texts:
It is amazing to think about a single-pilot jet with that much range. They have a site, they have some 2 minute videos talking about the aircraft... but there is no video of the thing flying or any review of its interior, no one talking about their experience of owning one...

Does SyberJet SJ30 really exist or is just a project that never made it off the drawing board?


texts: Why don't tanker aircraft have ejection seats?

texts:
Apparently, the KC-135 has no ejection seats (they used to have parachutes to allow the crew to manually bail out, but those were removed in 2008 to save money), and, according to this Quora discussion, that's the case for all tankers (presumably excluding the ones converted from bombers), not just the KC-135.

This seems somewhat illogical to me, as tankers act as potent force multipliers; to quote the linked post:

  It is quite possible that a sophisticated opponent will go after the tankers, as an easy way to disable a lot of aircraft without actually having to shoot them down. Doesn't really matter if they go down from a missile hit or lack of fuel. The math on that one looks very good - shoot down a tanker, and you have probably shot down four or five smaller, agile, hard to hit strike aircraft.

Not only that, but tankers are big, slow (for military aircraft), and generally devoid of any defensive armour or armament, making them easy targets relative to combat aircraft.

Even in peacetime, the role of a tanker aircraft inherently places it at a much greater risk of a midair collision than most aircraft are ever exposed to (example) - and, with most MACs, the only way to survive is to abandon aircraft.

So why don't tanker aircraft have ejection seats for their crew?


texts:
For my pre-scientific work I now need some general information about contrails. I searched for websites that explain the process of contrails being formed in detail but couldn't find any so far.

I realized this question hasn't been asked on Aviation.SE so far, so I decided to ask it now.

I would like to know, how the whole process works and what it needs for it to form a contrail.

What temperatures are needed?
How wet does the air have to be?
What exactly is a contrail then? Only condensation, ice, ..?
Is the contrail made from humidity from outside-air or from the vapor of the engine?
How does a contrail vanish again? What makes the difference between a 20 second contrail and a 2 hour contrail?
Everything that you know and is important to know.

Some of the questions may sound strange, but I found this topic is really complicated and also confusing and I want things to really understand now.

I (and probably many other people googling for this question in the future) would really appreciate a nice, informative, in detail answer, thanks!


texts: Are there differences between the runway lighting on a land runway and on an aircraft carrier?

texts: How are the lights on aircraft carriers placed and are there differences to the color/position/number of lights at normal airports?


texts: How to increase your chances of survival in a plane crash?

texts:
More than 90% of plane crashes in recent years had survivors.

  In America, for example, there were 568 plane crashes between
  1983 - 2000:   Out of the collective 53487 people onboard, 51207 lived
  to tell the tale. That's a survival rate of 96%.

  Some experts believe that almost one-third of deaths in aeroplane
  accidents could have been prevented if people knew what to do and took
  action. (source)

Question:
Beyond bringing on board special items, what are the things a passenger can do to increase his chances of survival in the unlikely event of a plane crash – including its aftermath ?

note: Although plane crashes are very rare, it's nevertheless a question worthy of contemplation both
– theoretically, for argument's sake, as it's an interesting thought all by itself
– and from the point of view that each preventible human death is one too many and unnecessary. For the tens of thousands who experienced a crash as well as their friends and relatives it's certainly not a theoretical question.


texts: what is the use and the locations of nacelle hinge bracket?

texts: i have seen on the webs about the additive manufacturing about this bracket here but I have no clues on where is it located and whats the purpose of it. Do give me any links if there are actually any if possible.


texts: Why is the seat belt mechanism on airplanes so different from the the one on cars?

texts: You pull a flap on airplane seatbelts, you push a button on car seatbelts. Why?


texts: What is the glide ratio for the new EX Cessna 208B with 8750 amphibian floats?


texts: Can you climb at Vxse when you cannot at Vyse in a multi-engine aircraft?

texts: Let's assume that you took off in a seminole and had one engine suddenly failed, say, at 400 feet AGL. You right away pitch for 88 knots (Vyse) to keep climbing, yet you start to descend because the density altitude is too high. In this situation, would pitching up for 82 knots (Vxse) give me a chance to climb back? Or would it only give me a greater descent rate?


texts: Why does the speed of commercial airliners fluctuate, sometimes as high as 1,060 km/h or as low as 800 km/h?

texts:
I've noticed that (long-haul) airliners sometimes travel at as high as 1000  km/h (I believe I've even seen 1040 km/h), but usually they fly closer to 800 km/h, for most of the trip.  This seems odd to me.

I would understand this if it was due to wind speed; however, usually those that travel slowly seem to do so for most if not all of the journey, regardless of the direction of travel (e.g. even if they are going up to the north pole and back down, and whether the net direction is west or east). I find it nearly impossible to explain this using wind speed.

Similarly, given that the speed of sound is around 1,060 km/h at 12 km above sea level, I find it equally uncompelling to reason that they need to go at less than mach 0.8 due to the speed of sound. I would understand it if they limited themselves to (say) mach 0.95 (obviously you don't want to do mach 0.99 due to variability etc.), but I routinely see top speeds that are around mach 0.8 for cross-continental flights, and I don't understand why.

So, what's the real reason?


texts: Is N1 and N2 and any N speed the revolutions per second for the rotor blades of compressors?

texts: For example the Airbus A350 has three N speeds I think is called Nucelle speed and N1 is for the fan or LP compressor, N2 is for the IP compressor and N3 is for the HP compressor. Even on the Airbus A320 with N1 is the L.P. compressor and N2 is the HP compressor. But anyways is the N speeds how many revolution per second it's doing or What?


texts: What would prohibit a T-38 Talon from being certified in the Acrobatic category?

texts:
The definition of the acrobatic category in FAR 23.3 reads as follows:

  (c) The acrobatic category is limited to airplanes that have a seating configuration, excluding pilot seats, of nine or less, a maximum certificated takeoff weight of 12,500 pounds or less, and intended for use without restrictions, other than those shown to be necessary as a result of required flight tests.

Considering that the Northrop T-38 is a two-seat, twin-engined supersonic jet trainer aircraft with a USAF service maximum takeoff weight of 12,093 lbs (from their factsheet), what traits of the T-38 would have prohibited Northrop from applying for a civil Type Certificate for the T-38 in the acrobatic category?


texts:
Why do flaps retract? I know, it might seem obvious at first, because of drag, but instead of retracting the flaps, can't they just make the flaps flexible enough to get into a reduced drag position, and act like an extended wing?

