texts: Do airliners have any cockpit indication of open doors?

texts:
A recent report into an "unnecessary" plane evacuation reports that, following an aborted takeoff

[The senior flight attendant] then ordered an evacuation of the 169
passengers onboard, but the pilot and co-pilot were not informed nor
aware until they noticed the evacuation slide had been deployed and
passengers were moving across the front of the aircraft. [my emphasis]

This led to dangerous situation because the pilots, unaware of the evacuation, kept the engines running while the passengers were trying to get out.
It raises questions about crew and cabin crew communication, but what I found most surprising is that apparently there is nothing in the cockpit to alert the pilots that the doors had been opened.
Even my car does that!
Is this something specific to the A320 or is it generally true that the cockpit doesn't 'know' what's happening with the doors?
 Laudamotion Airbus A320-214 which had emergency evacuation (source)


texts: Is this vintage altimeter from the Cuatro Vientos?

texts:
My father who was a pilot, passed away some years ago and I have a vintage altimeter that he told me someone gave him.  They assured him that it belonged to the Cuatro Vientos airplane, but I'm not sure if this is the case. I've seen some pictures from the Cuatro Vientos's cockpit, and this instrument isn't very similar to the instruments in the photos I've seen. However, the painted text reads "Altura kilómetros", instead of "Altimeter". The text below that reads

Pioneer Instrument Company
Brooklyn New York
199-2044

I hope someone can help me find out if it was from that airplane. (Sorry for my English; I'm writing from Mexico City.)
Thanks in advance.
-Miguel Anaya


texts: Which air traffic controller is responsible for a taxiway between parallel runways?

texts: When an airport use two runways that are parallel at the same time, my question is which tower controller owns the "ground space" between the runways?


texts: How can I see the revision history of a particular FAR?

texts:
For instance, I don't remember paragraph 61.51(e)(iii) at all from way back when I studied it to determine when I could log PIC time.  I'm fairly certain that it has been added since then (actually, there was no sport pilot license back then so I know that it has at least been changed), but I would like to know when it was changed and what the changes were.
At the bottom of the reg, it includes this:

[Doc. No. 25910, 62 FR 16298, Apr. 4, 1997; Amdt. 61-103, 62 FR 40897,
July 30, 1997; Amdt. 61-104, 63 FR 20286, Apr. 23, 1998; Amdt. 61-110,
69 FR 44865, July 27, 2004; Amdt. 61-124, 74 FR 42549, Aug. 21, 2009;
Amdt. 61-128, 76 FR 54105, Aug. 31, 2011]

This tells me when it was amended, but not what was amended.
Does the FAA make that information available?


texts: What is the purpose of these winglets on the Chinese version of the An-2?

texts:
The Shijiazhuang (now part of AVIC) Y-5B, a Chinese version of the Antonov An-2, has winglets of a particular type:

Photo by Linshuo at Airliners.net

Quite a futuristic design for this old biplane of 1958, still in production. Not all version of the Y-5 have such wingtips though:

B-50AG. Photo by Weimeng, AirTeamImages

What are the advantages of these winglets in this case, compared to more common ones? Why only one the upper wing? Are they used on other aircraft?


texts: What prevents companies like Cessna and Piper from connecting multiple alternators to a single engine?

texts:
Firstly, I'm not even sure if there's only one alternator connected to the engine in a C172-like aircraft. But if that is true, then why don't manufacturers connect multiple alternators to a single? What are the draw-backs of doing so, other than a waste of generated power?

I just want to know whether it is possible - and preferably without any major draw-backs.

Without too much increase in weight and complexity, one more alternator could together produce twice the electricity - this might actually be primarily useful for large air-liners relying more on electricity than hydraulics, like the A380 and the 787 Dreamliner. So, again, why not?


texts: In turbojet engines, does the fan play a key role in the air intake to the inlet?


texts: Can a CFII log Dual Given if flying as SIC?

texts: I am an MEI/CFII/ATP type rated and authorized jet pilot in Part 135 operation.  On the legs where I'm SIC slinging gear and working radios, is it ok to log this time as "dual given" and PIC time as an instructor?  Let's assume that I do in fact provide some form of instruction to the other pilot (whether or not this is wanted or needed).


texts: What would happen if one of the engines failed during takeoff and other engine is on full power?

texts: Assume the left engine failed and the right engine is at full power. The pilot has pulled his nose up and turned towards left. Is it possible for him to land the plane on a runway to his left? The plane is an ATR-72 turboprop design


texts: What determines the "acceleration" and "thrust reduction" heights?

texts:
Thrust reduction height is the height at which automatic thrust reduction from takeoff thrust to climb thrust happens. And acceleration height is the height at which you start accelerating the plane from takeoff config to clean config.

But is the acceleration height always the same as the thrust reduction height, just sometimes, or will it depend on the company's SOP (standard operating procedure)?


texts: What safety systems are currently being developed for crash situations?

texts:
I know commercial airplanes are gradually becoming safer thanks to the development of systems that are able to avoid the conditions that would lead to a fatality. But is anybody developing systems for minimizing deaths if a plane crashes? For example, cars have airbags and airfighters can eject the pilot's seat in critical situations.

It's a little bit disappointing to see that an aircraft's cabin still breaks into pieces when it crashes during takeoff or landing, causing deaths or injuries. Isn't there any way to make the cabin structure more break resistant at landing/takeoff speeds? Wouldn't airbags prevent people hitting their heads against the cabin's walls?

And now the probably naivest question: couldn't giant parachutes be installed on airplanes to prevent them from falling in case of stall or engines failure?


texts: Why do fighter pilots use night vision goggles rather than normal light inside the cockpit?

texts:
I've seen military personnel using night vision goggles (NVGs). With their flight altitude, I don't think the enemy can notice them. I thought it may be due to eye strain, but other units use red lights during long jobs that need looking at a screen. Also, you should consider some fighter pilots have short missions and their eyes won't get tired from light.

I wonder why they don't use normal light. Normal light versus red light versus night vision. I never used night vision, but I don't think it's comfortable to use.


texts: Are aircraft sounds publicly available in a repository?

texts:
Referring to the automated callouts and sounds made by the fwc, tcas, gpws, pws, etc. — are these available to download in one repository at all? For any aircraft, Airbus or Boeing.

Understandably, these may not be freely available, but I'm curious otherwise too (e.g. the likes of Air Crash Investigation must do this).


texts: Best way of learning the aviation alphabet?

texts:
I want to learn the aviation alphabet, and when searching the Internet on how to, I see a plethora of approaches, so I thought of asking here!

If it's primarily opinion based, let me know.


texts: What is the methodology for assigning airport codes?

texts:
Pearson airport in Toronto has the airport code YYZ, which does not reflect the name Pearson or the city of Toronto. This seems contradictory to other IATA codes like LGA (Laguardia), JFK (John F Kennedy), LHR (London Heathrow), and DFW (Dallas Fort Worth).

Is there a specific methodology in place for assigning these values?


texts:
My understanding of Continental Express flight 2574 is that a de-icing boot on the horizontal stabilizer of the EMB120 was missing screws and therefore detached, leading to the tail separating.

I would appreciate an explanation, with as much aerodynamic information as necessary, for how the tail separation could be caused by the boot removal.


texts: What is the proper procedure for leaving class D airspace?

texts:
So one thing that always struck me as kind of odd was when you depart a class D tower (VFR) and you get your departure instructions, that's kind of ... it. You just go on your merry way and switch off frequency whenever you want to.

Do people just stay on the tower frequency listening until they're outside of the airspace? Or do you give the tower a courtesy call (N123 leaving the class D) when you get to the boundary, and then switch off?

Or, is it legal to switch immediately to another frequency as soon as the tower says 'left turnout approved, resume own navigation'? It always seemed a bit of a hole to me. But, are controllers bothered by a extra "check out" on leaving the class D?


texts: Why are fighter jets rated differently than passenger jets?

texts:
Recently I watched a video on the economics of running an airline. They mentioned that passenger planes have a life span rated in cycles. That got me thinking because as far as I know, fighter jets are rated by flight time hours.

My answer to this was that the only thing that gets pressurized is the cockpit as opposed to basically the entire fuselage. But surely that would still limit the fighters cycling? Or can they simply change the canopy because it is the softest part and absorbs all the flexion?


texts: How do runway declared distances affect my takeoff distance?

texts:
See these questions.

What is balanced field length?

What are runway declared distances?

My multi-engine jet airplane uses a balanced field length concept.  Most airports served by airliners have declared distances.

Obviously, my takeoff distance can't be longer than the runway length.  Does it have to be lower than all the declared distances?  TODA?  TORA?  ASDA?  LDA?


texts: What happens to the control systems of a BAe 146 when the aircraft runs out of fuel?

texts: On a BAe 146, is there any way to control the aircraft when it's out of fuel? Does the APU run on a separate tank? Can the engines be windmilled for power generation?


texts: Hydro-pneumatic fuel controls and hydro-mechanical fuel controls

texts: What are the advantages and disadvantages of the hydro-pneumatic controls against the hydro-mechanical controls?


texts:
This really keeps coming to my head.

A brand new 172SP costs a quarter million while a older one (10 years older or a little bit older) costs for less than 100.000 Dollars and the only visible difference is the G1000 NXI and a AoA indexer next to the compass.

Its maybe my ignorancy on the specifications but with the price difference I could:

Buy a brand new avionics suite turning the plane to a spaceship. everything from a autopilot to the Class S transponder.
AUX tanks
And maybe a brand new, upper model engine by selling the original one!

And I would STILL have surplus money!

Things is... As long as the owner of the second hand plane treats the engine good and doesnt abuse the airframe for aerobatics I dont see a SINGLE reason to NOT buy that plane.

So why waste so much money for a factory installed AOA Indexer that can be bought for less?

I am not acquinted with helicopters but the same "250K Brand New vs 100K Owned" thing applies to them too, I see. (Robinson R22)


texts:
I haven't looked at the Grand Canyon on a sectional yet, but I know that it is definitely big enough (by far) so that someone could fly a plane under the level of the rim and stil meet all of clearance requirements for VFR flight.

Is it legal, and safe to take an airplane into the canyon?


texts: Why do helicopters not roll over when flying forwards?

texts: Related to this answer: with velocities so different at forward going and rearward going blade, why does the helicopter not roll over? The higher airspeed at the forward going blade should cause more lift, shouldn't it?


texts: Where in the world is it possible to be a foreign air traffic controller (non-military)?

texts:
To work as an FAA controller, you must be a U.S. citizen. To work as a EUROCONTROL controller, you must be a national of one of their member states.

