texts: Are there take-over requests from autopilots?

texts:
I am thinking of the driver take-over request in automated driving, when the system limits are reached and the back-up driver has to intervene / drive manually. Is there something similar in aviation, e.g. autopilot is engaged and has reached its system limits? Maybe you can give me some examples.

Edit: The reason why I am asking is, that there is a lot of concern about take-over situations in the automobile industry because cars are getting more and more automated. Since automation has a longer tradition in aviation than in automobile industry I assume there is a thing or two to learn from you guys. So basically I want to know what take-over situations there are and what is done to make take-over easy for the pilot (airplane or helicopter pilot).


texts: How is a variable sweep wing constructed?

texts: How is a variable sweep wing able to change its sweep?


texts: Instructor can't talk when H10-13.4 is plugged in

texts:
I'm a student pilot and I just bought my first own headset because the standard one in the plane does not really fit me.

I got a david clark h10-13.4.
My instructor uses either his private Bose A20 or the standard (active) Aerostar that is in the plane.

Today I tried my DC-headset for the fist time and there was a problem: I could talk just fine and the mic worked great but I could not hear my instructor anymore. He had to yell into the microphone to activate the intercom and even when he was loud enough, the sound quality was aweful. This was the same for both the A20 and the Aerostar headset.
Also others could not hear him when he tried to communicate with other aircraft over radio. They said there was just noise transmitted.

As soon as I switched back to the Aerostar headset, everything was fine again.

After today's flights I tried to use my headset with a handheld radio and the quality of my transmission was good (both ways).

My first idea is an impedance- or level-mismatch; but I thought, all fixed-wing  aviation headsets had about the same impedance.
Are there ready-built circuits to adapt my headset to the intercom?

I really don't want to stick with the standard headset. Neither do I want to blow 1k€ on a Bose as I really like the H10.

Apart from it being a Becker I don't know anything about the radio in the plane but I've been told not to mess with the configuration of the radio, as it works in all other setups.

Edit:
After having found a datasheet for both the A20 and the H10-13.4 I'm more confused than before.

DC-Headset-Datasheet: http://www.davidclarkcompany.com/files/literature/10-13.4.pdf

A20-Datasheet: https://assets.bose.com/content/dam/Bose_DAM/Web/consumer_electronics/global/products/headphones/a20_aviation_headset_Orion/pdf/a20_hdst_PDF_ownersguide_EN.pdf

On page 38 of the A20's datasheet there is the technical data with the microphone output levels. It sais:

  Typical output is 600 mV at 114 dB SPL

The David Clark sais:

  Mic Sensitivity: 400mV+/-6dB into 150Ω load @ 1kHz for 114 dB SPL input

which seems to be tested under the same conditions. But the amplitude of the Bose is higher. Shouldn't the effect we have seen be the other way around? With his mic working and mine not activating the intercom? Or with him being very distorted due to clipping in the amplifier?
Hope someone knows better than me.


texts: What are the consequences of disobeying cabin crew during emergency?

texts:
I was wondering what would be the consequences of disobeying flight crew due to emergency.

I was watching a video of Singapore B773 enroute on Jun 27th 2016 that landed, had a wing on fire, and passengers were made to sit and wait with the plane on fire. I would find it very hard not to attempt to evacuate plane.


texts: What is the typical touchdown angle of a large airliner?

texts:
Following up on my previous question about the typical vertical speed during the touchdown, I am now curious about the typical touchdown angle.

Airliners touch down with the main landing gear first, and only then the nose wheel. Hence there is some angle between the runway and the aircraft's body longitudinal axe. Let's assume that the runway is flat and that there is no slope in the runway.

Of course, the angle depends on many, many factors. It's theoretical maximum would be limited through a tailscrape event - and since aircraft are different in length, there is no general answer to this one. Theoretical minimum would be 0 degrees (or less, but then we have a nose wheel first landing). But, as highlighted in answers to my previous question, is there any information in operating manuals about typical angles, or can pilots provide some insight into which angle they are trying to achieve during touchdown?

Besides the typical angle, is there an optimum angle for any reason?

Again, I am not interested in the approach, only the touchdown after the flare.


texts: Is it hard to hover a coaxial rotor helicopter?

texts: Convetional rotorcrafts are hard to hover as when we increase collective, even tail rotor pitch needs to be compensated. But in coaxial design, will just increasing the collective do the job as torque doesn't change?


texts: I just saw a plane drop off online radar; should I do anything about it?

texts:
I was watching Flight Radar 24, positioned near my house, to see what planes I could spot, and noticed a Cessna 550's transponder just dropped off @ 5,325 ft in a high-speed descent!

Is there something I should do about it? Or do I assume somebody in ATC has seen it?

Is there anything anyone should do in similar circumstances?


texts: In a Cessna 172 flying VFR on long final, when do I extend flaps to 10, 20, and 30 degrees?

texts:
At the pilot-controlled airfield I use most frequently, we fly a standard rectangular pattern.

The normal-landing C172 flap sequence goes

Downwind: 10 degrees past the “abeam point” and airspeed in flap range
Base: 20 degrees
Final: 30 degrees when assured of making the runway

When making occasional landings at a nearby Class C airport, ATC sometimes puts me on vectors resulting in a long, straight-in final. In relation to such an approach, when do I extend flaps to 10, 20, and 30 degrees?


texts:
What type of fuel is used in helicopters?

Do they use Aviation Turbine Fuel (jet fuel), which is used widely in commercial airlines?

Also, where would be the fuel tank located in a helicopter?


texts: Can a IFR flight plan be amended or cancelled whilst in flight?

texts:
I'm asking, because ForeFlight states in their demo training video that an IFR filed flight plans can only be amended or cancelled up to 47 minutes prior to it being filed (and up to 2 hours after, for VFR flight plans that have been filed. Not sure why that's time restricted at 2 hours?).

website: https://foreflight.com/support/video-library/watch/?v=how-to-filing-icao&list=filing-briefing

But in the movies you see jets owners telling the pilots to alternate their course to an alternative location (even International flights).


texts: People say that modern airliners are more resilient to turbulence, but I see that a 707 and a 787 still have the same G-rating. Why is this?

texts:
The 707 was introduced in the late 50's, the 787 in 2009.
Back when Air France 447 had recently gone missing, many were speculating that the aircraft had broken up in the turbulence associated with the massive thunderstorm it was flying through. Some aviation spokesperson, who I believe were associated with Airbus, said that the planes are designed to withstand the worst storms with a 50% safety margin.
Several airliner models from the 50's and 60's have broke apart in flight due to turbulence associated with thunderstorms (A 720 B, A BAC-1-11, and a F-27 in 1981). There were also breakups involving clear-air turbulence (707, Mt. Fuji, 1966, and a Consolidated Airlines F-27). I checked to see if their G rating was lower than the planes of today and they were the same - 2.5+ G Limit Load, with a 50% safety margin, so 3.75+ G Ultimate Load (beyond which structural failure occurs).
Why is this? Shouldn't the G rating be much higher if modern airliners are more resistant to violent turbulence?


texts: Can you request a new squawk code if you don’t like the one being assigned?

texts: Just out of curiosity. If you get assigned a squawk code and you don’t like it out of superstition or other negative associations you have with it, can you request a new one?


texts: How do you search for all incidents of a Canadian airline online?

texts:
Where can I find records of all incidents (per ICAO's definition) for a specific Canadian airline, e.g. WestJet? Typing in 'Westjet' on TSB Canada's site produced only 7 results and none this year: this is wrong because per Google (and Canadian news sources), WestJet has suffered problems with their Boeing 767-300s in 2016.

Avherald has more results, but is difficult to read as it does not enable sorting by date: but what are their sources? And shockingly, Aviation Safety Network neglects WestJet (the second largest airline in Canada)!


texts: Is the wingtip fence as effective as the winglet?

texts:
My guess would be no because it does not reflect the air as well.Wingtip fence

Winglet

What I am basically asking is does the wing tip fence have the same amount of drag reduction (wing tip vortex) as the winglet?


texts: How would we calculate the load factor on an aerial vehicle while landing due to sudden gust loads?

texts:
In order to design the landing gear (wheels and suspension) of our model Airship, [say "m" kg -expected mass], I wanted to know, is there any way to calculate the loads which might be experienced by the wheels on impact with the ground (taking into consideration the unexpected gust loads - with gust velocity downwards say "V-gust")•

For simplicity I am Modelling it as a rigid body for now.

Note:- I thought of one way to calculate it, using momentum transfer.

Rate of change of Momentum = Force = density(rho) x projected Area(A) x (V-gust)^2.

Hence,( Gust force + Weight -Buoyant Force) ÷ Mass (m) will give me resultant acceleration.

Q1. Is this a right approach to calculate load?
Q2. Even if it's right, is this the load the wheels will experience during impact?

Please help me clear my confusion.

Edit:- Basically I want my designed landing gear with a normal sink speed upto 3m/s to be able to endure the landing impact even in case of an additional vertical downward gust upto 10m/s at the moment of touching the ground.  This is as specific and clear I could get.


texts: What are some disadvantages that come with a design like a B-2 spirit bomber?

texts:
Here is a B-2 Spirit:

source

Source

Many different things can get in the way with a design like a B-2. Although it has really good stealth and looks, does it have any disadvantages that come with the good stealth and looks?

What kind of disadvantages would this aircraft have of an
airliners design or another bombers design like the B-52 or B-1?
What system does this aircraft use to overcome not having
stabilizers?
Why have only 22 ever been built?


texts: Do you have to update weight and balance charts after installing new avionics?

texts: The POH always has weight and balance charts. Let's say you install some new avionics, hence changing the weight of the aircraft. Do you need to update the POH binder with new weight & balance charts? What about take-off/landing distance information?


texts: How can I calculate the effect of winglets on aircraft performance?

texts:
For a project at university I am having to produce a SIMULINK model of a Nimrod MR2 aircraft. The next step is to increase the endurance of aircraft and a possible route for this is adding winglets to the tips of the wing to increase the efficiency of the wing. However I am struggling to calculate the effect this will have on the performance of the aircraft.