Maybe there is a reason we should look into this technology, since it could really help out in terms of climb rate. Or, was this already looked at, but engineers decided something was wrong about it, and threw the idea away?

And by the way most of the answers involved automatic retraction of the flaps, even though I never said anything about making the flaps being automatic. Just a disclaimer.


texts: What are the regulations for non-aircraft targets in airport movement area?

texts:
In the movement area at a controlled airport, I would assume any airworthy aircraft is automatically eligible to make requests to enter into, exit from, transit through movement areas, for the purpose of aviation related activity.

What about the other ground vehicles and pedestrians? Do they need some  special permit, or can simply make requests like a crew member?


texts: What are the US definition and restrictions on aerobatic flight?

texts: In the US, what is the legal definition of aerobatic flight? What are the restrictions (both for the aircraft and its location/maneuvers) applied to aerobatic flight? I remember reading something about a restriction on degrees of pitch or bank, but I was looking around for it and can't seem to find it again.


texts: Why does the 737 auto-land trim up at around 400 feet RA?

texts:
From the 737NG FCOM:

400 Feet Radio Altitude
The stabilizer is automatically trimmed an additional amount nose up. If the A/Ps subsequently disengage, forward control column force may be required to hold the desired pitch attitude.
If FLARE is not armed by approximately 350 feet RA, both A/Ps automatically disengage.

For the media component, you can listen to the trim wheels in this auto-land video (YouTube).
While I understand the design reason may not be public, educated guesses wrt the aerodynamics involved, and/or answers from experienced 737 pilots, are welcome.
When the plane trims up while in auto pilot, the auto pilot would push the control column forward. So what I'm thinking of, is during a go-around, somehow it's better to relieve this control column pressure for a nose-up, rather than pull back?
I checked the A320 since it is of the same category, and as far as I've looked, it looks like the A320 doesn't use that system, which tells me it may not be a certification requirement (not 100% sure).


texts: What is the suggested position for a canard?

texts: In a canard aircraft, what is the suggested position of the canard, with respect to the wing positioning? Considering the effect of down wash of the canard on the wing, what is the suggested position for a canard? Mid canard? High canard? Low canard?


texts: Can passenger movement in an airliner make it stall?

texts:
This question shows a couple of air hostesses dancing during mid-flight and the co-pilot came out of the cabin to record it.

This made me wonder:  Can flight crew or passengers moving around in flight cause the airplane to stall?


texts: What is the meaning of "static pressure"?

texts:
I don't really know what static pressure is. Does the ASI (Airspeed Indicator) use cockpit pressure as static pressure, to find the dynamic or differential pressure?

I just found this statement :

  if the instrument static pressure line becomes disconnected inside a
       pressurized cabin during cruising flight the altimeter and airspeed
       indicator will both read low.

Could anyone help me understand static pressure and this statement?


texts: What happens when a turbo-prop is over-torqued?

texts:
What does one need to do when a turboprop engine gets over-torqued?

I haven't over-torqued an engine before, but it seems it could happen inadvertently, say while doing a go-around.

My questions are:

Why is important not to over-torque an engine?
What happens if you do over-torque an engine?


texts: How is a meatball calibrated and checked?

texts:
The visual glide slope for aircraft landing on a carrier is a stabilized indicator, the "meatball":

Source.

The slope is about 4° relatively to the horizontal plane, and stabilized because the carrier is usually rolling, pitching, and heaving.

How is the meatball calibrated, and then checked for accuracy?


texts: How much time it will take a B787 to fuel completely when empty?

texts: When a big jet like B787 needs to be fueled with empty tanks, ideally how much time it will take to go full?


texts: How do propeller planes sync their propellers?

texts: While reading this question, I found that the answers did not address the point I had come for.  On planes with electronic propeller synchronization, how is it actually accomplished?  I know why propeller synchronization is useful but I am curious about the mechanisms behind how it works.


texts: Why are TFRs issued around stadiums during games in the U.S.?

texts: I want to know the FAA's reasoning behind issuing TFRs whenever a game is going on in a stadium. Is it just because of a large crowd of people? Do engine noises just bother people? Could an aircraft's wake blow a ball off course?


texts: How do you compare private jet and commercial jet efficiency?

texts:
I'm curious about commercial airplane efficiency vs private jet efficiency.

I was trying to compare something like a modern 737 flying a full commercial flight from NYC to LA vs an Embraer Phenom 300 at full capacity (8 people) flying the same route.

I know there are many variations of the 737, so can we just use the most common commercially flown 737?

If fuel costs were the same (I understand that big airlines get discounts) is there a simple way to compare the flights simply in terms of cost of the flight, or how much fuel each plane would need for the flight? I didn't want to get into profit, crew, etc. Simply the cost of flying both planes from NYC to LA.

Thanks for any help.


texts: Why does a DME ground station wait 50 microseconds?

texts: The FAA says that a DME ground station sends a response exactly 50 microseconds after having received an interrogation from an aircraft. For what reason is there a 50 microsecond delay?


texts: What is NH overspeed test and how it is preformed on DHC Q400 aircraft?

texts:
In the Aeroplane Operating Manual of DHC Q400 aircraft it is written that, at the time of normal engine shutdown, the engine system tests the NH overspeed circuitry by using it to shutdown the engine.

