texts: In what airspace may gliders fly in clouds in the UK without an IFR flight plan and without contacting any air traffic control facility?

texts:
In what airspace may gliders (sailplanes) legally be flown in clouds in the UK without an IFR flight plan and without contacting any air traffic control facility?
Also, how high does this class (classes) of airspace typically extend in areas where cloud-flying in gliders is commonly practiced?  (A general range is fine--the intent is to allow the reader to compare and contrast with Class G airspace in the US1, which rarely extends higher than 1200' AGL.)
Footnotes--

Cloud flying in gliders in the US is rare for several reasons, including the fact that the pilot would be required to have an instrument rating in airplanes (see FAR 61.3(e)(3)).

Some other related ASE questions and answers of interest--
Can you fly a glider in a cloud on primary instruments?
Can you fly a glider in a cloud on primary instruments?
Can you fly a glider in a cloud on primary instruments?
"Teaching Instrument Flying"-- Instructor Training Notes-- Dartmoor Gliding Society
"Instrument Flying Training Notes"-- Dartmoor Gliding Society
Cloud Flying endorsement webpage from Motorglide.co.ok


texts: What advantages come with the wing on the Boeing Bird of Prey?

texts:
I noticed this picture yesterday of the Bird of Prey and wondered about the wing design and what advantages would come with this unique wing design compared to other aircraft?

Source:(www.wired.com)


texts: What plane was this hotel room converted from?

texts:
The below image is of a converted aircraft now functioning as a hotel of sorts.
I am having trouble identifying the type of the aircraft. It is not on the listing page either. Does anyone know what aircraft this was?


texts: Any script to plot multi axis FDR / flight-test data (such as the ones used in air crash investigation)?

texts:
I am looking for a script or tool to create flight test and/or FDR plots with several vertical axis, such as the ones used in aircraft accident investigations.

Does anyone have any hint on a MATLAB or Python script that does it? I have the data and I know how to code, just didn't want to reinvent the wheel here.

Example:

Source


texts: What are the safety demonstration time-constraints?

texts:
On airliners, the safety demonstration includes many items (seat belt, life vest, evacuation, etc.) and each of those items may raise questions from the passengers (when to inflating the life vest, how to unlocking the seat belt, ...) and thus need more time to explain why those items are detailed.

Given the following elements:

the safety demonstration should begin while leaving the gate.
an average passenger may not pay attention for more than few minutes
the briefing should be finished before take-off (I hardly see flight attendants moving and manipulating life vest, seat belts and other objects in the middle of the aisle while taking off)
many items may need a better (and longer) explanation

I have several questions:

Are there any regulations about the timing of the safety demonstrations?
Is it up to the airline (automated videos are quite easy to time)?
What if the safety demonstration are not finished when the aircraft is ready to take off (on the runway with all clearances)?


texts: What structural design methods were used for early turbojets?

texts:
I have had this question for long time. Can anyone please give me some references on early turbojet engine design methodologies?

For example P&W J57 which was designed in early 1950's: How were vibrations, resonance and aero loads calculated and analyzed, most probably without having computers? I'm not too sure whether there is any closed form analytical solutions anyway.


texts: Could improper deplaning of a flight with full fuel tanks cause the plane to tip?

texts:
Reading this article regarding an Alaska Airlines 737 Flight that had to turn around back to the gate. There was a following statement:

  At the gate, passengers were unloaded five rows at a time, to minimize the risk that the plane would tip under extra weight of fuel.

My general understanding is that the fuel tanks are usually placed near the COG (wings, cargo tanks). Assuming the tanks are still full, why would unloading of passengers all at one time possibly cause the plane to tip? Or is this bad reporting?


texts: Is this angle of attack animation backwards?

texts: Is this animation of the angle of attack sensor in this video from 25:30 to 25:50 correct?  It seems like motion of the sensor is the opposite of what it should be based on the angle of the aircraft.  For example, given an angle of attack sensor mounted on the right-hand side of the aircraft, I would suspect that a strong nose-up attitude would cause the blade on the aoa sensor to turn slightly clockwise with respect to the body of the aircraft.  But to me the animation displays a counter clockwise turning for the nose-up attitude.


texts:
I love aviation and I love learning new things about it.

I was wondering if anyone knew all of the squawk codes and in particular what squawk 7500 means.


texts: What method does ATC use to calculate distance between two aircraft?

texts:
The distance between aircraft must be larger than the minimum separation all the time and is therefore quite important for Air Traffic Control (ATC). As I need to calculate the distance between aircraft for my research, I'm wondering if there are any regulations (in Europe) about how exactly the distance is determined.

How exactly does ATC determine the distance between two aircraft?

I suppose that they are working with latitudinal and longitudinal coordinates and probably the altitude to determine great circle distances. To get the coordinates, they could use either radar or the position which is communicated by the aircraft.

The task to calculate the distance from coordinates is not that trivial as it may sound from the first impression. One method to calculate the distance is the haversine formula. In all methods, the assumed earth radius is rather crucial. If the distance is calculated in that manner:

Which value is used as the earth radius?
Are the different earth radii from the equator to the meridian regarded?
Is the altitude of flights included in the calculation?


texts: What are the legal effects of an inoperative anti-collision light?

texts:
In an airplane which is only equipped with a beacon for anticollision lights (1967 Piper Cherokee, for this example), what is the effect of an inoperative beacon?  Obviously, per part 91.205, anticollision lights are required equipment for VFR Night.  But, since the aircraft was certificated before 1996, it is not required under 91.205 for VFR Day.

Now, the interesting part is, under 91.209, since the aircraft was equipped with anticollision lights, it sounds like the aircraft would not be airworthy.

The guidance I've heard on this seems to be conflicting.  One argument was since the equipment was disabled and placarded, it doesn't qualify.  Alternatively, in 91.213(d)(2)(iii) (also referenced by AC 97-61 figure 2), it states that if the equipment is required by part 91 FARs, (91.209 seems to apply here), it is unairworthy (and deactivating/placarding is not an option).

A final point of confusion, specific to this in example: the beacon was an optional feature of the 1967 Cherokee according to the manual... which brings me here: any other opinions, short of a more formal clarification? I'm inclined to err on the side of caution, especially since the definition of "equipped" isn't getting any clearer (other than seeing that little red light on there and the "inop" marking on the panel).


texts: Is this "wing-wave" early after takeoff really a pilot tradition?

texts:
I saw this video of a "wing-wave" immediately after takeoff of a 747-8 pop up on my Instagram feed. In the description, someone says that their friend is the pilot and that he did it to wave goodbye as it was the planes last visit to the airfield and that this is a tradition among pilots.

To the layman like me, it doesn't look too safe - but since the pilot did it, I'm sure it is. Is this really a pilot tradition and do they do this on passenger flights and most importantly, was this safe?

A comment (for what it is worth) said:

  Steep banking an aeroplane few seconds after rotation at dangerously low speed and low altitude is always dangerous. Waving goodbye is not uncommon however this would be considered reckless. I would not be surprised if his competent authority and Company would have an issue with this.


texts: What is the purpose of the small fins on top of the wing surface of Boeing aircraft?

texts:
I've noticed on most Boeing aircraft that there are small fins on the upper surface of many of their wings. They are about one inch high and maybe two inches long (it's difficult to judge size from inside the passenger cabin without any reference) and spaced about a foot apart.

On the 737 there are eight of them spaced about a third of the way from the wing's root to its tip. On the 757 and 777 they are spaced out to almost the wing's tip, and I can't see them on any pictures of the 747's wing.

Here's a picture of them on the 737's wing:

What purpose does these serve?

The only thing I can think of is that they somehow discourage span-wise airflow, but they seem too small and short to accomplish much. The stall fences I've found in pictures via Google are all much larger and extend around and under the leading edge.

OTOH, a diagram I found here suggests that they are placed at just about the place where the airflow turns span-wise.

They must serve some purpose.


texts: What is the nominal frequency of the satellite communications terminal on MH370?

texts: What is the nominal frequency of the aircraft terminal on flt 370? (The terminal used to provide the handshake with the satellite). The raw data provided by the accident team does not specify this frequency.  This frequency info would help in checking their BFO calculations.


texts: Under what circumstances can Part 91 allow compensation for air transportation?

texts: Can a commercial pilot fly passengers for hire without an air carrier certificate, considering that the aircraft is owned by a private company that hires the pilot and the plane has room for 5 passengers and 2 crew?


texts: How can I identify the aircraft’s phase of flight in this picture?

texts: It’s me again, can anyone explain how to know the aircraft’s phase from this picture? Is it cruising or descending if so why its flaps up?


texts: Can a pilot who is not a CFI give instruction?

texts: Can a pilot (other than an ATP) who is not certificated and current as a CFI give instruction in aircraft required for the issuance of a pilot certificate, e.g. a private pilot certificate?


texts: What kind of batteries are allowed to be transported?

texts:
I am based out of India and I have to send two mobile phones along with batteries to Japan.  I thought of sending it by DHL.  This link gives information about regulations regarding the batteries.

I want to know whether the following batteries if put inside the phones and discharged is acceptable for courier or not:

A relevant paragraph at the end of the linked article is:

  Due to the fact that PI965 is forbidden on passenger aircraft we offer
  a limited service. PI965 Section II requires separate dangerous goods
  account approval, since April 2016. For additional information please
  contact your local DHL representative. Lithium ion batteries packed
  with equipment (PI966) or contained in equipment (PI967) are
  acceptable for transport.

Does that mean if I pack the batteries inside the phones it is acceptable ?


texts: How is the effect of wind on arrival time handled?

texts:
If a commercial plane encounters strong tailwinds, would the pilots set the autopilot for a fixed arrival time (if that is possible), or would it be ok to arrive way ahead of schedule?

I imagine this could disturb airport operations, and that there are fuel economy considerations: if I was the airline, I would try to minimize fuel consumption.

But if I were ATC, random arrival times could cause chaos. Passengers in turn would probably be happy to arrive as fast as possible. It seems like there are conflicting interests.


texts: Is there anything in any airport called a "warm apron"?

texts: I heard a pilot said they are located at big airports like LAX. But I couldn't find any information about it.


texts: What‘s the thrust of two stacked propellers?

texts:
Let‘s say that you have two identical propellers and each is powered by their own motor and together they produce a thrust of 1 kN. How does the thrust change if instead of operating them side on side I stack them one over/behind the other? I‘m sure they wouldn't still produce 1 kN but how much would it approximately be?

