom" of the autorotation, i.e. how energy is stored and dissipated in the rotors?


texts: How can I calculate which runway to use for landing, based on the wind?

texts:
I have a project where the user enters the name of the airport. We fetch the wind direction (degrees) for that airport. Then we use the wind direction and the data about the runways at that airport to calculate which runways the planes will land at. What is the best way to do that?

My approach:

Find the compass direction, for instance 90 degrees is equivalent to east. Then, if the direction of the wind is east, the plane will land from the west (to land against the wind).

My question:

How do I calculate which runway the plane will use to land? There are multiple runways at some airports. Do we use runway heading, or runway longitude/latitude, assuming wind is the only factor affecting landing? Is there a mathematical way to calculate which runway the plane will use? I am asking because I will have to do some calculation to accurately give that answer to the user.

Any expert/aviation help would be greatly appreciated.

Also, I am using the airports and runways table from ourairports.com/data.

Also, what do HE and LE mean in the context of runways?


texts: What are the Autopilot Minimums for a C-172 G1000?

texts:
(GA Pilot)

On a C-172 (G1000 Avionics), what would be the AutoPilot minimums OR at what altitude would one need to disengage the auto-pilot and take controls for:

1) Precision Approaches

2) Non-Precision Approaches

3) Visual Approaches ..?


texts: If several standby cabin crew members called in sick and there are no more available can standby pilot called to perform cabin crew member duties? Probably it would be more economical than postpone flight let say with 200 passengers...


texts: Are there technical means to enforce aircraft speed limits as well as regulatory means?

texts:
Do any aircraft have a device which can be pre-set or can be controlled from the ground in order to prevent the aircraft from exceeding a speed limit?

These could be similar to what they have for buses in many places so the bus driver can't go beyond a speed limit.


texts: How do airlines provide crews for the return leg of a long-haul flight?

texts:
In a video, a Swiss International Air Lines crew flies an Airbus A340-313 (flight LX38) from Zurich to San Francisco. Then, they can be seen (I am not sure if this is on the very same day) visiting downtown and the Golden Gate prior to getting back to the airport for the return flight (LX39), which is scheduled for departure around three hours later.

The question here is:

How do airlines handle crew turnovers in long-haul flights?

Is it the same crew who is demanded to command the return flight? Or is there, oddly enough, a replacement crew in each destination airport? Or do they carry the crew for flight LX39 onboard flight LX38?


texts: Why is there a difference between nosegear retraction directions?

texts:
I've noticed that on almost all aircraft (Boeing, Airbus etc.) the nose gear rotates forwards for retraction.

However, on a some aircraft, in particular a few Russian models, the opposite is used: the nose gear is rotated towards the rear for stowage:

(this includes the Tu154, Tu134)

Is there any logic behind this decision? I imagined it was better to place it folding forwards, such that the gear was assisted into place by the air, especially for manual free fall. Looking at pictures of the TU-154 with its gear down, there seems to be plenty of space forward.


texts: Has the Boeing 737 MAX MCAS system successfully prevented a stall or approach to stall condition outside testing?

texts: The Boeing 737 MAX MCAS system has been in the press a lot as it has been implicated as a possible cause of 2 fatal crashes. The MCAS system was put in to prevent a wing stall caused by excessive Angle of Attack. My question is, outside of testing, has the system ever operated as intended and prevented a stall or approach to a stall?


texts: How much lift comes from the fuselage on modern jets?

texts: I understand this question is broad, but specifically referencing modern jets where composites are used a lot to get complex surfaces (such as in the Beechcraft Premier 1), how much of the total lift is generated by the fuselage versus the wings, perhaps as a percentage of total lift? The fuselage is obviously a lifting body and I’ve noticed the same in other current designs.


texts: What are the advantages of a Trimmable Horizontal Stabilizer?

texts:
What are the advantages of a Trimmable Horizontal Stabilizer (THS)? For example, a THS is used on some Airbus and Embraer aircraft. What is the most important advantage, and why don't some other successful airliners have this type of horizontal stabilizer?

Image used under CC BY-SA 3.0 (Source). Depicting the right side THS on an ERJ-170

Note: A Trimmable Horizontal Stabilizer (THS) differs both from a Stabilator and a horizontal stabilizer with a trimmable Elevator


texts: How to match ATC requirements to work in EU?

texts:
My Brazilian boyfriend is finally planning to move into the EU zone (he actually got an Italian passport). He would be glad to keep his work as an Air Traffic Controller but despite his 10 years working experience he told me he should start the training all over again.

Can someone point us out the shortest way to match the requirements for EU Standards and/or suggest us where to find this kind of information?


texts: Will wind tunnel modelling ever be completely replaced by computer models?

texts: With computer-based fluid simulation already being extremely realistic (and likely faster and cheaper than physical wind tunnels), are they, anywhere, completely replacing physical wind tunnels? If not, is this planned anywhere, or even possible?


texts: Where can a civilian obtain centrifuge training/testing?

texts:
Where can a civilian get high g-force training/testing in a centrifuge?  (Likely by paying.)  Preferably with and without a g-suit.  Preferably based in the US, maybe Canada.

I'm betting the US Air Force centrifuge in San Antonio, Texas, and Canada's military centrifuge in Toronto would laugh and/or hang up the phone if asked.

Crossing my fingers there's a private or educational facility that would be an option.


texts: How should I interpret this raw SID data from the FAA?

texts:
I am trying to make sense of the SID structures from the FAA's 28 day NASR subscription files (SSD and/or STARDP, raw data in txt files), and I have two questions.

First, I notice that there are SIDs without any path: no transition FIX/NAVAIDs and no main bodies. What's the point of referencing a SID that does not contain anything else except the airport(s)? Take this SID for example (no other records exist for BELLEVUE SID):

D0075     NA N4729353W12212567RNT     BELVU3.BELVU BELLEVUE THREE
D0075     AA N4729353W12212567RNT

Second, another thing that prevents me from interpreting these SIDs is the difference between "NA" airports and "AA" airports. From the layout file which explains how to read and interpret the records, I read that "If there are airports served by the DP that are not served by any body, there will be one or more records describing these airports, with the FIX/facility type code field containing an 'NA'".

The problem is that in each SID where an 'NA' record exists, another one 'AA' record exists for the SAME airport described by the 'NA' record, so I cannot really understand if they are served by the SID's main body (if any). I am not sure how to interpret this, or the fact that SIDs like the one already mentioned (BELLEVUE) contain neither a main body nor any transition paths.

Another example is this SID; every "NA" airport seems to be also an "AA" airport:

D0161     NA N3832426W08950067BLV     CARDS1.CSX   CARDS ONE
D0161     NA N3844553W09022121STL
D0161     NA N3834133W09009183CPS
D0161     NA N3853237W09002456ALN
D0161     NA N3839436W09039074SUS
D0161     AA N3832426W08950067BLV
D0161     AA N3844553W09022121STL
D0161     AA N3834133W09009183CPS
D0161     AA N3853237W09002456ALN
D0161     AA N3839436W09039074SUS
D0161     ND N3845099W09021395CSX     CARDS1.BDF BRADFORD TRANSITION
D0161     R  N3921383W09013256SKYPE K5
D0161     R  N4004061W09003391SKUTR K5
D0161     NW N4109350W08935163BDF
D0161     ND N3845099W09021395CSX     CARDS1.LEBOY LEBOY TRANSITION
D0161     R  N3922076W09033098DEECE K5
D0161     R  N3926003W09034230LEBOY K5
D0161     ND N3845099W09021395CSX     CARDS1.NEENS NEENS TRANSITION
D0161     R  N3923033W09025555MYKEY K5
D0161     R  N4014535W09031538NEENS K5
D0161     ND N3845099W09021395CSX     CARDS1.SPI   SPINNER TRANSITION
D0161     R  N3919223W09000200TEWHY K5
D0161     NW N3950230W08940398SPI

Am I missing something here? I apologize for the lengthy post but I would really appreciate if someone could point me to the right direction.


texts: Can anyone identify the plane in this old photo?

texts: It belonged to my uncle. May have been 1930s vintage.


texts: What is the purpose of a freewheeling unit in an helicopter, if a centrifugal clutch is already present?

texts:
Some helicopters such as the Bell 47 are fitted with a centrifugal clutch.
Centrifugal clutch will engage only at certain engine RPM. If the engine fails, the engine RPM will reduce and the centrifugal clutch will disengage the rotor from the engine. So, why is an additional freewheeling unit needed?


texts:
According to Wikipedia, 6 million pounds were spent developing the Bristol Brabazon, and the only prototype was scrapped for 10,000 pounds, that is a 0.17% loss recoup. There was a lot more value in keeping that plane intact than scrapping it, maybe for future projects, or special assignments, or further testing, like an An-225. It held more value as a museum piece, or a "sculpture" in Bristol, than the value from the scrap metal.