I didn’t understand that, how the NH O/S circuit is used to shutdown the engine and how it is tested?
And what are the conditions that will ensure the correct operation of NH O/S circuit?


texts: What is the difference between BHP (brake horsepower) and HP (horsepower)?

texts: So far as I know, brake horsepower (BHP) and horsepower (HP) are the same.  But some books tell me that the two concepts are totally different.  What is the difference between BHP and HP?


texts: Why don't airliners have any mirrors or cameras?

texts: It seems odd that airliners do not have an easy way to monitor critical components on the exterior of the aircraft, should for example, a bird or something else strikes hard enough to cause damage. A mirror or camera would allow a pilot to see and react to a possible dangerous situation quickly. Also, a camera helps a pilot to see what's behind.


texts: Why do landing gear bays in commercial aircraft not have a fire extinguishing system?

texts:
Landing gear bays in modern commercial aircraft have fire detectors installed, but there is no fire extinguishing/suppression system in this area.
What is the logic behind having fire detection in this area when we don’t have extinguishing?
Why doesn't this area have fire a extinguishing system like other unpressurized areas like engines and APUs.


texts: Why does a flight booking mention that the plane has wingtips?

texts: Often when booking flights the plane is listed as having wingtips.  For example, it would say 737 (wingtips).  I get what the wingtips are for, but what is the purpose of telling the passengers that the plane has them at time of booking?


texts: Do aerobatics pilots do more to account for turbulence in their flying than passenger plane pilots?

texts:
Non-aviator here. I was trying to make a comparison when talking to a friend earlier about how when you're trying to do something complicated and delicate, you have to do more to account for environmental factors that are out of your control.
I made the analogy of a passenger plane pilot that can just kind of "push through" most turbulence as opposed to an aerobatics pilot who has to "play the wind" more, accounting for the turbulence instead of just barreling through. It occurred to me, though, that I don't know whether this is actually true. Is my aviation analogy incorrect, and if so, is there a way to make it better?


texts: Is it possible to calculate the distance to climb to 1000 Ft in Cessna 172S?

texts:
Is it possible to calculate the ground roll and distance to climb to 1000 ft in a Cessna 172S?

Why?  I live near a small airport with 2 active flight schools.  As part of a new noise abatement procedure the circuit path will be moving from 500 ft altitude to 1000 ft altitude with no turns below 1000 ft weather permitting.  I'd like to be able to calculate some typical scenarios that will result in determining approximately where the end of the departure leg and the start of the crosswind leg of the circuit will happen to understand what the net change will be.  If I can get the ground distances, I can use the scale line drawing tools on a Google Earth satellite image to draw in some eastward and westward ranges for where the crosswind leg might start, for example on a typical sunny early September morning like today.

I'm not a pilot.  I'm a retired computer systems techno-geek who doesn't mind plunking parameters into formulae to crank out numbers.  I'm just having trouble finding the formula or reference chart.

I've downloaded a Cessna 172S Pilot handbook and have the performance info.  I can get current weather conditions for the airport thru their AWOS or from aviationweather.gov.   I have a binder half full of reference material, sample pilot exam questions, definitions and terminology.  I have the current aerodrome chart for the airport.  I'm starting to muddle my way thru calculating the ground roll and distance to clear a 50 ft obstacle using that reference material.

What I can't find is anything that extrapolates that and figures out the distance along the ground to climb to what is essentially a 1000 ft obstacle.

Can anyone help?


texts: Has there been an aircraft with multiple type of engines?

texts:
Has there ever been an aircraft that can fly using at least two different type of engines? For example, a piston engine and a turbine engine, or a piston engine and a electric motor.

To clarify the question:

It is not necessary to operate both engines at the same time. However the pilot must have the ability to switch from one engine to another engine while in the air.
The engines must generate power using completely different mechanisms.
VTOL/STOL aircraft (e.g. V-22, F-35) does not quality because the aircraft is simply directing thrust from the same engine elsewhere.
The question is not asking about variants of an aircraft model where each variant is fitted with a different kind of engine. Both engines has to be fitted on the same airframe and operable at the same time.


texts: I am currently working on taxi-way route optimization. Are there any systems that store the taxi routes taken by the aircraft either by hour or by day or by airplane?


texts: What does the indication "ATC" in some Take-Off Minimums mean?

texts:
While studying FAA's Standard Instrument Departure Procedures, I came across the La Guardia Five Departure SID. Take, for example, the Take-Off Minimums for runway 13L:

  Rwy 13 (Coney Climb): 400-2 or Standard with minimum climb of 280' per NM to 500. ATC climb of 900' per NM to 1500.

How should I interpret this "ATC" indication? What difference does it have from the previous minimum climb gradient requirement ("climb of 280' per NM to 500") which omits this particular indication?


texts:
source

I recently heard pilots discussing a landing technique that some instructors are now teaching.

To assist new pilots in flaring, they instruct the pilot to adjust their attention toward the far end of the runway or horizon. There was some discussion that it won't work for a pilot short in height. As they look toward the end of the runway or horizon they are suppose to use some type of reference, such as "the horizon expanding".

What is this technique for landing and how is it suppose to help?

Update: According to the "Rod Machado" YouTube video provided below, it is the runway width that is the primary reference, not the horizon or end of the runway. The pilot is viewing the end of the runway for peripheral vision of the width.


texts: What does it mean when pitch numbers move all over the HUD screen?

texts:
In this video from an F-16:

You can see pitch angle move out of screen or be on the side at the end.


texts:
When I'm driving my car, I almost always put some music on. It's really relaxing for me.

I know that piloting a plane is nothing like driving a car, but it would be great, at least for me, to listen to some music while piloting.

So here is my question:

Is it allowed to listen to music while piloting a plane? Maybe with some device that mutes the music when someone is speaking in the radio?


texts: Can I fly a glider in Europe on a Canadian Glider License?

texts:
I currently live in Canada as a Permanent Resident and I recently received my Canadian Glider Pilot License. I will be going to Europe soon so I was wondering what I have to do to be able to fly a glider there. I will be going to the Netherlands if this makes any difference and I still have my Dutch Citizenship. Do I have to convert my license or just do some extra training?

Also would it help if I got a FAA glider certificate/endorsement on top of my TCCA license?


texts: Would mechanical indicators have helped in the Air France 447 incident?

texts:
NB I am not an aviation professional.

I saw a documentary about the terrible Air France 447 disaster the other day.

I was struck, as were the experts in it, including David Learmount, who's known as a great aviation expert here in the UK, by the way all 3 pilots were completely unable to grasp what was really happening because of their fatal inability to trust the electronic instruments.

I had a thought: is it not the case when flying any aircraft, whatever its size, that you always need to know, particularly in an emergency, two things?

air speed
attitude

I know this is VERY VERY obvious, but please bear with me.