Furthermore, what if I added another propeller of this type and so on?


texts: Where does the transponder read altitude, or does ATC get it from radar?

texts: When flying instrument approaches in a rented plane, Approach called out an altitude discrepancy between the assigned altitude which is being flown using the altimeter and the altitude being reported by the Mode 3/C transponder.  Back at the hangar, the question is: does the aircraft have or need an encoding altimeter interfaced to the transponder to report altitude, is it built into some transponders; or was the Approach controller using altitude as reported by the radar if it has height finding capabilities?


texts: Why does the Ikarus C42 pitch down when stalled?

texts: Apparently, the C42 nose pitches down shortly after stall, like in this video. I know part of the video might be pilot input to recover from the stall, but I've read on various flying forums that this will happen naturally without input anyway. Why is this?


texts: Why do fighter aircraft manufacturers still focus on making their planes more dogfight-worthy?

texts: In today's age, when dogfights are simply a relic from the past, why do manufacturers keep on increasing their aircraft maneuverability, in order to make them better dogfighters. It is more understandable if they were to make stealthier or more efficient fighters, but when the dogfight is extinct, why make planes even more agile and maneuverable?


texts: What exactly is tower enroute control? Is this similar to 'preferred routes'?

texts:
I am reading about 'Tower Enroute Control' and I saw this on wikipedia "Tower en-route control is a collection of published low-altitude, short-distance IFR routes through large metropolitan areas that require no level of air traffic control higher than approach-control facilities" I also see that you can get these out of the A/FD.

My question is when do you use tower en-route control? Is it commonly used or rarely used? How is an IFR flight different when on a tower en-route control flight then on say, a preferred route?


texts:
We are in the research process of a panel upgrade in a M5 Maule.
The ac is used for transportation and aerial survey to support ground survey. We frequently fly tight, low alt grids. Lateral and vertical deviation limits are 50’.
Is it possible to display WAAS enabled GPS Flightlines on older mechanical flight directors such as S-tec?


texts: How does ATC ask a pilot to resume flying a published SID / STAR?

texts:
Let's say that you are cleared for and are flying the ZZOOO2 departure out of KSAN and you get vectored off of the departure before you complete it.

At some point, ATC wants to put you back onto the departure.

How would ATC ask you to get back on the ZZOOO2 departure, adhering to all altitude and speed restrictions along the way? Is there standard phraseology that exists?


texts:
Would this two-rotor hovercraft design work? The bold black line is weighted metal on the lower to stable it. If it helps, this is a human sized hovercraft.

Would it work if:

prop1 lift > prop2 lift
prop1 lift = prop2 lift
prop1 lift < prop2 lift

The difference between prop1 and prop2 lift should be in a range of 0-30%

NOT TO SCALE, assume that lower weighted bars are equidistant from middle of hovercraft.


texts: What are advantages and disadvantages of flaperons?

texts: What are some advantages and disadvantages of flaperons? Do they cause some issues or are they top-notch reliable?


texts: Can someone identify this scrapped high-wing plane?

texts: I consider myself to be a decent aircraft identifier, and when I saw this plane when exploring an aircraft graveyard, I was not able to identify it. I took a pic and showed it to several aviation Facebook groups, and nobody was able to identify it. Maybe we’re just being dumb and it’s something simple, but can somebody help? Thanks!


texts: Why aren't "fuel polishing" systems removing water & ice from fuel in aircraft, like in cruising yachts?

texts:
Should you sump fuel tanks when the fuel system is below freezing? the question

should one sump fuel-tanks before flying, if in freezing-conditions?

but this implies another question that boggles me:
Why don't aircraft have "fuel polishing" systems, to remove water from tanked fuel, especially since the cost of having a line block with ice, is so horribly high?
Cruising boats sometimes have such things, & given the peace-of-mind it'd give, why aren't these devices in play, in aviation??
( btw, it essentially is a filter & water-bypass thingy, so the water goes to the bottom of the glass bowl, & the fuel, above that, goes through the filter, if they combine them, or maybe the water-separator & the filter-unit are separate, in sequence, but both are present, before the fuel goes anywhere near the engine... )
I believe a fuel polishing system is run before firing-up an engine.
This removes all the contamination before the engine's fuel-pump even starts.
edit 2:
Marine Diesels, in the stuff above...
Also, this is in light of some events written about years ago...
1 was a small jet that lost power at high altitude due to slush-ice in fuel,
another was a jetliner that smashed after the same problem, ttbomk...

slush-ice in the fuel clogged something in the fuel-system, causing...

a drop in power, so therefore the crew...

increased thrust, which caused ALL the engines to clog/die, so the new recommendation was...

if in that type, at high altitude, in cold, if power reduces unexpectedly,
then reduce thrust to unclog the lines, & it should clear...

also many apparently have had problems with ice in fuel messing things up for them in piston aircraft...
also I know some are running automotive-conversions,
& if anyone ever has ethanol-blend gas in their aircraft,
& that ethanol has absorbed water, & gets cold, it can separate out,
leaving 2 distinct fluids in the tank:
ethanol-water & gasoline.
( I'm not saying running auto-fuel is legal in an aircraft,
but rather that I know human-nature. )
edit 3:
that link above includes some interesting stuff
also, the whole idea may be bunk,
if the amount of ice-slush in a jetliner's tanks is measured in tonnes, rather than litres,
as no catching-out device is going to handle that kind of volume.
I don't know what volume is involved.


texts: Why is the use of tail-down force so common?

texts: Why is the use of tail-down force so prevalent in aircraft design?  Why not use canards to avoid induced drag?


texts: What are the most common cockpit system and instrument failures in small airplanes?

texts:
What could one expect to be the most common cockpit system and reliant indicators to fail in a small airplane like a Cessna 172 or Piper Archer? Would gyroscope failures or vacuum pump failures be one?

Edit: This question is different than this one: What component of an aircraft is most likely to fail? because I am not asking about components, I am asking about systems and instruments.


texts: What percent of the world's airline operations are in the USA?

texts: What percentage of the world's airline operations are in the USA?  And how does this number compare to other first world countries such as the UK and Canada?  How about places like China and India?  And finally smaller third-world countries?


texts: What do Air Traffic Controllers (tower supervisors) say to pilots before takeoff and landing?

texts: I would like to know exactly what Air Traffic Controllers say to pilots pre departure and pre arrival. (In terms of exact information rather than specific example) For example what dialect they use and what info they give.


texts: Was a six-engine 747 ever seriously considered by Boeing?

texts:
The Boeing 747 can carry a fifth engine on the side. As the airframe looks quite symmetric, I think that it would not be big work to hang a sixth engine on the side as well.

From here, we seem to be quite near to the six-engine aircraft - a few extra pipes and wires are probably all we need to get these engines turning.

Was a six-engine 747 present at some time of its development history? I think this could be, assuming:

less powerful engines than eventually were available
maybe it could take off with less runway
some special uses with very heavy payload.

There are no six-engine variants mentioned, built or proposed, on Wikipedia.

The expected answer would mention some sources relevant to the design decisions through the history of this aircraft.


texts: What US customs procedures must the pilot of a private aircraft follow when traveling in and out of the country?

texts: As the Pilot In Command of a private aircraft, what are the customs procedures that must be complied with before leaving, before returning, and upon arrival to the USA?


texts: Why are the pitot tubes on supersonic combat aircraft so long?

texts:
I've noticed that on combat aircraft the forward (nose-mounted) pitot tube is usually very long, on the order of half a meter to well over a meter on some aircraft. Why are they so long? Surely the body of the aircraft is not disturbing the air in front of the craft, neither during subsonic nor supersonic flight.

Example, from an AIDC F-CK-1:

Example, from a Mirage III:

Note that I couldn't find any good pictures of the Mirage in which the entire pitot tube actually fit in the photo!


texts: Why would a runway friction measurement improve over time?

texts:
Why would a runway friction measurement that I've just made (with a SARSYS friction tester) give better (condition improved) results than a measurement that I made 6 months ago? The runway has been in use in the interim and no repairs have been made in the interim.

The runway is asphalt and 15 years old. For both measurements, the runway was dry.


texts: What is the technical name for the “time boxes” on an instrument approach plate?

texts: Some instrument approach plates include a list of groundspeeds and times from the FAF to the MAP. What is the real name for these time boxes?


texts: What’s the difference between “approved” and “legal” procedure?

texts:
I occasionally see these two words used in opposition; for instance [emphasis mine]:

  In the United States, aircraft usually join the pattern at a 45° angle to the downwind leg and abeam midfield. Although aircraft may legally join the pattern at any point, the AIM clearly states that the only approved pattern entry is the 45[° angle entry].1

In the referenced circular AC 90-66B CHG 1, the words “approved” and “legal” don’t appear except in other contexts.

So,

Is this just imprecise layman terminology in use on Wikipedia?
Or do the two terms have defined meaning somewhere?

My guess is that a pilot-in-command can deviate from “approved” procedure to other “legal” procedure whenever deemed necessary by exercising PIC authority, but deviation from “legal” procedure would be allowable only in emergency (“mayday”) or urgency/distress (“pan-pan”) situations? Or perhaps also if controllers direct or authorize deviation?2

I’m curious primarily about flying under FAA and ICAO regulations, but if this terminology differs in other jurisdictions, I’d be interested in that as well.

1 From English Wikipedia, “Aircraft traffic pattern”, retrieved 16 Aug 2019 20:30Z

2 Wording in the circular §8.2.1:

  The FAA does not regulate traffic pattern entry, only traffic pattern flow.

gives a clue in specifying that the 45° entry is not regulated.


texts: How can a person receive an expired life vest?

texts: I wonder if passengers could receive an expired life vest because who else would they give to.


texts: How fast do four Tire-Propellers have to rotate to lift 2000 lbs?

texts:
I just saw this come out, Goodyear's Tire-Propeller Concept – a combination tire that can also act as propeller (well, more like a ducted fan I guess).

There's a neat video that goes with it, describing how the fan blades need to bend while being used as a tire. (Otherwise, one winter in New England would take them out!)

Any ideas how fast something with say four 18 inch diameter wheel/propellers, and 3-4 inch fan blades, would have to spin to generate enough downforce to actually get 2000 pounds off the ground?