Was there a reason for being scrapped, other than the 10k in scrapped metal?


texts: How often is the fuel sampled in turbine aircraft?

texts:
In planes using avgas, sampling fuel from the tanks is generally done before every flight, or at least before the first flight of the day and then after any refueling. This is done because water contamination is fairly high risk. Gasoline does not mix with water, so it collects at the bottom of the tank, and because it does not burn, when it gets to the engine, the engine will quit.
Water does mix with kerosene though so this isn't as big risk and it can't be checked this way anyway because it won't collect in the sump. It could detect other contamination though. For example in this incident hugely excessive addition of biocide caused damage to the engines, and in this case the report says the biocide did form a separate layer below the fuel.
So how often is fuel in turbine (turboprop and jet) aircraft usually sampled? And is it subjected to any additional tests beyond visual inspection?


texts: I've got a job interview next week and the interviewer asked my colleagues this question. I didn't find the answer online, I personally don't think that there is a certain duration for a wind shear because it's a sudden change in wind direction and speed. The question is annoying actually and I really want to know.


texts: What do numbers signify in airport codes?

texts:
As an Air Cadet, we go gliding very frequently. However, I've noticed something about the airport that we go to. The airport that we go to, Markham Airport, has a different airport code. CNU8.

Meanwhile, other airports, such as Toronto-Buttonville, Toronto-City-Centre, and Toronto-Pearson all have the following codes respectively: CYKZ, CYTZ, and CYYZ.

Do the numbers in airport codes signify something? If they don't, why is there a mix of both letters and numbers?


texts: Why do the inlet cones on an SR-71 retract at higher speeds while the one on a MiG-21 extends at higher speeds?

texts:
As shown by this illustration in the SR-71 flight manual, its inlet cones (spikes) retract as its speed increases:

 (source)

Meanwhile, the Wikipedia page for the MiG-21 describes the opposite behavior for its intake cone:

  On early model MiG-21s, the cone has three positions. For speeds up to Mach 1.5 the cone is fully retracted to the maximum aft position. For speeds between Mach 1.5 and Mach 1.9 the cone moves to the middle position. For speeds higher than Mach 1.9 the cone moves to the maximum forward position.

No source is provided for this part of the Wikipedia article. If the info about the MiG-21 is accurate, why does its intake cone behave differently than the SR-71's? Do the two aircraft's intake cones serve different aerodynamic purposes?


texts: Can one fight medical rejection due to depression noted 14-15 years ago?

texts:
My husband's dream was getting his private pilot's license which he just got in August.

He was diagnosed with depression about 14 years ago and in medication less than a year. He has been great since - no depression or meds.

He did his physical this summer and got the all clear - he answered everything truthfully. Fast forward - he passed his tests and flight and has been flying since. Today in the mail he gets a letter from FAA saying his medical is rejected because he had a history of depression.

can he fight this and how?
how long is a depression bout from early 20s going to follow someone in life?


texts: Is there a maximum possible size for an airplane?

texts: Is there any theoretical or practical limit to the maximum number of passengers - and therefore size - one can build an airplane for?


texts: Shouldn't the instructor in this scenario try to avoid a deadstick landing?

texts:
In the Netflix drama "The Crown" (season 1, episode 4) Prince Philip has flight lessons with Group Captain Townsend (below is an image of that scene, I was unable to identify the plane).

After Prince Philip complains about the noise of the engine, Group Captain Townsend deliberately turns it off, and they both enjoy the silence for a while. After some chat, Prince Philip notices the ground getting closer:

Prince Philip: "Shouldn't we get her started now? The ground seems terribly close."
Group Captain Townsend: "No, it's too low to restart, sir. We'll do a dead-stick landing."

And they land safely.
My question is: if that was a real event, shouldn't Group Captain Townsend (as the instructor) interrupt the relaxing gliding with a warning? Something along the lines of "excuse me, sir, we're losing altitude, if you want me to restart the engine we have to do it now", or even "I'm restarting the engine now". I mean, shouldn't he be checking the limit altitude for restarting the engine?
I'll not ask why Group Captain Townsend didn't do that, it would be off topic, opinion-based and, despite the Group Captain being a real person, that scene is fictional anyway (The Crown is not 100% historically accurate). I'm just curious about the most probable behaviour of a real instructor in a situation like that.


texts: What is the difference between the words "airlines" and "airways" semantically?

texts:
I wonder what the difference between the words "airlines" and "airways" is. Do you have any information on this?

I am asking this question to find out why some air carriers use "airlines" while others use "airways" on their brand names.


texts:
The current METAR for Stanstead in the UK says:

  EGSS 031520Z AUTO 29011KT 9999 FEW021/// //////TCU 07/02 Q1022

I do not know how to interpret the /// and //////. From what I remember multiple slashes means that data is missing, however the data in this metar seems complete.

What does FEW021/// mean?
TCU means Towering Cumulous, which makes sense, but what do the leading ////// mean in this context?


texts: How do pilots travel from remote private airports after landing?

texts: What if you fly your own personal plane to a small private airport in the countryside that has no public transportation? I imagine that most pilots don't have a car parked at each private airport they intend on flying to. That is, of course, unless your car is small enough to fit inside your plane. If you want to go somewhere twenty miles from the airport, for example, do you just call a taxi or ask a friend in that town to pick you up in their car?


texts:
The Bernoulli Principle states that as the velocity of a fluid increases, the pressure of that fluid decreases. However what if it were to be reversed: As the velocity of the fluid decreases, the pressure increases; is this possible?
I am looking at pressure differentials and how pressure is 'high' on the lower surface of the aerofoil. But is the pressure truly 'higher' or is it of normal pressure of the surroundings of the aerofoil?
So this is where the question comes in: If the pressure of the airflow is greater ont the lower surface of an aerofoil, then doesn't that mean that the airflow is slower? Or is the 'high pressure differential' just a word to help differenciate the concept of pressure on an aerofoil, and truly the pressure on the lower surface of the wing is normal?


texts: How many checklists are there for a commercial pilot for the entire flight?

texts: I wanted to know the number of times a pilot has to refer to his/her checklist for the entire flight (before startup to engine shutdown).


texts: Is it possible to control an aircraft on the runway if the nose gear collapses?

texts:
I have read and seen some articles in which, for various reasons, the aircraft's nose gear collapsed after landing during the roll out. This resulted in the aircraft going off the runway.

Is it possible to still control the aircraft during this weird event? Or is it more or less inevitable that the aircraft will run off the runway?


texts: What are the criteria for "variable" in METAR reports?

texts:
Regarding variable wind direction in METAR reports, what are the criteria for VARIABLE when the authority uses "VRB"?

An Advisory Circular mentions the authority uses "V" when the wind direction varies by 60 degrees. But how about "VRB"?


texts: What regulations exist for ATC real time RADAR simulator software?

texts:
Does professional ATC RADAR simulator software need to comply to some regulations or requirements in order to be used for real life controller training?

Have ICAO, Eurocontrol, EASA or FAA published any such regulations or requirements in their documents? If so, any reference to a document is appreciated.


texts: What are Forward flight, Straight flight, Level flight, and Cruise flight in a helicopter?

texts: Pretty straightforward: what is the difference between forward flight, straight flight, level flight, and cruise flight in helicopters?


texts: What effect would there be if the brakes were locked at touchdown?

texts:
I'm imagining if you had a panicky passenger sitting in the right seat who had both feet firmly on the brakes while landing. Unless you had a crosswind and needed rudder as you touched down it's possible you wouldn't be aware of it. Or if there was a malfunction causing them to be locked. How likely is it that could cause you to have a bad day?

What if only one side was locked up (which seems worse to me)?

I'm mainly asking about small aircraft. Would it be any different for an airliner?

What if you were aware of it? What action would you take?


texts: What is the process to disconnect ground electric power before pushback?

texts:
While commercial airliner are parked at the gate, they have electrical power connected to the aircraft (if available at the airport). This needs to be disconnected before pushback - what is the process to do so?

How does the ground crew know it is safe / ok to disconnect ground power? (ask pilot if Auxiliary Power Unit (APU) is running?)
When will it be disconnected? As late as possible before push-back?

Thanks!


texts: How many total airframe cycles should a B737-400 be put through before it becomes too costly to maintain?

texts: I know maintenance can extend the lifespan of an aircraft but when looking at large aircraft such as the 737-300/400 is there a standard amount to go by?


texts:
What does the following mean and what ramifications does it have when purchasing an aircraft?

  term R/H-1958 HOURS SMOH@26/02/1988   - BULK STRIP 27/03/1998  ENGINE
  1472 SMOH

Does it mean the engine will be at its lide use and has to be replaced with another or am I correct that they replaced some parts to extend the time based on condition and will require a full overhaul 528 hors?


texts: Why does the airport plate list a VASI that does not exist?

texts:
I have a small but quite busy GA (General Aviation) airport I operate out of that gets over 140,000 of operations per year.  It's a popular GA destination, has an active school, and the area schools use it as a great short, narrow, practice runway. The AFD (Airport/Facility Directory) entry for the airport lists the runway as having a Tri Color VASI (Visual Approach Slope Indicator) at each end.  It doesn't exist.  As far as I've gathered it might have existed 20 years ago.

How does an oversight like this exist for such an extended period of time?

Is this something that should be reported?

The instrument approach plate lists the VASI as well, but it's never been NOTAM'd out of service.  Does this create a hazard to potential IFR traffic?


texts:
This question has me wondering: do passengers/crew have to to through customs at refueling stops?

Does it matter if they stay in/with the aircraft vs. going into the FBO, e.g. to use restrooms?

If it is different for different types of flights (e.g. airline vs private), please answer for each.


texts: What is this open panel at the rear of this airplane?

texts:
I saw this photo at another interesting question:

There's an open square panel. What is it?