The fact of the matter is that you can obtain totally reliable information about both these aspects, regardless of darkness, regardless of electronics, regardless of Pitot tubes, at all times:

air speed: by having an incredibly robust, small structure outside the front of the cabin window which would flex visibly according to windspeed, thereby making the invisible (air flow) slightly less invisible: at 0 knots this would be inclined downwards; at over 150 knots the windspeed would cause this to become fully horizontal.  Lack of horizontality would therefore indicate a low speed. One thing I have appreciated since posting this question is the intensely hostile environment this structure would be facing: freezing temperatures, high windspeeds, sometimes containing ice, etc. No doubt one of the reasons why during the development of aviation this has not been considered possible. But materials are being developed now which are much stronger than ever previously known.  One candidate might be carbyne.  It would also presumably have to be heated.
attitude: by having one of those completely mechanical floating compasses (as used on ships) in a prominent position in the cabin. Much confusion has been created in some of the comments about apparent gravity. But apparent gravity has effect only when acceleration other than gravity (down!) and lift equal to 1G (up!) is present. The fact of the plane accelerating/decelerating (in any or all of the 3 dimensions) could be indicated by a system of calibrated inertial accelerometers in all 3 dimensions, with lights varying in intensity according to acceleration.

Obviously such a bendy thingy would have to be very tough to withstand the speeds, battering, temperatures, etc. But it is at least conceivable that this is not beyond the wit of humanity.  Designed carefully, a change in the way it was flexed would then indicate without any possible doubt when an aircraft was in or near a dangerously low speed.

Wouldn't these two measures have had a good chance of providing the pilots of AF 447 with a true and totally irrefutable mental picture of what was actually going on?

PS it has been objected that such a system, even if feasible, would be redundant. But redundancy in critical systems is a desirable thing: what's worrying is if you don't have redundancy, and the aviation industry has made gaffes in the past over insufficient redundancy: Boeing 737 rudder issues; MD80 horizontal stabiliser: "The absence on the McDonnell Douglas MD-80 of a fail-safe mechanism to prevent the catastrophic effects of total acme nut loss" (Alaska Airlines 261, NTSB report quoted).


texts: What are the typical max range and max flight time (endurance) Mach numbers for the A320?

texts: What are these speeds? Average numbers will be fine.


texts: What is the difference between Part 121, Part 135, and Part 91 operators?

texts: What are the important differences between Part 121, Part 135, and Part 91 operators?


texts: Can longer paths consume less fuel than the (shorter) great circle path?

texts:
Is the most fuel-efficient route between points A and B always along a great circle ?

Although somewhat counter-intuitive, this comment on an aviation blog seems to suggest that longer paths (in terms of geographic distance covered) can save fuel:

  Oceanic Flights these days are not restricted to the old “defined
  great circle routes”. Modern computerised flight planning systems
  definately take weather into account, and go searching for the best
  winds (tailwinds) or least adverse (headwinds). Particularly in the
  case of westbound flights across the Indian Ocean, where headwinds are
  often ferocious, the tracks actually flight planned, and actually
  flown, are often a long way off “great circle” routes.


texts: How would a fighter be changed from having static stability to having relaxed stability?

texts:
A good portion of aircraft, especially those designed before the 1970's, possessed static stability. However, modern fighters (and some airliners) have been build with relaxed static stability.
This question was aroused by the book Designed for the Kill by Mike Spick. On page 119, it states (in reference to the Shenyang J-8 II Finback B):

In 1991 improvements were stated to be in hand to improve subsonic manoeuvrability, and one of the obvious moves would be to introduce variable camber by using leading edge slats. There can be no doubt that FBW and relaxed stability would also benefit it considerably, while weight reduction could be achieved by the use of composites.

How would a fighter such as the J-8 physically be changed to change the centre of gravity in relation to the centre of lift? Would the wings be resized/moved? Would the tailplane be made smaller? Would internal items be shuffled around to put heavier ones at the back? Or could some sort of clever aerodynamic device be added to modify the airflow somewhere?


texts: Is a reversal of heading allowed in the NYC Hudson VFR corridor?

texts:
The special rules chart indicates that northbound traffic should follow the eastern edge of the Hudson and southbound should follow the west one.

Suppose a pilot wanted to only go mid-way through the corridor and then turn back, would it be allowed to make a 180 turn, merge into the traffic along the opposite edge, and simply go back?


texts: What is this object that followed me up the street?

texts: I saw my first UAV last night as it followed me up the street in Lancaster, PA. Does anyone know what type of unit this is or who would own one? I am guessing it was the police? I am curious.


texts: How often are passenger oxygen masks deployed?

texts:
In commercial passenger aviation, how frequent (or infrequent) is the case that oxygen masks deploy?

Please include links to statistics.


texts: What is the impact of lack of stereoscopic vision on a first class medical in the EU?

texts:
I have just completed aero-medical examination for first aviation class. I was refused due to the lack of stereoscopic vision. In the book with squares with circles in 3D, I saw only 4/9. The medical examiner said that I will get class 2 and if the aviation school issues a certificate that I can take off and land without any problems, he will "try" as an exception to approve class 1.
Does it make any sense to spend money and waste time, or am I already deleted? What are my chances?
PS. I'm from Poland.


texts: VFR Navigation, rerouting timing corrections due to wind - rule of thumb?

texts:
Consider this reroute on a VFR nav trip from Great Malvern to Chipping Norton.
Maintaining 120 TAS.
Track 110 °M
Heading 103 °M (taking 3/4 of Max Drift - MD)
In still air this 30nm section would take 15 minutes.
However, with a 5-10 headwind the groundspeed would be lower than TAS, around 110-115 kts
Is there a good rule-of-thumb, or quick method in the air to estimate the timings and ETA when considering the effect of headwind or tailwind on the timing of a reroute leg?


texts: What is an afterburner and how long can a jet fly on afterburner?

texts:
I heard this word so many time in military documentary about jets, especially fighter jets, but I don't fully understand what it is or how it works. In a documentary from the Discovery Channel, all but one fighter needed to engage afterburner to reach supersonic speed. Could you tell me why is that?

The documentary also states that a fighter jet rarely engages this system. If the afterburner system can make a jet fly faster, why don't they use it all the time? Is that because of the airframe cannot handle supersonic airflow for a long period of time?


texts:
Here is a polar for a piston single-engine aircraft:

(This is lifted from a Russian manual for Yak-52, so $C_x$ is drag, $C_D$, and $C_y$ is lift, $C_L$).

1 is the 'normal' case without propwash. 2 is nominal, and 3 is the max takeoff power.