Could anyone offer some help on this topic please?


texts: How many flying hours does one need to become a commercial pilot in the Philippines?

texts: I'm trying to calculate all the expenses to become a pilot in the Philippines.


texts:
I have a list of of aircraft types like so:

0      320
1      76B
2      DH4
3      E95
4      319
5      76A
6      321
7      77F
8      CR9
9      77E
10     OAAG

I was able to identify most of them:

320: Airbus A320
DH4: Bombardier DHC8-Q400/Q400CC (DH4)
E95: Embraer ERJ-195
319: Airbus A319
321: Airbus A321
CR9: Bombardier CRJ-900

However there are some that I cannot understand exactly which model they are. I guess they are Boeing 767 and 777 but I am not sure which model.
Can you help me out to find out which aircraft are these:

76A
76B
77F
77E
OAAG


texts: What are these "portholes & panels" on the fuselage of the Omega Tanker DC-10?

texts:
If you take a look at the photo (source: still from this YouTube video), you'll notice a pair of "panels" on the fuselage of this Omega Tanker DC-10 (reg: N974VV), circled with green.

There is also a pair of "portholes" (circled red).

What are all those? Any relation to this being a tanker?

Note: Here's a photo that shows the "panels" closed on the ground.


texts: Why does the P-3 Orion use an engine driven compressor instead of bleed air for pressurization?

texts:
In another question, an answer mentions that the P-3 Orion uses a gearbox driven compressor for cabin pressurization, even though the aircraft uses T-56 turbine engines that supply bleed air in other designs.
(How are turboprops and other propeller planes pressurized?)

Brief research suggests that the "EDC" exists, but I can not find any rationale for it.
(http://blueaero.com/wp-content/uploads/2016/11/Heico_P3_EDC_Repair.pdf)

Does using gearbox driven compressors help in some way with the mission, possibly in dealing with the environment? Is it an anachronism/carryover from the L-188 Elektra? Is it not actually gearbox driven, but somehow an exchanger for bleed air?


texts: If turning off electronic gadgets is so important, why are there no detectors used to find them?

texts: It's supposed to be that electronic gadgets' emission are dangerous for airplane systems. If this is true, why don't they use any detectors to locate such emissions?


texts:
Does the US military use the metric system for aviation?

For example, does it use:

feet or meters for altitude?
nautical miles or kilometers for distance?
knots or km/h for speed?
inHg or hPa for pressure?
°F or °C for temperature?

If so, how do they work with ATControllers who are used to using customary measurements?


texts: How likely could there be a loss of cabin pressure?

texts:
You often on commercial aircraft (whilst on the ground to the runway) hear on the safety video:

  in the event of a loss of cabin pressure, oxygen marks will be released from the panel ....

What could cause a loss of pressure? Is it at all even possible for it to just drop?

Season's greetings :-)


texts: What is the groundspeed history of an aviation of such as a Boeing plane?

texts: I would like to see groundspeed data of civil aircraft for distances such as 300 miles. What could it look like for a popular model such as Boeing 737?


texts: Plss help me. I got a exam question about comparing the advantages and disavantages of short duct turbofan and long duct turbofan. Anyone knows the answer plss help me !!!


texts: In a B737 NG, when a TO is flown with an Assumed Temperature N1, is the subsequent CLB N1 also adjusted (lowered) accordingly?

texts: The Title is my question. Because I think that if one uses a very high Assumed Temperature, the subsequent Max CLB N1 maybe higher that the TO N1.


texts: Does Jeppesen display runway declared distances on their charts?

texts: I noticed that Jeppesen includes additional runway information on their 10-9 or 10-9A charts.  Are these listed values consistent with FAA runway declared distances?


texts: How did this Vampire's takeoff damage the runway so much?

texts:
This appears to be real, but, what's the cause?

Aircraft is a DeHavilland Vampire on takeoff from a small airfield, but the runway's surface disintegrates from jet blast

Full file at https://i.imgur.com/NaK5yAr.mp4

Is the Vampire's jet blast that strong?  Or is it weak/old tarmac which is being pushed over the limit of adhesion?

I suspect the field would be closed for repairs becuase of this damage, and the the runway's now lack of smoothness,  but could that plane land again right away?   If the loose bits were picked up?  Would it have to land on the grass verge instead?

Would this have happened with other aircraft on the same runway?  Or is the vampire special?

Other info

Plane's registration number is WZ507

https://www.facebook.com/Vampire-WZ507-351376189100/

This airframe is also the poster photo on https://upload.wikimedia.org/wikipedia/commons/thumb/d/d5/Vampire_3_%28cropped%29_copy.jpg/450px-Vampire_3_%28cropped%29_copy.jpg


texts: Why can planes generally take more positive g's than negative g's?

texts:
Most commercial airliners are rated to take +2.5g and -1.0g.  Why is this?  Is it designed that way on purpose?  To clarify, this would mean that the cost difference between -1g and -2.5 g is minuscule, so price (and thus engineering difficulty, which drives price) isn't really a factor.

Or, are there in fact significant difficulties with creating a frame that can handle a lot of negative Gs?  (And if there are, what are they?)


texts: Could airliners have cameras to let the pilots see the engines and wings?

texts:
Why can't jet airliners have a camera installed on the fuselage and a monitor in the cockpit so that pilots can see engines and wings which are normally behind them and hidden from view? Something like the system they have in cars today?

This might help in an emergency engine fire or wing damage. I don't believe that any jet transport today has cameras to monitor the wings and engines (I see where they do have other cameras) and this was the cause of a recent accident where an engine was on fire after landing and the pilots were unaware of it until the fire was out of control and the pilots were almost killed.


texts: What happened during this foggy landing?

texts:
Several years ago, I was flying from the USA to Buenos Aires. That's a very long flight, and it was overnight for us.  When I woke up it was early in the morning and we were over Argentina.  I don't remember exactly what the plane was, but it was a very large jet. 767 or something like that.

As we got close, the pilot came on the intercom and announced that it was too foggy down below to land, but we still had plenty of fuel reserves left and so he was going to fly in circles for a while and see if the rising sun didn't burn off some of the fog.  After about 15 minutes, he came on again and said that the fog was burning off, and we were about to begin our descent into Buenos Aires.

I was in a window seat, and I looked outside.  We went into a cloud... and never came out.  Literally the first clue I had that we were anywhere near the ground is when I felt the wheels hit the runway.  And to this day I've always wondered what in the world was going on in the cockpit.

I don't care how good the pilot's eyes were; there was zero visibility outside that airplane.  That fog we were in was the metaphorical "pea soup", and he could not possibly have landed visually.  But we came down safe, exactly where we were supposed to be, which means he must have made some sort of instrument-guided landing.  But if he was capable of making a perfect instrument landing at that runway all along, why was the fog reducing visibility ever a concern in the first place?

Does anyone here have enough experience to explain what happened that morning?


texts: Is it practical to install seat belts in airline lavatories?

texts:
Many times passengers might found themselves in the lavatory, when turbulence happens. During such times, do the handlebars inside the lavatory provide adequate support to the passenger, or does it makes more sense to install some kind of seat belt?

My question comes from the premise, that if a passenger is in the lavatory when sudden turbulence hits, he/she may not have such necessary aids to prevent injuries, which might lead to a claim of negligence against the airline.

I am mostly looking at answers concerning commercial airlines.


texts: Why would the Pakistan airspace closure cancel flights not headed to Pakistan itself?

texts:
The India-Pakistan feud has heated up again, with Pakistan closing its airspace as a result.
I know many international routes fly over Pakistan, and that the closure would cause issues, but this report surprised me:

Thousands of people were also stranded by affected airlines that not only land in Pakistan, but fly over its airspace -- one of the major routes from Southeast Asia into Europe.
Thai Airways announced that all its European routes "departing near midnight of 27 FEB through early 28 FEB" were canceled "due to sudden closure of Pakistani airspace as a result of tension between India and Pakistan."

Why would the airspace closure force flights over it to cancel entirely? I would think you would just reroute them around it.


texts: How thoroughly can WINGS phases substitute for a flight review?

texts: If a pilot is unable to act as PIC because they need a flight review, can they instead earn WINGS credits and complete a phase? Everything I have read, including §61.56 and AC 61-91J, suggests that the answer is "yes", but apparently nobody else is discussing it because I can't seem to find the answer on the internet.


texts: Can I accept a SID if I can't make the required climb gradient on a single engine but have no problem on two engines?

texts:
Can I accept a clearance containing a Standard Instrument Departure (SID) with a climb gradient that I can easily make on all my engines but can't make the required gradient on one engine inoperative?

If I can and I lose an engine on departure what should I do so I don't hit anything?


texts: How long does it take to restart a turbofan engine inflight?

texts: I'm especially interested how long it would take to restart a turbofan engine after a hypothetically erroneous shutdown of an engine immediately after takeoff i.e., at an altitude at which the air is reasonably dense. Is windmilling enough or would you need crossbleed and starters again?


texts:
Here are few facts:

A flight is basically climbing, staying high, then descending toward a runway

Changes in altitude increase the distance an aircraft flies. Given the climb/descent angle, this increase may be insignificant, but it still exists.

The path followed by an airliner may not be direct

Given many elements (TSA, other traffic,...) I imagine an airliner can almost never take a direct route. Not to mention the path leading to the approach.

An airport may have several runways whose length may not be the same

The departure point may be the parking position, the beginning of the runway, the end of the runway, the point where the aircraft reaches $V_2$,...
The same goes for the arriving point.

The precision of the maximum range of an aircraft is really precise

When looking at ailiners' performances, one key figure seems quite strange: the range. It seems quite precise (few miles). Lets take the ERJ-140ER as example. Its maximum range is 1250nm. Given this number, I imagine the precision is less than 10nm (3 significant digit), i.e. about 3 to 4 times an international airport's runway length (4km for dubai international airport).