Per standard governmental employment laws, I assume most countries around the world have similar requirements. Are there any exceptions? Are there any places more open to employment of foreign controllers?

I know there are a few U.S.companies that perform contract air traffic control services in other countries, such as RVA, Midwest ATC, and Serco, but I believe this is mostly for the U.S. Department of Defense. Are there any countries that have foreign contracts for civilian ATC services?


texts: Is it possible to fly backward if you have really strong headwind?

texts: Is it possible to fly a plane backwards if you have a really really strong headwind? I mean when you are aloft, you have positive airspeed and airflow over the wings but you have negative ground speed.


texts: On an aerofoil or circular cylinder why does the airflow stay attached after passing the point of maximum thickness?

texts:
Why does it follow the curvature rather than separating?
Its not due to the coanda effect as the accelerated flow near the surface of the aerofoil can't be considered a jet. It's not due to surface tension because there is no interface between two fluids. I know the flow of a fluid is due to pressure, inertial and viscous effects.

Is it due to viscous effects on fluid particles in the boundary layer?
Is is due to the pressure normal to the surface of any body submerged in a fluid?
Another reason?

Thanks for your answers!


texts: Can a barrel roll really be executed at a constant 1G?

texts:
I see this stated from time to time, for example in an answer to Can large airliners do aerobatics such as loops?

  A barrel roll is one thing; they can be performed at constant load factor of 1 G (assuming sufficient control authority).

In a properly executed barrel roll, however, I do not think there is any point in the trajectory where the vertical velocity is constant. In particular, the entry and exit of the maneuver require transitions from level to ascending, and from descending to level trajectories, respectively. In these two cases, at least, I cannot see how a load factor greater than 1 can be avoided.

This IAC guide states a maximum in the range 2.5 - 3 (and a minimum of about 0.5), though it is probably not intended to be a minimum feasible value.


texts: Starting on the left magneto only - why?

texts:
I had been flying a PA-28 Archer III for quite a few months before I sat down to properly read through the POH. Something stood out to me about the starting procedure (emphasis mine)

Open the throttle lever approximately 1/4 inch. Turn ON the
battery master switch, alternator switch, left magneto switch and the
electric fuel pump.
Move the mixture control to full RICH, verify the propeller
area is clear and engage the starter. When the engine fires, release
the starter switch, and move the throttle to the desired setting. Turn
ON the right magneto switch. Check the oil pressure for a positive
indication.

Having previously flown aircraft where a key operates the starter, and that key has to travel past left, then right magneto to the start position I was starting with both Mags in the ON position (For those unaware, the Archer III varies in that the left & right magneto are operated by a rocker switch).
The obvious answer to the question of "Why start the engine with only 1 magneto live?" is "Because that is what the POH says to do!" - I am nonetheless interested in the electrical or mechanical reason why? Or perhaps there is some safety aspect at work?
Does anyone know the details?


texts: What does N mean after a runway visual range (in a METAR)?

texts:
This morning's METAR for Cambridge looked like this:

EGSC 110720Z 11001KT 0150 R23/0200N R05/0175N FZFG BKN001 M02/M02 Q1028

Note the bold runway visual range (RVR) indications. What does the N mean?


texts: What is the equation for the energy balance between turbine, compressor and propeller?

texts:
Let's consider the next turboprop arrangement:

What I am looking for

I am looking for an equation that involves $\dot{W}_T$, $\dot{W}_C$ and $\dot{W}_P$ (i.e. the power done by each component). This needs to be done through an energy balance in the shaft.

What we know

We know that the shaft has an efficiency of $\eta_{\text{shaft}}$, and the gearbox has an efficiency of $\eta_{\text{box}}$.

My try (#1)

Since energy is derived from the turbine, we adopt the convention $\dot{W}_T>0$, therefore $\dot{W}_P, \dot{W}_C < 0$. In other words, energy is required to move the compressive devices.

Following the definition of mechanical efficiency: $$\boxed{\eta_{\text{shaft}}=\dfrac{-\dot{W_C}-\dot{W_P}}{\dot{W_T}}}$$

However, I don't know how to incorporate the efficiency $\eta_{\text{box}}$ into this equation. This led me to try and find another expression.

My try (#2)

Following an hydraulic analogy for the power, I thought that whatever power the turbine generates needs to be invested in:

Increasing the temperature of the bearings of the main shaft (because the shaft is not ideal and has an efficiency of $\eta_{\text{shaft}}$).
Moving the compressor.
Increasing the temperature of the gearbox (because the box is not ideal and has an efficiency of $\eta_{\text{box}}$).
Moving the propeller.

Following this thinking, I can intuitively find this next equation (which I don't know if is correct or not): $$\boxed{\eta_{\text{shaft}}\times \dot{W}_T = -\dot{W}_C-\dfrac{\dot{W}_P}{\eta_{\text{box}}}}$$

The thing is I don't know if I assigned the efficiency $\eta_{\text{box}}$ correctly or not. Is there an easier way (i.e. less intuitive/more mechanical way) to apply the energy equation? What if we had 2 or more shafts?


texts: What happens if the gust alleviation system on an A380 fails?

texts:
In an answer, a user linked to this video of the gust alleviation system (GAS) on an A380. This seems like a complex system with many moving parts—all the ailerons move completely independently. What happens if the GAS fail, if for instance two ailerons get stuck in an extreme position?

Or maybe even worse: imagine a sensor failure that produces two opposite extremes on each wing, such that e.g. the left wing have all its ailerons in the up position, and the right wing ailerons in the down position.

Could this be fatal?
Are there procedures for this in some checklist?

This is a follow-up for my other question, What is a gust alleviation system?.

This is not question Why do some aircraft have multiple ailerons per wing? as far as I can possibly see (though it was marked as such).


texts: Are there any cases on record of an aircraft crashing into an occupied air traffic control tower?

texts:
Aircraft frequently1 crash, or come close to crashing, from almost every cause imaginable, on or near airports, these being places where aircraft of all sizes take off and land and sleep with many other aircraft in close proximity, and where being a hundred feet above or below or to the left or right of where you should be has much worse consequences than it does up where the only things to hit are other aircraft (which are small targets which ATC does their best to keep at least five to ten hectofeet away from you vertically, and several miles away horizontally); this is why airports have specialised ARFF units, while your neighbourhood fire department probably doesn’t.

Usually (and hopefully, at least from the airport’s perspective), the only things that get damaged are the aircraft itself, one of the runways, and some grass, but aircraft also occasionally crash into hangars, and approach lights and ILS antennae are semiregular victims of errant aircraft.2  Surprisingly, though, I can’t seem to find any instances of an occupied ATC tower being hit by an aircraft, even though it’s a tall structure in the middle of an airport - are there any known cases of an aircraft crashing into an active tower, or have the controllers just been lucky so far?

1: Well, more frequently than they crash most other places, at least.

2: Which is why they’re made to be frangible (break apart harmlessly when struck); okay, usually frangible.


texts: Is it really cost effective to put a motion system underneath a Full Flight Simulator?

texts:
Civil full flight simulators are mounted on top of a motion system. It is an expensive system, requires higher and therefore more costly buildings, and requires greater structural integrity of the simulator itself. A cost driver of considerable proportions.

Why do we have to have motion systems on simulators? We get motion information from our central and peripheral vision, right?


texts: Is there any regulation to ensure that life jackets and safety cards are on-board?

texts: On many flights, I was told that a life jacket is under my seat and safety card is in the pocket in front. Is there any regulation that ensures that life jackets and safety cards are on-board on all flights?


texts: Can we replace an attitude indicator with a ball half full of liquid?

texts:
Attitude indicators (artificial horizons) use a gyro to display pitch and bank.

I was wondering if it would work to use a ball half full of liquid to replace the artificial horizon (using the water level as reference)?


texts: How much air is recirculated (vs. bleed air injected) in modern airliners cabin?

texts:
Air in the cabin of airliners is a mix between:

new air (engine bleed air or ram air in some aircraft) and
recycled air pumped out of the cabin, filtered and re-injected.

How much air is recirculated? What are the reasons for recycling air instead of using bleed air only?


texts: What were the rules about night flights from LHR in the 80s?

texts:
I was just reading a question over on movies.SE: How could Ryan land in New York in early morning?, and the accepted answer suggests that Jack Ryan's plane takes off from LHR at about 4am.
One of the comments on the accepted answer says:

...there are no mid-night commercial flights from any commercial airport (especially LHR) due to night-time noise restrictions...

But were there at the time the film is set?
The film is "The Hunt for Red October", which is apparently set in 1984.
So, I did some searching, and found the following:

Heathrow does still allow a limited number of night landings, but that takeoffs aren't allowed before 6am.
There were court cases in the 90s and early 2000s about the noise caused by night operations at LHR. See this ECHR case from 2001.
An obituary for John Stewart, an anti-noise campaigner, which mentions noise (but not night flights) in the 70s, and the narrowly-lost ECHR court case.
This article about Dan Air, which talks about, in 1982, "...flights to Eilat in Israel. The late night flights, [...] departing from Gatwick". Obviously, that's Israel, not America, and Gatwick, not Heathrow, but it's the right era.

So, my question is this:
During the mid-80s, were there scheduled night flights from Heathrow to the US East Coast, such that Jack Ryan could plausibly have caught one at about 4am, were he not fictional?


texts: Can a CFI give training outside the US in a non-N registered aircraft?

texts:
My question is if a US CFI can give instruction in other countries with an airplane that's not registered in the US (N) (as long as he has certifications to fly those airplanes in other countries)?
Must he be a flight instructor as well in those other countries where the airplane is registered?
The perfect example would be a US CFI who is also rated as a CFI in Argentina.
Can he give a Flight Review or training required towards a US PPL certificate in Argentina (with an airplane registered in Argentina)?


texts: Should an aircraft's registration match with its tail number?

texts:
What are the requirements for an aircraft's tail number to match the registration?

What happens if an aircraft changes its number? Is it grounded until the new number can be painted on?


texts: Why is the N-number on the tail of aircraft sometimes shown in both large and small font?

texts: Why is the N-number on the tail of aircraft shown again much smaller and above the main N-number? They are both the same group of letters and numbers.


texts: What exactly is a hot air pressure regulating valve, and what is its purpose?

texts:
Someone else has asked this question but the answer just says that it regulates the pressure of hot air, and I don't understand what that means. Does "hot air pressure" just mean "hot air"?