It is evident that the whole lift curve slope $C_L^{\alpha}$ is increased significantly (by some 30%) as the engine revs up, with $C_{L_{max}}$ reaching 2.

But what immediately follows, amongst other things, is that the AoA (pitch) stability should increase accordingly: it is proportional to $C_L^{\alpha}$ (as well as to the distance from NP to CG).

However, somehow I've never seen this fact mentioned explicitly, despite it being quite significant. Can anyone confirm it, either from literature of experience flying higher-powered prop aircraft?

(It may not be very obvious to feel the difference because other conditions are rarely the same between idle and full power, but the closest approximation I can think of is glide descent vs full power climb at the same speed: the aircraft should be 'stiffer' and possibly more oscillatory in pitch at full power. However, propwash over tail may mask this effect; perhaps a twin is a better testbed for this...)


texts: Has anyone attempted to recreate the Sack AS-6 (German Saucer-wing)?

texts:
I remember seeing pictures of this as a kid and wondered whether anyone has since recreated this saucer-wing aircraft and made it work?

Source (excuse the pun)


texts: Are there any regulations on who can sit next to emergency exits?

texts:
Whenever I fly with Lufthansa, if I want to sit next to the emergency exits, I have to satisfy some criteria such as:

  Be able to communicate in German or English
  Be at least 16 years old
  Be able in good physical shape so as to be able to open the door(I don't recall the exact wording Lufthansa used)

Now this is not a full list, but it gives you an idea.
Later on I took a flight with another company (still an European company). This company was proposing to get those seats for an additional cost (as they have much more leg space), and with no criteria to satisfy. Upon boarding the plane, I noticed that the people sitting in those seats were above 60 y/o, so I doubt they would be able to open the door. So I wonder are there any regulations in EU?

I saw an answer for the FAA regulations over here: link, but I wonder how is it in EU.


texts: What is the heaviest payload ever carried by a single main rotor helicopter?

texts: What is the most heavy payload ever carried by a single main rotor Helicopter?


texts: What are some of the bigger differences world wide in VFR charts?

texts:
While discussing Aviation Charts in this SE question, JanHudec &  Jwentin commented that VFR chart symbols are not internationally standardized - including airspace names and procedures.

What are some of the most important differences world wide compared to FAA (NOAA)?


texts: Is Jet-A used in turbojets or is it just used in turbofans, turboprops, and the SMA SR305-230 for Cessna?


texts: Compute great-circle track from longitude

texts:
The Aviation Formulary defines Clairut's formula to compute the intermediate track  (bearing) for a GC based upon latitude, but any given GC (ignoring one passing through the poles), crosses a given latitude twice (below the maximum latitude where track = 270 or 90).

For my application I'd easier compute the intermediate track based on longitude, since this will have only one solution, but I'm insufficiently capable at spherical triangle math to re-arrange the available formulae to give that result. Any hints on computing immediate GC tracks based on longitude, or modifying the computation based on latitude to select the 'rising' or 'falling' solution, would be welcome.

For context, this is for a navigation device emulation in a simulator, to show the desired track along a leg. All the other values (eg, cross track error) are provided by existing formulae.


texts: I have this question is the pressure measured in the entry of the pitot tube the same  when the plane is flying headwind  or  turning a 360 degree turn while maintaining the same indicated airspeed?


texts: What is the static thrust of a Piper Arrow III?

texts:
I want to find out what's the static thrust of a Piper Arrow III (non-turbo) with Mc Cauley propeller at T/O (max) power as function of the air density.

I can't find it in the manual, I know the engine is rated at 200 HP and had a look at some formulas but they require some other parameters like the propeller efficiency which I can't find.


texts: Why were the toggle switch guards in the Space Shuttle titanium?

texts:
I recently found out that the little protective rails over the toggle switches in the space shuttle were made out of titanium.  I'm not sure of which alloy specifically, but probably 6AL4V (or "Grade 5").  I heard rumors that the covers for each switch cost near $800 (USD).  Titanium is heavier than aluminum, so what was the reasoning for using it to make the switch covers?

All I can think of, is in the event of a crash the titanium would better protect the switches than aluminum...  But I'm not sure how high that is on their list of concerns in the event of a crash, or similar event.


texts: Does lack of a curved taxi-line indicate a turn is not permitted?

texts:
Does the lack of a curved taxiway centerline between two taxiways indicate that a turn is not permitted?
Take for example the complex of taxiway connections at KATL here: 33.636153, -84.421919 (see on google maps). At this intersection, there are several connections between taxiways that don't have a curved line between them. See the attached image for specific examples. Does this indicate that aircraft are not permitted to take this path, whether it's for operational, safety, logistical, or other reasons? If so, are there exceptions to these rules in certain circumstances?


texts: How is it possible for manufacturers to constantly get data from their planes all over the world?

texts: I've heard that manufacturers (like Boeing and Airbus) constantly get data from their planes. So in the case of an emergency, ATC's or pilots can contact the manufacturers for assistance. How do manufacturers constantly get this data and how is it stored (cause considering the number of planes flying today, it must be a lot)?


texts: How is horsepower measured for aviation piston engines?

texts:
As far as I can tell, aviation piston engine power output is typically measured in HP (horsepower).

Automotive engine power output is typically measured by running the host vehicle on a rolling road, or dyno or dynamometer.  This directly produces a torque curve, which may be integrated with respect to RPM to provide a power curve.

Obviously it wouldn't make much sense to put a piston-engined aircraft on such a device.  Instead, how is horsepower measured for aviation piston engines?


texts: Is the commonly assumed UFO (flying saucer) design aerodynamically efficient?

texts:
Is this design, a circular disc (or flying saucer) slightly humped on the top and bottom aerodynamically efficient? And if, we are able to use it for commercial purposes , would they give a better efficiency than existing aircraft?

This article states that this would be a better design. Is this true?


texts: What are the disadvantages for using short-field take-off technique?

texts: It is obvious that using the short runway takeoff method(hold the brake till engine get full power) could get the aircraft in air within a shorter runway distance.Then why it is not used for every takeoff for all different runways? My understanding is that occupying less runway should always be a better option, isn't it? What are the disadvantages for using short runway takeoff method?


texts: Has Jeppesen stopped providing ARINC424 data?

texts:
As far as I am aware of, Jeppesen appears to be the main distributor of navigational data (Airports, SIDs, STARs, IAPs etc.) coded in ARINC424 format. However, I can not find on its site any product based on the aforementioned digital format. Moreover, all related links are currently broken (e.g. ARINC 424 NavData Services, previously active based on google cache).