The weight is the vehicle with 4 motors, 300 pounds of batteries, 600 pounds of passengers & baggage; comparable to my 2500 lb max gross weight airplane, but with weight savings of no wings or tail structure, and batteries vs fuel. 4 motor/fans, and allowing (requiring?) the lift off process to be from a stop, so that all 4 motor/fans could be rotated from road use to propeller use (vs rolling on 2 like the video shows). I imagine 14,000 RPM or some high speed would make quite a lot of noise, compared to the takeoff noise of my 180 horse power engine and 86 inch propeller.

Edit: This rim-driven propeller wheel doesn't look like it would have much total blade are for moving air. That would take even more speed, wouldn't it?

The Moller Skycar seemed quite noisy for a comparison.


texts: How do we determine whether the airfoil trailing edge should be cusped or pointed?

texts:
I'm working on a project and I need to decide whether an airfoil has a cusped or pointed trailing edge given the x and y coordinates of the airfoil.

What is the difference between the two trailing edges?


texts: Where can I go to sit in the cockpit of a Boeing?

texts:
This might sound like a silly question to some, but is it possible to go and sit in the cockpit of a Boeing 737, somewhere in the UK? (Otherwise in Europe, or beyond).

Maybe at a museum or something? I'm building a [currently tiny] home cockpit based on a 737, and I'd like to see how the real thing looks and feels.

I tried searching online, but I couldn't find anything.

Hope this isn't too dumb of a question, i.e. "not possible Jim!"


texts: What are early/inside and late/outside turns (see, e.g., PBN Manual Order 8260.58A) and when do pilots perform them?

texts:
While studying FAA's PBN Manual (Order 8260.58A), I came across the concept of early/inside and late/outside turn construction (Section 5-3. Turning Departures).

For each of the possible cases, it provides instructions for constructing different Obstacle Clearance Areas.

Here are some examples:

  a.) Early and inside turn construction

  1. Turn following VA leg.

  2. Turn follow VI leg.

  3. Turn-at-fix (FO or FB).

  b.) Late and outside turn construction

  1. Wind spiral application

My question is, what are these kind of turns exactly? Are they special cases of a "normal" (expected) turn? In addition, how do pilots know when they have to perform such turns?

What also confuses me is the fact that the PBN manual, which describes the design of IFPs, covers such cases that have to do with a pilot's/ATC's "on the spot" decision. When designing, for example, a SID, shouldn't you end up with one (multi-branched or not) Departure Procedure, with specific waypoints selected after the evaluation of specific Obstacle Clearance Areas covering "normal" turns and not special cases?


texts: How do I get permission to fly when diagnosed with Sleep Apnea?

texts:
I was diagnosed with Obstructive Sleep Apnea a few weeks ago.  I'm told that this somehow complicates my ability to get a license (I haven't started on my license yet.)  I'm having a hard time figuring out what the FAA page is trying to tell me (and what the accompanying "helpful chart" means.)

Could someone who speaks FAA style legalese give me a run down of what is being said?  I just want to know if I'm allowed to fly with treated sleep apnea, and what I need to do to make sure my medical is completed properly...


texts: How can I fix the stalling of an RC plane after the addition of floats?

texts: I'm modifying a RC plane into a bi-plane with floats and it keeps stalling. I don't have a bigger battery or better motor to add so how do I fix this? This is the biggest challenge I've ever faced.


texts: Does the profit from selling duty-free items on board justify flying the carts?

texts: Some airlines have duty-free carts (2) with items for sale on board. It seems that only a few items get sold each flight. Does the profit from selling a few items justify the cost of having this extra weight/volume on board?


texts: How does an operator change an aircraft's maintenance program from high-interval to low-interval?

texts:
I have question for CAMO operators. If you have a maintenance program that is high-interval and the aircraft operates in excess of the maximum permissible hours and cycles you must go to a low-interval maintenance program.

How do you do the bridge check from high-interval to low-interval if you find yourself overdue for a low-interval check when you make the switch?


texts: How do I find the shear center of an unsymmetrical airfoil?

texts:
I'm quite a newbie of these systems and I am designing the wing box of a drone. I know where I want my shear centre. However, I have been trying to determine the shear centre of my idealized airfoil. My airfoil is the NACA6412 and it's highly unsymmetrical.
I know this subject have been touched in this forum before and I have read T.H.G Megson a lot, but I think I am missing something.
I have been stuck in this problem for 3 months now and if someone can provide some light on it, it would be great. My goal is to implement this determination in a script or in excel for future situations.


texts:
I came across the term "Boundary layer tripping" but I can't really underastand it. After searching on internet I cannot find any video or an image explaining that concept. Could you please explain what is "Boundary Layer tripping" with some figures/illustrations if possible?

I appreciate your help.


texts: Why are there many pilots who don't say "mayday, mayday, mayday" to declare an emergency?

texts:
I've been listening to some ATC from some major commercial pilots and in every video where there's been some confusion about declaring an emergency they've used some terminology other than "mayday, mayday, mayday" (here's an example).

Given that how unmistakable saying the word "mayday" is three times in succession to people of different languages and accents, and that it's much quicker than saying "declaring an emergency, declaring an emergency, declaring an emergency", I'm trying to understand why the "mayday" terminology isn't universal. I can't come up with any situation where a triple mayday call won't be the clearest and quickest way to indicate an emergency situation, regardless of whether or not the controllers and pilots speak English or not?

Are there any good reason for not using triple mayday for declaring an emergency? Are there some ATC controllers that wouldn't know what it means? I just don't understand because it seems to be clearly understood every time whereas alternative often aren't, even with two native English speakers.


texts: Why is Landing Altitude displayed in amber on B777?

texts:
When I set the landing altitude manually, an amber LDG ALT and Landing Altitude EICAS message is displayed. There are no failures nor has the landing altitude been set incorrectly.

Why do I still get the EICAS message ALT LDG in amber?


texts: Why is it not practical for the USN T-45 to be fitted with oxygen systems used in other trainers?

texts:
Back in April, the US Navy (USN) grounded all of its T-45 training flights due to issues with the cockpit oxygen system.  I personally heard about this before the grounding secondhand from someone in the program, who was familiar with an instructor who did not remember landing during a training flight.

A number of questions arise, but in order to keep with the single question style that seems to be preferred on this board, I will limit myself to one:

Why is it not practical for USN T-45 trainers to be fitted with oxygen systems used in other trainers?

The T-6 Texan II, used in the USN Primary Pilot training phase uses an onboard oxygen-generating system (OBOGS). I would assume that the US Air Force jet trainer uses one as well.  It surprises me that with a problem that has spanned several years and with a program that has been grounded for three months (and counting) and no solution on the horizon, such alternatives are not being considered.


texts: What is the relation between altitude and vertical speed?

texts:
I recently saw 2 graphs on a flight path on BBC, shown below. For those interested, it's the path of the recently crashed Boeing 737 max flight ET302, but that's irrelevant to my question.

My question is about the relationship between the two graphs. I would expect the bottom graph to be the first derivative of the top one - with altitude increasing when vertical speed is positive and decreasing when it is negative. However, this does not entirely hold. At around 5:38:45 for example, the altitude clearly drops, while the vertical speed remains non-negative.

Am I missing something about the definitions? Like, vertical speed being defined relative to the wind and the plane stuck in a down-gust. Or, if or example, is there some well-known error caused by the way these quantities are measured by the instruments?


texts: What are the main visual differences between Spitfires and Hurricanes?

texts: I've heard that Supermarine Spitfires and Hawker Hurricanes were both great fighters, but what are their distinguishing features?


texts: What was the average duration of a Me-262 combat mission during WWII?

texts:
Me 262 in 1945

Maximum speed: 900 km/h

Range: 1,050 km

Service ceiling: 11,450 m

Rate of climb: 20 m/s at max weight of 7,130 kg

Thrust/weight: 0.28

Could a Me-262 fight for (1050 km) / (900 km/h) = 70 minutes?


texts:
AVweb reported: 2018.07.30 - A former pilot for Alaska Airlines was sentenced on
  Wednesday to a year and a day in federal prison, for flying two
  flights in 2014 with a blood alcohol level more than three times the
  legal limit.

  Arnston flew from San Diego to Portland on June 20, 2014, and then
  from Portland to John Wayne Airport, in Orange County. After landing,
  Arnston was selected for random drug and alcohol testing by airline
  personnel. Two breathalyzer tests showed Arnston had a blood alcohol
  concentration of 0.135 percent and 0.142 percent. The federal limit is
  0.04.
  BoardingArea reports: 2018.09.02
  Prosecutors allege he struggled with alcohol addiction over those two
  decades and routinely piloted commercial flights under the influence
  of alcohol.

Are there any published statistics on the percentage of pilots tested or otherwise gleamed for alcohol that failed?

How often do pilots fly drunk?

Youtube 1
Youtube 2
Youtube 3
Fox News


texts: PPL 40 hours requirement, are you really ready?

texts:
Are 40 hours of flight really enough to gain experience to fly a small private plane alone anywhere? The rules state so but from experience off you pilots, is it really enough or should be more hours be clocked with another experienced pilot next to you before venturing out?

Today I had my first flight on a 152 from Dar es Salaam International Airport, and the area is quite busy. There were bigger aircraft taking off and approaching and  many other taxiing.

Putting an inexperienced pilot that has barely 40 hours in an environment like this could cause serious problems even though he has gone through courses and exams. As you know one thing is theory and another is practice.

I would appreciate some clarification.


texts: Are variable area exhaust nozzles or variable area throats more impactful?

texts:
I was reading this NACA research paper where, while discussing an adjustable plug-type nozzle, they state:

Although this nozzle did not have independently variable area throat and exit areas, as would be required for optimum turbojet application...

I tried looking into the claim, but could not come across any examples of variable throat nozzles in any convergent-divergent afterburner nozzles, all are variable exhaust. Given that the paper was written in 1953, were the authors just wrong or is a variable area throat just not impactful enough to be built into modern aircraft?


texts: Are jet simulators a commercial business or are they owned by airlines?

texts:
Are simulators owned by airline operators or are they property of private companies who are specialised in this business and offer the services on an outsourcing basis to airlines that require it?

I'm talking about proper simulators like the Airbus or Boeing ones and not PC based ones.


texts: Do any airports have a steeper standard approach than London City?

texts:
Watching the CS100 certification of the 5.5deg steep approach into London City, I wondered if there were any airports with steeper standard approaches. By standard I mean published.