Given all those elements, how is a leg length (distance of 1 flight between 2 airports) calculated for an airliner?


texts: Are flights being shown as "hijacked" on airport departure screens in case they are?

texts: In the movie The Net a flight appears as "hijacked" on a departure/arrival screen. Would these screens really show an airliner as hijacked when they are, and did this ever happen?


texts: Why does the landing gear control have 3 positions (up/down/off) on Boeing 737-800?

texts: I've noticed that Boeing 737-800's cockpit has a 3-position landing gear lever. During takeoff, the pilot moves the lever from DOWN to UP and then to OFF position. What's the point of the OFF position? Why not simply have UP/DOWN positions?


texts: What is the function of Boeing C-17 Globemaster III in Indian military?

texts:
Why does India need Boeing C-17 Globemaster IIIs?
What purpose do they serve in Indian military?


texts: What do the dashed extended green lines on this PFD mean?

texts: The most important source of information for the pilot is the PFD


texts: When and how can pilots waive wake turbulence holds in the US?

texts: According to FAA rules, controllers are required to hold aircraft 2 or 3 minutes for wake turbulence under certain conditions. When is that wake turbulence hold required, and when are pilots allowed to waive it? What is the correct way to request a waiver?


texts: Is wheel well overheat detection (not brake temperature sensor) necessary for commercial jet aircraft?

texts: Some aircraft do have this detection system (many Boeing aircraft), some do not. Why? What's the main purpose of the wheel well temperature detection system, even though there are brake temperature sensors.


texts:
I stumbled on a new chinese one here: The "Snow Eagle 601".

Can someone expand a little?

At first sight, I can't make any relevant difference from a regular one (It just looks like a stock DC3 fitted with new turboprop engines + snow skis for the purpose).

Anything to do with the plane's performance required by the toughness of elements in the poles?


texts:
Cessna 414 ram conversion

What's this fuel line for that is coming to injector , other then the one from fuel disturbutor  ?


texts: What % of horsepower in a turbine is used by the compressor section?

texts: If a turbine generates 10,000 shaft horsepower, I am trying to understand how much horsepower has been used to compress the air.  So the turbine that generates 10,000 hp must in fact generate 10,000 hp plus X hp for the compressor.  What is the amount 15%, 25%, or what?  Thanks for your response.


texts: How do the European ATC strikes affect us as pilots?

texts:
So every once in awhile I see an article talking about the air traffic control strikes in Europe like this one:  European air traffic controllers to strike.

How does this affect me if I am flying to Europe?  Do they just close the doors and all airspace becomes uncontrolled airspace?  I'm guessing not, but that's what I envision when I hear that!  What happens if they go on strike while I'm over the ocean on my way there?


texts: What does "the other's right" refer to in 14 CFR Part 91.113?

texts:
There's a part in 14 CFR Part 91.113 (regarding airborne right-of-way rules) that's been confusing me:

Converging. When aircraft of the same category are converging at approximately the same altitude (except head-on, or nearly so), the aircraft to the other's right has the right-of-way.

Specifically, I don't fully understand the phrase "the aircraft to the other's right" - it would seem both aircraft will either perceive themselves as being to the left or right of the other meaning either both aircraft or neither aircraft would have the right of way. This is obviously not what is intended in FAR, so could someone give a more intuitive explanation of this? Thanks!


texts: Why is the manufacturing process of an aircraft mostly manual?

texts: Why is the manufacturing process mostly done by humans, and not by robots as in case of most other industries?Video


texts: Is there any particular reason the A380 doesn't have a centre wing tank?

texts:
Today I learnt something new, but apparently the A380 has no centre wing tank, which leads me to ask, is there a specific, design reason for this? Or did Airbus just think those huge wings were big enough to hold all the fuel they'd need?

Although, I've heard rumours that the A380F if built would have had a centre tank (no idea how true this is), but this shows the engineering is possible, Airbus just chose not to go with it for the passenger version. Any reason why?


texts: Is there any reason to use only UTC standard time in aircraft and not GMT?

texts: Why are we not using the GMT time standard in an aircraft? Why is only UTC the standard on-board?


texts: Do pilots breathe the same air as passengers?

texts:
Do pilots breathe the same quality of air as passengers ?
(i.e. identical parameters: same O2, CO2 and O3 levels, same temperature, same humidity, etc.)

Do pilots breath the same air as passengers (shared air) ?
(i.e. the air a passenger exhales will be inhaled by the pilot [or vice verca], which also means that smoke in the cabin will inevitably end up in the cockpit)


texts: Why can't the flex temperature be lower than Tref? Also why can't we perform a flex takeoff on a contaminated runway?

texts: This is a huge grey area and my quest to find answers for them is never ending. I have referred to many performance books but to no avail. I hope this question can be clarified. Thanks


texts: Is the 737NG hydraulically controlled or electronically controlled?

texts: I know that the 737NG is not fly-by-wire, but are the control surfaces controlled with hydraulic systems that transfer the input from the pilot to the control surfaces via fluid (hydraulics), or is the pilots' input transferred to the control surfaces' electronic actuators via electric signals?


texts: What type of microcontrollers are used in large scale UAVs?

texts:
What type of microcontrollers (in terms of processing power, clock speed) are used in large scale UAVs such as the Northrop Grumman RQ-4 Global Hawk, the General Atomics MQ-1 Predator etc. ?

Also, are smaller, low powered microcontrollers used for controlling subsystems such as the INS and control surface movements. If so, then in what range does their processing power and clock frequency lie?


texts: What is the relationship between the Center of Pressure and flap deployment?

texts:
I have been reading regarding the Center of Pressure of an airfoil (Cp) and the relationship with angle of attack.

What is a good way to explain in layman's terms why the pressure changes in such a way as to move the Cp forward as AOA is increased?

Also, in a flap deployment situation; the Cp moves aft. My reasoning here would be because now the aft portion of the airfoil is now at an increased camber, meaning that you have more lift production towards the aft of the airfoil, the Cp (average of the lift production across the wing) would be moving aft. Is this correct?


texts: Help clarify Pilot's difficulty balancing forces acting on aircraft during cruise stage?

texts:
How does the ideal disposition of the four forces in an aircraft relate to the nose-up or nose-down pitching moments? What are the difficulties that the pilot can face to maintain such an ideal disposition for each of the forces while cruising? And also, Do these forces values and positions depend on the airspeed and the angle of attack?

THANKS.


texts: What is the history of the CFI spin endorsement requirement?

texts:
FAR 61.183(i)(1) requires that a Flight Instructor candidate receive a logbook endorsement certifying proficiency in slow flight, stalls and spins.
How long has the requirement for spins been in the regulations?
Is it possible that there are CFIs in the field that do not have this endorsement?


texts: What are the basics of flying non-revenue?

texts:
I've never worked for an airline, but I know that one of the benefits of working in the industry is that you can fly for free or almost free on a space-available basis.  I realize that every airline is slightly different, but what's the general procedure for this?  To provide a concrete example, let's say I live in New York and want to non-rev to Miami tomorrow.

How would I know if a space is available?  How far ahead will I know that I have a seat?  Can more senior employees beat me out or is it first come, first served?  Do I need a boarding pass?  If not, how do I get past the TSA checkpoint?

In general, how does flying non-rev work?


texts: How to calculate the zero lift drag coefficient for a wing with data from airfoiltools.com?

texts:
I'm currently trying to write a script in python that I can use to optimalise a flying wing aircraft. I've run into a problem when trying to use data from airfoiltools.com. I've tried to calculate the zero lift drag coefficient using a value for Cd and Cl found on airfoiltools.com, I used the following equation:
Cd = Cd0 + Cdi
Cd0 = Cd - Cdi -> I then substituted the induced drag coefficent:
Cd0 = Cd - Cl**2/(piARe)
The symbols are:
Cd0 = zero lift drag coefficient
Cd = total drag coefficient (from airfoiltools.com)
Cl = Coefficient of lift (from airfoiltools.com)
AR = The aspect ratio of the wing
e = The oswald efficiency factor
The problem is that this equation gives me a negative value for Cd0, which is not possible for obvious reasons.
Please, does anyone see my mistake here? I'm not formally schooled in aerospace engineering so I don't know all the theory behind these equations, thus I may not understand wether I can or cannot use them in this situation.
Thank you in advance and kind regards,
Remco van Woerkom


texts: Fixed-wing aircraft (just about all of them!) have static wicks to dissipate static charge buildups before they can become obnoxious or shocking.  Are helicopters fitted with them? This answer suggests they are not.


texts: Why does elevator dropdown occur in some loss-of-flight-controls accidents, but not others?

texts:
In some instances of an aircraft suffering a catastrophic failure of its primary flight controls, the loss of control force on the elevator allows said elevator to drop down under its own weight, causing an immediate crash.

Examples:

THY 981 (DC-10, 1974, Paris)
LOT 007 (Il-62, 1980, Warsaw)

In other loss-of-flight-controls accidents, however, the elevator either stays stuck at its position immediately prior to the control failure, or floats in the airstream:

JAL 123 (B747, 1985, Mt. Takamagahara)
LOT 5055 (Il-62, 1987, Warsaw)
UAL 232 (DC-10, 1989, Iowa)
DHL OO-DLL (A300, 2003, Baghdad)

Why does elevator dropdown occur during some, and only some, loss-of-flight-controls accidents?


texts: What are the various fees associated with flying?

texts: I am aware of airport landing fees, fuel fees etc, but it was brought to my attention that there is airspace charges? And especially in Canada, the fees are horrendous. What are the various types of fees airlines and private planes have to pay in terms of airspace and air traffic control fee around the world, and Canada and the US?


texts: What does the NCrit parameter indicate in a CFD analysis?

texts:
When analyzing an airfoil in the XFLR5 software I am asked to input some data regarding the free stream. For this, a dialogue box pops up that has the following options:

One field contains the expected Reynolds and Mach numbers for the flow.

The other field says Ncrit. What is this parameter, and what does it have to do with the trip location (top and bottom) which can be inputted together with it?


texts: Is special equipment required to perform high-voltage line inspections?

texts:
I was watching a youtube video about high voltage cable inspections performed with helicopters. It can be seen how the helicopter has to reach the same electric potential as the wire, something that normally does not occur to other crafts.

I was wondering, is there any kind of special instrumentation/equipment that must be installed on the helicopters to perform such operations?

Are the pilots aided in any special way to maintain a stable hover or it boils down to skill and training?


texts: Is it legal for pilots to transport or use marijuana?

texts:
More and more states are legalizing the recreational use of marijuana. What does that mean for pilots?