So I've been learning about an Airbus A320 and its air conditioning system and I'm wondering what's the point of the hot air pressure regulating valve? Why can't bleed air, which is hot compressed air, be used as hot air? Send some of the hot compressed air to the packs and some hot compressed air to the trim air valves to heat the air from the mixing unit.

Please explain what is the purpose of the hot air pressure regulating valve and even what it is. What's even the purpose if you have bleed air? Please don't tell me that the hot air pressure regulating valve regulates the pressure of hot air, I already know that. I just want to know why it is generating hot air pressure, why not just hot air? Or is hot air pressure the same thing as hot air?


texts: When aircraft is flown by the pilot and when by the autopilot? What are common procedures?

texts:
I am courious about different phases of flight in which airplane is flown by the Pilot, and when by the Autopilot.
For example, I'm quite sure that generally pilots have full control during takeoff and landing (full control? stick and throttle?) but during cruise at high altitude is the autopilot that has control.
But when a pilot activates autopilot? immediately after takeoff? And when take control again?


texts: Do cockpit panels have an indication that oxygen masks in cabin have been deployed?

texts: Do cockpit panels have an indication that oxygen masks in cabin have been deployed for Pilot information?


texts:
Inspired by this question...

How does a taildragger take off? Does it rotate?

I imagine if a taildragger has to land front wheels first it has a very limited range of Angle of Attack (if the pilot wants to avoid a prop strike) during landing.

So do they land tail first by default?
If not would a tail first landing be an issue?


texts: Why is there a difference between military parachutes and those used for skydiving?

texts:
A couple hours ago I was watching a youtube video where skydivers jump using the skydive parachute, and after that, a military training where the soldiers jump using "old" type parachute, the dome shaped one.

Why is the military using the dome shaped one?

The skydive parachute is smaller, and more compact, and has manoeuvrability (as I can see, I'm not an parachute expert).

Is it because of protection against enemy fire? Since it's larger it can take more damage of enemy firepower, or what?


texts: Does the FAA require a specific grade of supplemental oxygen for part 91 operations?

texts:
In a recent FAA knowledge exam, a question was asked whether medical grade or industrial grade oxygen can be substituted for the aviation grade supplemental oxygen for General Aviation, Part 91 flight. I have looked in the FAR/AIM for answers. But, there is not a specific regulation prohibiting the use of medical grade oxygen in aviation.
The FAA Safety Brochure OK-09-439 recommends that medical grade oxygen should not be used. Yet, there is a Civil Air Patrol document (another government entity that is regulated in part by the FAA) that refutes this due to changes in the understanding and delivery of supplemental medical grade oxygen.
Does anyone have a clear cut and recent regulation or document that clarifies this question? Please include links to the documentation.


texts: How is the Max Zero Fuel Weight used in calculating weight and balance?

texts:
In some weight and balance apps there is an option to "Use Max Zero Fuel Weight".  Having never seen this in any of the aircraft I have experience flying, I am curious how this value is typically used in the calculation of an aircraft's weight and balance.

Can someone give me an example of how this value is used in a weight and balance calculation?


texts: If a stall is at the same angle of attack what is the stall speed?

texts: So I of course know that the wing can stall at any angle of attack, but what then is the stall speed? Is that the speed at which the wing will always stall and it may stall at a higher speed?


texts:
I am a brand new student pilot pursuing my private cert.  I don't need to know this for a while, but I'm trying to learn about VOR navigation to enjoy my sim flights more, in the meantime.

My question is this: is the VOR frequency for a given station static/permanent?  If you're looking at a chart from ten years ago (which, granted, I'm sure you're not supposed to be doing) and it shows a freq for a given station of 116.20, is that frequency likely to still be 116.20 for that station today?

That's a bit exaggerated of a timeline, but another way to ask this question is this: how often do VOR frequencies change?  How recent does a chart have to be, for you to rely on a frequency as printed on that chart?


texts: What are the curved centerlines at taxiway intersections for?

texts:
At all airports where I've looked out the window during taxi, the taxiway intersections have been painted with nice circular arcs connecting (the centerline of) each entry to the intersection with each exit.

I've always assumed these lines were there to guide planes through the turns -- that is, if the nose wheel follows the curved line exactly then you're guaranteed that there'll be pavement under the path the main gear will follow, and there will be sufficient wingtip clearances for the aircraft types allowed to use the intersection, etc.

However, in this question it comes to light that pilots can't even see the curved centerlines while they're turning and rely on spatial intuition instead. Very well, that seems to work fine in practice.

Which leads to the question: Who are the curved centerlines for, then? What would go wrong if they weren't there and instead just the straight centerlines of the intersecting taxiways continued through?

Possibly the pilots of smaller aircraft than the intersection is built for (say, a Dash-8 in an intersection that can take A380s?) can see the curved lines ahead of them while they turn. But in that case they should have plenty of room to do the turn by intuition too, right?


texts: What's the difference between CPM and LDM?

texts: I know CPM is cargo pallet message and LDM is load distribution message, but what's the difference between them ?


texts: Are VOR airways being replaced by RNAV routes as VORs are decommissioned?

texts:
I understand that VORs in the US and elsewhere are being removed from service gradually. The FAA plans to maintain a Minimum Operational Network, but still I imagine many VOR airways will also have to be removed when their respective VORs are shut down.
Is there any indication that the old VOR routes will be replaced by RNAV routes (Q and T routes)? Or will the VOR airways be removed without replacement, leaving pilots to file direct routes instead of using published routes?


texts: What happens to an airborne plane when its type is grounded by an authority?

texts: Many countries have (temporarily I think) banned 737 Max 8s from taking off or landing. What happened to the ones in the air? Do they get special permissions or are they forced to divert to a different country that is allowing them to land?


texts: Can a person with Type 1 Diabetes get a medical and learn to fly?

texts: A friend of mine has had Type 1 diabetes most of his life, and has it well under control.  How does he go about finding out if he can get his medical and learn to fly?


texts: Can Airbus A320 doors be opened mid-flight?

texts:
Today I learned how airliner doors are typically an outward facing plug and cabin pressure would make them nearly impossible to open mid-flight.
It's easy enough to see that for the shape of Boeing 737 doors, for example.
But looking at this video of the A320 door operation, it doesn't exactly look like it forms a plug.  So if it were unlatched while the cabin is pressured, would it get pushed open?


texts: Why CFM International has changed the profile of the fan struts used at their CFM 56 turbofan?

texts:
See images below

Image of a early version of a CFM56 turbofan showing the fan struts

[![Image of a CFM56 7B26 showing the fan struts][3]][3]

 image description here]5]5ttps://i.stack.imgur.com/aZLjZ.png
Image of a CFM56 7B26 showing the fan struts


texts: Is it legal to use GPS to navigate VOR Airways?

texts:
A previous question concludes that it is legal to fly an aircraft in the US with only an IFR-approved GPS/WAAS system and no other navigation equipment on an IFR flight plan. My question is about how the pilot is then allowed to navigate.
Specifically, must a pilot fly on GPS (T and Q) Routes? FAA Advisory Circular 90-108 discusses using RNAV systems on conventional routes, so it seems that a pilot could also fly on VOR airways, for instance. In fact, 90-108 specifies exactly what a pilot can use their RNAV system for:

Determine aircraft position relative to or distance from a VOR, ... DME fix, ...
Navigate to or from a VOR,  TACAN, NDB, or compass locator.
Hold over a VOR, TACAN, NDB, compass locator, or DME fix.
Fly an arc based upon DME.

Navigating on a VOR airway involves navigating to and from VORs, which is covered by point 2. However, the list does not include navigating to a DME/radial fix off a VOR. After taking off IFR the departure controller may clear an aircraft direct to a fix on the airway e.g. "cleared direct BOONE". Could a pilot legally use only GPS/WAAS to fly to BOONE or any other VOR radial/DME point?


texts: What do the different dates in a TCDS mean?

texts:
I have been trying to interpret Type Certificate Data Sheets and am coming up short on how to understand some of the dates listed. For example, here is the TCDS for the new Citation Longitude:

How is one to interpret these dates? Did the type certificate get issued in 2020 or 2019? The Textron Aviation website has a news release in September that claims certification occurred in 2019; so is the 2020 date specific to the TCDS being released, even though FAA approval occurred in 2019?
Also, how does this related to the Revision numbers? Does the 2020 date refer to Revision 4 and the 2019 date refer to a different revision? I can't seem to find the earlier revisions on the FAA website either, so I am not sure whether they even exist as official/released FAA documents.


texts:
Recently a Boeing 747 aborted a take off while still on the ground due to the failure of one engine.

Can a Boeing 747 take off fully loaded on 3 engines?


texts: Can you become a pilot with an Asperger syndrome diagnosis in Europe?

texts:
I have the diagnosis results for Asperger syndrome (scored 177 out of 76 required to get the diagnosis). Are there any regulations in Europe that can stop me from achieving my life goal: To fly commercial jets?

My autism makes me very strongly interested in aviation, programming and audio design. But aviation is absolutely on top and has been since I was 6. The others have come as I age.

It might be a little off-track: So I'll add this little story just to add some "meat" to the question:

I just recently went on a trip with a few of my co-workers that included a trip on a B737-800. They thought it was special that I filmed the takeoff and landing, took pictures of it at the gate, and viewed out the window the entire two hours trip (my neck still hurts). They also had a funny reaction when I explained why the airflow to the cabin (packs) suddenly went silent as the engines start up. There is nothing more that I enjoy than flying, and I feel like I really belong up there (that poor kid in the seat in-front of me had a very different opinion).

I really wanted to see the cockpit during these flights. But asking is hard for me with Asperger. It kind of makes me feel like a 4-year-old.

It might not count for much in the real world, but I have logged over 16,000 landings on my little home-simulator. Three of them are intended crashes just to test the simulation.

All I ever wanted since I was a kid was flying commercial jets.


texts: What are the disadvantages of a delta wing biplane design?

texts:
The idea of a delta wing as I understand it is to reduce stress on the wing and drag on the leading edge. Now using two delta wings on separate planes, on one frame would presumably allow for a reduced wing size, and therefore less drag. I imagine it could also lead to a nice compromise with better control in slow flight than delta wing designs?