I have seen very steep non-standard approaches, but this is not the point of this question.


texts: ExpressJet IATA code before "merger" with Atlantic Southeast?

texts:
Before 2011, Atlantic Southeast had the IATA 2-letter code "EV". Then,

  On November 22, 2011, both ExpressJet and Atlantic Southeast Airlines achieved a single operating certificate that allowed them to operate as one carrier, using Atlantic Southeast's former call sign "Acey". Effective December 31, 2011, all flights began operating under the name ExpressJet.[7] ExpressJet currently operates as United Airlines Express.

(so says Wikipedia.)

What IATA code(s) did ExpressJet, or airlines which became ExpressJet, use until that time?


texts: Why do all fifth generation fighters (J20, F22, SU57) put their wing above the fuselage?

texts: I heard that upper wing could increase stability, but why do fighters need it? Or are there some other reasons? Please specify.


texts: What guidance is there for pilots when reporting braking action?

texts:
I was listening to "[REAL ATC] Eastern B737 (candidate Mike Pence) OFF RUNWAY at LaGuardia!"(1) and the LGA Tower asks for and receives reports of braking action from several landing pilots. I assume that this was during inclement weather, such as snow. Several pilots all report braking action as "fair" for their types.

How is "fair" determined? Is it totally subjective, or is there an objective measure? What are the classifications (of braking action) that a pilot can report?

 (1) Please note, I did not tag this as LGA, since the question is meant to be a general one, unless each reporting is airport specific.


texts: When taxiing a taildragger across a kerb, is it best to cross straight-on or at an angle?

texts:
The grass taxiways at my local aerodrome are sometimes crossed by hard surfaces. Where they cross, the levels don't quite match, so there's a bump as you cross: not quite a pavement kerb, but still a sudden change in surface height.

What's the best way to cross these safely? Crossing straight-on carries the risk that the mainwheels will both stick against the ledge, lifting your tail and in extreme cases maybe causing a prop strike; like trying to cycle up a kerb and going over the handlebars. Crossing at an angle makes sticking less likely, but it rolls the aircraft slightly, and in a low-wing airplane you risk touching a wing-tip.

What's the best way to balance these risks and safely cross the kerb?


texts: How does altitude affect the TAS and thrust of an electric fan powered aircraft?

texts:
I'm confused about the relation between IAS, TAS, thrust, and shaft power, for an electric application. Yes, higher air is thinner, and thrust goes down due to higher airspeed. What I've researched uses only air breathing engines for calculations.
Gas turbines either are limited to lower altitudes or higher altitudes with high speed, to intake enough air to maintain combustion. The other limiting factor is they have very strict maximum rpm. Modern turbofans do not have a variable transmission to counteract this. The same concept applies to electric motors, to a lesser degree.
For example, an electric driven ducted fan has a tip speed of Mach 0.85 and was set to maintain the same power output of say 50kw no matter the altitude.

What would happen to the TAS, IAS, thrust and the shaft rpm of the motor as well as tip speed of the ducted fan as the altitude increases?

Is the power necessary for an increase in TAS and a constant IAS the same up to the point where the increase in rpm (less load) due to thinner air causes the fan blades to see supersonic tip speeds?

If an aircraft can fly at 60 knots with 50 kw at sea level, does that mean at 50,000 ft it can realistically fly at 185 knots TAS for the same given power? (I used this calculator).

Also, how does thinner air affect static thrust?  Is the same thrust maintained as long as the same amount of power is given to spin the fan?


texts: Are pilots required to notify the tower when they are flying "under the hood" for IFR training?

texts: I was reading a question about flying under the hood for Instrument Flight Rules (IFR) training when this question popped to mind.  Are pilots flying under the hood required to notify the tower?  Does it change the towers approach to that plane at all (especially in VMC conditions)?


texts: What happens when a propeller is placed in beta while feathered?

texts:
Could someone explain beta range to me?

What happens when we set the throttle control lever to the beta range (reverse thrust) while the propeller blades are in the feathered position?

Will the blade angle change from feather to reverse pitch or will the engine over torque?


texts: Can you safely operate a 777 with diesel?

texts: Is it possible to safely operate a Boeing 777 on diesel instead of Jet-A? Are there any regulations that prevent this? Would it cause any damage?


texts: Historical gap in high aspect ratio wing transport aircraft

texts:
Reading about recent Boeing's high aspect ratio wing concepts for commercial aircraft, such as TTBW and SUGAR, I couldn't help but think of the Hurel-Dubois aircraft, where similar aerodynamic choices seem to have been made back in the 1950s.

Why has there been such a long gap in aircraft history, to see a rebirth of such a high aspect wing ratio transport/commercial aircraft family, since advanced materials to improve the concept were already available in the 1970s?

(TTBW)

(SUGAR)

(Hurel-Dubois 34)

(Hurel-Dubois 10)


texts: Does ARINC 429 have any error correction methods?

texts:
I'm currently studying the application of ARINC 429, and have noticed that ARINC 429 doesn't have an error correction but an Error detection set in the parity bit (bit-32).
Are there any means for error correction within ARINC 429? If there is, how does it solve for failed data transfer between two systems?


texts: What is that letter in the top of the tail of that Jumbo?

texts:
Aristotle Socrates Onasis, after marrying Ja. Kennedy, bought, from Boeing, a 742, the Olympic Eagle - now left in Hellikon Airport to rot, after the Olympic Airlines went public ..

At the top of its tail the character 'B' appears, what does it mean?


texts: What are the pros/cons of ram air turbines?

texts:
Commercial aircraft are equipped with ram air turbines that can be deploy to provide power in case all other sources of power are lost. Ram air turbines have the benefit of providing power as long as the aircraft is moving through the air. However, aircraft are almost always designed with internal generators, driven off of the engines.

There is a limited case of adding generators to older aircraft. But they are also used to power large accessories, like the jamming pods on the EA-18 Growler. The EA-6B, which the Growler replaced, was also a modified attack aircraft using jamming pods with ram air turbines. Larger aircraft that are modified for the electronic warfare role don't seem to go this route though.

Obviously the turbine will add drag, and it seems like internal generators are more efficient, since almost all aircraft are designed to generate power that way.

So my question is: what are the benefits or drawbacks of using ram air turbines to generate power? While they are generally saved for emergencies, what makes them more useful in cases like jamming pods, compared to other options?


texts: Why is the Priority Takeover button used?

texts:
On the sidesticks of Airbus aircraft, there is a Priority Takeover button. Wikipedia has this to say:

In typical Airbus side-stick implementations, the sticks are independent. The plane's computer either aggregates multiple inputs or a pilot can press a "priority button" to lock out inputs from the other side-stick.

On US flight 1549, the CVR transcript shows that Sully hit the Priority T/O button, after the co-pilot (Skiles) handed over control of the aircraft:

15:27:23.2 - Sully: My aircraft.
15:27:24.0 - Skiles: Your aircraft.
15:27:26.5 - FWC: Priority left.

I'm curious as to why there's a need for this button at all?
Here's a short video on YouTube, demonstrating this:


texts:
According to Wikipedia the definition of taxiing is:

  the movement of the aircraft on the ground under its own power [however]
  push-back is not considered taxiing

In contrast, Eurocontrol seems to define it as:

  any movement on the ground including push-back

Any other reliable sources to look up for the correct definition?


texts: Are ADS-B Airborne Squitters inherently inaccurate?

texts:
Right now I am reading related passages/sections from ICAO Annex 10 Volume 4 and Technical provisions for Mode S Extended squitter.
Airborne position squitters are randomly distributed in between 0.4 and 0.6 seconds. Even if we update Airborne Position Register 05 with utc-synced estimated position, transponder's choice of transmit time might cause in shifting into next epoch(basicly 0.2 second lag).
Increasing rate of update(5hz suggested for now) might only reduce the problem.

Are ADS-B Airborne position squitters inherently inaccurate?


texts: How can I tell a GPS installation is acceptable for IFR use?

texts:
I am evaluating an aircraft for use under IFR.  I want to know if the GPS that is installed is acceptable for use under IFR.  I have access to the logbooks and documentation.  I want to check:

That the GPS unit itself is acceptable
If the installation is acceptable
If the database is current

Operational considerations and limitations may be discussed, but are secondary to the scope of this question.  Citations to the AIM and AC 20-138 should be in a bulletized summary.


texts: What does the acronym PDA stand for in the aviation domain

texts:
While reading an article about Hang Gliding reserve parachutes, I came across the acronym "PDA".  The article seemed to imply that this is a type of parachute and a further google search seems to confirm that.

What I haven't been able to find is a source explaining what this acronym stands for.  Wikipedia disambiguation offers no help and neither do several aviation glossaries I a familiar with.  Lastly, a search for "PDA" in this forum provides no results.


texts: Can a turbojet jet or turbofan powered aircraft land and take off from water?  How much clearence from the water surface would it need for its engines so that it does not suck up water?


texts: If airplanes can't use reverse thrust in flight, what am I hearing?

texts:
I've flown on a few commercial flights, and on several of them I recall a phase of the flight during descent when the engine seemed to go idle (or at least, the engine noise subsided substantially) and then all of the sudden, the engine got really loud and I could feel the plane slowing down substantially, as in, I felt the same as if I was in a car that was slowing down suddenly.  This seemed to last between 5 and 15 seconds, or possibly slightly longer, and then the engines got more quiet and the noticeable deceleration stopped.

Living under an incoming flight path for a few years I have also noticed many times that a plane will be going overhead by the fact that suddenly the engine will get few loud for about the same amount of time.

This seems to be rather common, and I always assume this was reverse thrust.  But today I am reading two separate questions: "Is it possible to use reverse thrust while airborne?" and "Why can't most jets safely use reverse thrust while airborne?", the answers to both of which seem to imply that using reverse thrust while airborne is very rare.

So what have I experienced / heard?  I'm pretty sure it's not an airbrake, because far as I can tell a speed brake is a more passive device that doesn't involve the engine, and it would seem to defeat its purpose to spool up the engine while using it.  I've never been in a seat where I could actually see the back of an engine to tell if a reverser was deployed, but I think at least in some cases the speed brakes were also deployed; from in front of the wing this made it impossible to see the back of the engine.