Is it legal for pilots to transport marijuana within states that have legalized it?
Can pilots use marijuana recreationally if their state allows it? Are there implications for medicals?


texts: Does wind provide lift for hang gliders in the air?

texts: Basically, if there are no thermals, but a strong wind, is there a way to use that wind to gain altitude?


texts: Let's say I was in the market for buying a Cessna. What benefits would buying a new Cessna have over an older one? With cars, the resale value does hit a floor as long as it is safe to drive. Are planes the same? Is the fuel efficiency worth buying a new Cessna or is it more of a status thing?


texts: Which altimeter setting is used to define airspace boundaries?

texts:
Let's say that we're flying VFR over the top of Class D airspace at 3,000 feet. The Class D extends up to 2,900 feet - we're above it, but just barely with a 100' buffer.
We're also talking to approach control for VFR flight following. Approach has given us the QNH for their nearby Class C airport, say 29.90", which we've dutifully and correctly set into our altimeter's Kollsman window.
However, it turns out there's a strong pressure gradient today. The QNH at the Class D airport underneath us is 29.80". According to that pressure setting, our altimeter would read 100 feet lower - placing us within the upper bounds of their airspace.
In a situation like this, which pressure setting actually defines the upper boundary for the Class D airspace? Would this aircraft have inadvertently busted the Class D airspace?
(One one hand, everyone within the Class D would be using the QNH reported by the local ATIS, and would expect nearby aircraft to be participating with the Class D tower. On the other, approach control would expect you using their given altimeter setting in order to comply with cruising altitudes and for vertical separation. The only rule I can find is FAR 91.121, which just requires using an altimeter setting within 100 nautical miles.)


texts: How can you stop your missile locking onto a friendly target?

texts:
In the modern day we have advanced planes, and advanced missile systems, however, how can you stop your missile firing at a friendly aircraft?

In planes like the F22 Raptor you can turn on sight lock, which is when you look at a plane through your helmet, the computer registers that there is a plane there, and it locks onto the plane with a missile.

However, let's say a friendly aircraft were to fly in front of you when you had sight lock turned on; would the missile fire at the friendly aircraft, or is there a piece of technology in the friendly aircraft which registers that it's with you? If so, could that potentially be used against you in modern day aerial warfare?


texts: What is this pod at the wing-tip of a U2?

texts:
In this image of a U2S, what it the very unaerodynamic looking pod at the wing-tip? It looks like it holds some sort of sensor package. However, it doesn't seem to appear on all U2s (at least not based on photos on Wiki).

Source: Wikipedia


texts: How is the induced drag calculated for a wing with elliptical planform?

texts: How is the induced drag calculated for a wing with elliptical planform ? Is this wing shape the most efficient ?


texts: Does full nose up trim provide approximately the elevator pressure for Vg?

texts: I heard during an aviation presentation that full nose-up trim provides approximately the right amount of elevator pressure for Vg with the power at flight idle. The presenter also followed up with that this is a certification requirement. Is this the case? Is there anything in 14 CFR 23 or 25 about it?


texts: Why do jet generators produce a higher frequency power then household electricity?

texts: I know in most homes your local transformer provides a 50Hz or 60Hz power source. So all your hairdryers, dishwashers etc. are built to consume 50Hz or 60Hz power at 110 volts or 220 volts, depending on where you live in the world.  On the aircraft engine generators use a much higher frequency (400Hz). Why is this?


texts: Why is the flight going north just to go south?

texts:
I am tracking my kid's flight from LAX to EWR. It seems like a pretty straight West to East kind of flight but the flight path has the plane moving somewhat north through Ohio and then angling back to the south

Why wouldn't the flight just keep going East?


texts: Is there any formula that directly relate density to altitude for a wide range of altitude?

texts: I am working on a code to simulate a vehicle trajectory based on forces act on it in different altitudes, I need a formula that gives density in an altitude range between 0 and 40 km to obtain lift and drag in different altitudes. Is there a formula that gives it to me even with a reasonable error?


texts: Can "a drone" damage the wing of "an aeroplane" to the extent it actually threatens its ability to fly?

texts:
I stumbled across this video by the University of Dayton, showcasing the amount of damage a certain type of drone can do to a wing, and they wrote a whole article about it. While most of said article sounds like marketing for their research institute with very little actual information about the video they just released, the key thing to take away seems to be that:

researchers in UDRI’s Impact Physics group launched a 2.1-pound DJI Phantom 2 quadcopter at the wing of a Mooney M20 aircraft. The drone did not shatter on impact, but tore open the leading edge of the wing as it bore into the structure, damaging its main spar.
[...]
The researchers then fired a similarly weighted gel “bird” into a different part of the wing to compare results. “The bird did more apparent damage to the leading edge of the wing, but the Phantom penetrated deeper into the wing and damaged the main spar, which the bird did not do.”

If we trust that the researchers accounted for the fact that a damaged wing's structure is obviously compromised in places and that they also accounted for bones making an actual bird slightly more rigid than pure gel, as well as repeating the experiments often enough to make above statement with a reasonable degree of confidence -- none of which the article mentions explicitly -- then what conclusions can we draw from this?
It looks dramatic. Sounds dramatic, too, if you know nothing about aviation at all, which I guess was the intention when they wrote the article.
But how significant is the damage really?
The article doesn't say.
One YouTube comment by one "Stephen Mann", appearing to claim piloting experience states:

You can throw, at 200 MPH, anything weighing 2 pounds at a sheet of 2024-O .04" aluminum, typical of aircraft wings, and get this damage.  I've seen worse hail damage.

and notes that:

the Mooney wing uses a thinner aluminum (0.038") than an airliner (0.04 to 0.05").  This made the Mooney lighter and faster, which was a marketing design.
I've had more than a few bird strikes during landing (none during takeoff that I was aware of).  Some were Canadian geese that weigh 10-15 pounds.  There was never any damage to the aircraft beyond cleaning up the bird guts from the wing.

while generally playing down the significance of the test:

Typically, no aircraft below 400 ft., where most drones operate, will be flying that fast.  On final approach most airliners are flying between 130 to 160 knots, and by the time a landing aircraft is below 500 ft. the flaps and slats are deployed and the A/C is probably going 120 knots.  General aviation aircraft, like the Mooney in this video, are typically flying between 70-110 knots on final approach.  Even slower on takeoff.

I'm reluctant to accept information from YouTube comments at face value -- especially since it may be biased. But if true, this may just reduce the usefulness of the test significantly. And although I guess that's quite possible, I'd like to think they put some thoughts into these experiments before conducting them.
So where does that leave us?
Can "a drone" bring down "a plane" by crashing into it? Most likely, if we're talking about these big US military type drones like the RQ-4.
But can a "hobby drone" (for lack of a better word) like the one shown in the video by the University of Dayton seriously threaten the fly-ability of "the average plane" (if such a thing exists)?
Or let's say we start at the Mooney and scale the damage up for larger planes. Would a plane with that kind of damage get into trouble whatsoever or would it just require a probably costly repair?


texts: Could simple fly-by-wire controls be installed in a prototype as quickly as a mechanical system with an autopilot?

texts:
It seems that fly-by-wire systems can take longer to get certified as the testing requirements are much more extensive. A prototype aircraft wouldn't have to pass these tests.

How much more time or complexity might it be to implement a fly-by-wire system for just one set each of ailerons, rudders, and elevators? An equivalent level of functionality in the mechanical system would require at least an autopilot.

Any links to regulations or example systems would be greatly appreciated.


texts: why are there no production canard GA aircraft?

texts:
You see a lot of experimental canard GA aircraft, and their performance characteristics seem great. Why don't we see any production canard designs?

EDIT

For clarification. I'm asking about small airplanes, competitors to the Cessna 172 or Piper Archer in size. I'm also asking about airplanes that you can purchase from a manufacturer, like the above aircraft. An example of a company attempting to eventually make a small canard style production GA aircraft is Raptor Aircraft


texts: What aircraft or airline differences would make the Sukhoi Superjet unsuitable for US regional airline operations?

texts: What differences in the "stock" production SSJ-100 (as compared to CRJ-900s or EMB-190s), or in US regional airline operations (vs Interjet's success-so-far with the SSJ-100 in intra-Mexico and Mexico-to-US ops) would put the Sukhoi Superjet out of consideration for US regional airline operations?  Would post-sale support be the killer, or would the only thing in the way be the US government not liking it (either by the FAA shooting down the idea, or by way of an exorbitant trade tariff making it more expensive than other options)?


texts: What's the definition and the meaning of “soft dirt runway”?

texts:
What's the definition and the meaning of "soft dirt runway"? You can read that expression in the following text:

  ..The aircraft's rolling resistance, μ, is determined by the type of
  runway surface and by the type, number, inflation pressure and
  arrangement of the tires. A thin, high-pressure tire operated over a
  soft dirt runway will have so much rolling resistance that the
  aircraft may be unable to move. A large, low pressure tire can
  operate over a softer runway surface but will have more aerodynamic
  drag if not retracted, or will take up more room if retracted. Values
  of μ for different runway surfaces are provided in the detailed
  takeoff analysis in Chapter 17. ...

Source: Daniel P. Raymer, Aircraft design: a conceptual approach. Chapter 5 Thrust-to-weight ratio and wing loading, paragraph 5.3 Wing Loading, sub-paragraph Takeoff Distance, page 88.


texts: If I have a float plane, can I land on any body of water?

texts: What are the rules with regards to landing a float plane on a body of water?  Can I land anywhere (non-emergency, obviously) that would also accommodate the take-off?  If not, how do I determine which bodies of water would allow it and which would not?


texts: What kind of motion will an airplane enter into when disturbed?

texts: When an airplane is disturbed from a longitudinal equilibrium position, what sort of motion will the aircraft experience? Will it be a phugoid or a short period motion? Or will it be both?


texts: Do any modern airliners have a non-flat floor in the passenger cabin?

texts: Are there any non-flat (sloped or stepped) passenger cabins in modern commercial planes? E.g. the floor at the back of the cabin is a few centimeters higher than at the front?


texts:
Regarding the events of MH370, if an modern aircraft (like the Dreamliner, or the A350) turn off deliberately all it's radio-communication under control and fly under the radar scope, is it really possible that with so many nowaday technology, there is still no way to know the whereabouts of an aircraft?

Are new fallback location beacons set?


texts: How much fuel do the new A320-Winglets burn vs. the B737-800?

texts:
Now that the new A320-Winglets have established themselves, I'm wondering if they have better fuel consumption than the B737-800?