However, clearly there are some major issues with this design, as a quick search uncovers no results for this design shape. therefore I pose the question: Why is it that designers have rejected this possibility; what are its major (dis)advantages?


texts: Do the likes of 737 or a320 or 777 or a380 as examples have keys to the aircraft or to initiate the flight deck? Or are aircraft unlocked and to start the engines it's just a flick of a switch or switches?


texts: What's the difference between True vs Magnetic headings?

texts:
What is the difference between a true and a magnetic heading?

Why are/were magnetic headings used in aviation?


texts: Why does the airplane not 'feel' the crosswind?

texts:
Apologies for multiple pictures but I thought they would depict my question more clearly than a lengthy description.

Image 1: Why does the aircraft still follow the straight path even if the wind is blowing from left to right?

Image 2: Why does it appear that the aircraft is sliding?

Image 3: Why is there no need to apply any rudder in the presence of a cross wind?


texts: Why are airliner seats higher than chairs and couches at home?

texts: I'm 6-feet tall and even I find airplane seats too high. My feet barely touch the ground when I sit upright. Why can't they make the seat cushion as low as a living room couch?


texts: Why use plywood to hold the bearings for the airbrakes on a fibreglass glider?

texts:
The ASK-21 is mainly a fibreglass construction.

However, the bearings for the airbrakes and their control rods are fitted into small pieces (some 10 cm wide) of what seems to be plywood molded into the fibreglass.

The following picture shows the plate holding the bearing for the airbrake, seen from the rear side in the space in the fuselage where the wing spars are joined. The bolt that sticks out holds the bearing of the linkage that transfers the brake movement to the rods in the wing.

The last picture shows the bearings in the wing where the rod to lift the actual air brake is fastened.

What is the reason for this choice of material - could the bearings not be fitted into the fibreglass structure without extra pieces of plywood?


texts: What is the material composition of aircraft compressor blades?

texts: I read up that aircraft compressor blades are generally made out of titanium. I was curious as to why is titanium the choice of material used for aircraft compressor blades? What alloys are involved and are there alternative materials used in the designing of such blades?


texts: Does form 337 need to be sent to the FAA prior or after the work has been performed?

texts: Is the Form 337 sent to the FAA prior to the work being performed? Meaning the mechanic awaits the FAAs reply and approval before actually beginning work on the aircraft? Or is the work performed, then documented, and sent to the FAA?


texts: What is the difference between a functional check and an operational check?

texts:
Can anyone explain what is the difference between a functional check and an operational check in aviation?
Basically I faced a problem to prepare the task card for functional and operational check of a FDR (Flight Data Recorder).


texts: How do Airbus planes flare in normal operation?

texts:
In reading the reports and Sully's comments regarding the flight that was ditched in the famous events of US Airways Flight 1549, I am wondering how the Airbus control system works to flare an airplane under normal flight conditions.

Sully stated that since the automated system did not let him flare as much as he wanted to, he was unable to reduce vertical speed further.

Is it that under normal flight, the aircraft has forward speed to generate lift, and the descent rate is thus less? I thought (I'm not a pilot) that it was desirable to basically stall by flaring at the last moment in normal powered landing, thus sticking it to the runway for traction, wheel spin-up, etc.


texts: Does an A320 revert to Direct Law if both engines flame out?

texts:
In the case of a  flame-out in both engines on the two-engine A320, does the aircraft revert to Direct law or does it maintain Normal Law?

An example is US Airways 1549 (the landing on the Hudson).


texts: For a given airfoil, with known Cl and Cd curves, how can I calculate the autorotation AoA range?

texts: I'm trying to tabulate the differences of (vertical) autorotating behavior for rotors of equal chord and span, but with different airfoils. Of course, they can be studied case by case, but there may be a simpler, less laborious way... Hence my question...


texts: Why can some runways only be used from one end?

texts: Is there any reason for why some runways can only be landed and taken off from one end and not the other, even though there aren't any obstructions (mountains, etc.) and apparently can be used from both ends?


texts: Why are some airfields not on any sectional chart nor listed in the directory?

texts:
I would have thought this was a safety issue.  Case in point - Hearst Castle Airfield.  This is located beneath William Randolph Hearst's Castle in California, located at  35°39'35.54"N  121°11'35.64"W.

It is very obviously a well maintained runway, although private;  yet is simply does not exist if you were to believe the VFR sectionals.  It did appear in older sectionals, as discussed on the forgotten airfield site (http://www.airfields-freeman.com/CA/Airfields_CA_SanLuisObispo.htm#hearst2), but now not.

If you look at skyvector (https://skyvector.com/?ll=35.658914169287556,-121.18517303105294&chart=301&zoom=1&fpl=3539N12110W), the runway should be right smack under the crosshairs inthe center, where the map is marked "ranch".  But it's not there.  How can this be allowed by the FAA?  Even secret CIA runways are listed on sectionals.

I assume that the Hearst Castle administrators requested removal of the field from the map.  Isn't this a safety issue - in the event of an in-flight emergency, this would be a perfectly good field to land on, but being unmarked, there is no way to know it is there.  How can this be?


texts: What configuration of autothrottle is required when pilots are landing an Airbus?

texts:
Do Airbus pilots normally disengage the Auto Throttle on a manual landing?

Do pilots (Airbus or Boeing) normally prefer a manual landing to a A/P landing?


texts: Why is the Boeing 757 undercarriage so high?

texts:
Compared to other wide bodies the 757 seems to stand on very tall landing gear.

Considering strength, weight, cost, stowage space and ease of ground servicing you would want the shortest possible undercarriage you can achieve. The B737 isn't a much smaller aircraft but is much lower, so low it was a challenge to fit modern engines.

Was there a specific design/operation reason or was it just styling - it certainly looks nice !


texts: How many flights follow the North Atlantic Track relative to those that don't?

texts: What is the ratio of flights that follow the track system in the north Atlantic and those that don't? Also what is the general trend in this ratio over time?


texts:
I was reading a Civil Aviation Safety Inspector from Transport Canada:

  I have met a few pilots who have flown all their lives without
  declaring an emergency. Pilots such as these are very rare.

Source

Emergency landing for this Boeing 727 flying into a serious hailstorm over Switzerland (source: ASN)

Is your experience in line with this TC inspector statement? Is it very rare to be a senior pilot with no emergency occurrence in history?

Let's define emergency as a mayday or pan-pan radio call or transponder code.


texts: Can the iPad use GPS data from a Garmin aera 660?

texts: Can the iPad use GPS data from a Garmin aera 660 portable GPS unit? I assume this would happen via Bluetooth, if it's possible. I would like the more accurate WAAS data from the Garmin for use with CloudAhoy.


texts: Can a commercial airliner be landed on a highway, e.g. Highway 405 in Los Angeles?

texts: In a famous sequence from the TV show 24, a Boeing 727 is forced to land on the 405 in Los Angeles. It is a well-known myth that the interstate highway system was set up as a series of airstrips. But would it be feasible to land a commercial airliner on the 405 highway from an aviation perspective, given that there were few if any cars on the road? (Of course, anyone who lives in LA will tell you that there is never a time of the day or night when the 405 is not busy - so this is purely theoretical.)


texts: What is the procedure to turn an airplane when it flying?

texts: As far as I know, there are two part devices that involved when turning an airplane when it flying: aileron and rudder. How they work? Which one is first over another when turning/banking? In this case, the airplane is the common commercial airplane which is has ailerons, horizontal and vertical stabilizers, elevators, and rudder. Not the V or /-shape empennage like mostly used in drone.


texts: Why are most weapons in AC-130 on the left-hand side?

texts:
Lockheed AC-130 gunship is a heavily armed ground-attack aircraft variant of the C-130 Hercules transporter. The plane is manufactured by Lockheed and converted by Boeing.

Why are most of the guns in AC-130 installed on the left-hand side (but not right)?

Picture Source


texts: How do airline pilots maintain night currency?

texts: Does flying as an airline pilot under 14 CFR 121 provide different ways to maintain night currency? Suppose a pilot were to bid only day trips and end up flying only during the day for over 90 days. Under the recency of flight experience requirements in 14 CFR 61 that would mean a pilot might not be night current anymore but do 121 operator's op specs have some way around this?


texts: I've never understood the purpose of yawing, i.e., rotating around the vertical axis by activating the rudder. Provided that airplanes have ailerons that allow banking (used for turning), why do they actually need to yaw? Furthermore, I've read that yawing induces an undesired banking because of the different lifts generated by each wing, due to the fact that one wing "feels" a higher airspeed than the other (a similar effect as a car's wheel spinning faster than the other during a turn). So, if yawing is so "useless" or bothering, why do airplanes have rudders? Moreover, could an airplane takeoff, fly and land without rudder?


texts: Are there any truly 'unrecoverable' situations?

texts:
I'm starting my quest to obtain a PPL this weekend. So I guess this question is contextualised around light aircraft like the Piper Tomahawk / Cessna, although it certainly would be interesting to get an answer that covers airliners too.

Baring a catastrophic technical failure, such as the wings falling off, a fire, or the horizontal stabiliser failing - is any [pilot caused] situation truly 'unrecoverable'?

I watched this video of a student accidentally starting a spin. Naturally, he looked terrified, but the instructor took over and recovered quickly and easily. This made me wonder, is there anything a student can do that the instructor will not be able to recover from? (obviously smashing the plane into the tarmac on approach isn't really something that can be helped, so I'm only asking about events at altitude here).


texts: How do check valves regulate the air in a multi-engine airplane's vacuum system?

texts:
This is one of the examples of a pneumatic power system in a multi-engine airplane. In systems like this, if one dry air pump fails - let's say the right-hand one - then the check valve manifold closes the right-hand part of the system. I can understand this and it makes sense, but I can't understand how the check valve manifold works.

I already went through an aircraft maintenance manual which has kind of this system, but I can't find any clue. My instructor guesses that inside the check valve manifold there's some kind of shuttle valve. But I don't agree with this. Could someone help me out to understand?


texts: What conditions cause the gear-up warning to sound on a Bombardier DASH-8?

texts: As the title says, what conditions cause the gear-up warning to sound on a Bombardier DASH-8?


texts: What is the meaning of nose-art on the Tu-160 bomber?

texts:
The BBC reports another Tu-160 interception on 15 Jan 2018 and it's clear that there is a large message painted on the side of the bomber.