Update: Everyone is saying speed brakes... how long are these usually deployed for?


texts: How do blade cuffs help cool the engine?

texts: How does the blade cuff (a fairing of suitable airfoil shape used to cover the shanks of propeller blades in order to reduce the aerodynamic losses) help cool the engine?


texts: What is the cause of the whiny noises in cabin of the Boeing 787?

texts: What are the various whine noises coming from the Boeing 787 cabin? Especially near the wing. I have seen tons of YouTube videos in which it has a noise during takeoff, or when flaps are being lowered or raised?


texts: Why did the Boeing 787 design change shape from the original renderings to the actual design?

texts:
Here is a rendering of the original Boeing 787 design:

The plane built can be seen here:

787 as built http://images.franchiseherald.com/data/thumbs/full/3042/570/0/0/0/boeing-787-dreamliner.jpg

Why were the shapes of the nose, tailfin and tailcone changed during the design process?


texts: How do I factor sweep and dihedral in the lift equation?

texts:
I'm guessing that you add cos(angle of dihedral) to calculate lift loss by dihedral, but I'm not sure how to factor in the lift loss by the wing swept. Could someone help me include lift loss due to dihedral and sweep? Thank you
Note: I mean without factoring it into the lift coefficient.


texts: How do you calculate the true bearing from a station (QTE)?

texts:
Assuming that :

You are flying on a compass heading of 141°,
The compass deviation is given as +3°,
The variation read on the chart is 3° East,
The wind correction angle is +10° and
The relative bearing to the airport is 307°

what would the radial from the station be to the true north?

I thought QTE was a standard term. I did not know that American pilots did not know it.

*QTE: True Eminent from station — What is my true bearing from you? QTE = Reciprocal of true bearing to station.

To derive the true bearing I did the following.

I assume that since compass heading is 141° and deviation is +3°

Magnetic heading should be 141-3 = 139°
True heading (would be without the variation given as 3°E) = 139 +3 = 141°
True bearing to station = True heading + relative bearing = 141+307 =  448°
True bearing = 448-360 = 88°
True eminent from station = 268°

However the answer given is 274°.

I want someone with more aviation knowledge to tell me if I am wrong and if so, where is the "break" in my logic?

Reason for question: Navigation problem with an answer given, however I believe the answer to be wrong - Needed an expert opinion.


texts: How exactly does a pilot engage the autopilot?

texts:
I have a number of questions about auto-pilots but rather than deluge you with a long prose here let me break them down into separate questions over the next little while.

From playing around with simulators I know that the pilot has the ability to enter desired altitudes, climb rates, heading etc into the auto-pilot. However, and forgive me, whenever I see a pilot engage the auto-pilot in movies etc, it is simply a flip of the switch.

So that got me wondering how the transition is made in actuality.

Does the pilot need to enter the current altitude, heading etc before flicking the switch or does the AP take the current numbers and hold those automatically.

If it is the latter and the aircraft is in say a climbing turn when the switch is clicked.. then what? Does the aircraft continue in that pattern or what?


texts: What is the range difference between LEAP and PW1000 powered A320 and A321 NEOs?

texts:
Mounted on the same aircraft, PW 1000G and CFM LEAP are two very different engines, with different performances, that should have an impact on range. And we know range is a very important aircraft parameter, since Airbus is developing longer and longer range versions of the A321.

So what is the difference in range on the same aircraft between the two engines?


texts: What are those trucks towing around, and why?

texts:
I was in Prague airport and saw those things going around:

As for title, what are they towing and why? I can imagine it could be to alter airport layout, but I don't see a use for it.

Sub question for and additional answer's virtual bonus: is it funny as it seems? I could imagine drifting those things around :-D


texts: Which aircraft have fought against its own type in active combat?

texts:
The criteria for this question are

The aircraft has to be the same type (but not necessarily the same mark)
The two opposing sides are actively hostile; but not restricted to nation states (so civil war a possibility)
The aircraft treat each other as an active threat
Cloned aircraft count, e.g. Tu-4 / B-29 or J8M / Me163 (neither of these occurred as far as I know)

It's difficult to see circumstances in which it would happen; but in over 100 years of air combat I think it likely to have occurred at some point.


texts: Can a person legally mount a fake gun on an amateur-built aircraft?

texts: Is there an FAA rule that states that no amateur-built aircraft are allowed to have a weapon mounted to it? (If so, I'd certainly like to see this rule and its conditions) Say I want to build an airplane that a friend and I made blueprints for a while ago, and it was about 60% fantasy. But the plane doesn't look the same without the guns. The guns really add a different feel to the plane, and to have no guns makes it feel as though it's missing something. But clearly I'd never use it. I just wanted to know if it is even legal to put a gun on an amateur-built aircraft,  which I'd assume it isn't. So to avoid any trouble, I think it'd be best not to put any functioning guns on my plane. So, this begs the question, Is it legal to put a fake gun on an airplane, or to put a functioning ball turret that has fake guns?


texts: How do I obtain permission to fly an airplane that isn't airworthy?

texts: How do I get permission to fly an airplane with a non-safety-related airworthiness issue, like being out of annual or having an inoperative radio in order to take it somewhere that it can be fixed?


texts: In the United States, is there any way I can fly without a medical certificate?

texts: I live in the United States. I haven't been able to get a medical certificate yet, but I'm interested in flying airplanes (or maybe other kinds of aircraft). Is there any way I can fly without having a medical certificate? What are my options here?


texts: What is the difference between Tilt-rotor aircraft and Tilt-wing aircraft?

texts:
I've  heard more about tilt-rotor aircraft like the Bell Boeing V-22 Osprey
more than a tilt-wing aircraft like the XC-142
What are the differences (other than one changing the degree of wing or rotor), pros and cons of the two?


texts: Why is vertical take-off restricted to lighter weight aircraft?

texts:
Vertical take off is a big advantage, but why it is only limited to low weight?

For example, fixed wing like An225 can lift more than hundred tonnes of payload, while the biggest helicopter is 25 tonnes. Why there is no effort to build a helicopter can lift 50 - 100 tonnes. What limits them? Economic or technical problem? I guess it is a technical problem because even the heaviest helicopter is just an experiment, but what is it?


texts: At which speed is a plane traveling at hypersonic?

texts: What is the measurement used when a plane is said to travel at hypersonic? How does the air act at the nose of the plane? Would the nose and wing have to be razor sharp to cut the air? because the nose of the space shuttle seems blunt.


texts: Would using a drone to pay for something count as commercial use?

texts:
If I were a drone hobbyist, and I flew a drone over to someone to give them money in exchange for something, would that count as commercial use and therefore be illegal? Here’s an example scenario:

I’m not licensed to fly drones commercially. I fly a drone with money and an order over to the local McDonald’s drive-through with some money. The cashier takes the money and puts a burger into the basket in return.  Assuming the McDonald’s is just across the street (still in visual range) and there’s no one in the drive-through that I’d be flying over, would that be legal? I’m not operating the drone for hire, and since I’ve payed for the burger, it’s my property (so I’m not illegally flying someone else’s property).

I certainly don’t intend to do this (and I am a commercial drone pilot), but I was just wondering if that counts as commercial use.  I couldn’t find anything specific in the regulations that explained it.


texts: Are there procedures to follow in case of a suspect Electronic Control override (hacking)?

texts:
I am a filmmaker who made a film most pilots have seen (405) http://youtu.be/Tpx6o4gvmXE

I am working a new production that also takes place aboard an airliner. In it a telekinetic little girl is overriding the flight controls. But it is thought to be some sort of electronic control interference for a short time. Are there procedures a flight crew would follow in the initial stages if their controls seemed "possessed?"


texts: What are the rules of airfoil thickness from root to tip on tapered wings?

texts:
I'm doing some research on wings and airfoils used in the 30s and 40s, and I'm trying to understand the rules about airfoil proportional thickness changes across the wing (root to tip) on tapered wings.

Many planes of that time used airfoils with thickness ranging from 15% to 9% (root to tip). (Source: https://m-selig.ae.illinois.edu/ads/aircraft.html)

So the question is: what are the rules for dimensioning airfoil thickness from root to tip?


texts: Are controllers aware of TCAS RA taking place?

texts:
When the TCAS issues a Resolution Advisory (RA) which contradicts an ATC instruction, the RA takes priority.

Are controllers aware (notified on their screen) that a RA has been issued between two converging traffic?
If yes, are the controllers also able to see the RA instruction issued to each specific aircraft?


texts: Can a CFI give required instruction and endorsements on a 3rd class medical?

texts: Let's suppose a CFI can no longer qualify for a 1st or 2nd class physical, or maybe her/his 2nd class physical was 18 months ago. Can she/he still give required instruction and endorsements as long as they don't charge for their time and are not paid for it in any other way?


texts: Flex temperature isn't actually "fooling" the FADEC, right?

texts:
I'll be using Airbus terminology here because that's what I know, but I guess the concepts are universally applicable.
The way I understand flex temperature is: It's a user interface for pilots to request a derating of engine power to reduce wear on the engine. Simple enough, makes sense.
But in understanding why this is being input as a temperature, I have often encountered confusing explanations. Many videos and forum posts will say something like this:

Flex temp will fool the FADEC to think the outside air is hotter than it actually is.

That cannot be correct, right? If the FADEC actually thought the air was less dense, then if anything it would increase engine power, not derate it.
What makes more sense to me is this:

By entering flex temp, you're intructing the FADEC to produce only as much thrust as TOGA would produce at that increased temperature.

Simple. We're not fooling the FADEC, it knows full well how much thrust it is producing and that's good.
Using a temperature value as the input (instead of some percentage of engine power) also makes sense because pilots need to be aware of this parameter anyway when considering altitude, runway length, and aircraft weigth to verify a takeoff is possible.
If I'm correct, why is this "myth" of fooling the FADEC so prevalent? I find this notion very confusing and counter-productive when learning about this.
Does the FADEC even actually deal with outside air temperature in its logic? Why and how? Or does flex temp really just translate to a thrust value (possibly together with altitude)?


texts: How do you set up your nav instruments and coms during ground operations and takeoff?

texts:
I have an HSI, an OBS, and a GPS. I normally set my HSI to runway heading, my bug to the wind direction, and the GPS to destination airport/waypoint (which will give me my turn out heading). I don't normally move my OBS. Once I get in line to depart, I set my bug to my departure heading.

For my coms I put the tower frequency in COM1 and the ground and guard in COM2.