I was told that Boeing used to be marginally better. Is that still the case?


texts: Does RPM refer to the speed of the engine or the speed of the propeller?

texts:
I followed discussion here: In a constant speed propeller, why does the RPM drop with a prop pitch increase?, I got confused about the RPM there. As the opening statement said in that discussion, "When a constant speed propeller changes its pitch from low to high, RPM would decrease."

From that discussion said that the RPM there is not the RPM of the engine that used to power the airplane, but the RPM of the propeller itself, how fast it rotating after the pitch was changed. The more pitch of course will produce more drag and as the product, the propeller will rotate slower than previously.

Please you masters of the aviation, please confirm if it is true, the RPM is the rotation of the propeller itself and not the RPM of the engine/turbine used to power of the airplane. That have confused me for quite long time and made me very difficult to understand many explanation.


texts: Regular procedure followed by the pilots before takeoff?

texts: What are the list of procedures (checks) followed by A320 and A380? Are these procedures decided by the airlines and (or) the manufacturer, or by the Civil Aviation Regulatory Authority of the respective country?


texts: Why was the Concorde painted white and not black?

texts:
It's well-known that the stated reason the Concorde was painted predominantly white was to mitigate heating problems.

However, given that the source of the Concorde's thermal woes wasn't excessive exposure to solar radiation, but, rather, direct conduction and convection of compression heat, I'm confused; in that case, shouldn't the Concorde have been painted black (or nearly black), like the SR-71, to better radiate heat away?


texts: What triggers the PTU (Power Transfer Unit)?

texts:
As highlighted by this answer and by this page the PTU (power transfer unit) is an hydraulic driven pump. It gets energy from one hydraulic system and uses it to pressurize another hydraulic system.

What triggers the functioning of this pump? Is it automatic or manual? Is this pump available even if a leak is detected in the hydraulic system it tries to restore pressurisation to?


texts: Is it OK to make an approach without any straight-in segment at all?

texts: Let's say you are on a 180° heading right of the airport and want to land on runway 36. Abeam 36 you can make a descending turn left, flare and start leveling off at the same time, touch down with the left gear, level off and finish the rollout. No problem in a GA aircraft. Can this be done in an airliner, for example in a circle-to-land approach? What is the minimum straight-in segment required for circle-to-land?


texts: Where can I find the German GAFOR online?

texts: Where can I access the GAFOR for Germany for free online (or at least something close)?


texts: Can quadcopters save energy by flying in formation?

texts:
If two or more quadcopters are aligned, would the effect of drag due to the lead quadcopter's slipstream lead to measurable energy savings? And if so, how would one determine the optimal distance between the quadcopters?

My thought are that some energy savings are possible, but that there must be some distance between the quadcopters to avoid the high pressure air behind the lead quadcopter interfering with the quadcopter that's behind. How great this distance is depends on the tilt of the lead quadcopter. Since the drag force is proportional with the square of the velocity this means that energy savings should be larger at high velocity, but unfortunately the tilt of the quadcopters will also be higher causing the minimal distance needed between the quadcopters to increase.


texts: So occasionally I will be flying my rc helicopter and I turn it left to right (rudder) but see nothing moving on the helicopter. On an aircraft there is a vertical stabilizer that has a moving rudder. So how does a helicopter work? The same thing occurs with my quadcopter.


texts: What is this cutout in the Spitfire cockpit glass?

texts: This is a still from the film Dunkirk. I realise this is not a historical document, but I have also found a similar feature in photos of real Spitfires. What is the purpose of this?


texts:
Gas Turbine Engine Starting Sequence
How to explain the figure above?


texts: May two different component manufacturers have the same component maintenance manual number?

texts: Is it allowed for two different component manufacturer to have the same Components Maintenance Manual number?


texts: Would turbine blade twist change if all conditions except the density of the fluid remained the same?

texts:
While designing a turbine, the blade twist is apparent from the velocity triangles, and this analysis only depends on the velocity.

However, would there be any difference for different media? When all conditions stay the same but the density of the fluid changes, would the twist stay the same?


texts: Is it possible to have an afterburner in a turbofan with bypass ratio greater than 1:1?

texts: Is it possible to have an afterburner in a turbofan with a bypass ratio greater than 1:1? At 1.05:1, say, can it have an afterburner?


texts:
In the latest twist to the case of the dead rabbit, an anonymous "airport worker" has told a reporter that it was killed by leaving it in a  freezer locker, contradicting the accounts of United executives who have claimed the rabbit was well treated. United also hastily incinerated the body without the owner's permission, preventing any kind of autopsy from occurring. This all happened apparently at Chicago O'Hare.

My question is why an airline would have a freezer at all, and why would they be putting luggage or pets into said freezers. I mean when I make connections I kind of assume they are not putting my bags in a freezer. Do airlines have freezers?


texts: Why do planes above FL290 need more vertical spacing?

texts:
At altitudes no higher than 29,000 feet, planes need only 1,000 feet of vertical separation.
However, planes over FL290 need twice that, i.e. they need 2,000 feet of vertical spacing between them and a plane with otherwise insufficient lateral separation.
Why is the extra vertical spacing needed, and why is it needed over FL290 specifically?


texts: is there difference b/w moving object in a fluid and static object in a moving fluid?

texts:
wind tunnel is usually based on static object in a moving fluid, but wouldn't stationary/semi wind inevitably fill the tunnel after collision, but in the real world the moving object is always meeting a new particle and the previous ones always leave the field.

if indeed there is an actual difference wouldn't that render turbulence simulation impossible?, and also incorrect CFD simulations?.

since wind tunnel do exist there can't be any difference but why?


texts: Why do certain airlines give names to their aircraft?

texts: That is the case for aircraft operated by e.g. KLM. Some aircraft are named after birds, some after cities. Is that common for other airlines as well or something that only KLM does?


texts: Are there any safety data on the aircraft used for skydiving?

texts:
I am planning a (first) skydive, a tandem jump with an instructor. However, I have not picked which school I will use yet.

I am convinced about the safety of the jump itself, but cannot find reliable data on accidents that have occurred during the actual flight.

How safe are aircraft that are used for skydives? What are the statistics compared to commercial aviation?


texts: What are the consequences of touching down at too low of a speed?

texts: The consequences of a high speed touchdown / high vertical speed are very much obvious. However, what will the consequences be of a low speed touchdown? How severe are they (if any)?


texts: What is this hole on the tail of an MD-88?

texts:
There's a little hole on the leading edge of the vertical stabilizer of this plane:

What is that? What is its purpose?
Thanks
Source: Airliners.net


texts: If all passengers moved to the back, front or one side, would they crash the plane?

texts:
all-time classic:

Would the load shift of all passengers herding at the back, front or one side make the plane hard or even impossible to keep in the air ?

Are there any passenger aircraft where this could be a problem ?

scope: Q2507 is about unspecified movement of some passengers ("passengers moving around"). This would hardly be a problem. The scenario presented in this question here is an entirely different one, viz a hypothetical extreme case where ALL passengers gather in 1 spot at the front or back. Also, it addresses a very famous airline myth, and as such it has a valuable purpose.


texts: What is the ASTERIX terminology for an atomic piece of information?

texts:
The ASTERIX standard defines the smallest piece of metadata information:

  Data Item: The smallest unit of information in each Data Category.

And the implementation equivalent:

  Data Field: Physical implementation for the purpose of communication
  of a Data Item, it is associated with a unique Field Reference Number
  and is the smallest unit of transmitted information.

But, neither of them are atomic. The most common example is Data Source Identifier (SIC/SAC) which contains two pieces of information: SIC and SAC. For instance, such a Data Item is defined in the 048 Category:

  Data Item I048/010, Data Source Identifier Identification of the radar
  station from which the data are received. Two-octet fixed length Data
  Item.
  bits-16/9 (SAC) System Area Code
  bits-8/1 (SIC) System Identification Code

So my question is: what is an atomic (minimal) piece of information called in the ASTERIX standard?


texts: What is the cheapest plane one can buy to fly above Mach 1 and be able to pull 8g plus?

texts:
Which plane would you suggest for someone who would like to be able to fly fast enough to break the sound barrier, yet also be able to pull lots of Gs?

What would be the price of such a plane, and how much would it cost per hour to run and be maintained?


texts: Why is there a difference between GPS Speed and Indicator speed?

texts: I just played with flight simulator and noticed that the GPS shows different speed from the speed indicator in the cockpit. Also, GPS speed is higher than the Indicator. Any Idea why?


texts: How are aircraft transported to, and then placed, in an aircraft boneyard?

texts:
I was looking at the boneyard at Davis Monthan Air Force Base and was wondering:
How are aircraft brought there, and then how are they placed so tightly together?


texts: Why doesn't ADS-B use satcoms like ADS-C?

texts: With ADS-C, in the middle of remote areas (like ocean), we can send position report via satellite data link.  So, why ADS-B systems on airplane uses ground based stations (VHF datalink) rather than Geostationary Satellites for data transfer?


texts: What is "Takeoff Minimum: NA" for US Airports as depicted in Terminal Procedures?

texts:
This question refers to US Air Carrier procedures for determining takeoff minimums, as published in FAR 91.175, 121.651, Carrier OpSpecs, and the US Terminal Procedures Publication booklet.

As nicely answered in this question, we know that low-visibility minimums for takeoff are outlined in a carrier's opspecs, with paragraph C078 granting approval for "lower than standard" visibility requirements, if the airport runway doesn't already have published higher than standard takeoff minimums.

An airport with a published higher-than-standard minimum for one or more runways is indicated on approach charts with the upside-down triangle with the letter T inside (although this may also indicated only an obstacle departure procedure, or both an ODP and a minimum). The published minimums themselves can be found in the US Terminal Procedures Publication.

My question is about runways marked as "Takeoff Minimum: NA". What does "NA" mean? Does it mean that "lower than standard" minimums may not be used.  Or does it mean "all other runways have comments, but no comments are necessary for this runway, so lower-than-standard takeoff minimums published in opspecs are fine and dandy"? There also seems to be different "NA" indications; some with comments such as "obstacle" or "ATC", and some without any comment at all.

I cannot find an answer in the FAA's Instrument Procedures Handbook, the AIM, or elsewhere.

One example is Columbia, CA which has a simple "NA" for runway 35.

Another example is Cloverdale, CA, and RWY 32 is marked as "NA" but has the comment of "Obstacle".