Could someone shed some light on this?


texts: What are the consequences of fouled spark plugs in flight, and how can I clean them?

texts: I've experienced spark plug fouling before but it was during the pre-flight checks and my instructor fixed it for me (by using max RPM and leaning the mixture a couple of times). But now that I have to fly all by myself, I'd rather know what to do and what not to do, especially during flight. What happens if the plugs become fouled in the air, and how do I clean them in flight?


texts: What is the distance from an airport from which an airliner climbs above 550 m?

texts:
Is it possible to determine a common distance from the runway threshold at which an airliner climbs above 300 metres and 550 metres above-ground-level (AGL)?

And for landings? Where do they descend below it?

I need to determine at least an approximate value of common distance. But in  the best case I’d like to determine:

the maximum distance
the minimum distance
the average distance or the distance which is used by most airliners.

I am not from aviation, thus I need to ask this question to professional pilots.
The aim is related with the “Bird strike problem”.
300 m and 550 m – is respectively the common height and the maximum height of flight of Black vulture - a bird species living in South and North Americas which caused the most strikes with aviation within its range. I’m doing the scientific research and study the risk of collision with this bird and the possible measures to decrease this risk.


texts: What is the average time taken to load and unload the luggage?

texts:
I was wondering, how are Lufthansa able to unload luggage (LH 760) of 500 passengers and load the luggage (LH 761) of another 500 passengers, in just a 2 hour gap for return leg of 7000 KM FRA-DEL journey.

What is the average time taken to complete a typical loading and unloading operation for a fully loaded A380? Some simple maths in this case shows its about 14.4 seconds for unloading and loading, pretty very high.  But that's assuming that no time is spent in any  task other than handling luggage, which is pretty foolish.

Bonus Question : How are the handlers able to complete this operation that fast?


texts: Are there regulations for water skiing in a ASEL aircraft?

texts: What are the regulations regarding water skiing with ASEL aircraft, as in touching your tires down in a particular body of water such as a lake or river? Sometimes referred to hydroplaning.


texts: What is the structural significance of 'dimples' on the fuselage of a Boeing 747?

texts:
I recently watched the following video:

In the video there is a mention that there are 'dimples' visible on the fuselage of a Boeing 747, when it is on the ground. It then goes on to explain that once the fuselage is pressurised - the expansion helps to "smooth" out the dimples and it will be flat.

I am curious as to what the structural significance is for 'dimples' on the aircraft?


texts: Are all engines fan blades made out of titanium?

texts: I was wondering if all engine fan blades are really made out of titanium.


texts: To what extent is LLF forecast of icing conditions a concern in VMC?

texts:
First off, I know that flying into actual icing conditions in an aircraft not equipped to handle icing is a Very Bad Idea ™ for any number of reasons. That's not what I am asking about here.

Rather, the situation I am asking about is where (for example) the low-level forecast indicates a possibility of or the existence of (particularly, light or moderate) icing conditions, while visual meteorological conditions prevail throughout the area of one's flight, and there are few or no clouds (scattered or clear) nearby.

In such conditions, is icing an actual concern?


texts:
ICAO Annex 14 (which deals primarily with SARPS for international airports) outlines requirements for rescue and firefighting that the airports shall have based on the fuselage lengths of the planes that visit said airports. Each category would define the equipment, amount of foam, discharge rate, etc.

Here the international airports comply with the users' requirements. It made me think of the other way around.

Suppose a pilot flies a tiny GA plane to a remote uncontrolled airport on a scenic tour. I don't expect that airport to have any means of rescue and firefighting apart from perhaps a call made to the local police.

But now suppose an air carrier decides to carry passengers to that airport.

Are there regulations that limit the airports an air carrier can visit based on rescue equipment? If not, how is the minimum level/category of rescue and firefighting guaranteed when not dealing with international airports?


texts: Do engines like the GE90 and Trent 1000 use transmissions (planetary gears?) for RPM reduction on the fans, or are they welded directly to the same shaft as the low pressure turbine?


texts: Why are there different starter limitations for dry cranking and manual start on the A320?

texts: I recently had this point clarified that when we place the mode selector to CRANK on the A320 we can dry crank the engine up to 5 mins. But the moment we place the mode selector to IGN/START then we are limited to 2 mins (I'm mainly referring to the 2 mins with regard to a manual engine start) Could someone please explain why there are these two different limitations?


texts: Why will the 777X be tested for crosswind handling with wingtips raised?

texts:
Wikipedia says:

As existing regulations do not cover the folding wingtips, the FAA issued special conditions, including proving their load-carrying limits, demonstrating their handling qualities in a crosswind when raised

Why?
Especially when this question says:

The 777X family (777-8/-9/-10) features wingtips that fold up on the ground to let the aircraft fit in tight spaces. These have to be extended and locked in place before a revenue flight can take place,

So, what is the point of certifying the 777X for wingtip up flight? I haven't found a reason for this in Wikipedia either. Is it for ferry flights or something?


texts:
When flying a glider, you have a polar curve. As your speed increases beyond best glide, your glide angle gets steeper. Say you are flying at best glide, you are looking through a specific point in your canopy to the spot you would land if you maintained this glide angle until you touched down.
Now say you double your speed. Of course your glide angle would get steeper, the spot will have moved down relative to the canopy at best glide. At the new pitch, looking through a specific point in your canopy to where you would land, would this point be higher, lower or the same?
The reason I ask this question is because I’m learning to glide. When you pitch the nose down to gain speed, it feels as though you are pitching down a long way, but your glide angle doesn’t seem to be affected as much as you would expect it to be. I guess a more accurate question title might be: “How does pitch relate to the polar curve?” But I’m trying to gain intuition on how glide angle changes in relation to what you perceive in the cockpit/canopy.


texts: Can airliners benefit from vertical take-off and landing?

texts:
A vertical take-off and landing (VTOL) aircraft is one that can hover, take off, and land vertically. We have several military fighter jets, which can takeoff and land vertically (like the Harrier Jump Jet).