Is there a standard procedure for setting up your nav instruments and coms? Is there a better or more efficient method than what I am doing? I have been thinking I could set my OBS up for the approach and my second option in COM1 as CTAF or tower at the arrival airport. What does everyone think?


texts: Do GA IFR flights out of airports w/ SIDs typically use them? What about STARs?

texts:
Besides the IAPs (which as an IFR flight you're guaranteed to use unless cleared for the visual), there are the STARs and SIDs, and using them in slow GA aircraft doesn't fully make sense to me.

For example, out of RIC there is the Colin Six Departure:

I would imagine that as a 150 KT puttering IFR GA aircraft you would be literally holding up any heavies behind you on a busy day, heading for that COLIN waypoint, that are trying to push the < FL010 250 KT speed limit.

Same for the STARs: your gentle 185 KT descent through 3,000 is a cork for the 747 at 240 KT on the same path but 10 NM back and 1,000 feet higher, getting lower and closer.

Does this simply come down to ATC's ability separate aircraft, and
Are these standard instrument approaches and departures always/often/at all used by small & slow IFR GA aircraft?


texts: Elliptical wing planform and elliptical lift distribution

texts: I know that there are similar topics already here, but after reading them I still do not understand everything. From what I know elliptical lift distribution gives the least amount of induced drag. That is because there is the least amount of lift at the wingtips compared to other parts of the span - is it true what I wrote? And know question with elliptical wing planform. Is  this planform generating the least amount of induced drag? And I read somewhere that this wing planform is most efficient among other planforms in subsonic flight. Is it true and if yes why? And does elliptical wing has elliptical wing distribution? Because I heard lot of versions.


texts: The US Military's use of drones has become commonplace, and widely known at this point. Although these vehicles are operated from nearby bases during these attacks, it seems like the latency (time of transmission) would be problematic as far as flying goes. Are these vehicles typically flown 100% by autopilot, where there's very little real-time reaction?


texts: Where can I look up FAA Letters to Airmen?

texts: I was recently asked if an airport was covered by a Letter to Airmen (LTA) providing IFR separation for VFR practice approaches, and I realized I had no idea. How can I look up LTAs for an airport, and do they ever expire?


texts:
I need to know how you tell the certification of new airport just built? how can you tell if airport is certified for International flights or not? approved for intl flights or not meeting requirements?
I find this recent airport in Egypt HESX with regional flights approved, yet it has no lights and it operates only during day time, so is it approved for intl flights or not?
Sphinx Airport Map


texts: Does an SVFR clearance extend to Echo surface extensions?

texts:
Sec. 91.157
Special VFR weather minimums.
(a) Except as provided in appendix D, section 3, of this part, special VFR operations may be conducted under the weather minimums and requirements of this section, instead of those contained in Sec. 91.155, below 10,000 feet MSL within the airspace contained by the upward extension of the lateral boundaries of the controlled airspace designated to the surface for an airport.

Suppose I'm granted an SVFR clearance to land at KSTS (a typical towered airport with a Delta airspace and Echo surface extensions). Can I fly through the echo extensions with only SVFR minima? (e.g. for helicopter just clear of clouds) Or do the 91.155 minima apply. This really boils down the definition of "designated to the surface for an airport".


texts: Why do cargo flight companies reposition their crew via passenger airlines?

texts:
U.S. airlines prepare plans to virtually shut down domestic service amid outbreak : Coronavirus

  This will cause massive issues for cargo as well. Cargo operators use commercial airlines to reposition crews.

What exactly does 'reposition' mean here?
Why do cargo airlines need passenger ones to 'reposition' crew?


texts: Why is the Eurofighter's nose gear door shorter than the bay?

texts:
The Eurofighter Typhoon has an interesting "feature" in that the nose gear door is shorter than the nose gear bay itself by a good few inches, as shown here:

Can anyone shed any light on the reason for this gap?  It isn't a simple case of the aircraft in the photo having a maintenance issue, as this gap is consistent across all aircraft tranches and customers.


texts: What's the benefit of this long flight (apart from marketing)?

texts:
The post Do promotional flight routes have a historical precedent? asks about previous occurrences.

I'm guessing this flight (shown below) was a test flight, as well as being a marketing attempt.

For a test flight, what would the benefit be?


texts: Does an increase in Mach number lead to a decrease in Total Pressure Recovery (TPR) for supersonic inlets?

texts: I am curious if the total pressure recover for supersonic inlets, in general, decrease for an increase in Mach number.


texts: Do any aircraft carry spare parts for making repairs?

texts:
I was curious to know, are there (or were there) any aircraft that regularly carry spare parts to be used for replacement or repairing the aircraft itself? If so, what are those spare parts?

I'm not talking about built-in redundant systems like a second radio, but rather actual physical spare parts. For example, a car carries a spare tyre.


texts: What is a jet engine's fuel flow at constant IAS?

texts:
Here is my assumption:

In straight and level flight of a jet turbine engine:
One IAS = One drag = One thrust = One fuel flow

Therefore, the fuel flow will be approximately the same for a given IAS, regardless of altitude, temperature, or RPM necessary to maintain this IAS.
Is that correct? If not, where is the fallacy?
EDIT : Here is a screenshot from ATPL course material which supports this idea and led me to ask the question as it seems doubtful to me. Propulsive efficiency vs RPM at high altitude at the end is not clear as well.


texts: Which 2-seat 4th generation fighter/engine/configuration (de-militarized) would the best supersonic long-range civilian private transport?

texts:
Seeing recently -with some surprise- that former military jets of fairly recent vintage can be bought e.g. here and operated by (skilled+licensed²+rich³) private individuals after all classified/restricted tech has been removed, I was wondering what plane would be best suited for a Max-Fuel configuration.

I think I use the right terminology and assumptions, but for clarification:

2-pilot-seat configuration: "Learner configuration", like in driving school, where both seats can "pilot".
I'm assuming, for every modern 2-seat airplane a "learner" version/configuration_kit exists.
Super-Cruise: I believe is a supersonic mode of travel without using the Afterburner
Gen-4: I believe this includes F16 and newer (and foreign equivalents)
Gen-3 and older: There aren't any Super-Cruise-capable specimens?
I believe, all civilian runways are long enough for Gen-4 planes
I'm assuming, using afterburner absolutely kills max range.

For example, Wikipedia says (ballpark numbers) an F-18 weighs 15 tons empty, and has a max take-off weight of 30 tons. Internal fuel capacity + maximum external fuel capacity is 12 tons. I'm assuming the remaining 3 tons are the ammo for the Vulcan Gun, flares, the pilot and other stuff you can drop or shoot in order to have a minimum onboard defense/offense power, and not just fuel. Wikipedia seems to say in the specs, that it can travel ~2300km with ~6tons of fuel.

I'm assuming, that a de-militarized version of this 15ton bird will be quite a lot lighter, i mean, no [gun, ammo, flares, armor, ECM, cameras, etc.] needed. I'm guesstimating that could slim the plane down to say 12 tons. I'm aware, that not all the remaining ~6 tons could be used as additional fuel weight, but by converting the gun/weapons bay to big tanks, and running fuel lines to the missile-mounts, surely a large chunk of that could be converted to fuel weight.

So, the above looks like an F18 learner could be "converted" to a max-range-model 2-seater "sports-car-for-the-weekend-trip" with a fuel capacity of ~16 tons and therefore a range of ~5700km. That gets you over every ocean.

Now all of the above does not take into account the fuel usage at Super-Cruise (iiuc), and I have no idea which plane/engine is the most "efficient" in this speed envelope.

SO, basically, my question is:
Which plane would a "bezos-rich" person buy, if he wanted something for super-sonic weekend trips with his (also former air-force-pilot) friend, and what modifications could/would be possible to extend (super-sonic) range to achieve the best average speed. Is it fast enough, or even possible (w.r.t. time-zones)  to have brunch on both sides of an ocean?

@ManuH pointed to a great example from pre-jet-times, the business exec version of the Cavalier_Mustang

@RonBeyer: Don Kirlin bought 40+ air-worthy F18s from the Australian Airforce

Edited to address comments.


texts:
Do most flight schools and FBOs in the US prohibit student pilots from practicing stalls while flying solo?

This question is asked in the context of civilian flight training in single-engine land airplanes.

I've heard of this policy actually being in effect with at least one flight school.

"Most" means more than half. "Student pilot" is not meant to include anyone who holds a pilot's license for airplanes or for that matter for gliders.

The reference to FBOs means that they are renting an aircraft to the student pilot involved.

The question is asking about a blanket prohibition that would include a student who is close to being ready to take his or her checkride, not something only applied to (for example) the first few solo flights.

People who have had personal experience with a large number of flight schools and FBOs will be in the best position to answer this question.


texts: How much does a Boeing 737 wing bend/deflect in cruise conditions?

texts: As a part of my ongoing research of a structural joint analysis of a Boeing 737, I have been looking for sources where I may be able to find the bending/deflection data during cruise conditions. I have found sources that may not be considered reliable, however; would anyone be able to assist me with the above data from source that would be considered valid for justification.


texts: Where can I find a cross sectional area plot for the A320 or other modern airliners?

texts:
I'm studying to become a pilot and stumbled upon the Raptor Aircraft a while ago.

In one of our subjects we briefly discussed the concept of the area rule but did not get into much detail since our teacher told us that for subsonic airplanes it is not very relevant, especially not for slow flying piston aircraft.

But the designer of the Raptor Aircraft gets into a lot of detail why the Raptor is shaped like it is and what performance benefits it provides.

To me the charts provided on this site make a lot of sense and it seems plausible that there is a drag reduction of 15%.

I get that for airliners 'ease of build' is a major factor and therefore the cabin is a cylinder (reasons described in this question). (Sidenote: as far as I know the A380 has a double bubble design.)

Here comes the question: can someone provide a chart of the cross sectional area like this one for the A320 or another jet airliner?

What interests me is how much performance gain/fuel savings/drag reduction could be achieved if one were to optimise the cross sectional area of an airliner.


texts: Why didn't the Concorde have flaps or slats?

texts:
It's well known that the Concorde had no flaps or slats.  The lack of high-lift devices considerably reduced lift at low speeds, requiring the Concorde to take off and land at higher speeds and angles of attack than if it had been equipped with flaps and slats.  As well as greatly increasing drag (and thus fuel consumption) during takeoff and landing, this greatly increased the force carried by the main landing gear and the speed at which its tyres had to spin; as a result, if and when a tyre blew out (due to, for instance, a piece of debris left by the previous airplane to use the runway), the results would be much worse than with a tyre blowout on a subsonic airliner.