P.S. Any tag suggestions are welcome. All I could think of was "tail".

EDIT: are there any other tags for this kind of thing? The APU tag seems to be a crystal ball because I had no idea what it was at the time.


texts: Why aren't requirements to use GNSS systems in the Regulations?

texts:
I've been sorting through the publications outlining the proper use of GPS in IFR scenarios.  Looking at AIM 1-2-3 (dated 10/12/17), it appears that there is some regulatory language in (b) and (c).  To me it seems this information belongs in Part 91 somewhere between 91.167 and 91.299, along with VOR checks, ELT's and ADS-B.

Why isn't this information in the regulations rather than in the AIM?


texts: Why do most commercial solid-state Inertial Measurement Units (IMUs) measure angular rate and not angular acceleration?

texts:
The vast majority of MEMS-based IMUs are formed by an accelerometer and a gyroscope, providing linear acceleration and angular rate measurements respectively.

However, having available the angular acceleration would be useful for a more precise kinematic model when integrating to find the pose. Judging by this IEEE review, there are sensors for angular acceleration, therefore it doesn't seem to exist a fundamental limitation in the ability to have direct measurements of it.

Why is it that the standard has become to have angular rate as the source of information for rotational motion and not angular acceleration?


texts: If commercial airliner cabin is depressurized, are pilots protected against it in any ways?

texts:
Basically, if the cabin in a large air liner is depressurized, are pilots protected in any way, specifically:

Is the cockpit separately pressurized from the rest of the cabin?
Can they keep consciousness if sudden depressurization happens?


texts: Is « Shepherd One » really used internationally by air traffic control for Pope's flight?

texts:
CNN:

  The President flies on Air Force One. The Pope flies on "Shepherd
  One." That's the Federal Aviation-approved call sign for the Boeing
  777 in which he'll be traveling around the United States, according to
  an official from American Airlines, which will be operating the plane.

Wikimedia:

  Shepherd One is the international call sign of any aircraft carrying
  the pope onboard. The airline which is used for such transportation is
  usually Alitalia

Source

Perdue site ('Cradle of Astronauts'):

  Flying Pope Francis – Purdue alum honored to fly 'Shepherd One'

From Crux Now catholic press:

  The plane isn’t really called “Shepherd One.” People in the United States
  call it that, but the phrase is a media conceit rather than an
  actual call sign.

Ghafla.com:

  Did you know it’s Americans who baptized the plane carrying the Pope
  ‘Shepherd One’? Well, their very own presidential jet is called ‘Air
  Force One’ so they thought since the Pope is a shepherd leading the
  Catholic Church, his plane should be called ‘Shepherd One’.

Question: Does ATC around the world, starting with Italy and the US, uses the specific call sign Shepherd One?


texts: Why does the Canard Rotor Wing use a Canard?

texts: Why does the canard rotor wing (CRW) use a canard?  The CRW is a helicopter using engine exhaust to drive the rotor.  The exhaust can be used in the normal way to drive the aircraft once high enough speed has been reached.  Why can't the CRW use a tail instead?


texts: Is there an increased concern for stall safety in a 1G steep turn?

texts:
Most people know the standard, "At a 60 degree bank, an aircraft experiences 2G's" checkpoint for load-factor on an airplane.

I assume that this statement has an underlying, unspoken assumption that the aircraft is maintaining a constant altitude in the bank.

This leads on to matters of increased stall speed during turns.

My question is, if no pitch adjustment is made while in a coordinated turn, which I think means that no additional load-factor is acting on the aircraft, is the stall speed still affected?


texts: Eye requirements for private pilots license in the US?

texts:
In the next couple of years, I would like to work on obtaining a private pilot license with the goal of eventually getting my own plane. But my eyesight isn't that great in my left eye.

As a kid, I was born with amblyopia/strabismus. Did eye surgery as a kid which didn't really correct the vision. Though my eyes appear normal, my right is 20/20 and my left is 20/80/100. I should also clarify that glasses cannot remedy the left eye in terms of acuity.

So my question is will I be able to get a license? If not, that's fine, but I'd like to know so I can focus my energy and interests elsewhere.

Thanks.


texts: Can Approach cancel my special VFR clearance if I'm already cleared?

texts:
Say I have requested a special VFR to enter Class D airspace. Approach acknowledges and clears me into the Class D airspace. After entering the Class D airspace the airport visibility drops < 1 mile.

Am I required to exit the airspace or can I continue as normal?


texts: Is there a website that shows past flight tracks of a few days back?

texts: I'm looking for a website, like Flight Radar, that can display the positions of aircraft going back a few days (i.e. not a live map)


texts: Where is the best place to sit on an airplane?

texts: I'm going on a flight soon and I am wondering where the best place to sit is as I want to be sure that if anything happens, I would want the seat to be convenient for most situations.


texts: Did Japan actually use any production aircraft with inverted gull wings during WW2?

texts:
The anime film The Wind Rises presents a fictionalized account of Jiro Horikoshi and the development of the Mitsubishi A5M. Throughout most of the anime, Jiro visualizes the plane with this shape:

I recognized this shape from a production aircraft, but being rusty on my WW2 aviation knowledge, assumed it was the A6M Zero (the designation is never stated in the film). In reality, the production A5M and A6M had fairly straight wings, but the prototype A5M (which is what is depicted in the film) had inverted gull wings:

I then realized that the inverted-gull wings aircraft that I was thinking of was an American fighter, the somewhat similarly-shaped Vought F4U Corsair:

This got me curious on whether any production aircraft used by the IJN (or any branch of the Japanese military) during WW2 used inverted gull wings. From the photos and diagrams I can find, it looks like Japan stuck exclusively with straight wings, but some aircraft are depicted from a side view where it's very difficult to discern the exact shape of the wings.
Did Japan actually fly any production aircraft with inverted gull wings during WW2?


texts: What's the difference between aquaplane and hydroplane?

texts:
If one reads through 10 articles describing a plane which overran a contaminated runway, the term aquaplane will be used 9 times and the term hydroplane once (and on that one time there will be a snarky comment at the end of the article.)

Articles describing automobile crashes, on the other hand tend, to use the term hydroplane much more frequently. A google N-gram search turns up far more instances of hydroplane but this is perhaps simply because more people write and think about cars losing control.

My question is this: Is the use of Aquaplane in aviation the result of some recognizable difference in the loss in braking/traction by an aircraft wheel? If so what is the difference between the definition of hydroplaning and aquaplaning? I've been unable to find an answer because most web searches just turn up information about the automotive phenomenon.

I'm beginning to think this is just a result of aviation preferring to use more technically correct terms (like saying a runway is contaminated rather than wet) rather than a scientific or etymological difference between the two terms (like how physicists use the term centripetal while the rest of us prefer centrifugal)

Can anyone cite an aviation-specific definition of aquaplaning that distinguishes if from hydroplaning?


texts: Do Alaskan bush pilots generate a Clmax of 5 with 90° flaps?

texts:
I understand the Alaskan bush pilots use 90° flaps in the Valdez STOL competition. I think this would stall the flaps. And if so, it wouldn't increase lift and reduce stall speed, but Javafoil says the opposite.

Perhaps this is more for lift/lower stall speed than drag. Since they land flat halfway down a long runway they don't need drag to slow down.

Just to do a test, I input a NACA 2415 foil in javafoil, 25% chord flap, 90 deg flaps deflection. And as expected, lots of drag, but Clmax jumps from 1.5 to 5 at about 0 deg AOA.

Is this realistic? If not, what is the real Clmax?


texts: What does flight categories "C", "G", "T" etc. mean?

texts: In a flight database that I'm working with on a project, there is a column of data called "flightCategory" with values "C", "G", "T", etc.  Any idea what those actually mean?  From what I understand, the database is from FAA.  But I'm not 100% sure.


texts: Can resistive fuel senders/transducers be repaired/reconditioned?

texts:
I need to replace two fuel senders in each wing of a Socata TB20, and a replacement is almost $500.

I wanted to know whether a shop exists in the US that reconditions these?

After some research, I'm still not sure if reconditioning resistive fuel senders is common practice at all. I only heard anecdotically about it


texts: How many passengers can an Airbus A380 carry?

texts: What is the passenger capacity of an A380, and how many suitcases could it carry?


texts: What is the maximum speed of all the stages of a geared bypass tubojet engine?

texts: What is the maximum speed of all the stages of a geared bypass tubojet engine before they start losing efficiency.


texts: What is the air/fuel mixture ratio in a turbojet engine?

texts: How does it relates to stoichiometry ? What are the possible extinction accidents related to air/fuel mixture ratio ?


texts: What is the maximum altitude of barometric altimeters?

texts:
An altimeter works by sensing static air pressure. As altitude goes up, the pressure decreases.

If I take a barometric altimeter up to space (e.g. up to satellite orbit), at what altitude does its reading become useless, i.e. the reading can no longer be trusted as a measurement of the height above sea level?

(While altimeter reading is different than GPS altitude even at low altitudes, it is still a very good measurement of height. I'm asking at what height, the air becomes so thin that it is implausible to measure altitude based on static air pressure?).


texts: Is there an aircrew bunk in the 747 cockpit?

texts:
Reading this article, I came across the quote :

  Pilots also enjoy its creature comforts: at BA the 747s are known as
  the ensuite fleet. “Our little bedroom is within the cockpit: you can
  stick your pyjamas on and clean your teeth without anyone seeing you.
  And coming out the bunk when you wake up, it’s a different light and
  you’re in a plane cockpit in the sky,” he says.