A third example is Merrill Field in Anchorage, Alaska, with the comment of "NA - ATC".


texts: Why is fuel quantity expressed in flight hours

texts:
Going through a few aircraft documentaries online, I've noticed the thing that they usually express the fuel quantity in flight hours.
Ex - A 747 burns 4 litres of fuel every second. So with a ton of fuel, it'll stay in air for roughly 3-4 minutes.
Why are flight hours a necessary term while consider fuel quantity? I mean shouldn't they be worried about how much distance they can cover in an emergency to reach an airport, instead of how long they can stay in the air?
Seems a question related to endurance but couldn't find any proper explanation


texts: Where can I find coordinates for Special Use Airspace (e.g. restricted areas) in the USA?

texts:
I am looking for exact specifications for a few prohibited and restricted areas near me so I can plot these areas in other mapping software.
I can use sectional charts to estimate, but I am curious if there is some kind of listing that contains coordinates that define these SUAs.


texts: Which dust size causes most damage to turbine engines?

texts:
I'm conducting some research on my bachelor's thesis on predictive maintenance and I have so far not been able to find a solution to the following question:
Which size of dust is more damaging to the engine when it comes to ingested dust?
So far I have found some papers covering the topic or moderately related to it but I can't seem to find a precise answer directly relating particle size and damage (i.e. from 200µm to 500 µm the damage is severe but under 200 µm much smaller damage is presented; for particles bigger than 1 mm no damage is presented as they do not enter the turbines)
I hope someone has found some insight on this topic.
Thank you very much.


texts: Is it normal to choose a left or right pattern based on the wind direction?

texts:
I fly at Las Cruces International (KLRU) which is in an area with high winds (20 knots or more).  My flight instructor wants me to fly the traffic pattern according to the crosswind direction on takeoff.  So if the crosswind on take off is from the right he wants me to fly right traffic, if the crosswind is from the left he wants me to fly left traffic.

I understand the rationale for this.  When you are flying into the wind you have more airspeed and if you suddenly turn out of the wind you lose airspeed and risk stalling.  In fact we have had accidents here where a pilot turned out of the wind on takeoff and stalled because they suddenly lost airspeed.

I have never heard of any guidance in my ground school courses on changing the traffic pattern based on crosswind direction.  So my question is how would an FAA Designated Pilot Examiner interpret me using a non-standard traffic pattern if I fly the traffic pattern according to the crosswind direction?  Could I get in trouble for flying a non-standard pattern even though it would technically be safer to fly into the wind?


texts: Are the actual locations of the North Atlantic Tracks entry and exit points published anywhere? I'm looking for definition (latitude, longitude) of the entry and exit points for North Atlantic Tracks.


texts: What to do when fuel is exhausted and we are denied landing by ATC?

texts:
What to do when fuel has exhausted and we are denied landing by ATC?
If we were denied landing it means we are close to the runway, and thus if we are intending for a forced landing, the runway could have been the safest option.  With time being a constraint, what call should be made to ATC?


texts: How much thrust is lost through a curved exhaust nozzle?

texts: In modern VTOL aircraft energy is usually directed through nozzles to achieve vertical lift. How much energy is lost when changing the direction of flow in static thrust conditions?


texts: Is rudder deflection sufficient to maintain directional control on the runway at high speed, or is nose wheel steering needed?

texts: If a fighter jet veers off the runaway, is nosewheel steering needed to counter, or can directional control be maintained with the rudder deflection alone?  Is there a chance that the rudder deflection alone won't be enough to change the aircraft direction?  Is there a speed zone or gap were the rudder deflection is not aerodynamically available, while at the same time steering of the front landing gear is ineffective due to loss of friction?  Or does the max speed for nosewheel steering and minimum speed for rudder effectiveness overlap each other?


texts: Do airlines staff extra crew members when disabled persons are check in?

texts:
The question "How are disabled passengers evacuated during emergency?" made me wander if minimum crew number required by regulation are enough in case of passengers requiring extra care in case of evacuation.

My question is restricted to cases where airliners know in advance that a passenger with reduced mobility, unable to run or jump (let's say the passenger requires either a wheel chair or crutch to walk) is scheduled on a specific leg. Do airlines staff extra cabin crew member(s) to improve handling of everyone in case of emergency evacuation?


texts: Can a small UAV restart its engine in mid-flight?

texts: Is it possible for a small UAV, say a small piston-engine aircraft with a low windmilling effect, to restart its engine in mid-flight following an engine shutoff?


texts: What kind of failover system do Airbuses with side sticks have?

texts:
Airbuses use joystick-style side sticks for controlling the aircraft. Among the features of this system is that there exists no mechanical connection between the joysticks and the control surfaces.

In case of an electrical failure, what backup system is in place to make sure the pilot still has control of the aircraft?


texts: What are the factors behind crew pairing and crew rostering?

texts: What are the factors to be taken in to consideration for crew pairing and crew rostering?


texts: Should the route be changed if the GPS RAIM prediction fails?

texts: Do i have to change the route if the GPS RAIM prediction has one or more outages along my route?


texts: How do Rapid Exit Taxiways improve aircraft movements?

texts:
I have been reading about Mumbai Airport (CSIA) (IATA: BOM ICAO: VABB). On it they mention:

  The airport has two intersecting runways. Both runways have been
  upgraded to Code F, which means they can accommodate larger aircraft
  like the Airbus A380. Following a presentation in March 2011 by UK’s
  air traffic service provider NATS on how the capacity of the airport
  can be increased, MIAL set a target of 48 aircraft movements an hour
  in an effort to reduce congestion at the airport. Both runways were
  operated simultaneously especially during peak hours to try and attain
  this target.MIAL scrapped simultaneous Cross-runway flight operations
  in mid-2013 after it found that single runway operations were more
  effective for increasing Aircraft movements per hour. Runway 14/32 is
  now used only when the main runway is unavailable due to maintenance
  or other reasons. The construction of new rapid exit taxiways helped
  in increasing flight handling capacity from 32 movements per hour to
  44 in 2012.

Can somebody share what are these rapid exit taxiways and how do they help to increase flight handling capacity ?

I did see the OSM page and was able to get this -

Maybe that could help in explaining what is being told to us. Have given/shared a more detailed diagram that I could find from OSM.

Also it would be nice if a sketch/diagram of how these rapid taxiways are laid on CSIA or failing that a diagram of any airport having similar/more/less number of rapid exit taxiways would be good too in order to understand how they work.


texts: Possible reason for diverting domestic flight to a distant country

texts:
I have just spotted something weird (at least to me) on Flightradar24. A Lufthansa domestic flight from Munich to Frankfurt flying toward... Warsaw in Poland:

My first, and quite obvious conclusion was a Flightradar24 error, as it happens from time to time. But then, I have opened flight LH121 recent details and to my extreme surprise it turned out, that the very same flight was diverted to Warsaw yesterday as well:

Is there any logical, business or technical explanation for this? Is there any logic at all in diverting local, domestic flight to a distant airport in not so close country? Because from mine -- real layman to airline operational rules -- this seems very, very wrong.

I mean, they have like about ten other airports in Germany, about six more in Czech Republic, not mentioning next six or seven in Poland itself, that this plane could land on, before reaching Warsaw.

Not mentioning for the fact, that looking at Flightradar24 track it seems like this plane would pointing Warsaw from the very beginning of takeoff. I mean -- Frankfurt is exactly opposite the way.

What am I missing?


texts: What is the difference between EPE and HUL on the Satellite Status Page of GNS systems?

texts:
For exemple on the GNS430 satellite status page you can read, in addition to the GPS receiver status :

EPE (Estimated Position Error)
DOP (Dilution of Precision)
HUL (Horizontal Uncertainty level)

I found here explanations about DOP computation, and GNS430 manual states that:

  "EPE uses DOP and other factors to calculate a horizontal position error, in feet or meters".

About HUL, the same manual explains that

  "the Horizontal Uncertainty Level displays a 99% confidence level that the aircraft position is within a circle with a radius of the value displayed in the HUL field"

It seems to me that EPE and HUL are exactly the same thing and differ only by the confidence level. If it's the case, what is the confidence level of the EPE ? If not, what is the difference between EPE and HUL ?


texts: How much, generally speaking, does it cost to learn how to fly?

texts: One of my life goals is to learn how to fly a plane. I can't do it now due to time constraints, but I am curious: How much, in general terms, does it cost to learn how to fly? I.e. piloting lessons, license fees, etc. I would be doing it in the US.


texts: How do engineers make sure UAV don't land on their front propeller?

texts:
Take, for instance, the following UAV:

and suppose you have a payload with a very big volume that fits exactly in the fuselage (and there is no more space), but is extremely light. Thus, the heaviest part of the UAV becomes the propeller and its engine.

How do engineers make sure the UAV stays balanced and doesn't land right on its propeller?
Do they add some weights somewhere near the rudder and elevator to keep its center of gravity somewhere near the wing's trailing edge?

Thanks.


texts: What is the exact meaning of "attitude", does it include translational movement?

texts:
Reading documentation it is clear to me that "attitude" means the study of orientation of a body. However sometimes it seems to be used loosely for the motion tracking of a body (both translational and rotational, not rotational only).

Is it a mistake or a common abuse of language?


texts: Why are Low Cost Carriers ordering several hundred aircraft?

texts:
Indigo is a low cost carrier, which already has 99 A-320s in its fleet has  ordered 431 more. This airline currently covers 35 routes, while the full service carrier Emirates has 221 planes, and covers a fancy 164 routes. In its home country as well, the biggest player Air India has 102 planes and covers 95 routes. So, what are these LCCs planning to do with so many aircraft? Renting could be an idea, but you just do not go for renting as much as 4 times of your crew size.

Similarly,

AirAsia has ordered 304 A320s,
EasyJet has ordered 100 A320s,
RyanAir has ordered 100 B-737.
Norwegian has ordered 100 A320s, 100 B737,


texts: What is the requirement of a higher glidepath/approach angle and is this a flight safety issue?

texts:
To reduce noise in the London urban area, Heathrow airport has announced plans to trial a steeper approach for aircraft landing - changing from 3 to 3.2 degrees. If this is successful, they will further steepen the landing approach to 3.5 degrees. Moreover, London City airport uses a 5.5 degree landing approach.