Interestingly, a "Concorde B" was planned for Concorde 217 and onwards, which would have been equipped with slats (although still no flaps); this, along with slightly larger wings and more powerful engines, would have allowed the Concorde B to dispense with afterburners, considerably increasing its fuel efficiency and range.  Unfortunately, production ended with Concorde 216, the aircraft immediately preceding the first Concorde B, so no Concorde Bs were ever built.

Why didn't the Concorde, as built, have flaps or slats?


texts: What geographic reference system do airport towers use?

texts: What geographic reference system (WGS84, EGM96, EGM2008 etc.) do airport towers use when measuring things like aiport elevation and current QNH for airport? Is there even a commonly accepted one worldwide? I couldn't find an explanation on this subject online.


texts: Who closes an airline's IFR flight plan and when?

texts:
ATA (Air Transport Association of America) defines the various flight phases (ATA Spec 2300, flight phases). The last phase is called Flight Close and is described as "The Flight Close phase begins when the crew initiates a message to the flight-following authorities that the aircraft is secure [...]".

In commercial airline operations, who closes the IFR flight plan? The flight plan is usually filed by the dispatchers, I guess. I have never heard a pilot actually close the flight plan before leaving the aircraft...


texts: Why is the center of pressure of a rocket at its centroid?

texts:
From thin airfoil theory, at subsonic speeds, the center of pressure of any uncambered airfoil is at quarter chord. For sounding rockets, however, the center of pressure is generally assumed to be located at the centroid of the projected area. Note that model sounding rockets generally stay subsonic.

What is the theoretical derivation for this? For this question, one can ignore the effect of fins and restrict to the axisymmetric slender bodies.


texts: Under what circumstances can a flight attendant unbuckle and get up during landing?

texts:
Lately I've been on several flights where the flight attendants had to talk sternly to passengers that were getting up either just before landing or just after (which is quite obvious to everyone since the talking to is done over the PA system).

Now this made me wonder what FAs can do if the passenger just refuses to comply? Can FAs get up and forcefully seat passengers (would they have to talk to the pilot first to abort the landing)? If not, are there any circumstances where the FAs can/should/must unbuckle during a landing?


texts: Where are the seaport conventions for VFR charts explained?

texts:
VRF charts contain information about seaports. For example, 00 - 50 in the formation block for HNL seems to be for a waterway:

Another example is 23W for 1C9:

Where are these conventions explained? I can't seem to find them in the Legend or User Guide.


texts: Is "lower pressurization" the correct term for the 787 Dreamliner?

texts:
In this blog, the FA refers to the 787 Dreamliner as having "lower pressurization":

http://theflightattendantlife.com/the-boeing-787-8-a-flight-attendant-takes-you-on-an-inside-tour-of-the-dreamliner/

The Dreamliner has higher air-pressure in the cabin due to its fuselage construction -- but this higher air-pressure makes the perceived 'altitude' lower.

Is the correct (air transport) term for this "lower pressurization" or "higher pressurization" or is there a better third alternative??


texts: What is the relation between IAS and TAS at a constant altitude?

texts:
I have noticed that when calculating True Air Speed for any given altitude, the faster the Indicated Air Speed, there seems to be a larger increase in TAS?
My thinking was that at a constant altitude the relationship between IAS/TAS would be linear, e.g you double IAS, and TAS would double.. But it seems to increase more? Not sure if I'm missing something here?

For example:
5000ft at 100knts IAS = 114knts TAS
, 5000ft at 110knts IAS = 126knts TAS

Only a couple Knots difference, and it seems to make sense but I can't find any answers on it to confirm it? Would appreciate anybody to shed light on it, thanks!


texts: What controls the brightness of the MCDU display and keys?

texts:
What brightness does the brt and dim on the right side of the MCDU MENU button change?
The brightness of the display, the keys or of both?
And if only one of them, what controls the other?

EDIT: As shown in this video, the brigghtness knob turns just the display on/regulates it's brightness.
What changes the brightness of the keys (They seem to be lit befor the MCDU is turned on)?


texts: Does it make sense towing airplanes to the head of airstrip by external (eg electric) means?

texts:
Does it make sense towing airplanes to the head of airstrip by electric means, whether internal or external?

Taxiing from the gate to the runway on jet power seems like a waste of fuel. Is it possible and it would make sense to tow the airplane to the start of take-off run by a motorized towing unit or perhaps with electric motors in the airplane's landing gear? Was this ever tested or assessed?


texts: What is the name of the Instrument that indicates roll?

texts: What is the name of the instrument that would indicate whether the wings are level or tilted (one higher than the other) as when flying IFR? Is it the inclinometer?


texts: What is this on the aft end of this GEnx engine?

texts:
In the next picture, corresponding to a GEnx engine, what is the item circled in red?

Thank you very much again.


texts: For how long is an engine start clearance valid?

texts:
If a pilot receives a clearance to start the engines, is the clearance void if he doesn't start them within a certain amount of time? How much time is allowed for starting the engines and where is it documented?

I'm asking for Thailand, but would like to know what the ICAO SARPs say.


texts: Does simulator time count as time in type?

texts: Can full motion simulator training time (FSI) be counted towards the required 100 hours that a part 135 captain is a High Minimum Captain?


texts: What is the difference between mist and fog?

texts: Fog is a form of a cloud and it is said clouds are visible moisture.  We all know that mist (baby rain) is also moisture so I am curious when will a METAR say BR (mist) or FG (fog)?


texts: Do the A380 ailerons act as air brakes on landing?

texts: Last month I was on an Emirates A380 to London Heathrow. I noticed on the landing, the right ailerons were fully up along with the spoilers when decelerating on the ground. Are the ailerons configured for acting as air brakes on landings? Or was the pilot perhaps counteracting a crosswind?


texts:
In Boeing 787 and Airbus 350 aircrafts, more than half of the aircraft body is made of composite material. The composite structure of the fuselage does not indicate the damage when the body is contacted and damaged by the ground support equipment. That's why an airline company I’m familiar with issued a statement for the entire fleet to the ground staff indicating "do not touch the aircraft while servicing" (a no-touch policy).

How can the passenger mobile stairs be aligned safely from the ground without contacting such high aircraft passenger doors?  Wouldn't it be possible for passengers to fall down from the gap between the aircraft and the mobile stairs, especially in windy weather?
What else can be done not to damage composite structured aircraft fuselage?


texts: Is there any publicly available research that projects pilots' loss of proficiency due to lack of flying (or guidelines to prevent it)?

texts:
The FAA requires 3 landings every 90 days to stay 'current', but as we all know, currency and proficiency are different things.
I'm looking for data than can describe how proficiency loss correlates with various factors. Relevant factors might include how long it's been seen you've flown, how much flying you've done in the last ____ days/months, how much time in type, time in seat, or total experience, etc.
And if there are evidence-based guidelines for how much flying a pilot should do to stave off loss of proficiency, I'd like to see that as well.
Thanks.
Edit:
I understand that it's impossible to accurately calculate how proficient someone is based on unique individual traits. That's not what I'm trying to do. Like the title says, I'm trying to quantify what's typical for "loss of proficiency due to lack of flying". In other words, how does flying 10 hours in 90 days compare to flying 10 hours in 6 months, as it pertains to proficiency degradation and, ultimately, increased risk of an accident/incident.


texts: What is the stick at the bottom of the tail on a ATR-72?

texts:
During my last flight I observed the ATR-72 has a stick protruding from the bottom of the fuselage, near the back of the airplane.

See the bottom of the fuselage in this picture, slightly to the left of the rear door.

I assume it impedes take off and must be removed before flight.

What is it?


texts: What are the differences between type B message format and EDIFACT message format?

texts:
IATA say's the standard format for transmitting passenger messages is UN/Edifact. Somewhere else it says the standard is type B format.

what are the differences between these two? Or are they a same format?


texts: What are the differences between wings made for 2 engines and wings for 4 engines?

texts: I have always wondered the differences between a wing made to hold 2 engines and a wing made to hold 4 engines, could someone please explain?


texts: Why does A320 Main Wheel need to be tightened 3 times during installation?

texts:
I have another question related to maintenance practices. During replacing MLG wheel of A320, it is said that we need to tighten the wheel nut 3 times with different torque values.
The first one has the highest value. Then, we need to loosen and tighten the wheel nut again, however, with lower torque values.
In my opinion, I think that the highest torque value is to put the wheel all the way on the axle, however, I was unable to find the answer for why we need to torque the nut again for 2 different values.
And are there any other reasons for tightening the wheel nut with different value?
Thanks for your answer.


texts: Is there a source of information on the Aerodynamics of Non Rotating Round Disc Wings?

texts:
Is there any published information on the aerodynamics of Fixed round disc wings like that used on the Nemeth Parasol?

https://disciplesofflight.com/nemeth-parasol-strange-aircraft/

All I've found so far is info on rotating discs like the Frisbee or Olympic discus.


texts: Why do pilots typically start out in piston-engined aircraft, rather than jets or turboprops?

texts:
Essentially all pilots begin flying with propeller aircraft powered by piston engines, rather than in turboprops or light jets, even though:

Operating a piston engine requires adjusting the mixture ratio, carburetor heating, ignition timing, and other such voodoo, whereas, with a turbine engine, you basically just turn on the ignition, press the START button, and you’re in business.
Jets and turboprops are orders of magnitude more reliable than piston engines, despite the latter’s decades-long head start in development; destructive failures of aircraft piston engines are much less common nowadays than in the 1940s and 1950s, when they were practically a once-a-flight occurrence, but piston engines still come up short compared to jets, most pilots of which go their entire careers without experiencing a single engine failure of any kind whatsoever.
And when a turbine engine does fail, it does so loudly and unmistakeably - none of those deadly invisible engine failures that killed off the market for piston-engined twinmotors, along with many thousands of their pilots.
In all but the coldest climates, jets and turboprops use Jet A (in the United States) or Jet A-1 (the rest of the world), two very similar kerosenes that are far safer to handle than the avgas burned in most piston engines (Jet A and A-1 have much lower vapour pressures, much higher flashpoints, and much slower flame spread rates than avgas, and, unlike avgas, are not full of tetraethyllead), and more widely available to boot; even in those extremely cold climates where the more enthusiastically flammable Jet B (a gasoline-kerosene blend) has to be used instead, it’s still safer than avgas.
Also, a turbine engine will run happily on avgas if the ground crew refuels it from the wrong container (jets are rightly famous for running on anything that flows and burns, as long as it doesn’t produce an exhaust containing refractory oxide particles), whereas accidentally fuelling a piston engine with jet fuel will cause it to blow its insides to bits just long enough after takeoff for you to now be over a residential subdivision or something similarly inconvenient for a forced landing.
Propellers come with their own complications; the propwash coming off the propeller and hitting the wings and tail creates nasty asymmetrical rolling and yawing tendencies, the pitch of most propellers has to be carefully managed (at least during ground operations, and sometimes in flight as well), and an even slightly nose-low landing, a gust from the wrong direction at the wrong moment, or a bump or pothole in the surface can easily cause an engine-destroying propstrike.