I know there are crew sleep areas on large aircraft but I've never heard of there being a bunk.

Does anyone have a floor plan for the cockpit which would illustrate how do they fit those cabins there?


texts: Is data on international air traffic volume in the US freely available?

texts: I'm looking for air traffic flow data which has the passenger air traffic from countries outside of the US to every international airport in the US. Ideally, I would like to know how many passengers came from other countries to the international airports in the US but I can also use load factors. I'm only interested in free data. Any ideas would be appreciated. I'm willing to parse together a data from multiple datasets/sources.


texts:
My charts have 13 September 2018 on them.  What time do they expire?

I thought at Midnight that night local time, but have been unable to find any corroborating evidence.


texts: What is the EASA definition of night time?

texts: EASA requires pilots to log separately night time and night landings in the personal logbook. Now, I'm not sure in which period of time a landing is a night landing and flight time is night flight time. I would appreciate your answer, maybe also with a trustworthy source.


texts: Why is port-starboard terminology used in aviation?

texts:
I am not a pilot - just a student & play Ace Combat sometimes

Intrigued by the words Starboard & Port-side I researched why these words are used instead of the simple ones, I found that:

  Port is derived from the practice of sailors mooring ships on the left side at ports in order to prevent the steering oar from being crushed. src

Also, quite notably:

  Since port and starboard never change, they are unambiguous references that are independent of a mariner’s orientation, and, thus, mariners use these nautical terms instead of left and right to avoid confusion. When looking forward, toward the bow of a ship, port and starboard refer to the left and right sides, respectively.src

I see both the reasons are derived upon the concerns of the marine world - so why do we use them in aviation world?

This is specially interesting if we consider the fact that flying machines can manevur in all 3D, newbies (me) tend loose track of my VS. plane's left & right when not in level flight. Then why the added confusion?


texts: How is Reynolds Number derived and used?

texts: Reynolds number is the ratio between inertial forces and viscous forces according to wikipedia. However, I still do not understand its derivation process and how to, for example, calculate the Reynolds Number for a cylinder in large pond of water with the water moving in a direction with speed v.


texts: Given an exact date, time, and coordinate, can I locate a plane that flew overhead?

texts:
I need to identify an aircraft seen at 36.841900,-87.673600 Kentucky on July 4, 2020, at 12:29am.
Is there a way to do this feasibly?

Figured out what it is:


texts: Can an airplane flying above 35,000 feet be heard on the ground?

texts: Can the sound produced by a commercial aircraft flying at 35000 feet be heard on the ground when the surroundings are quiet?


texts: What regulations apply to changing liveries on private jets in the US?

texts:
Things like the manufacturer's livery, do they need to follow that?

Anything else that will be required when purchasing a new jet and changing the paint to the new owner's choice and requirements.


texts: How does the VFG make various frequencies? And while it makes the other value of frequency, how the generator apply consistent 400Hz to the other component?


texts: What is the procedure to appeal an FAA DPE who conducts exams in a manner that conflicts with certification standards?

texts:
Does the FAA have a formal process to allow applicants and instructors to appeal a DPE who does not conduct pilot examinations in a manner consistent with the ACS/PTS guidelines?

If yes, how does the process work?


texts:
Is it sensible to harness wind energy on an airplane?

Actually the idea is to build an electric aircraft whose power comes from solar and from wind while the plane is landing. instead of using spoilers as airbrakes, these wind turbines separately mounted could add drag and harness energy at the same time . In other words, regenerative braking.


texts: IAP / "Instrument Approach Procedure (IAP) Charts" What does "Procedure NA" Mean?

texts:
The image below is of an FAA "Instrument Approach Procedure"

The entire thing is the "Procedure"

It contains a "Procedure Turn", which when not required typically states: "NoPT"

Now, in some places it states "Procedure NA" (red arrow near top) which seems to implicates the entire Procedure NOT the Procedure Turn.  However, the red arrow indication at top also seems to implicates the Procedure Turn because we're basically straight in from that location, so it wouldn't be needed, But again, NoPT would make more sense.  And why would the entire procedure be NA?

If we look at the two "Procedure NA" notes on the plan, then the entire "Procedure" would be NA from most approach directions.

So, Which is it?
Does "Procedure NA" mean The entire Instrument Approach Procedure?  or just the Procedure Turn?  If just the Procedure Turn, why does it use different vocabulary? Why not just say NoPT ?
Is there some other significance?

I looked in the chart user guide and can't find "Procedure NA" in it

Thanks


texts: How do I calculate this question? find the position of the centre of gravity in %

texts: Find the position of the centre of gravity in % of the MAC (mean aerodynamic chord) if the distance from the datum to the LEMC (leading edge of mean chord) is 13 meters, the distance to the TEMC (terminal edge of mean chord) is 19 meters and the distance from the datum to the centre of gravity is 15 meters?


texts: Would there be a purpose for a set of compressors in an electric turbo fan?

texts:
This is actually a two part question. Would there be a purpose to a compressor in an electric turbofan where there is no need for a combustion chamber, and if not, is there then a purpose for a bypass as well?

Sorry if I'm unclear, as i am not an industry professional perhaps my wording may not be clear. What I mean to say is that in a regular turbofan engine there are compressors that push air into a combustion chamber with higher density (presumably to get more potential energy per volume of air) where fuel is introduced and ignited to create higher pressure/kinetic energy to run the turbines,  which in turn move the front compressors and the fan. However, in an electrically driven fan, since there is no combustion happening, and the fan is driven by an electric motor, does the engine then need the compressors? Do they perform any benefit in a system that does not use combustion to create pressure?

Then if not, is there any benefit to the bypass system in an electrically driven fan engine? Or does it make more sense to simply switch to a ducted fan system?


texts: What advice would you give a novice pilot on controlling the rudder?

texts:
I've recently picked up flying lessons for ULL (similar to LSA in N.America). I've thought I've been doing pretty well (I guess my experience with computer simulation helped considerably).

Yet more and more I seem to have trouble with my feet and controlling the rudder - my instructor(s) tell me that I just seem to be "unwilling" to move them, yet it just seems to me somehow unnatural and awkward.

Are there some tips for novice pilots on how to dive into the rudder-control, best feet stance etc? (I tried to do a web search but couldn't find anything useful.) Or is it a normal thing for beginners to struggle with this?


texts: Would a drone strike be more dangerous than a bird strike?

texts:
Let's say you have a seagull and a drone of a comparable size.  Pretend either one was going to be ingested by large turbo fan engine, like the one found on a 737 (eg., the CFM-56)

Which would cause more damage and why?  I'm particularly interested in how the fan blades and compressor stages will be affected by the difference in materials.


texts: Can I apply for ASEL and Glider class ratings at the same time?

texts:
I would like to get both FAA Private ASEL and Private Glider class ratings.  I was told I could take lessons for both ASEL and Glider at the same time under a Student certificate.

Can I apply for a Private certificate with ASEL and Glider ratings at the same time? And is it more beneficial to do this than to get ASEL first then Glider?


texts: Can an aircraft have a lifting fuselage that only generates lift at certain speeds?

texts: I came across the blended wing body designs and their advantages etc. They are still very far from reality and require 20 more years till we see them fly. Isn't a conventional fuselage design with a somewhat flattened shape that generates lift during cruise only, a better alternative for now. Would it be possible? If yes, then that means the fuselage usually stalls in all other configurations but during a cruise at a particular AOA. That does mean that drag increases during climb and decent but the efficiency gained during cruise should mean that it is beneficial for a long-range flight?


texts: Could a person damage a jet airliner - from the outside - with their bare hands?

texts:
Given just a small hammer, I'm pretty sure I could disable a large airliner with a few well-placed blows.

What about with my bare hands?

In other words, are there any parts of a large aeroplane that are:

exposed
delicate enough that they could be damaged without using tools
critical to the plane's operation?

The only think I can think of are the pitot tubes and angle of attack sensors.

(Throwing oneself into the engines while they are idling does not count.)


texts: Does Nitrogen inside commercial airliner wheels prevent blowouts on touchdown?

texts:
I just watched the first episode of Inside Mighty Machine where civil engineer-turned-host, Chad Zdenek, discussed innovations of the 747. One innovation he discussed was the increased number of wheels and trucks, along with this tidbit:

  When the 747 touches down, the wheels must accelerate from 0 to 150 mph in a heartbeat, making them skid before they start to spin. That's why they smoke on touchdown. That friction causes heat to build inside the wheel, creating the risk of an explosion, so the 747's tires are filled with nitrogen, an inert gas which, unlike oxygen, won't aid combustion. That helps protect the plane from blowouts and keep landings safe.

That seems like an oversimplification and backhandedly suggests that the alternative is to fill the tires with pure oxygen—a surefire recipe for combustion I would think.

So, (1) is nitrogen really "the thin line" between safe landings and blowouts on modern commercial airliners and (2) is nitrogen landing gear inflation a legitimate innovation of the 747?


texts: Where to find Tach hour and clock hour equivalence rpm?

texts:
There is a revolution counter built into the face of the Tachometer in most piston powered GA planes.  This counter is calibrated in hours.  Most planes also have a Hobbs meter, which is a clock.