Looking at the Wikipedia page, it seems this style of nose-art is common among the Tu-160 community; the style is similar, but whatever it says, they're all different.

It would be interesting to know what's being said here, and who is making the choices. Official propaganda,  or personal messages?

(source: BBC)


texts: ETOPS between Johannesburg, South Africa, and Perth, Australia

texts:
South African Airways flies over 6 000km across the Indian Ocean from Johannesburg, South Africa, to Perth in Australia.

I don't see any airports along the way in the event they need to divert.

Does anyone know what would happen in an emergency?

PS Yes, yes, I know that ETOPS does NOT mean "Engines Turn Or Passengers Swim"!


texts: Do I need to get a new AFSP approval if I change to a new part 61 instructor?

texts: I have an AFSP (TSA) approval to train with a part 61 provider. I want to transfer from them to an individual part 61 CFI. Do I need to go through the AFSP approval process again?


texts: Approach plate does not require DME, but DME used in the published missed?

texts:
This approach plate doesn't say "DME REQUIRED", but the published missed approach uses DME.

Can I still fly it without DME equipment?

If this approach didn't say "RADAR REQUIRED", could you fly it without being in contact with ATC, and how would you manage the DME in the missed?


texts: How is the phraseology of IFR clearances different between the US and Europe?

texts:
In this question, a comment says that the phraseology of IFR clearances is very different between Europe and the US:

  especially the VFR phraseology (but not only) is really different in
  europe and the US. If we just take the IFR clearance into
  consideration the differences are huge

What are those differences, at least the main ones?


texts: If pure N2 (not gas generator) is used for evacuation slides, why is CO2 still needed?

texts:
In the answers to Aircraft Emergency Evacuation slide inflation system: Why is a mixture of CO2 & N2 used instead of pure N2?, it's mentioned that the nitrogen comes from a gas generator.

Yet the bottles I'm familiar with are labeled as "55% of N2 and 45% of CO2", how so?

The maintenance manuals do not mention a pyrotechnic gas generator. So if pure N2 is used for evacuation slides, why is CO2 still needed?

Is there a technical reason, or simply a simplified labeling?


texts: Can anyone identify this aircraft in the AMARG area of Davis Monthan?

texts:
Anyone has an idea what this thing in AMARG area of Davis Monthan could be?

Googlemaps link: https://www.google.com/maps/@32.1512545,-110.843407,25m/data=!3m1!1e3?hl=en


texts: Why did Concorde not have horizontal stabilizers?

texts:
The Concorde did not have horizontal stabilizers or elevators. As a result, the pilots have to move fuel around the aircraft to trim it up or down, as sluggish and hazardous move.

Why did the design team chose not to use a horizontal stabilizer? Was it because of the understanding of supersonic aerodynamics and/or technology of the time? Or, was it due to some aerodynamic principles? If someone were to design the Concorde today, would they still use the fuel transfer method to balance the CG?


texts: Is a "GPS required" ILS (or other navaid-based) approach considered a "GPS approach" for alternate planning's sake when TSO-C129/196 gear is in use?

texts:
If you have TSO-C129/TSO-C196 GPS gear (vs TSO-C145/146 WAAS/SBAS gear), you either have to have a non-GPS approach at your destination, or a non-GPS approach at your alternate.  If your choices are either conventional approaches or GPS-only approaches, this is simple to understand.

However, some approaches have arisen that are hybrid approaches -- combining GPS intermediate guidance with a ground based navaid (usually an ILS) for the final approach course guidance.  An example of this can be found at Jackson Hole, WY, where the KJAC ILS Z or LOC/DME RWY 19 approach is listed as "GPS REQUIRED" on the approach plate due to the use of GPS to set up a curved feeder leg onto the ILS final, bypassing some terrain to the north of the airport and allowing much lower minimums as a result.

Are these "hybrid" approaches considered the same as a GPS-only approach for alternate planning if you are TSO-C129/TSO-C196 equipped?  Or are they considered as conventional approaches for alternate planning purposes?


texts: Are there any airports which use a metro to transport cargo?

texts:
Many airports around the world are increasingly being joined by Metro conveniencing people. Majorly, it is people who probably will use the metro. I do have a sneaking suspicion that the metro would also be a pretty inexpensive good carrier. Two things which I think work in its favor -

a. Security on Airport Metros is higher so that much less hassle.
b. Most of these Metros run on specific times so it's easier as it's consistent.

Are there any airports that people know that transport air cargo via metros after being bought by Aircraft ?


texts: For large commercial aircraft, how are the tires changed?

texts:
Something at least the size of a 737, all the way up to the A380. How are aircraft tires changed for large commercial aircraft?

Are they actually jacked up like with a car?


texts: How do CFIs typically determine proficiency for complex and high-performance endorsement?

texts:
I'm working on getting checked out in our flying club's Arrow II. Our club's insurance requires 10 hours of instruction if you don't have any retractible time.

I've done a few hours with an instructor, and he signed off on my complex endorsement, which I also need from an FAA standpoint. So I'm FAA endorsed, but I need more time to satisfy club insurance.

§61.31.(d)(2)(e)(i) says:

  (i) Received and logged ground and flight training from an authorized instructor in a complex airplane, or in a flight simulator or flight training device that is representative of a complex airplane, and has been found proficient in the operation and systems of the airplane;

What defines "found proficient?" What is the list of things an instructor "ticks off" their list to be able to give that endorsement?

Same question for the high-performance endorsement?


texts: What sources of weather are approved by the U.S. National Weather Service?

texts:
Part 135 and (I believe) Part 121 operations all have a requirement to use a source of weather that has been approved by the U.S. National Weather Service:

  §135.213   Weather reports and forecasts.

  (a) Whenever a person operating an aircraft under this part is
  required to use a weather report or forecast, that person shall use
  that of the U.S. National Weather Service, a source approved by the
  U.S. National Weather Service, or a source approved by the
  Administrator. However, for operations under VFR, the pilot in command
  may, if such a report is not available, use weather information based
  on that pilot's own observations or on those of other persons
  competent to supply appropriate observations.

  ...

Does the FAA or the U.S. National Weather Service maintain a list of weather providers that have been approved and are legal for us to use?

If not, then how do we know whether a particular source has been approved?


texts: Is hybrid propulsion widely used by UAVs?

texts:
Is it common to have hybrid propulsion in UAVs used for terrain mapping with long endurance, short range and altitude? Is the technology and research mature enough to make hybrid propulsion?
Background: I have college project of UAV design and manufacturing and I want to be a part of it as a propulsion head.


texts: Should you blow through the final approach course if the ATC forgot about you?

texts: So you were being vectored for the final approach course (ILS/RNAV/whatever) and the controller forgot about you for some reason (busy). Assume you called them and they were not replying. Also assume you were not yet cleared for the approach but they told you to assume the x approach. Would you blow through the final approach course and wait for them, even though you might conflict with traffic, or turn inbound even though you had not been cleared and potentially take a beating later?


texts: During inverted banking, what happens to heading?

texts:
In normal flight, a plane that banks will turn and change heading.

What happens if the plane is inverted?
If the plane rolled 180° to wings-level inverted flight, then it will not be turning.

But if the plane rolled 135°-- 45 degrees beyond wings-level inverted flight-- what would happen?

Will the aircraft's heading tend to change toward the earthward wingtip, or toward the skyward wingtip?

Does it matter if the wing is positively loaded (e.g. the aircraft is performing a barrel roll) or negatively loaded (e.g. during a "slow" roll, or while performing a banked turn during sustained inverted flight?)

During sustained inverted flight, would the pilot be pushing the stick forward to maintain altitude?


texts: Is (L/D)max achieved at a specific speed or AOA?

texts:
I'm little bit confused about the (L/D)max.

So I've read this blog: https://joeclarksblog.com/?p=4155
and the author shows this graph:

So if I understand it correctly the (L/D)max is at the intersection of parasitical drag and lift-induced drag. Thus, at the point which has the minimum total amount of drag. Which is achieved at a specific speed.

Skybrary states the following:

  The maximum lift/drag ratio occurs at one specific CL (Lift
  Coefficient) and AOA (Angle of Attack (AOA))

https://www.skybrary.aero/index.php/AP4ATCO_-_Lift/Drag_Ratio,_Forces_Interaction_and_Use

Here is is the lift coefficient:

Source: https://en.wikipedia.org/wiki/Lift_coefficient

The graph shows that the airfoil is the most efficient at a specific AOA. Thus in the ranges between 15° and 18°.

sciencedirect.com states the following:

  The L/D is not constant for a given wing, however, but changes with
  the angle of attack. Researchers thus normally use the maximum
  lift-to-drag ratio, L/Dmax, to characterize a given wing.

https://www.sciencedirect.com/topics/earth-and-planetary-sciences/angle-of-attack

I'm confused because one source tells me that (L/D)max is achieved at a specific speed. The other source tells me that (L/D)max is influenced by the AOA.

Can you clarify this thought twist?


texts: Does a long time to solo hurt your chances of becoming an airline pilot?

texts: I've heard that on job applications for airline pilots that they ask the question: "How many hours to Solo?".  If it took someone 30 hours to solo but they had more logged flight time than someone who took 10 hours to solo, would the person who soloed in 10 hours have an advantage?


texts: Can an aircraft engine be started midair?

texts: Can one start the aircraft's(commercial/fighters) engine midair at high altitudes especially turbojet or turbofan engines?


texts: Why is the force that moves an airplane forward called THRUST and not PULL?

texts:
As we know, there are four forces acting upon an airplane. Thrust ($T$), Drag ($D$), Lift ($L$), and weight ($W$).