Given all this, why do pilots generally make their debut in piston-propeller aircraft, instead of in light jets or turboprops?


texts: What is the Specific Fuel Consumption of CFM56-7B24/26/27 engines?

texts: I think the title completely says what I need. I use FSX (Flight Simulator X) to simulate flights and while flying the B738 I saw that it consumes much more fuel than the estimated amount, which is calculated by the software. By doing some research in the airplane folder I figured out that the problem is because the wrong Specific Fuel Consumption (SFC) is  entered there. And by some research on the net I also found the type of engine that B738 uses. So, right now, I need to know the SFC of the CFM56-7B24/26/27 engine so that I can enter the correct value in FSX.


texts: Can cold thrusters/roll posts be used to control/stabilize an aircraft (like a satellite)?

texts:
Aircraft use control surfaces to control their motion/direction. Would it be a good idea (i.e., more efficient, less weight, better responsiveness, less drag, etc.) to use thrusters/roll posts to control roll, yaw and pitch, like the roll posts an F-35 uses for hover?

this question refers specifically to a continuous flow system like the F-35 roll posts. no rockets no turbojets


texts: Do airline SOP normally recommend an in-flight engine restart in the case of an unexplained shutdown?

texts:
You're flying along at cruise in say a 737 or similar twin-engined yet. Suddenly, one of your engines shut down for no apparent reason. (or no abnormal indications such as low oil or similar)

Do you:

Attempt a restart and either divert or continue?
Divert and leave it off for an emergency landing?


texts: Help identify an unknown airborne object

texts:
In the wee hours of the morning of last Saturday (July 30, 2016), while out stargazing, I saw something odd which I am unable to explain.

The object was traveling with a bearing of about 5-20° east of straight south.
The object flew nearly straight overhead, somewhat near the star Vega, sometime between 1:10-1:30AM local time (6:10-6:30AM GMT).  I was stargazing at the latitude and longitude 44.795614 N, 94.377516 W (https://goo.gl/maps/FB4yDsR8GYv).
The object was moving at a speed similar to an airplane.
The object's light blinked 3-4 times, but at a seemingly lower frequency than a typical airplane.  Also, while planes typically have a very short duration flash, this object had much longer flashes (1-2 seconds, probably), with the light being lit for about the same proportion of time as it was unlit.
I did not hear any propeller sounds, indicating that either that the object was relatively far away or that this was not a plane/helicopter.
The light also seemed brighter than a typical airplane's light, although I can't be entirely sure.  It was certainly brighter than every star in the sky.
After the 3-4 blinks, there were no more blinks (and this is on a wonderfully clear night; it's not possible that it was obscured by clouds, as I could still see the stars along the path it was flying)

From all this information, I am able to deduce that it was not a satellite, as satellites don't blink like this.  It is presumably not a typical commercial or private flight, even though there is a small airport roughly 4.5 miles north of where I was, because the lights stopped blinking, and that is presumably prohibited in nighttime flights.  I have not heard of any plane crashes nearby, which I expect I would have, had this been a plane that went down in flight.

Any ideas what I might have seen?


texts: Why is the Antonov 225 (almost) always chocked at the third wheel?

texts:
Recently I was looking over pictures where the An-225 is parked (because that's a normal thing for a normal person to spend their time doing). I noticed that the chocks are almost always placed around the third wheel from the front in the undercarriage:

(Thanks to ratchet freak for the better picture).

Presumably that's because the centre of mass (COM) is closest to that wheel? But why would the undercarriage not be centered around the COM?

Bonus question: Very occasionally, I've seen the chocks placed around the entire undercarriage, in front of the first wheel and behind the last wheel. Why the occasional difference?


texts: What is the difference between the Bell 412 and the Bell CH-146 Griffon?


texts: Does the FAA require a rating for night VFR?

texts: Does a PPL require a specific rating or endorsement for night VFR in the US? Night flying seems like a special challenge and I'd think the FAA would want you to show that you've had proper training for it. This question talks about currency requirements, but I can't find anything on a night VFR endorsement.


texts: What is the procedure for getting permission to operate an aircraft within a pop-up VIP TFR?

texts:
Consider a situation where there is a Temporary Flight Restriction (TFR) due to VIP movement (i.e. the President of the United States is in Los Angeles), and I am based at an airport that is within the TFR.  I'm a VFR pilot and I want to go for a little flight from my airfield that doesn't have a control tower, exit the TFR, and then return later in the afternoon (re-entering the TFR) and land at the same airport.

What would be the procedure to get permission to:

Take off and exit the TFR-covered area (non-towered airport), and
Return to the same field later on a different flight (same
non-towered airfield)?


texts: Why is the altimeter unwinding unevenely during a spin?

texts:
Spencer Suderman recently did a world record 81-turn inverted flat spin, and dropped over 21 thousand feet while doing so. The entire thing is documented on youtube. The spin starts at 3 minutes into the clip. Looking at the footage, in the beginning of the spin, and also (although to a lesser extent) at the end of the spin, the altimeter is unwinding very unevenly, being almost steady for a second and then quickly unwinding 3-500 feet before steadying (or actually increasing the first couple of turns) for another second. Why is that? It seems unreasonable to me that it would actually be leveling out.

It's worth noting that in the middle of descent, when spin is perfectly flat, it's unwinding evenly.


texts:
first time here so bear with me please.

So it looks to me like there are A LOT of small plane crashes.  Pretty much every week a couple of people die in small planes, at least.

Is this due to the planes themselves, to the pilots, to the bad maintenance on the planes?

Main reason I ask, I'd like to learn (maybe, just maybe) how to fly, or at least try a class once, but I'm very afraid of those small planes statistics.  Are there any websites or similar that explain why so many accidents on those and the reasons?

I asked, can't really start learning with a bigger plane with "real engines" :-)


texts:
What is true static pressure? How do we define it? Is it same as corrected static pressure for installation and errors?
ARINC 429P1-18 defines Static pressure as corrected and uncorrected where in few places I have heard this term "True static pressure".


texts: Can US pilots fly VFR OTT and/or VFR at night in Canada without additional ratings?

texts:
In the US, private pilots flying under VFR are implicitly allowed to fly without visual reference to the ground, eg. over an overcast cloud layer, as long as they maintain appropriate VFR weather minimums. The same is true for flying VFR at night.

In Canada, a separate add-on "VFR OTT" rating is required in order to operate "over the top", and there's also an add-on rating for flying VFR at night.

US pilots can operate Canadian-registered aircraft through a Foreign License Validation Certificate, which as far as I can tell confers the privileges of one's native certificate. According to the ICAO, "certificates of competency and licenses issued or rendered valid by the contracting State in which the aircraft is registered, shall be recognized as valid by the other contracting States".

So the question is: do US pilots operating Canadian-registered aircraft via a FLVC need additional ratings to fly VFR over-the-top or at night in Canada, or are the inherent privileges of their US pilot certificate extended to Canada as well?


texts: What is the difference between APV I and APV II?

texts: Been reading all these ICAO documents about APV I and II and none of them clearly describe (from a pilots perspective) the difference. Please help


texts: Has any prior accident been caused by a psychologically unstable and/or suicidal crew member?

texts: I am aware a lot of psychological tests are given to pilots to prevent such a scenario, but those can hardly be perfect, so has any aviation accident been caused (or attempted) by the conscious intention of one of the crew?


texts:
My question intends to find out how maps are downloaded/buffered at Ground Control Station's for UAV operations. I understand GPS transmitters relay the exact location of an aircraft on a map. However, the map needs to be loaded/buffered in real time as the UAV covers ground.

For a UAV as large as the RQ-4 Global Hawk, with a range of 14000 kms, how is the map loaded in real time?

On the other hand, for amateur or small scale UAVs/MAVs, is the map updated in real time as the aircraft/rotorcraft covers more ground? Or is that the map is downloaded pre-flight, based on the range of the aircraft? This would be preferable in terrains with poor or no signal connectivity.


texts: Is the Harbin Y-11 a fully indigenous Chinese design?

texts: One book characterized the Harbin Y-11 as a "successor" aircraft to a design based on the Antonov An-2, however, it looks completely different than the An-2, which is a single-engine aircraft. Is the Harbin Y-11 a fully indigenous Chinese design with no significant elements copied from some other aircraft?


texts: On what principle(s) do aircraft smoke detectors work?

texts:
I know there are smoke detectors in aircraft but on what principle(s) do they generally work?

Commercial smoke detectors can use several different techniques like optical sensing, heat sensing and particle sensing. Do aircraft smoke detectors also work using one of these technologies or something different?


texts: What is the ICAO code and callsign for Amazon Prime planes?

texts:
Looks like Amazon started flying its own planes to transport goods - check out the announcement here. Apparently they've been flying since at least August 2016, and I just found out about it now, lol.

This is their promo video.

Anyone know what their three letter ICAO code and their callsign is?

Edit: Looks like CNBC confirms that Atlas Air operates flights for Amazon in this crash. There may be others.


texts: Can a commercial aircraft be detected by ATC's / Radar systems if all its engines fail?

texts: In an event of failure of all engines of a commercial aircraft in mid air and no secondary backup or generators powering the plane (plane is virtually powerless and no comp systems work on board), would the ATC still be able to detect the aircraft with accuracy and if yes how is it done ? Are there any conditions that it has to be flying in an area which is monitored or any basic stuff which HAS to be working for ATC to detect ?