Only at a certain RPM are tach hours equal to clock hours.  This equivalence rpm is different among the various manufacturers and models, and it is published somewhere.  For a Piper Archer II with the standard Lycoming O-360-A4M engine, what is the equivalence RPM, and in what document is it found?  It is not in the Type Certificate Data Sheet (TCDS) for the Archer II (PA-28-181).


texts: How can the same runway have two different gradients?

texts: In an unrelated answer rbp linked to this Atlanta airport info page, and runway 8R/26L caught my eye. If I understand correctly, these two runways are the same piece of pavement, but refer to the use of the runway in opposite directions. According to that page, 8R has a gradient of "1.0% DOWN," but 26L has a gradient of "0.4% DOWN." It seems like a physical impossibility - if one is sloped down, the other must sloped up, right? So what am I missing?


texts: Why were turbojets the first kind of turbo-engines, instead of turboprops?

texts:
During WW2, the first jet engines appeared en mass in combat aircraft. Britain and Germany made the first ones.

But why were turbojets first? Why not turboprops, which are easier since the turbo-machinery is smaller for a given thrust. Turboprops have propellers so it would've been a much easier evolution too. If I'm not mistaken, turboprops can fly higher and faster much more easily than piston-props, so it would've conferred an advantage.

So why were turbojets first? Did the concept of a propeller attached to a turboshaft just not cross the minds of engineers during the war? Was it tunnel vision onto the much more powerful turbojets?


texts: How much does basecoat/clearcoat paint cost for an airline?

texts:
Suppose an airline with 15-20 A320 wanted to change the paint for the entire fleet, how much would it cost approximately?

I need this for my thesis, but unfortunately, paint manufacturers I contacted (PPG, AkzoNobel, Mankiewicz) don't want to give any information, since I don't work for an airline.

I understand that for an Airbus airplane the basecoat most likely is 9008 or 9008B900D.
Paint color should be white.

Note: Basecoat/Clearcoats reduce overall paint system weight, since they require fewer paint layers.


texts: Why do some A320s have double-bogie landing gear?

texts:
I believe this is actually a rare sighting, but why do some A320s such as the VT-ESD have double-bogie landing gear? Does Airbus have a specific reason for making such A320s?

Update: Found an image in the former Indian Airlines livery,


texts: How do electric anti-icing systems work?

texts:
How do they work for GA propeller planes? More specifically, how is it implemented on the leading edge of the wing and propeller blades? I'm more interested in the mechanics of electric heating, not the theory or where it gets power from (alternator or batteries).

What are the pros and cons of electric anti-icing compared to other systems?


texts: Why would an airport use crossing runways for takeoff and landings?

texts:
I was listening to some RealATC this evening and came to this one about an accident at LaGuardia airport. This question is not about the accident in any way, but I am using this video because it has an example of what I mean and has a labelled diagram as well.

As the clip advances, it becomes clear that at that time, planes were landing via ILS Runway 13. However, planes were being directed to takeoff from Runway 4.

Under what circumstances might a major commercial airport have planes landing and departing via crossing runways, instead of on the same, or at least parallel?


texts: What kind of waypoints/routes are used to prepare a flight plan in practice?

texts:
I have noticed that FAA provides data delivery service where both waypoints and ATS routes are available to download. By looking at the files, I realize that there are a variety of waypoints and routes. I really want to pick the particular type of waypoint, which are used for pilots to prepare a flight plan in reality. Could you please let me know which types of waypoints/routes are used in practice?
For reference, I am attaching the screenshot from which the types are categorized.

Types of Waypoint:

Types of ATS Routes:


texts: Can thrust be selected manually in a plane with autothrust? If yes, how?

texts: I'm getting into the autothrust world and I have the question of whether it would be possible to disengage it and select the thrust manually in a plane that already has autothrust. How could it be done? Maybe it differs from plane to plane.


texts: I have kids working on a model of a Boulton Paul Defiant, a WWII-era fighter plane. When we found images of this plane, it shows two rods sticking vertically down from the belly of the plane. Some of the images show them to be quite long-- the plane would have a hard time landing if they remained that length! After doing some searching, it seems like these are called "ventral masts". What are these for? Do they retract for landings? Thank you!


texts:
If airport is reporting FEW001 or SCT001 and RVR is above 600m, does it means that there will be no LVO because ceiling is defined as more than 4/8 and DA/DH will be more than 100ft because DA/DH is defined in the name of ceiling.
Or what if some of the SCT001 clouds will get over missed approach point, which is exatly at DA/DH, when pilots have to make decision. So they might not see the RWY at DH200ft, because of SCT001.


texts: Is this test question correct about the causes of detonation?

texts:
So detonation is explained brilliantly in the answer of this question. In the accepted answer, NathanG goes on to say the following:

  the octane rating of a fuel is basically the amount of pressure it can take before it detonates

From what I understand, the higher the number on the octane value, the more pressure the fuel can take, which is why it is used in engines with higher compression ratios.

Assuming octane works exactly the same way in aircraft piston engines as in cars, this has left me confused about a question I was faced with on a small test:

  Which of the following situations may lead to detonation in an aircraft engine?

  A: Running the engine at too rich a mixture setting

  B: Running the engine at too lean a mixture setting

  C: Using fuel of too high an octane rating

  D: Using fuel of too low an octane rating

I thought the correct answers to this were B and D, yet the correct answers were apparently A and C. Can someone explain why this is the case? I'm just not seeing it.


texts: How does the pitching moment change as the speed of A/C approaches critical Mach number?

texts: In an aircraft performance course, I saw that pitching moment goes backwards as the speed of A/C approaches critical Mach number. In fact, that results in nose down pitching moment. But, according to my notes, there must be shock waves at the back of the A/C. In this situation, should not these waves behave as force pitching down? How can it be possible? And why?


texts: Is the old paint removed before applying a new one?

texts:
I've heard that paint on large airplanes weigh 250+ kg.

When an aircraft gets a new owner, do they remove the paint that was previously on or simply paint over it?

If it is removed, how is it removed? What is the correct procedure for painting/repainting an aircraft?


texts: Why do ribs have diagonal struts,why not vertical as seen in airfoils of Citabria airplane?


texts: Do pilots have to consider unplanned delays for Part 135 duty time exceedance?

texts:
When flying under Part 135, is it legal to takeoff knowing that you will exceed the allowable duty time due to an unplanned delay after the start of taxi?

135.267(d) says:

  Each assignment under paragraph (b) of this section must provide
  for at least 10 consecutive hours of rest during the 24-hour period
  that precedes the planned completion time of the assignment.

So if the determining factor is the planned completion time of the assignment, am I good if my passengers showed up late on an earlier leg, or if I have to wait at the runway for 30 minutes before I takeoff if it will cause me to exceed the limit?


texts: What are the aerodynamic differences between the nose designs of the CSeries and the Boeing 737?

texts:
The Bombardier CSeries and the Boeing 737 are two aircraft in the same class. Their nose shapes are very different from each other though as can be seen in these two images. What are the major aerodynamic differences between these two nose designs?

CSeries:

Image Source

Boeing 737:

Image Source

Note: This question and answer set don't really answer my question here because it talks about a generic nose form of aircraft made by Boeing and Airbus. I am looking for specific aerodynamic differences between nose cone shapes on specific models of Boeing and Bombardier aircraft. The Airbus part of that question cannot answer the Bombardier part of this question.

That question also does not talk about specific model as it says at the bottom:

  This image is only an example and my question is not about any specific model.

I want the specifics for the nose cone shapes of Boeing 737 and the Bombardier CSeries, not specifics on the aircraft themselves. This is more like asking for for the aerodynamic difference, for example, between a blunt nose and an ogive nose than something to do with aircraft corporations.


texts: What are the requirements to obtain the ATP license in Canada?

texts: How much exams does a person need to do in Canada do become a ATP pilot and how many hours will be needed to become a pilot, for example ground school time, flight hour time etc....


texts: How are cloud bases and tops reported on PIREPS?

texts:
Let's say I read a PIREP as follows...

KATL UA/OV KATL/TM 1522/FL080/TP C210/SK SCT013-TOP079/WX FV05SM
 HZ/TA M04/WV 24540KT/TB LGT/RM IN CLR.

I'm in KATL where the field elevation is 1,026, so if I were reading a METAR that reported bases at 013 I'd expect to enter the clouds at 2,300' MSL. I'm reading a PIREP here though, so based on this am I expecting to enter the bases as 1,300 MSL or 1,300 AGL? I have the same question with the tops.


texts: If this is not a Lippisch L-13, what is it?

texts: The image comes from a 1956 Nestle, a chocolate maker, sticker album. 'Maravillas del Universo', serie 1. Chapter has 3 pages, and is entitled: 'The sound barrier', signed by the woman test pilot: Jacqueline Cochran. It indicates it's a Lippisch L-13, but it's not, Lippisch L-13 was a rearwards swept Delta design, with a thick Vertical Fin that included the pilot's cabin, it was tested as a glider. Final version had to use a Ramjet, fueled by burning coal in a rotating basket. YouTube video link.


texts: When helicopters are instructed to air-taxi direct to an airport location, are they allowed to pass above other aircraft and people?

texts: When helicopters are instructed to air-taxi direct to a location at the airport, are they allowed to pass above other aircraft / people / road traffic?


texts: What is the purpose of these odd "control surfaces" on the BAE Taranis?

texts:
I was looking at a video of the BAE Taranis, and noticed these weird control surfaces:

There is a matching pair on the underside. They don't seem to move at all throughout the video, even on landing, and yet they seem to be slightly extended.