What are the requirements of higher angle landing approaches and how do they affect flight safety?


texts:
This specifically pertains to VOR approaches, but I guess it can apply anywhere else that has a hold in lieu of procedure turn (HILPT) also. There are numerous examples but let's try one: KUKI VOR-A.
If you were approaching from say the North (thus a teardrop entry is most suitable), does the hold constitute your course reversal, or must you conduct the procedure turn to get established for a simple ASEL? 5.3 miles out seems pretty good to get distance to get established, but maybe I'm missing something as an early instrument student? Do you have to contact ATC to let them know this is the way you'd conduct the reversal?


texts: How does a normal aircraft exhaust nozzle (the base model) generates a lot noise?

texts:
How does a normal aircraft exhaust nozzle (base model) generates noise and, whats the difference between the operation of the normal base model of aircraft exhaust nozzle and the new design of aircraft nozzle with an add of chevrons ?
Is the chevrons effects the aircraft or engine performance in any way ?


texts: What is an example of a system like MCAS?

texts:
The related question "Is it common for automated control systems to use non-redundant sensors?" does not ask about a specific example, nor are specific examples provided in the answer.

The criteria for my question:

Activates on its own, or always active.
No light/text indication of it being active.
No specific disable switch.
Relies on 1 sensor when 2+ exist.
The system is not disabled when the 2+ sensors disagree.

As you can see, these properties are modeled after what is known about MCAS.

This question isn't about the 737 in particular but about any commercial (fly-by-wire or not) airplane, so eventually the answers should specify the model, and if possible the justification of the design.


texts: Dangers to the Engine if CHT goes below minimum in flight during descent?

texts: What are the dangers of CHT going below minimum in flight during descent since the power setting will be around 10inches in a power descent?


texts: How can I get more details about information in a NOTAM?

texts: In doing some planning for an upcoming flight, I noticed my destination (a towered airport) has a NOTAM about the runway: "FICON PATCHY ICE". That seems rather vague, I'd like more information before departing. Who should I contact to get more details about the runway conditions and how it might affect my flight?


texts: 125 cc engine, 64" propeller 3 blade, 180 kg gross weight, will it climb?

texts:
I'm a government teacher in school, currently I made an RC aircraft and flew it, now I'm working on a single engine light weight aircraft, I want to use a Honda CG 125 (single piston) engine, with 64" propeller 3 blade, engine RPMs are 3000, wings length is 29' feet and width is 4'6" approximately, and the length of aircraft is 20', empty weight of aircraft is 130 Kg, gross weight will be 250 Kg.

I want ask you: will this climb?


texts: What is the role of baffles in Fuel Tanks?

texts: I think there are many baffles inside the shape of Fuel tank. What kind of advantage they do?  Do they help in managing the oscillations in-flight?


texts: Why is there a time range for holdover times charts?

texts:
2016-2017 FAA Holdover Time Guide

The FAA publishes holdover times for each winter season and gives a time frame for how long each type of fluid should protect the aircraft from further contamination.

Why is there a time range for these numbers?  Are there different procedures to follow if your takeoff will be before, in between or after the specified time?


texts: what are the ways to avoid skidding off the runway apart from thrust reversers?

texts:
what are the different ways to avoid skidding off the runway apart from thrust reversers?

Do crew have any option if thrust reversers are not available and the ground is too slippery which is making the vessel skids off the runways sideways?


texts: Are there types of instrument approaches besides precision and non-precision?

texts: In the 1990s there used to be two basic types of instrument approaches: precision and non-precision. How many different kinds are there now, and what are the differences.


texts: I have seen that ceramics take a lot of heat to melt (3240º F). So, I'm wondering, why aren't ceramics used as the compressor levels in turbines? Is there something to do with the strain? or is ceramic too heavy? Is it something to do with the way the crystals align?


texts: Are two twin-jet flights more efficient than one quad-jet flight?

texts:
Ignoring for this question the issue of flexibility for the airline, would it be more (fuel, cost) efficient to have a single flight with a 4 engine plane than to have two flights with 2 engine planes.

I imagine, that 2 flights of twin-engine planes move more dead mass than a single flight of a quad-engine plane with the same capacity.

As one concrete example, say one A-380 @ 15000 km and 650 passengers vs. two A-350 @ 15000 km and 325 passengers each.

Some further clarification

The two (full) twins carry the same number of passengers as the (full) quad
The two twins and the quad fly the same (long haul) distance
Efficiency can be either consumed fuel, the cost or any other interesting parameter.


texts: Could the Perlan II glider be used for nearspace tourism?

texts: I asked the same question about the SR-71 Blackbird, and I'm also curious about the Perlan II sailplane which travelled above 70,000 ft, and is planned to be flown to 90,000 ft, if it could be used for nearspace tourism and what some issues might be with that. Its starting location would have to be near a high enough mountain range where it can use enough lift to climb that high, and this is best at certain times of the year I guess. A major advantage would be that this form of nearspace tourism would be 100% environmentally friendly (for those who bother).


texts: Are there any hybrid planes (planned), or would this be impossible because we don't have big enough batteries?


texts:
In the US, is it legal to cover up some of the required gyro instruments during flight under IFR in actual IMC?

The purpose being for "partial panel" practice.


texts: What is the estimate for total number of flight hours in the world?

texts:
Working on a type of estimate model for aviation and was wondering if there was an approximate total number of flight hours in a year across the industry as a whole?

Edit: Counting only Commercial Flights


texts: I have some question about Systemic Culture, so what is a systemic culture, and how systemic culture related to the aviation industry?


texts: Can civilians who buy ex-military fighter jets get the necessary maintenance information for them?

texts: I was looking for fighter jets which are available to be bought by private citizens. I was wondering: how would you schedule the maintenance, as most of the jets are ex-military and there are no maintenance plans?


texts: Statistically, what are the failure points on sUAS (drone) aircraft?

texts:
It is generally recognized that operator error and unairworthy aircraft are the principle factor in sUAS (drone) system failures and accidents.  But looking just at the hardware, are there published studies on the aircraft systems components which cause the greatest number of system failures?

For example, batteries.  Or motors.

Has anyone done any kind of a large scale study of failures and published it?


texts: Which aircraft are required to have a black box?

texts: When is an aircraft required to have a Cockpit Voice Recorder or a Flight Data Recorder?


texts: What is the significance of the speed of sound to aerodynamics and aircraft design?

texts:
Almost every aspect of flight seems to be affected by the speed of sound, somewhat in the same way that nearly everything in physics is determined by the speed of light.

Obviously it's not exactly the same - it is possible to travel faster than the speed of sound, unlike the speed of light - but still, what happens below the speed of sound is quite different from what happens above the speed of sound, while the region close to the speed of sound seems to be a mysterious transition zone.

This isn't just limited to aerodynamics, but also for example to the way the fuel/air mixture burns in a jet engine.

So, why is the speed of sound so significant for aerodynamics and aircraft design?

I presume that it is something to do with a limit on how fast information about the movement (or pressure changes) of air molecules (i.e cause and effect involving air molecules) can travel through a medium of those molecules, and that "speed of sound" is shorthand for that speed.

These movements of air molecules presumably also might be in a form that we wouldn't ever actually hear (frequency too low, frequency too high) or indeed that we wouldn't ever experience as a sound (a single pulse rather than a vibration); in this case "speed of sound" seems to be a rather misleading way of describing it.

I assume that there are analogous issues around the speed of information of pressure changes in water, so that hydrodynamics has to deal with them too. I imagine that because is much less compressible than air, that the speed would be much higher, so perhaps less likely to trouble hydrodynamic designers and engineers.

I think my high-school physics seems to be more or less enough to deal with these concepts, but the language around speed of sound does seem to hide away some of the key ideas, and leads my intuitive grasp in the wrong directions.


texts: Do any other nations have an equivalent of the "Air Force One" call sign?

texts:
Air Force One is the official air traffic control call sign for a United States Air Force aircraft carrying the President of the United States. - Wikipedia

Do any other nations have an equivalent call sign for an aircraft carrying their head of state?


texts: Why do fighter jets pilots use an oxygen mask?

texts:
I always wondered why fighter pilots need to fly with a facemask.
Since the cabin in pressurised wouldn't the oxygen level be the same as in any commercial jet so sufficient for the pilot to remain conscious and aware?
Thank you


texts: Why don't American passenger airlines operate dedicated cargo flights any more?

texts:
I was reading recently that Northwest Airlines was the last American passenger carrier to operate dedicated Cargo aircraft. Why do none of the large US airlines operate dedicated cargo flights anymore? This seems to be common among international Airlines (Lufthansa, China Airlines, Qatar Airways, EVA, etc).

Presumably UPS and Fedex's extensive networks have something to do with it? I'm surprised that none of them find it economical, however.


texts:
While may be possible to look up the dimensions of high lift devices in an aicraft's documentation, there is no information on what the underlying design choices are.

Using Wikipedia, I found out that flaps are used to increase the wing camber, to increase the wing's lift coefficient and decrease stall speed. However, there is no information on how much extra camber is desirable, and how the surface area of the flaps relate to the camber increase.

So, how exactly are the dimensions for flaps on an aircraft chosen? While I'm specifically wondering about large airliners, such as an Airbus A380, I would also like to know if the method for determining the flap size is generally the same for all aircraft, or if there are differences depending on size or mission profile.


texts: Is it currently possible to build a jet engine with 1,050 kN of thrust? (236,049 lbf)

texts:
Do we currently have the engineering know-how to build a 1,050 kN jet engine?

This question originated from the idea of changing a 4-engine aircraft into 2-engines. I chose the A380 since it seems to have the highest takeoff weight.

One A380 engine produces a max of 350 kN. If one engine goes out, the A380 still has 1050 kN available, and per regulations that should be enough even for takeoff. So if we switch to a two-engine aircraft, per regulation we need enough thrust for takeoff even if one engine dies, which means each engine would need 1,050 kN max.

I read this and this. They're in the same context of reducing a 4-engine plane to 2-engines, but do not answer the question if 1050 kN is achievable for a single engine.


texts: For a small flying wing, can two motors with different speeds replace the ailerons?

texts:
I was thinking about a way to get rid of the aileron, and I was wondering if:

I install two motors on the wing, and make the right one spin faster than the left one, will my wing roll to the left ?


texts:
New FAA Notam site marks certain notams as Snowtam and provides Runway Condition. I can decode E) part using FAA Runway Condition. But how can I decode the Q section. Is there a comprehensive source for decoding Notams?