Would it be possible to design an airliner (for example as big as a A320 carrying over a hundred people and travelling at 0.85 mach) to perform VTOL?


texts: What happens if a plane breaks down away from a maintenance facility?

texts:
I am curious about what happens when a large plane, such as a commercial passenger jet, has an equipment problem at an airport where the company does not have a maintenance facility.

For instance, do airlines have mechanics at every airport that they serve? And do those airports have a supply of spare parts?

Even if those answers are no, I imagine it's easy enough for an airline to fly in parts and staff. What happens if the repair requires some large piece of equipment to complete?


texts:
I am currently living in the UK, engaged to a US citizen and we are looking to marry and move to the US. The plan is to travel to US with a K1 Visa as fiancé, get married there and apply for adjustment of status. This would give me the right to live there, not work until work permit is issued.

Will I be able to start flight training with a flight school without work permit? Would I be able to apply for AFSP or would I need to wait for Adjustment of Status? Most flight schools seem to offer US Citizen or International Students option and I'm not sure which category I would fit in my situation.
Would I be able to obtain a FAA Medical with K1 Visa? Are these unrelated?


texts: Is it common for a cold reciprocating engine to stop at idle?

texts:
The other day I started the engine of a PA28 and put it at 1200 RPM as per the checklist but the sound didn't seem right - so I tried each magneto and the power dropped a lot on one of them. I then pulled the throttle to idle and the engine stopped. It was on for maybe 30 seconds so it was still cold.

I restarted the engine, went through the standard checklist and everything was fine the second time (I ran the magneto and idle checks once the engine was warm).

Is this behaviour expected from a cold engine (large power drop on single magneto and engine stop at idle)?

For reference, the aircraft is a PA28-180, I believe the engine is a LYCOMING O-360-A4A with ca. 500 hours. The outside temperature was 15C.


texts: What is the two-person cockpit rule, as of February 2020?

texts:
In the comments to the accepted answer on this question, there is some conflicting information about the current regulations around the 2 person cockpit rule.

I was under the impression that there must be 2 people at all times after Germanwings Flight 9525.

What is the rule currently (Feb 2020) in both EU and the U.S for minimum number of people in the cockpit?


texts: What are the advantages and disadvantages of elevons?

texts: I'm in as student, I wanted to know the advantages and disadvantages of elevons?


texts: How do STOVL and V/STOL aircraft differ?

texts:
Wikipedia's page for STOVL begins with

  A short take-off and vertical landing aircraft (STOVL aircraft) is a fixed-wing aircraft that is able to take off from a short runway (or take off vertically if it does not have a heavy payload) and land vertically (i.e. with no runway).

while V/STOL is

  A vertical and/or short take-off and landing (V/STOL) aircraft is an airplane able to take-off or land vertically or on short runways. Vertical takeoff and landing (VTOL) aircraft are a subset of V/STOL craft that do not require runways at all. Generally, a V/STOL aircraft needs to be able to hover.

On both pages, it is stated that the respective type should not be confused with the opposite one.

Essentially, it says STOVL is not the same as V/STOL and vice versa.

However I have trouble understanding where the differences lie between them.

I was about to clear it up on my mind when I thought STOVL definitely requires some (short) distance for the aircraft to clear before taking-off, while V/STOL aircraft are simply able to start hovering in order to take off. But apparently, it's possible for STOVL aircraft to do so if they don't have heavy payload.

What am I missing here? Both are supposed to be able to land vertically so I suppose there's either a difference on the take-off or if not, there are differences on the wing structure/geometry of each type of aircraft.


texts: From which aircraft are these parts (plane crash on "Dallas" TV series)?

texts:
I'm trying to identify the aircraft in this scene from episode # 014 <2.09> entitled "Survival" of the classic "Dallas" TV series (filmed and broadcast in 1978), which featured the debris after a plane crash.
The footage was reused in 1984 as "a day for night" shot for another plane crash in a "Falcon Crest" episode, so this is the last aircraft missing in the "Falcon Crest" database I'm programming.
Please note:
I am not sure if the production company used parts of a real aircraft to stage the scene or if this is a complete mock-up.  The "SF" logo (for "Southfork Ranch" on "Dallas") is definitely a prop the movie studio’s art department added to the debris.
I have no idea if it is possible to get any clues from the debris about the make and model these parts might have come from  --  if these were real airplane parts at all.
Any input is appreciated.  Thank you so much for taking a look!


texts: Do aircraft use their lights to 'say hello' to each other?

texts:
On the KLM website, I found this strange quote:

  If planes pass each other at night they sometimes use light signals to say hello.

Is it true and common? How it is done (which lights/patterns)?


texts: Is trigonometry used by commercial pilots?

texts:
Do pilots (for example commercial pilots) need to use trigonometry (directly, with trigonometry knowledge) as part of their routine job?

If so, when is it most used and for what?


texts: Flight management System(FMS) related to Performance Managment

texts: What are the recommends criteria and requirements for a Flight Management System (FMS) for transport aircraft related to Performance Database or Performance Management


texts: What punishment will I get from CASA if I fly in a cloud while a student pilot?

texts:
I am a student pilot in Australia. Someone said he saw me fly into a cloud at 1700 feet above ground level for five seconds. But I am sure I did not fly in the cloud. I have no instrument rating, nor a pilot license yet. I am grounded and waiting for further investigation.

What punishment will I get from CASA if it rules I flew through a cloud?


texts: how does a jet engine work? (explanation for non-aviation related people)

texts: Which day-to-day example would you use to explain a person (who is not involved into the aviation sector) how does a jet engine work? Would objects such as a hairdryer, a vacuum cleaner or a fan be appropriate?


texts: Can I log PIC instrument time in a sim without a current medical or flight review?

texts: Just wondering if one is on land and in a simulator, if you need a current medical and flight review to train and log PIC time?


texts: How would a helicopter deal with auto rotation when it transports a hanging payload?

texts:
How would a helicopter deal with auto rotation when it has a payload? Will it deploy it's payload and continue with auto rotation as normal? Can't find much online, this research is for my senior design.

Any help would be greatly appreciated. If you can give me something to read and learn further for myself, that would also be great.


texts: Why aren't compressor and turbine blades flat?

texts: Why are the compressor and turbine blades of a jet engine shaped as airfoils?  Why can't they be flat?


texts:
An ETOPS APU has to be on-demand, i.e. must be able to start at any altitude. If it can't, then it's not shut down for the entire flight.