What are they?


texts: Where can you find wind tunnel visualization data online?

texts: I was wondering if there was a repository of flow visualization results somewhere online, preferably of wing sections categorised in some manner.


texts: Why do the Diamond DA-42 and DA-62 have a minimum fuel temperature requirement?

texts:
On the turbo diesel DA-42 and DA-62 aircraft there exists a minimum fuel temperature limitation where you may not start or operate the aircraft below that.  Does anybody know why this is?  It seems strange as the turbo Diesel engines themselves have their own dedicated engine fuel pumps which raise the pressure of the fuel to 19,500 psi prior to infection in the cylinders.  This should make the fuel plenty hot for combustion.

Is this minimum fuel temperature requirement typical for all reciprocating Diesel engines?


texts: Does the FAA have a best practice for highlighting memory items on a checklist?

texts:
voretaq7 mentioned the following two months ago in an answer:

  The process of designing a good checklist is an interesting Human Factors problem - there's a lot of literature on it but it's way out of scope for this site. The usual solution to badly designed checklists is that pilots get frustrated and write our own.

Funny he mentioned that, because I'm frustrated with a badly designed checklist and I'm writing my own.

Are there FAA-specific best practices for creating checklists in general and highlighting memory items in this specific case?

By this I'm referring to underlining, red-boxing, font changes, color changes, and so on.


texts: If maximum speed was a priority for modern military fighter jets and bombers, approximately how fast would they likely be?

texts:
Burt Rutan talks rather passionately about the lack of innovation in space flight, but also mentions how fighter jet (maximum) speed performance has stalled:

In fact, from what little I know regarding fifth generation fighters, not only has the maximum speed stagnated, but it is degrading.

Traits such as stealth prohibit variable intake geometry and variable wing geometry, the maximum speed appears to never be used in reality, it is probably costly and creates other problems (we only have to look at the SR-71 here). Furthermore, other engine characteristics are probably more desirable, such as supercruise and good acceleration in the range where this is critical and actually useful.

However, in this question I'm asking what, approximately (mach 4, 5, 6?) would the maximum speed likely be, if maximum speed was allocated a similar budget and priority akin to that during the cold war era?

The reason I feel this question can be answered at all, is that I imagine there are some very real, practical problems with very high performance aircraft that require extraordinary solutions to overcome. An answer that identifies where these approximately are would thus go a long way towards a satisfactory answer.

Basically, the crux of this question is to identify if there have been any significant aerodynamic, engine, or other performance related advancements that would enable a fighter jet to travel significantly faster than e.g. the F-15 or MiG-25, while still retaining the same functionality as namely the same types of aircraft.

Similarly for a bomber, it is well-known that sustained mach 3 flight can be achieved by looking at e.g. the XB-70 or SR-71. Even with designs from the 1950s. What is realistic today?

Just to be clear: I'm not expecting an exact figure here, but if there are any studies that have looked into this, it would be a very interesting read. If there are no studies, perhaps someone would want to take the challenge and offer a somewhat comprehensive answer as a conjecture anyway. Any math/physics would be great.

I assume that in order to even begin to answer this question, it must be defined what a "fighter jet" is, must it have an air breathing engine, or can it also have a rocket engine, akin to the X-15? Since I'm asking the question, I will also take the liberty to arbitrarily define this here: The engine type is irrelevant, there may be more than one engine, of different types, of the same type. Whatever would make sense in the context of a fighter jet, or even a bomber. Furthermore, it must be a manned aircraft. If it can reach suborbital flight and beyond, like the X-15, it is still an aircraft (again, arbitrarily defined).

An answer that separates the air breathing and rocket engines as two different categories is fine.

This definition of making if fighter jet/bomber is mostly based on wanting to exclude unmanned experimental aircraft, even if hypersonic aircraft such as the X-43 probably serve as a good reference, I feel they have little root in reality, having no life support, no weapon systems, and perhaps no practical purpose whatsoever beyond data recording.

It may also seem like a pointless question, but this might be quite useful in terms of bridging the gap between aircraft and spacecraft, or any other application one might think of -- suborbital passenger jets, etc.


texts: Can I use my aviation handheld transceiver on MURS?

texts:
Is there a regulation or rule about using handheld aviation transceivers e.g. Icom A-24 for ground to ground communication on MURS frequencies?

Can I just use Icom A-24 for ground to ground? or do I need FCC licence?

Update:

Can I use my handheld aviation transceivers (Icom A-24) for ground to ground communication? or do I need a FCC license?


texts: Is it possible to "pimp up your aircraft" with an audio system?

texts: Can aircraft be modified to have an enormous audio system, like the ones in cars? Has the FAA got any regulations on this (or maybe on in-cabin maximum noise volume?), would power be a limitation for the audio system?


texts: Are ATCs required to notify pilots when they use MVAs?

texts: I understand ATCs may use minimum vectoring altitudes(MVAs) when they deem it as appropriate. When they do that, do they notify the pilots of the fact that they are being radar vectored based on MVAs? Or are pilots expected to query ATCs when they find the newly assigned altitudes below the MEAs on the charts?


texts: Why is the fuel pump in the startup procedure for a Cessna 172?

texts:
I thought fuel pumps were reserved for fuel injected planes in startups and during critical flight phases for all planes?

However. There are some X-Plane flight tutorials that tells us to use fuel pump in startup of C172 aircraft as if we are flying a fuel injected plane. I don't think its necessary for an gravity fed engine but why would someone use fuel pump in a high wing carburetor plane start up? Isn't it a waste of battery?


texts: What is the 3 click sound when the autopilot is disconnected on Airbus aircraft?

texts: On Airbus aircraft what is the 3 click tone that sounds once autopilot is disconnected? I have tried researching on the internet but could not find anything


texts: What defines the end of a "cross-country flight" for ppl aeronautical experience purposes and for general logbook purposes?

texts:
Assume "pilotage" is used for all flights other than circuits around the pattern.
Assume, in the flights that follow, at any point where required, an instructor travels to the departure point and approves the flight.
At what point in the following sequences must the pilot stop logging the accumulating flight time as one single cross-country flight--

For general logbook purposes
For meeting the cross-country aeronautical experience requirements for a private pilot's license under part 61 in the USA? (NOT the "long" cross-country requirement.)
To meet the 200-hour cross-country experience requirement for the ATP rating under part 61?
To meet the 100-hour cross-country experience requirement to act as PIC under part 135?

Please explain your answers.
Let's say a pilot does the following:
Case 1:

a) Takes off
b) Flies to a point 60 miles away, full stop landing
c) Flies back to start, full stop landing
d) Flies to a point 60 miles away, full stop landing.

In case 1, would it change the answer in any way if I revealed that the pilot got out of the airplane and slept overnight between steps b and c only?
How about if she got out of the airplane and slept overnight between steps c and d only?
Case 2:

a) Takes off
b) Lands at a point 60 miles away, full stop landing.
c) Flies to a point 10 more miles away, full stop landing.
d) Gets out of the airplane at eats lunch
e) Flies to a point 10 more miles away, full stop landing.
f) Gets out of the airplane and stretches
g) Makes 10 circuits around the pattern without using pilotage, with full stop landings.
h) Flies to another point 60 miles away, full stop landing.
i) Gets out of the airplane, takes a nap.
j) Gets back in airplane, flies to a point 60 miles away from both the latest takeoff point and the original start point, full stop landing.
k) Rents a motel room and stays over night.
l) Flies on to another place 100 miles away.
m) Stays with a friend for a month, while making 10 short flights around the airport without using pilotage.
n) Flies back to the original starting point.
o) Makes 10 more short flights over the course of the next month without using pilotage.
p) Flies to a point 60 miles away.

In case 2, would it change the answer in any way if I revealed the pilot was on a long vacation and the aircraft and pilot were actually based at the point that the last flight "p" ended up at, and he had departed from there two days previous to the first flight in the list (a)?
Relevant: http://www.boldmethod.com/learn-to-fly/regulations/logging-cross-country-flight-time/


texts: For a large commercial plane on landing, does the L/D ratio increase, decrease, or not change much?

texts:
Consider a large commercial aircraft coming in for landing. The exact part I'm interested in is the flare (where the aircraft noses up yet does not actually go higher above the ground), with flaps extended, but before any ground effect comes into play.

Compared to normal cruise, does the Lift-to-Drag ratio increase, decrease, or not change much at all?

Increasing angle-of-attack increases both the lift and the drag, but probably not by the same proportions. I'm not really sure which way the curve goes for a typical airfoil.

Also, there's a really harsh complication: the flare also results in the engines pointing upwards too. This means that some "lift" is generated directly by the engines' vertical component of thrust. It's not really lift; a more accurate way to say it is the wings don't need to produce as much lift as before, because the engines do a direct part in helping to counteract gravity.

So that might suggest the L/D in fact decreases, which seems so counter-intuitive.

Actual numbers for the L/D at both stages of flight would be the most rock-solid answer possible. But I wonder if the L/D's cited by the manufacturers are derived from a simple wind-tunnel test (at different AoA and flap configuration) or if they actually take into account the upwards-pointing engines and their typical thrust during flare (which would be best measured as a percentage of aircraft weight at that point, and the mess gets messy).


texts: What does the runway distance mean under "Additional Runway Information" on Jeppesen plates?

texts:
See my previous question

What are Runway Declared Distances?