Since most propeller-driven airplanes over history have had the propeller mounted in the front, the power or forces generated were to pull, not to push. So why is it called thrust (the meaning of which is equivalent to push), and not pull??


texts: Is it normal ops to dispatch an airplane after a stick shaker was on throughout the previous flight (Lion Air 610)?

texts:
I've been studying Figures 5 and 7 of the Lion Air interim report and cannot understand why the airplane was dispatched on the "Loss-of-control" flight when the Left stick-shaker was on throughout the entire previous flight (Figure 7). Can this occur in normal operations everywhere?
I have no experience with ground operations (just 35 years with design of flight control equipment), so I'm asking the airline folks here. (I understand that often multiple causes lead to a crash, so I'm looking for understanding, not blame.)


texts: Why did multi-wing aircraft (two or three stacked wings) eventually fade off to single-wing aircraft?


texts: Is there a career path to fly fast, military jets without being in the military?

texts: I would like to pilot or fly in fighter jets however as I have mild asthma I cannot join the Royal Air Force. So is it possible to fly in or pilot these kinds of aircraft as a career without being in a branch of the military?


texts: Why does Vx have a relationship with thrust but Vy has a relationship with power?

texts:
https://www.boldmethod.com/learn-to-fly/performance/vx-vy-altitude-and-where-they-meet/
After I watch this article, now I understand the relationship between altitude and the rate of climbs.
But I wonder why Vx has to do with thrust and Vy has to do with power.
Could you explain them for me?


texts: What is this gigantic dish at Ben Gurion airport?

texts: As the title asks, what is this thing for?  Have never seen anything like it at other airports I've been to.


texts: What unique challenges/limitations will I face if I start a career as a pilot at 45 years old?

texts:
I'm contemplating a mid-life career change. I made some money in another industry, and now have the luxury of choosing a job that pays less, but provides enjoyment and satisfaction. I suspect being a professional pilot could be the ticket. I'm currently an active glider pilot with 300+ hours, and I am just loving it! I learned to fly gliders very quickly and I am confident that I could learn to fly powered aircraft quickly as well. Fortunately, I can afford the training and the cost of building up hours, potentially in my own plane.

I know it takes a long time to work up to flying an airliner, but I'm not sure that's even what I want to do. Flying smaller planes appeals to me more.

Am I crazy to try to start a piloting career at my age (45)? Is the system going to be biased against an older trainee like myself? Should I go to an aviation college? Will I ever make a decent salary given how many working years I have left? Also, see the question in the title. Thanks.


texts:
Before examining this XB-70 picture

I thought that all canard were one single flight control surface (as seen on many fighters such as the Eurofighter Typhoon), and that there functionning were comparable to stabilators.

But the XB-70 exhibit something that looks like large flaps at the trailing edge of its canard. Apparently, it is not the only airplane with this feature (e.g. the Saab 37 Viggen is also equipped with similar canard).

What is this canard flap? How does it work? Is there any pro/cons of this configuration compared to a all moving canard (I don't know if this can be called stabilator as this is not located on the tail)?


texts: How should I read these climb and descent profile notations?

texts:
I use a tool called SimBrief to build virtual flight plans for a desktop flight simulator. As I've been getting more familiar with procedures, I've also been exploring more advanced settings in the builder as well as some parts of the OFP output.

One thing that I can't figure out even after consulting the tool's docs is how ascent and descent profiles are represented: for example, for a 737-800 on a medium-haul route, one of the available ascent profiles will be 250/280/78, while one of the decent profiles is 78/280/280.

How should these be read?


texts: Why would one plane in this picture not have gear down yet?

texts:
This image (as posted in another question) is a YouTube video's thumbnail:

I noticed that the lead twin (737?) has gear down, the 747 behind does not (appear to) have gear down, but the third plane in line (another twin) does have gear down as well.

Why would the 747 not be gear down at this point?


texts: There is any technical reason for the new Airbus shades? Or they exists just because it is sexy?


texts: How do you open and get a IFR clearance while in the air?

texts:
I once had a traffic controller give me a hard time about how I requested IFR clearance once in the air. I had previously filed an IFR flight plan, and took off from my untowered home airport. On approach control's frequency, I said:

  Tampa Approach, Cirrus 123AB, 5 miles southeast of Tampa Exec at 1000 feet, IFR to Ft. Lauderdale Exec

The approach controller responded, annoyed, saying something like "Well do you have an IFR flight plan or are you reporting IFR??"

I had always used that phraseology because it seems the least wordy way to get the info across, which can be helpful when the freq is busy. What is the technically correct way to get an IFR clearance on an existing IFR flight plan?


texts: What is the correct way to get established on the outbound track on this approach?

texts:
If you have been cleared to LCA (from the direction shown by the red arrow) then outbound on the procedure, what is correct way to get established on the outbound track?
Ideally, I'm looking for an ICAO/PANS-OPS reference or similar (not US).
Many thanks!
---- Edited for clarity ----
So, to avoid a situation like this:

What is the correct action to take?
Is it to request the arrival pattern hold to better align yourself:

Or manoeuvring space to the south to better align yourself:

Or something else?


texts: What does it mean when autoland is fail passive / fail operational?

texts:
The below explanation is what I've got from the internet about fail passive and fail operational:

Fail operational - Where you have 3 autopilots engaged, such that any single failure will result in the remaining 2 autopilots being able to safely land the aircraft. That is if there is a failure autoland remains operational.
Fail Passive - Where you have 2 autopilots engaged, such that a single autopilot failure will result in the disengagement of both autopilots with no significant deviation from the established flight path. In this case the pilot must manually take control and go-around/land. (avsim.com)

Can someone confirm whether the above explanation is correct?
I've read that the A320's Autoland is fail operational but that does not match with the above explanation (since the 320 only has 2 AP's hence making it fail passive).
And also (if possible) can someone give examples of aircraft whose Autoland is fail operational/passive?


texts: Are there rules governing the conduct of flight attendants?

texts:
What are the rules and regulations specified by FAA about the code of conduct of flight crew members?

And, are there any rules which specify behavior of passengers with crew members?


texts: Do F-22's use cartridge start to start engines?

texts:
What method does the F-22 use to start its engines?

In the video below, you can see a flap open and flame and steam shoot out as the engine starts to spin up.  Is this an example of cartridge start?  If so, could anyone explain how this works in greater detail?

Video of F-22 engine start:


texts: Is a Phenom 300 single pilot able to fly non-commercially in Europe?

texts: Can a personally owned Phenom 300 be flown non-commercially by a SP typed pilot in Europe?


texts: Do ballonets control the buoyancy of a Zeppelin NT?

texts:
Ballonets are bags of air inside the lifting body of the airship.

I have read about Zeppelin NT, a semi rigid helium filled airship. It uses ballonets to maintain constant over-pressure inside the aerostat. I can't see how this airship would use ballonets to ascend/descend. However it has swiveling engines and actually takes off heavier than air.

I have read that ballonets were also used to control altitude of an airship. However I can't see how it could work since air is neutrally buoyant in air. Maybe in older airships the air in the ballonets was slightly pressurized to make them heavier. Maybe on the landing hydrogen was released and ballonets were filled with air to maintain constant pressure.


texts: Can an ultrasonic sensor mounted on a drone pick up another drone strongly enough to sense and avoid?

texts:
I am asking this question to see if mid-air collisions of drones can be prevented using simple analog sensors. Can an ultrasonic sensor mounted on a drone pick up another drone strongly enough to sense and avoid it?

I know that the sensor is range limited so the aircraft cannot be flying towards each other very fast, but to even do any sense and avoiding, can this sensor work? Or does the drone not provide enough of a return?

Also, could the range of sensor be increased if both drones emitted ultrasonic energy to be picked up on the sensor more strongly at a distance?


texts: What is the maximum range of a BAe 146-300? Can auxiliary fuel tanks be added?

texts:
What is the maximum range of a BAe 146-300? I saw one on Flightradar24.com which started in western France and is still flying non-stop to Greece (flight in progress at the time of posting).

I was really surprised, I guess they probably have an additional fuel tank? I know that some airlines do add extra tanks  to their planes (e.g. on a B737) to increase the maximum range; but is it possible on on a BAe 146-300?


texts: Does going from SPL with TMG to PPL(A) automatically give me a PPL(A) TMG rating?

texts:
I am currently training for PPL(A) while holding an SPL with TMG rating.

Since I have more than 24 hours on TMG, I only need 15 hours of flying to obtain the PPL(A) license according to the EASA Part FCL.

My question is: Will I automatically receive the TMG rating with my PPL(A) after my skilltest, or will my TMG rating only be associated with my SPL?

In my opinion, I would find it strange, if I was not allowed to use my TMG rating on my PPL(A), since I was taught to fly powered aircraft on a TMG.


texts: Are retired airline pilots allowed and able to help in an emergency situation?

texts:
My dad is a pilot who flew over 15000 hours in 777.
Will he be able/allowed to help the crews if the same plane is in emergency?


texts: What would happen if pilots were locked out of the flight deck?

texts: Imagine in a hypothetical situation that a commercial airliner was left on autopilot at some cruising altitude. Next imagine that all pilots left the flight deck and the door slammed shut behind them (presumably locked). Would they all be completely trapped outside the flight deck or would there be a way to enter should there be a situation like this?


texts: How to understand US military aircraft designation on the vertical stabilizer?

texts:
There are many letters and numbers printed on the vertical stabilizer of US military aircraft. They identify the plane's design and purpose.

What are those letters and the meanings?


texts: Why does Canada recommend a minimum rate of climb for ultralights of 300 ft/min?

texts:
What is a safe minimum rate of climb for ultralights? I understand most ultralights climb at least 300-800 ft/min and in fact the Canadian ultralight specs recommend a minimum rate of climb of 300 ft/min. Even the Lazair's specs note a rate of climb of 400 ft/min.

Why does Canada recommend 300 ft/min specifically? Why not 120 ft/min?  60 ft/min? Even at 60 ft/min, you could clear a 4' fence in 4 seconds. Of course you would want some clearance, so say 20 seconds. Seems pretty good in my book. Need to clear 50' trees? Just kite around in a circle.


texts: Identify a change in Altitude based on direction and WCA applied?

texts:
Question below is from study material for the EASA PPL license MET course.

It's an unlikely question but it's interesting to review.

You are flying from west to east with WCA +6°. How is your true altitude changing with all else remaining un changed.

A) It will degrees
B) It will increase
C) Will remain stable(unchanged)
D) None of the above are correct.

My Question, how is this easily explained, does it have to do with Buys Ballot's law ?


texts: Where do I place pressure ports on an airfoil?

texts: What are the criteria for placing pressure ports, i.e. is there any procedure for determining where to locate them? I have a NACA 0012 airfoil with a chord length of 150mm and I want to add pressure ports to it. How should I proceed?


texts: How does the Guardian counter-MANPADS system work?

texts:
I came across this picture of a FedEx McDonnell Douglas DC-10 equipped with an anti-missile defense system.

(wikimedia.org)

According to the picture description:

  FedEx became the first U.S. carrier to equip its aircraft with an anti-missile defense system in 2006. The gray oval Northrop Grumman Guardian pod can be seen on the belly of this FedEx MD-10 between and just aft of the main landing gear.