FAA publishes same notam in 2 different formats. I am interested in decoding ICAO Format.

ICAO FORMAT:

12/057 NOTAMN  Q) ZBW/QMRXX/IV/NBO/A/000/999/4221N07100W005
  A) KBOS  B) 1912310152  C) 2001010152
  E) 09 FICON 5/5/5 100 PCT WET  OBS AT 1912310152.

DOMESTIC FORMAT:

!BOS 12/057 BOS RWY 09 FICON 5/5/5 100 PCT WET OBS AT 1912310152. 1912310152-2001010152


texts: Could fly-by-wire protect against a takeoff tail strike?

texts:
If the takeoff weight is underestimated, rotation will be done too early and may result in a case of tail strike.

One example of such mistake is a 747-400 (F-HLOV) in 2006 (case 8 in this study). The crew entered ZFW for TOW (100 tons lower), VR was underestimated by 32 kts.

Boeing documentation mentions every aircraft can be subject to tail strike, at different degrees. Airbus documentation for tail strike prevention doesn't mention any specific protection from FBW.

(source: The Aviation Herald.)
UA B744 tail strike on Sydney takeoff (photo may not be the actual May 7th 2010 T/O).

I wonder why such basic mistake may be done. Weight could be sensed in some way by the instrumentation, and crew entered values should be challenged if really different.
To prevent the crew from being forced (or tempted) to rotate the aircraft beyond the maximum safe angle, isn't that possible to monitor the T/O progress and in case of low performances alert the crew, and provide an opportunity to reject the T/O.
Airbus FWB embeds many security systems (compared to Boeing), this is surprising that they cannot prevent such T/O tail strikes. I'm sure there are good reasons, just asking to understand the difficulty.

Edit: Based on the answer from Marky Mark, who references the EK407 case, I checked a study published in the aftermath of EK407 tail strike: Take-off performance calculation and entry errors: A global perspective and noted this recommendation for 'TOPMS':

  While the above recommendation does not preclude data entry and
  calculation errors relating to take-off performance parameters from
  occurring, Transport Canada (Department of Transport) agreed that a
  take-off performance monitoring system(s) (TOPMS) would provide a
  significant safety benefit. However, before regulatory authorities
  establish a requirement for the fitment of TOPMS, a certified system
  would need to be developed (Transport Canada, 2010).

  Basically, a TOPMS, which assists pilots in determining whether to
  continue or reject the takeoff, can be defined as (Brown & Abbasi,
  2009, p. 7).

Are TOPMS now in place?


texts: What is the maximum decibel noise level of a stage 4 rated engine?

texts:
I was just wondering if anyone is able to help me. I need to find out, what is the maximum decibel noise level of a stage 4 rated engine (as defined by the Federal Aviation Administration)?

Some more information: I need this information because the General Electric Honda HF120 engine has a noise level rating of stage 4. This is a small turbofan engine that is designed to be used on small business jets, such as the HondaJet. I have tried searching all day, but I cannot seem to find anything.

Thank you for your time and any help would be greatly appreciated.


texts: Are you required to fly a full hold when doing a course reversal?

texts: When doing a hold in leu of a procedure turn are you required to do a full hold for the course reversal or just the entry to the Fix and then proceeding in bound for the final approach course?


texts: Why choose a seaplane for crew rotation at sea, supply of spares to ships, long-range search and rescue and surveillance?

texts:
The Indian government has been discussing with Japan since on buying Shinmaywa US-2 aircraft which would be used for various roles such as crew rotation at sea, supply of spares to ships, long-range search and rescue and surveillance according to Flight Global.
The partnership is strategic for Japan that seeks to contain the rise of China and India that can not get an alliance with Pakistan, but that, we do not care. It is also the return of Japan to the club of countries selling international aircraft.

Yet, my question is : why choosing such an atypical airplane for such missions ? In France I know that SAR missions are done by Falcon 50 and 200, which are long-range business jets, or helicopters. Neither of them are able to land at sea but jets are faster and helicopters have divers to be to take care of the SAR mission.

For crew rotations, it is true that the US-2 can carry up to 20 people. And if this kind of missions only concerns large boats where my lack of knowledge in the Indian Navy suggests to me that they still have helipads, the NH-90 carries as many troops as the US-2 and can even land directly on it if it has one. Furthermore it can land anywhere, but the sea indeed.

Thus why choose a seaplane for search and rescue, crew rotation at sea, supply of spares to ships, long-range search and rescue and surveillance ?

To my mind, their is lots of positive aspects using this aircraft as far as it would enable them to be faster in crew rotation at sea, supply of spares to ships but to be slower for SAR and surveillance, which seems to me to be the most important mission. Is it a difference of philosophy between French and Indians ? Or is their a deeper reason to prefer seaplane ?


texts: What are some differences that make the new 737 MAX winglets more efficient than a conventional winglet?

texts:
I was reading this article about the Boeing 737 MAX final assembly and it was saying something about the new winglet generating lift and increasing efficiency. Can you explain to me how this works, and what other changes to the new winglet are made to make it more efficient?

source:Gizmag


texts: Is the autopilot system capable of taking off and landing a plane?

texts: I am aware of the fact that the autopilot is engaged after takeoff and disengaged before final approach but I was just wondering whether or not the autopilot is capable of landing or taking off a plane.


texts: What is the minimum altitude for dumping fuel?

texts:
In this question, a comment mentioned that if a 4-engine airliner suffers a 3-engine failure shortly after takeoff, the only way to stay aloft may be to dump fuel.

What is the minimum altitude which fuel dumping is possible? Possible here means, the fuel will not cause a hazard to the airplane or anyone on the ground.

Is the altitude MSL or AGL? (i.e., is it "it takes 2,000 feet for the fuel to fall before it evaporates", or "the atmosphere pressure at 8,000 feet makes fuel evaporate a lot quicker, so you can do that if you're at 8,000 pressure altitude even if the ground elevation is 7,000 feet"?)


texts: Is it possible for me to work at NASA or other research companies as aircraft mechanic?

texts:
I know NASA is huge but is it possible for me to work there or other companies similar to it?  If possible, how?

I currently work at an MRO as aircraft mechanic. My work is mainly on flight controls. The only aircraft that I have experience on is a320 family.

We do some structural works too, knowledgable to SRM.

I'm from Philippines btw.


texts: Flying in V formation with multiple planes

texts:
Logistically choreographed using air-traffic controllers to pair like planes headed in the same direction or by scheduling flights together, how much fuel could be saved pairing planes to fly in a tight V formation throughout a fleet?
Maybe an autopilot could both keep a heading while maintaining an optimal position with in the formation; or in other words, Auto-formation.


texts: How can passengers help in the cockpit in an aviational emergency?

texts:
During an emergency solely related to aviation (ie not a medical situation), suppose that some airline passenger believes that he/she can help in the cockpit. Since the cockpit door is locked for security, how can he/she volunteer their services and enter the cockpit to try to help? I am guessing that someone with minimal flying experience (such as an amateur gamer of Microsoft Flight Simulator) can help.

This question presumes the ability of airline passengers to help. Here is a real-life example: According to the Mayday episode on Air France Flight 447, while attempting to recover from a stall, the first officer pushed his yoke up (wrongly), while the reserve first officer pushed his yoke down (correctly).  This opposition in pushing nullified each other and the plane continued its fall in its stall.

The captain was out of the cockpit at the start of the stall. He returned afterwards (I don't recall exactly when), spent some critical time surveying the control panel, but didn't apprehend the problem in time. Might a passenger have helped to perceive the problem (without spending time examining the instruments)?

Please feel free to edit this post; I'm not an expert on aviation.


texts: Why haven't the remaining TRSAs been converted to Class C airspace?

texts: The communication and radar equipment is already in place to provide radar services. ATC staff them. It seems like the biggest investment to get them converted to class C is charting. Why haven't they been converted in the 25 years since the airspace reclassification?


texts: How to completely track a plane, not a flight?

texts:
This probably has already an answer somewhere, but probably don't know the proper search keys to find the information.

Out of curiosity today I was trying to track a flight: one of my friend texted me about her flight being a lot late, and for fun I wanted to try to see if it was possible to understand what caused the delay. I knew flightradar24 by fame and found too flightaware by chance; I tried with the flight number (EZY2604...if this is the flight number) and couldn't find many information, 'till I realized that EZY2604 is probably something like the callsign for the route plus the scheduling, so with that I can only find details for this combination. And I can only track a plane which is flying, it seems.

TL;DR: how can I go from a flight number to the full route of the physical plane in the previous hours?


texts: Why do small jets usually have one low flap setting?

texts:
For example, the CRJ has a flap setting of 0, 8, 20, 30, and 45 degrees.

The Learjet has similar features across their models, as far as I can see which is 0, 8, 20, and 40 degrees

Why do smaller jets have one low flap setting? Why not have 0, 8, 15, 20, 40? Comparing to larger aircraft like the 737, they have a flap setting that captures just about every degree you can imagine.


texts: In what way(s) will making an airplane electric help to make it "quiet"?

texts:
In this blog I read about the Quiet Flight Initiative, which - if I understand correctly - will be quieter than a comparable carbon fueled plane at least in part because it is electric. It's an engineering challenge associated with Embry-Riddle Aeronautical University.

What aspects of the plane design - when switching from combustion engine to electric motor - will help reduce noise? I had thought that most external aircraft noise heard on the ground (in this case, National Parks) is associated with the propellor, and so noise is closely linked to performance, not the particular method of torque generation.


texts: What qualifies for "mass disseminated data" for an abbreviated briefing?

texts:
I'm reading about the different types of pre-flight briefings you can get and in the section for Abbreviated Briefing (AIM 7-1-4c) is mentions the phrase "mass disseminated data".

  Request an Abbreviated Briefing when you need information to supplement mass disseminated data...

Is there a particular definition or list of what qualifies for "mass disseminated data"? I often use aviationweather.gov to get a good overview of what's going on before a flight. Does that qualify?


texts: Under EASA regs who is responsible for part m continued airworthiness? Lessor or Lessee?

texts:
If an aircraft is leased out by a lessor to an operator does the lessee (operator) take full responsibility of continued airworthiness or does the lessor have some liability?

Perhaps it's similar under FAA law?