On Jeppesen 10-9 or 10-9A charts, there is a section dealing with Additional Runway Information.  Does these distances correspond to the declared distances in the A/FD?


texts: Where can I find ATC Guidelines for handling Airport Incidents?

texts:
Immediately after an airport incident (e.g. a crash, runway overrun, fire etc.) it is fascinating to hear in recordings the ATC handle various duties so deftly . e.g. Ground vehicles, Fire, Go arounds, the actual aircraft involved, police, medics, tugs, closing runways or airports etc.

Is there any training material on this? I want to read more (My day job is in Chemical Plants & I'm thinking there is stuff we could learn from Aviation Incident Response Procedures).

I imagine these incidents are rare so any given controller doesn't get much by way of prior experience. So the best way to readiness would be via learning from past incidents or guidelines etc.

NTSB reports & past ATC tapes do help a lot but has anyone compiled these learnings into advisory documents? Just like pilots use checklists for difficult situations are there any similar ATC checklists?


texts: How did Airbus A380 overcome corrosion issue in which aluminium wiring used?

texts: The corrosion of aluminium is generally recognized to be a major problem. What new technologies or technics might be used in aluminium wiring to get away from the corrosion issue?.


texts: What are the lettered and numbered signs next to airport runways and taxiways?

texts:
What do these numbers signify?

Can pilots see them while landing?

Do they matter while taking off?

Do Control Tower mention these while guiding planes on runway?


texts: What are these wavy lines on fighters' canopy?

texts:
As shown in the images below, what are these wavy lines on the canopy of the aircraft? Do these lines have any utility?

These are mostly captured in videos of cockpit views of carrier-based aircraft.


texts: Why is the A330/A340's angle-of-attack protection disabled in alternate law, even if the AoA vanes are operating normally?

texts:
Reading about Air France Flight 447, to quote Wikipedia (emphasis added):

  ... A second consequence of the reconfiguration into alternate law was that stall protection no longer operated. Whereas in normal law, the aircraft's flight management computers would have acted to prevent such a high angle of attack, in alternate law this did not happen. (Indeed, the switch into alternate law occurred precisely because the computers, denied reliable speed data, were no longer able to provide such protection – nor many of the other functions expected of normal law).[55] The wings lost lift and the aircraft stalled.

But whether an aircraft stalls or not has nothing to do with its airspeed - the only things that matter are the wing's angle of attack and configuration (e.g., are the slats extended? is the leading edge damaged? have we got ice on the wings?).  The aircraft's configuration was completely normal, and the AoA vanes were unaffected by the blocked pitot tubes (as evidenced by the fact that the aircraft's stall warning correctly sounded due to its excessive AoA during the period of time that the pitot tubes were blocked and valid airspeed data was unavailable).  Why does the A330/A340 disable high-AoA protection in alternate law if airspeed data is lost - even if AoA data remains perfectly valid?


texts: How do I translate this propeller start procedure into English?

texts:
I'm translating a documentary from Hungarian to English. There is a scene where the pilot of an aeroplane with a propeller is preparing for take-off.

He says (seemingly into a 2-way radio) two short sentences, literally: "Propeller pushing. Propeller free." Could anybody help me with info about what an English-speaking pilot would say in this situation. A million thanks in advance!


texts: What are common downsides to leasing an aircraft to a flying club?

texts: I plan on owning my own plane in the coming years and using it to get my PPL.  I've recently been turned on to leaseback with flying clubs.  The pros seem to heavily outweigh the cons, but I always wonder.  What are the common (and uncommon) downsides to employing a leaseback with your own airplane?


texts: Why is the fatality rate in the Diamond DA40 so remarkably lower than the SR20/22?

texts: I assume it has a lot to do with the stall characteristics, but with the SR20/22 having a combined 1.6/100,000 Fatal rate and the DA40 having .35/100,000 Fatal, it seems like a very stark difference. Additionally, the SR-- has a ballistic parachute and the DA40 does not.


texts: Is there a source of deicing holdover time tables?

texts:
Depending on the types of de-ice and anti-ice fluids used, the HOT changes.
Is it possible to post some HOT table here?


texts: Why weren’t the Comet’s overhead ADF windows roundified along with its passenger windows?

texts: Following the crashes of two Comet 1s in early 1954 due to metal fatigue, all future Comets (and the few surviving Comet 1s that were rebuilt rather than scrapped, all of them in military service) were redesigned to mitigate fatigue stresses; among other changes, the passenger windows were changed from round-cornered squares to circles.  However, the windows in the roof of the forward cabin for the aircraft’s ADF antennae, which are of almost identical construction to the passenger windows except for being filled with opaque fiberglass (in which the ADF antennae were embedded) rather than transparent panes, and which are considered to be one of the two possible locations (the other being one of the passenger windows) for the rivet hole that gave birth to the fatal crack in one of the crashed Comets (no wreckage was ever recovered from the second crash beyond that floating on the surface, as the depth of the water would have made salvage operations cost-prohibitive at the time), retained their original rounded-square shape.  Admittedly, the Comet’s subsequent service history seems to have vindicated this judgment (no Comet would ever again break apart in the air from fatigue damage, despite still having squarish ADF windows), but de Havilland didn’t know that at the time, and they thought it prudent to roundify the passenger windows, so why didn’t they do the same for the ADF windows?


texts: Why are the Phugoid and Short period approximated instead of calculated exactly?

texts:
We can calculate the period and half-amplitude time for phugoid and short period using equations of motion. We will get an exact answer.

Then why is there a need for doing approximations to equations of motion for calculating period and half-amplitude time for both motions?


texts: What are the specifications of this Zenith bush airplane's gear and tires?

texts: I would like to know the name (if any) and the specifications of Zenith's bush airplane? I would like to know the size, the diameter, the maximum load, bearing number/type, and so on. Seems that the front gear and the main are different in spec.


texts: What kind of material should I use for rudder skins?

texts:
I’ve done some research on this topic for awhile now, but I’m not exactly sure how to go about it. I’ve heard and read that on some World War Two aircraft had fabric covered fuselages, such as the Hawker Hurricane. The Mosquito aircraft was made of plywood and covered with fabric entirely. My primary concern is how the fabric will hold up and interfere with the yaw compared to metal, and I’m also occupied with costs, repair, and maintenance. This question might seem vague to some, but control surfaces are essential to performing maneuvers and controling pitch, yaw, and roll.

The aircraft speeds expected from the V8 engine are a top cruise speed of 193 knots and an economy speed of 170 knots. The rudder situation is an H-tail configuration, single engine powering a four bladed propeller. The aircraft wing is elliptical, in which the wing extends straight out for six ribs, then slants upwards at an angle of 15 degrees. Landing gear is retractable, taildragger configuration. Flaps are plain with a deflection full deflection of 45.


texts: How does an aircraft move on the ground?

texts:
Does an aircraft such as Airbus or Boeing have motors similar to cars, so that they turn the wheels?
or do they move on the ground with their engines, the same way they fly?


texts: Are jet engines affected by small bird (e.g. hummingbird) strikes?

texts: If a hummingbird got sucked into a commercial jet engine at takeoff would the pilot notice? This is a serious question.


texts: How does carb heat increase the risk of dirt ingestion?

texts:
In this question about turning off carb heat just before landing, one of the justifications for doing so is to reduce the likelihood of ingesting dirt into the engine.
How does carb heat (or the lack thereof) affect the amount of dirt that might be ingested into the engine?
I am not a pilot, but I would think there would be some sort of air filter like there is on a car/truck. Also, I would think that, if anything, ice in the carb (while Not Good™/potentially fatal, especially on landing), would reduce the likelihood of getting dirt into the carb by acting somewhat like a filter - i.e. giving dirt a place to land before making it all the way through and into the cylinders.


texts: Why don't we use hydrophobic (icephobic) coatings over traditional anti-ice methods?

texts:
I am a design engineer on GA aircraft and I had a thought whilst flying in icing conditions the other day. I know there are lots of ways we deal with ice buildup (as per the chart below from this post, many of which are complex in nature and require more attention in design and operation as compared to passive coatings.

Why don't we use hydrophobic (or rather icephobic) coatings instead of using the more common methods like deice boots, TKS or bleed air? I would think a strip of hydrophobic material such as this 3M™ Microfluidic Diagnostic Film or a hydrophobic paint additive that covered the leading edge would work on most general aviation aircraft. I am sure there are downsides that I am not seeing otherwise it would be used much more.


texts: What is the relationship between fuel mixture, throttle setting and engine temperature?

texts:
I'm trying to understand the relationship between mixture, throttle, and engine temp.  In this article from AOPA, it states

... a lean mixture of 16 to 1 is not going to burn as hot as a rich mixture of 8 to 1. ... an engine [runs] hotter on lean mixtures.

This seems in general contradictory but what I'm gleaning is that there are some instances in which a leaner mixture will result in a higher engine temp and other instances in which a richer mixture will.  Perhaps this comes down to throttle?
Could someone clear up for me what are the "primary points" so to speak with regards to engine temp that I should be aware of?
Further, does there exist a general graph somewhere with mixture, throttle, and engine temp on the x, y, and z axes, respectively?  I might expect to see local maxima at full lean, full rich, and stoichiometric and local minima at I don't know where.


texts:
How practical might it be, to carry military tanks by helicopter(s) to remote areas?