How does this system work? Does this successfully work in countering all types of missiles? Can it be reused over multiple missile strike incidents? Are all commercial airplanes compatible with this system? Is it economical for a major airline to fit all of its fleet with this system?


texts: Is the number of relief pilots regulated?

texts:
This article hints that the number of relief pilots isn't mandated. Wouldn't requiring more relief pilots for longer flights be safer and ethical? I personally prefer airlines that overwork their pilots less!

I'm asking more about North American and European airlines, not just Asia.

  As part of the agreement ending the strike, CAL [China Airline] pilots promised not to strike for three and a half years and the airline increased the number of pilots rostered for long haul flights. CAL now rosters three pilots on flights over eight hours, up from two pilots previously, and four pilots on flights over 12 hours, up from three pilots previously.


texts: Is turning off engines before landing "Normal"?

texts:
I was traveling by Airbus A380 recently and I was sitting near the wing.
Throughout the flight, I could hear the airplane noise even with headphones on.

Suddenly before landing, everything went silent. There was no noise at all.  There was a strange silence throughout the aircraft.  Everyone was scared and looking at each other, some even started praying.

But we landed perfectly fine. It was like routine landing.

So, I want to ask, whether it was normal? Or the pilot avoided telling us something went wrong?

P.S. Before starting the landing process, the pilot informed about the weather being fine and said "there's a safety manual in your seat pocket."


texts: Why do airlines seem to go out of business suddenly?

texts:
FlyBMI are currently in the news for failing and stranding passengers abroad. This is not the first time an airline has halted operations seemingly overnight and left passengers without a way to get home.

Why is it that airlines stop operating so suddenly, compared to other businesses which seem to go through a more protracted period of profit warnings, administration... and generally more orderly windup?


texts: What is the tallest tower (AGL) identified on a sectional chart within the Class-E-to-surface airspace surrounding an airport in the US?

texts:
What is the tallest tower (in terms of AGL) identified on a sectional chart within the Class-E-to-surface airspace surrounding an airport in the US?

For the purpose of the question, "within the Class-E-to-surface airspace surrounding an airport" means within the part of the sectional chart that lies within a dashed magenta line that completely encloses the airport and is not separated from the airport by another dashed magenta or blue line.  I.e. not including within Class-E-to-surface "extensions" that are separate from the Class-E-to-surface that actually surrounds the airport.

For simplicity, let's NOT include Class D or higher that reverts to Class-E-to-surface at night, etc.

"Tower" means any type of structure-- radio antennae, whatever-- that is depicted on the sectional chart with a tower symbol and has the AGL elevation of the top of the tower identified on the sectional chart.


texts:
Suppose that I buy a case of oil.  For some reason I stop flying and the oil sits in storage for a sufficiently long time.  After that, I decide I want to put it in my engine.

Is there a point after which (reciprocating) engine oil should no longer be used after being kept in storage?

If the answer is "Yes", what sort of time range is it?  Months, years, decades?


texts:
I would like to know the meaning of the phrase and especially the meaning of "running torque":

  Torque the inner plug to between 75 and 85lbf.in. Loosen half a turn
  and RETORQUE to between 15 and 20lbf.in more than the running torque.

So how do I find out how much is the running torque?


texts: Can drones/UAVs fly over international waters without being subject to the FAA's regulations?

texts:
Can UAVs or drones (consumer/commercial scale) operate over international waters (12 miles out from the shore) without being regulated by the FAA?

Just wondering if companies can do things like BVLOS* testing out in international waters if they wanted to, instead of getting exemptions or leasing private airspace.

And, this is meant to be living and residing in the US, and operating outside of US' waters.

* Beyond Visual Line Of Sight


texts: What does "radar contact" mean in ATC calls?

texts:
When ATC mention 'radar contact', what does that mean?

In what conditions ATC might contact you and mention 'radar contact' in the call? and what would be the appropriate responses?


texts:
I recently acquired what appears to be an extremely rare photograph. It was purchased at an estate sale auction in Europe. The photo was listed simply as "Flieger in seinem Doppeldecker "Bülow" (aviator in his biplane "Bülow"). No other I.D.

The "Flieger" is recognizable as Ace Leutnant Walter von Bülow, but he seems to be sitting in the rear seat, of a 2-seater biplane. This is evidently a photo from very early in his service (FA22? FA300?), before he joined Jasta 18 where he flew an Albatros D.III. This plane is clearly no Albatros D.III.

Based on the triangular bracing over the fuselage, I suspected this could be some AEG or Rumpler design.  What's leaving me completely confused, is that the wings have a third pair of struts, just visible at the left edge of the photo. Could this be a single-engine two-seater bomber of some type?

The photo doesn't give much to go on, but I know this aircraft must be from early in the war; probably pre-1917.

Can anyone help me identify this plane?


texts: What is the significance of 104% for throttle power and rotor speed?

texts:
I noticed this initially when learning to fly Robinson Helicopters but fail to remember the reason my instructor gave me; this again came up when watching a video about the ISS.

In helicopters (Robinson R22/44), the main rotor typically operates at 104% RPM.
On the space shuttle, after max q, they throttle back up to 104%.

What is the significance of 104%? If this is the maximum, why is this not called 100%, and everything scaled back to fit? This seems the most fit place to ask this, as I have only seen this in aviation / aerospace.


texts: Are there ILS approaches where descending by the glide slope outside final might be dangerous?

texts:
Are there ILS approaches out there where descending by the glide slope on a segment of the approach that's outside the final approach segment would cause the aircraft to descend below the no lower than altitude for the segment?

Here's why I'm asking. It's not uncommon for pilots to intercept the glide slope before the published glide slope intercept point and then to track it all the way down. If doing this could be dangerous or might not provide the protections ILS approach are designed to provide, it might be a better procedure to descend using step downs to the no lower than altitude for each segment only intercepting the glide slope at the published point for all approaches.


texts: How big is the TP400-D6 turboprop installed on the A400M?

texts:
I am trying to re-create the A400M TP400-D6 engine in CAD, mainly the nacelle and propeller, yet I can't find any detailed dimensions for it.

Europrop specifies a 0.92m diameter for the TP400-D6, so I assume the nacelle used on the A400M is roughly 2 meters tall and 1.5 meters wide - is this a reasonable estimate? Or even better, where can I find more information on the actual size of the A400M nacelle so I can accurately model it in CAD?

Thanks a lot.


texts: Are there security checks on private flights in your own plane?

texts:
On commercial flights there are some "typical" security checks - metal detectors, luggage X-rays, etc. - are there similar security checks if you're flying in your own private plane?

Are there different or additional security checks when flying into other countries (such as a trip from Canada to the United States)?


texts: Why scrap an A380 with only almost 10 years?

texts:
Accordingly to this article "First commercial Airbus A380 turned to dust", first A380 was scrapped.

Apart be a sad news for an aviation fan, it sounds me a bit strange because it was an airplane of only 10-12 years, while generally a plane flights for more than 20.

Ok, I know that A380 was sadly almost a commercial flop but it was not an old plane, I thought that could continue to flight with another airline.

In which way could be more convenient to scrap it instead of sell it flyable to another company?


texts: What is a biplane propeller and how efficient is it?

texts: Lazair ultralight series II used biplane props to absorb more power from the engine....so my question is what really is a biplane propeller and are they efficient in comparison to a four bladed prop?


texts: Is there a software to calculate parameters from certain inputs on a flying wing?

texts:
I want to build something similar to this

https://www.parrot.com/de/drohnen/parrot-disco-fpv#parrot-disco-fpv-details

but with two holes in the wing, where I want to put two propellers. But I need to make the proper calculations (shape and size of the wings, I'll work on the propellers separately). It should be a simple design, just a prove of concept.

Is there a software that can help me do this? I can have an idea of the weight I need to lift, the velocity, and need the design (with the two holes).


texts: Will manned aircraft have to defend ground targets against unmanned aircraft in the future?

texts: Given that current Unmanned Combat Aerial Vehicle (UCAV) development is mainly directed towards the strike role, is it most probable that a future manned vs unmanned combat aircraft scenario will involve manned aircraft attempting to defend ground targets against attack by UCAVs?


texts:
I am very new to airplane design. I am working on this project to design a flying wing glider (no propeller) that would glide in a circular pattern with a fixed radius of 250 m after being released at a height.
Here is all that I know now:
I was reading around the internet that a choice of delta wing would be good for maneuverability of the glider, however it would be bad for operating at low speeds. I guess that this design would not fit me because it has very poor lift. But at the same time a wide plank kind of design would not be able to perform a turn that well. So I've decided to choose a swept wing for the flying wing. However, I am not able to decide properly the angle of sweep required. I know that the stall angle and the twist of the wings depend upon it, but I don't really know how to tackle the problem (as I guess I would require a high stall angle to provide me the lift).
When it comes to choice of airfoils, I am currently looking at HS522, MH60, and NACA 22112 and Eppler 186 airfoil. However, again I can't really choose between them. From my understanding, I require a reflexed airfoil with high camber and high thickness to provide me with good lift as I plan to operate at slow speeds close to ~20 m/s.
Wing loading and banking of the turn is another thing that I understand is related to each other but I don't understand how I can reach a common point between them. From my preliminary analysis of the situation, I have reached a bank angle of 9°. Is that a good angle? I read on online resources that the standard bank angle is 25°. Is that relevant in this case? Or do I approach this problem by deciding the wing loading and then move on to the bank angle?

Thanks


texts: Do controllers take wind into account when giving headings?

texts:
When ATC gives you headings to fly, do they consider wind correction? In theory they should because they call it a heading and not a track, but do they? After all, the heading they want you to fly depends on wind direction and airspeed.

Or do they actually mean track instead of heading?


texts:
What is the optimum separation between contra-rotating propellers?

What factors determine the distance between the two sets of propellers?


texts:
In the very interesting answer from Jan Hudec to a question about the various flight control computers on Airbus planes, two different means to trim the aircraft are mentioned: The stabiliser and the elevator.

How does this work in practice? How is the aircraft trimmed in flight, both as seen from the flight deck (i.e., the user interface to the pilots) and as actual input to the control surfaces?


texts: Any unique characteristics to identify aircraft engine?

texts:
I love to find out the engine manufacturer and make, used in all of the aircraft I fly.
Can anyone provide hints on how to identify an engine uniquely?