Wikipedia lists the M1 A2 Abrams tank at 65 metric tons.
HeliPress lists the Russian-made Mi 26 copter as being able to carry 56 tons; it’s unspecified as to which type of tons.
Might it be practical to carry in by helicopter a crane of sufficient lifting capacity to assemble “reasonably quickly”, a tank that had been disassembled to weights that could be carried by helicopter(s)? I believe it would be practical to carry in such a crane, & assemble it reasonably quickly.

Then there’s the aspect of what sort of areas might tanks need to be flown to: High elevations permit smaller payloads, as do hotter temperatures. Presuming the helicopter(s) would take off from an aircraft carrier, how far would the flight likely need to be?
Thank you for your attention to this.


texts: How do ADS-B and ADS-C get used on transoceanic flights?

texts:
I have three questions regarding ADS-B and ADS-C. (Hopefully you don't feel my questions are not related.)

(1) What's the scope of availability of ADS-B? Let's say an airliner equipped with all the necessary equipment for ADS-B in the US flies over to Tokyo. When or where does ADS-B stop working?

(2) I read from this post that ADS-C is used in some oceanic environments including the Pacific between certain flight levels. Roughly what percentage of transoceanic flights currently take advantage of the ADS-C system?

(3) I assume ADS-C is not a common transoceanic surveillance system, if it's true ADS-C is only used above certain flight levels. If so, what are alternatives to ADS-C? What other (surveillance) systems are being used to follow transoceanic flights? Self-reporting? GNSS? Or what?


texts: What is this wire going from mid-fuselage to the tail on this 737?

texts:
In  this question the following image is shown, with the question what the two bulges at the aft fuselage are.

However, I'm wondering what this wire is that starts somewhere midway the fuselage, and goes to the vertical stabilizer.
Is it also radar related?

Image Source


texts: What does it mean to move a single flight control to its full deflection?

texts:
It is the speed below which you can move a single flight control one time, to its full deflection, for one axis of airplane rotation only

This is part of the explanation of maneuvering speed.
What does 'full deflection' mean?
Is applying full rudder full deflection?
Is turning the yoke 90 degrees full deflection?
What about in the pitch axis?


texts: Why do military turbofan engines use a low bypass ratio?

texts:
I know that the most civilian engines use a high bypass ratio which is good for fuel economy and noise reduction.

What prevents military engines from using the same technology instead of opting for low bypass engines?


texts: Why don't transponders have active and stand-by value like radios?

texts:
This answer explains how pilots when switching code on transponder should either carefully avoid temporarily squawking one of the emergency codes, or should temporarily put the transponder in stand-by.

Radios (both comm and nav) usually have an active frequency and a stand-by frequency and the pilot selects the stand-by frequency and then activates it with a button, which avoids temporarily selecting different frequency and limits the time when the radio is not receiving.

Why don't transponders have similar mechanism? It seems it would be much more useful for them than it is for the radio.


texts: Which countries in Europe allow for the use of Pilot-Controlled-Light?

texts: In Europe is very uncommon to see this feature at airports due to the local regulations in different countries, but still some are allowed and use this system. What countries allow for its use? Please name at least one airport for each country which uses it.


texts: Why are aircraft windshields not unbreakable?

texts:
From a materials engineering standpoint, cockpit windshields,
  typically weighing between 25-40 pounds, depending on the type of
  windshield build, are typically constructed of several layers:

  (1) A glass face-plate, roughly 1/10" thick;

  (2) A Polyvinyl Butryal (PVB) layer, about 1/8" thick;

  (3) A stretched acrylic layer, approximately 1" thick;

  (4) An additional PVB layer, nearly 1/10" thick;

  (5) An additional stretched acrylic layer, approximately 1" thick. Source

But even then, it is not unbreakable. We have had several cases of broken windshields, as mentioned in above source. Also, the co-pilot  in Varig Flight 254 crash was wounded from a tree, which struck his shoulder after crash landing.

So, why are aircraft windshields not made from unbreakable Glass Ceramics ?


texts: Are there any reported cases of noise from helicopters causing damage to property?

texts:
In the Netherlands, three cases have been reported of Chinook helicopters' rattle noise (low frequency sound) damaging solar panels. The Dutch defense ministry recognises this problem and the lawyer representing some of the victims says these may be the first cases (worldwide). Source (in Dutch)

I'm wondering if there are any more of such cases (possibly involving damage to property different than solar panels or involving different helicopters). I found the following literature study on rattle noise (in Dutch, sources mostly in English). The study states that damage to buildings is possible according to laboratory tests, however, as far as I can see it does not name any real world examples of such damage.

My question is if anyone knows of any such damage (different from this report in the Netherlands) to (civilian) property caused by rattle noise from helicopters.


texts: Will high blood pressure affect my pilot medical certification?

texts:
I will most definitely start a training for a glider pilot license at our local flight club. This of course requires a medical certification for pilots. The only concern I have, is my blood pressure.

I am an 18 year old male with an overall healthy condition. However the last few times I had a doctor's appointment, I had a somewhat high blood pressure (it was always between 150/70 - 180/85 mmHg). Online I haven't really found that much information about the limit of the blood pressure in order to still get the Medical.

I have found some sources saying that everything below 220/125 is good, but I think those sources we're only speaking about passengers of airplanes, not pilots.

For your info: I live in Germany, and I suppose there are other regulations regarding the medical in other countries, but overall I think the requirements don't differ that much.

Hopefully someone can tell me if I should be concerned or if my blood pressure is still okay to fly.


texts: Why don't airships / blimps use frontal stabilizers or thrusters?

texts:
Is there any reason why frontal stabilizers aren't used on blimps or airships to ease maneuverability in, e.g., gusty winds? Even the indoor blimps have a tail rotor, not the nose rotor for rapid yaw movements.
Also, is there any reason why the "pusher" motors are used instead of puller-ones in the front (with an exception for the Lockheed Martin P-791)?


texts: Can any aircraft adjust the wing dihedral in flight?

texts: Are there any aircraft that can mechanically modify the dihedral angle of the wings whilst in flight? Would this solution give any advantage?


texts: How much does it cost to fly a plane? INCLUDING lessons, and everything else

texts:
It seems very difficult to find this information on any legitimate sites, so I'm going to ask here. I know nothing about flying, and this wouldn't happen for years to come, but I am curious.

Let's say I want to someday go into my backyard, get into my plane, and have  flight to start the morning, then land back in my property (which would obviously have to be quite large).

How much, generally speaking, would ALL of the following cost me:

-Flight lessons, from complete noob to completely done

-Small, modest, low-tech, possibly used, two seater personal plane

-reasonable range for the upkeep costs of a plane (fuel, maintenance, etc.)

I realize that this is difficult question to answer, but I'm looking for a very general, rough idea. At least an order of magnitude estimate.


texts: Do French, Spanish, Italian, and Greek controllers still speak to their native pilots in their native language?

texts:
At the time of my retirement in 1999, controllers in France, Spain, Italy, and Greece typically spoke to their native pilots in their native language in spite of the fact that English was/is the international language of aviation and is specified as such by ICAO. Not following the ICAO convention deprived non-native speaking pilots of valuable situational information.

Does anyone know if any of the aforementioned countries have come around to having their controllers always speak English?


texts: When designing a new plane, does aviation industry use style designers like car industry, or are the decisions made by aerodynamicist; will they solely determine what the plane will look like?


texts: This question has been intriguing me for some time. In Autogyro the rotary blades merely acts as what fixed wings act in normal aircrafts to generate lift. So why not simply have a fixed wing instead of rotary "wings"? What advantage do this rotary nature of wings provide compared to fixed wings? In both ordinary planes and autogyros the propulsion is generated by the front or aft engine.


texts: Can a non-IFR rated pilot accept an IFR clearance, provided the operation occurs in VMC only?

texts:
According to this FAA ruling a pilot can operate an aircraft under an IFR flight plan even if the aircraft is not IFR certified, provided the operation occurs in VMC.

What the ruling doesn't differentiate is whether the pilot doing that operation must be an IFR rated pilot (the ruling is with respect to instrument training, which implies there will be a properly rated CFII onboard).
I can't find the regulation that states that you must have an IFR rating to accept an IFR clearance/operate on an IFR flight plan. So, my questions are:

What regulation (if there is one) requires a pilot to have an IFR rating in order to operate an aircraft on an IFR flight plan?
Would a "VMC only" modifier change this requirement?


texts: How do I find the historical arrival procedure GOLDN6 for SJC that is no longer valid?

texts: I don’t know exactly when this procedure disappeared.  It was used in 2013, but not sure how much longer.  It was used primarily by SEA to SJC flights.


texts: How did NASA Langley end up with the first 737?

texts:
This answer shows N515NA, CN/MSN: 19437 as an early 737, and mentions that it may be the first one.

Was this a special design built for NASA, or perhaps a prototype that nobody wanted for commercial use?


texts: How much time does it take to calculate the leveling and weighing of big and small aircraft?

texts:
What methods are used to achieve that?

According to my search :

For old planes they use a plumb bob and measuring tools.
On new and big planes, the process is computerized. Built-In Electronic Weighing like the Boeing 777