The CFM56 on a Boeing 737NG is easy. It has a flat bottom.
The GENx was at first easy to identify due to sawtooth pattern chevrons near the exhaust. But now the Trent 1000 too uses it.

Any easier ways to identify most popular engines?
Pratt and Whitney? Rolls Royce?


texts: How robust are modern parachutes to folding errors, wear, or other problems?

texts:
My 8 year old recently got a guided tour of the parachute-packing station at the local sport airport. Afterwards she asked me what happens if the parachute is improperly packed. Since it seemed to me that each parachute is packed by one person, there is no checking of human error.

How resilient are modern sport parachutes to packing errors? I would include in that any improper packing method or the packer overlooking some detail such as wear or tears. I'm not a parachutist so I don't know the intricacies to ask a more nuanced question.

Proud father update: A bit belated, but she's no longer eight years old and she enjoys, in her words, floating on imagination.


texts: Calculation QNE and QNH, with flight level and QNH set lower (higher) than QNE

texts:
Hi Student pilot here.

Lets say Mr pilot is flying at FL75 and QNH is set at 995 hpa, however there is a mountain in the way at 7000', will he below or above the mountain?

If you could visually explain that would be even better.


texts: How does a bearingless rotor work on a helicopter?

texts:
I have read about some helicopters now using a mechanism referred to as a "bearingless rotor". From what I've seen online, the system involves a flapping hinge.
What I struggle to get my head around is how the rotor spins without a bearing. How is this achieved?


texts: How fast does cabin air pressure leak after a total engine failure?

texts:
When an airliner loses all engines while at cruising altitude, two things happen:

The plane is a glider. It will descend no matter if you want to or not.
The cabin pressure is no longer maintained. Although the valves are closed automatically, they are not air tight - air will slowly leak out until the air pressure is equal to the atmospheric pressure outside.

My question is, which one happens faster? Are the valves able to maintain cabin pressure until the plane has descended to 10,000 feet, or will the oxygen masks deploy before the pilots can complete their descent at best glide speed?

EDIT: For the purpose of the question, let's assume it's s fuel exhaustion and ignore the APU. I'm specifically interested to know if the crew would encounter a situation where they have to choose between oxygen and best glide.


texts: What happens during a checkride for a private pilot license?

texts:
For a Private Pilot License in USA, what happens when a student takes his/her checkride? I want to know the sequence of events. According to my knowledge, which is sort of vague, things proceed as follows:

Student takes an oral and written exam (not sure if it's on the same day of checkride or prior to that).
Examiner asks student to plan a cross-country flight.
Examiner and students go for this planned cross-country flight.
Examiner may or may not cancel this plan and ask student to go back (does not affect result).
At the end, examiner tells the student if he/she has passed or not.

What I do not know is:

How much of the above is accurate?
And how long does it take?
How are emergency procedures created and tested?
Who makes sure that the weather is suitable for flying?
What if the checkride has to be cancelled for reasons not controlled by student?
What else did I miss?


texts: Are there standard visual cues or other methods for flaring in a B737-800?

texts: Just a newbie in the 737. I've flown 100 hours - in real life - in this lovely beast and found the landing to be very confusing: my main problem is every time just from 50 feet, the sink feels too much. I don’t understand the right time to flare, almost every time it’s early or late. Also that I can’t flare at one go. Very very frustrating. Maybe a lot to do with seating position? Can you suggest the right visual cues or other techniques to use?


texts: Using a Foreign-based FAA license while getting permanent license

texts:
I am an American Expat who got my EASA PPL(A) license while living abroad.  I am about to move back to the US and looking into a permanent conversion to an FAA license.

Per I have a European EASA license - what do I need to do to be allowed to fly in the US?
 the best option seems to be re-taking the FAA tests.  Otherwise I would have to find an EASA examiner in the US to avoid my EASA license expiring (perhaps thats not as hard as I assume?).

My question is am I allowed to file/use for the foreign-based license while training for the full license?


texts: What's the minimum timeline for fixing the issues/finding from NTSB/FAR?

texts: When air-crash investigation completes, either NTSB/FAR/other investigating agency finds some issue with instruments/equipments. What is the minimum timeline given to instrument/equipment manufacturer to fix the issue? (May be based on the severity of the issue).


texts: Is Doppler navigation still in use for civilian aircraft?

texts: Is it possible to find an airliner nowadays with Doppler radar used for navigation purposes?


texts: How does the automatic battery cut off logic prevent complete battery discharge on ground in the A320?

texts:
I was reading in the electrical systems of the a320 FCOM and in one of the notes it stated that the batteries have an automatic cutoff logic which prevents them from getting completely discharged when on the ground. (Parking)

But how does this logic exactly work? As the batteries are permanently connected to the hot bus in which they will continue to discharge


texts: In the US, are there any operational control towers located in surface-level Class E airspace or in Class G airspace?

texts:
(This question pertains to the airspace of the United States.)
FAR 91.126 gives some general rules for operating at or near airports in Class G airspace, and FAR 91.127 gives some general rules for operating at or near airports in Class E airspace.
Section (d) of 91.126 and section (c) of 91.127 pertain specifically to operations at airports with operational control towers.
a) This seems to beg the question, are there any operational control towers located in surface-level Class E airspace or in Class G airspace?
b) Were there ever?  (Counting from the September 16, 1993 "alphabet" airspace re-organization onward.)
c) If "no" to a and b, then what is a practical example of how a pilot's behavior might be altered by the need to comply with 91.126(d) or 91.127(c)?  After all, it appears that generally speaking, it is not possible to get within 4 nautical miles of an airport with an operational control tower, at 2500' AGL or below, without entering Class D (or higher) airspace.


texts: Can a light glider without thermal protection land from the orbit, starting from the orbital speed?

texts:
I ask about a glider without any special thermal protection (pilot in the space suit), so both answers to the other question do not cover the topic.

When the glider enters the atmosphere, it starts generating lift. Could this lift keep the glider high enough, in low density air, and this way prevent the heat damage? The glider then would fly a long distance, losing speed and altitude slowly, until reaching speed and elevation at which it can safely land. Seems that lots of lift could be generated at speed and air density where the metal burns already.

Is there any analysis ever been done if such landing is possible?


texts: How do I find the registration or serial number for the aircraft I flew on specific trips in the past?

texts:
I understand that there are various paid subscription services that allow me to search back up to a year in the past for the IDs of any flight and the histories of any aircraft.

Is there a free (or one-time fee) service or API for identifying the aircraft I've flown on specific dates and flights in the (up to several years) past?


texts: Would an airliner fly more efficiently on a fatter wing at a low altitude?

texts:
Flying at 1000 ft, would giving an airliner wing more girth but not length, allow the plane to fly more efficiently than it normally would at that height?
Yes, airliners fly best around 35,000 ft, but if it was restricted to fly at 1000 ft., what would be the best shape wing for it?


texts:
Here's the KLAX METAR 2153Z observation:

  KLAX 102153Z 27010KT 10SM FEW002 BKN200 24/16 A2997 RMK AO2 SLP147 FG
  BNK S-NW T02390156 $


texts: What make and model are these two small propeller planes?

texts: What are the makes and models of the two planes in the picture? The registration numbers are ZS-JNJ and ZS-LCY, the year was 1981 and the place was Botswana.


texts: What effect would a afterburner have on the compressor if the nozzle outlet is not increased?

texts:
In order to operate an afterburner, it is necessary to adapt the nozzle outlet area. As far as I understand it is necessary to open up the nozzle when the afterburner is increasing its temperature or the mass flow rate would decrease. It is also necessary to close the nozzle when the afterburner cooling down or the turbine would rev up and exceed the critical rpm.

  Now, what I want to know is what happens with the compressor if the outlet area is not adapted?

If the afterburner temperature increases and the nozzle is not adapted I guess that the compressor will reduce its normalized rpm $u/\sqrt{\gamma R T}$ because of the reduced mass flow rate and it will also come close to a compressor stall (surge).

Is it right that the compressor rpm is reduced or does it stay the same and the mass flow rate gets throttled?


texts: Why is it said that the Tupolev Tu-144 had superior aerodynamics to the Concorde?

texts:
A quote from this article:  "The Concorde had better range, braking and engine control but the Tupolev had vastly superior aerodynamics."

What is the basis, if any, for this statement on the aerodynamics of the two aircraft?


texts: Did the Westland Lysander have a helmet/face mask for radio communication during WW2?

texts:
I have a character in some war-time fiction I'm writing 'acquiring' an aircraft (a Westland Lysander).

Just need to know: was there a helmet/face mask for radio communication for these aircraft? And, by default, was it present in a 'parked' plane?

fwiw...my character's genned up with the entry, startup and takeoff procedure.


texts: How many antennae are there on a typical small aircraft, and how are they connected to the avionics?

texts:
As far as i know there are a bunch of antennas on board of a small (EASA CS-23) plane:

GPS is for GPS navigation in MHz
VHFVOR is for NAV and Glideslope/Localizer
ADF is for ADF
DME is for DME
VHFCOM is for COM

Questions:

So there are three, two or one VHF antenna?
How is the VHF signal split?
If I have two NAV instruments (KN53 and GNS430)
how would the antennae would be cabled to them?


texts: Which CS-23 airplane has the lowest takeoff speed?

texts: Among the currently certified CS-23 airplanes (or "Part 23" in FAA-land or your personal region equivalent), which has the lowest rotation speed ($V_r$)?


texts: How is the centre of lift and centre of gravity misalignment problem solved in Delta wing aircraft?

texts: Since Delta winged aircraft don't have horizontal stabilizers to produce down force, how is that problem solved ?


texts: Why is there no alarm when the transponder is turned off?

texts: When the transponder on Malaysia Airlines Flight 370 went off, there was no ALARM. The satellite kept getting pings, and apparently "knew" that the transponder was off. Would it not be a great idea if the Malaysia Airlines got an alarm indication that the transponder was off on one of their planes? The airline could have radioed the pilot and asked what the trouble was. If the pilots did not respond, some jets could have been scrambled to checkout what is going on. The scrambled jets could have followed the airliner for hours and watched them crash in the ocean, when they ran out of fuel. We would know EXACTLY where the airline crashed!


texts: Are large jet turbofans so easy to spin?

texts: In this question, in the accepted answer, there is a comment by alephzero that says one can actually rotate a large turbofan's blades with one finger! Is that true, can someone elaborate? As an example, does this apply to my google search for strongest turbofan GE9X too?