Compared to a normal APU, what are the design differences that would allow a start in a wide range of density altitudes and in the ram air of the cruise?

My guess is a combination of movable doors in the inlet and maybe special compressor stages.


texts: How does the B-2 Spirit fly without a rudder?

texts: On the B-2 Spirit bomber there are no rudders on the back of the aircraft, how does it fly without entering a flat spin or losing control, because when other aircraft like commercial liners lose their rudders it usually ends in a crash?


texts: What is a straight wing? I need this for my science project. I have looked for other answers on this website, but I cannot find any. Please help!


texts: When communicating altitude with a '9' in it, should it be pronounced "nine hundred" or "niner hundred"?

texts:
It sounds a little odd, but trying to understand if that's the recommended way to communicate.

E.g. 9900
"Nine-thousand-nine-hundred"
vs
"Niner-thousand-niner-hundred"


texts: What is the rejected takeoff procedure for a blown tire?

texts: When I got a tire/wheel issue during takeoff, how should I execute the rejected takeoff procedure? Is it different than the typical rejected takeoff procedure for an engine out that is applying the max brake?


texts: Can jet fighters be made to be 2 or 3 times bigger than they are today?

texts:
I was watching videos on the Su-27 again, and this fighter appears to be a heavy version of jet fighters, which means it has longer range and can carry more weight.

This got me thinking on what is the upper limits of fighters, in terms of size and weight. Is there a fundamental limitation on how big a jet can be and still pull 9+ g's and use very high angle-of-attacks?

Why don't they make them any bigger to get more range (or endurance)? Is there a practical limit? Would it require too much strengthening of the larger wings or something like that?

For simplicity I put a number to it: 2 or 3 times bigger. Can fighter jets be made 2 or 3 times bigger and still have similar performance in maneuverability and thrust/weight ratio?


texts: How do pilots clear an aircraft to fly through a hurricane?

texts:
This video shows a pilot (Tim Gallagher/NOAA) flying what looks like a small jet into the eye of hurricane Matthew by Miami. It's clear that it is quite an interesting ride. The (small) caption states that the purpose of the trip is for "scientific research". I naïvely imagine that the research in question is the gathering of an idea of the velocity field, pressure, atmospheric aerosols, humidity, and spectral density/radiative transfer rates between different "parcels" of air within the large and complex structure in three dimensions. I'm a physicist, but not an atmospheric physicist, so I'm not entirely sure why you would undertake such an expensive and potentially dangerous trip like this.

As a result, I've got two questions:

How exactly would you pick an aircraft to survive a trip through the eye of the storm. Is it a big risk? I imagine that $V_{ne}$ of a fighter jet is an order of magnitude bigger than the bulk flow of any storm on earth, but the aircraft that he is in is not a fighter jet, and I could readily believe that there could be turbulent patches of air moving very quickly. Likewise, what is the risk of stalling the entire wing, or unexpectedly entering chaotic regions of airflow that could cause problems to control surfaces? How would you perform a "risk assessment" on what I presume is -- by the fact that it is a scientific flight -- the unknown?
What exactly are aircraft storm chasers after that cannot be measured from elsewhere? Satellites would provide potentially quite a lot of information about the highest few layers of the structure, and one could imagine that overflying it and dropping probes would be much safer, and more readily parallelised to getting some sort of information from more than exactly one path in $(\mathbf{r},\,t)$.

Here's a screenshot from the video, showing the sort of large wind/water flow the aircraft is experiencing; it's quite dramatic!


texts: Is an engine surge classed as an engine fire?

texts:
Sometimes flames come out from the exhaust due to bearing distress or turbine blade fracture.

Can such flames/fire be considered an engine fire?


texts: What are the eyesight requirements for a medical certificate in India?

texts: Does it matter what your eye power is, if your vision can be corrected to 6/6 (20/20) vision?


texts: How can I consider a UAV thrust power for wind effects?

texts:
Sorry that I can't write English well.

I was wondering how can I consider a UAV thrust power for wind effects.

Assuming a wind velocity of -7 m/s, uav velocity of 10m/s and the stall speed is 10 m/s.

Considering that the desired velocity of the uav must be close to the stall speed. And, assuming that the wind is opposite to the flight direction.

With this information the uav velocity should be 3m/s? And if that's the case, how can I calculate the thrust force.

I'll add a figure and clarifying question.
first, I desire minimize thrust power of UAV for flight.

Like a figure, If the wind speed is 7m/s and the UAV speed is 10 m/s, ground speed must be 3m/s.

however, I thought relative velocity for a UAV is 17m/s. And To minimize thrust, The UAV closed to the stall speed(stall speed is 10m/s).
I thought the UAV need only UAV speed over than 3m/s.

And if that's the case, how can I calculate the thrust force.


texts: How could a wood and fabric aircraft be controlled after a fabric tear mid-flight?

texts:
This question is specific to wood and fabric aircraft.

What would happen should the fabric for a wing tear mid-flight and what should the pilot do to increase his survivability following such an incident?

For the sake of the question, assume it's bird strike or similar that caused the tear, to one wing only, without any additional structural damage other than to tear the fabric.

I'm aware that for a large tear, the aircraft would spin out, and for a small tear it would have only a small effect(?), so I'm thinking specifically for a tear large enough to have a significant effect, but small enough that the pilot has a chance.

I've found very little about what to do following a fabric tear mid-flight. I found several AAIB reports - but these talk about the damage and what happened, not about what options the pilot had after whatever event caused the damage in the first place.


texts: Why does the speed tape on the Lockheed U-2 go the opposite way?

texts:
I found this clip online that shows the speed tape on the Lockheed U-2 going what I perceive is the opposite direction to the 'normal' convention. On most aircraft, the higher values are above and so the tape scrolls downwards, but in this case it is mirrored.

Observe indicator on left for the first few seconds in the following clip:

Here's a photo as well from a french forum, actual source unknown:

Why do this? On every aircraft I can think of it is the opposite.

Is it the fact that you pitch down, speed increases? Then you got the speed/altitude indicators moving in different directions, so I don't see how that would make it any more clear, especially when it appears it's the only aircraft doing this.


texts: Who does ATC call when a plane disappears with no response?

texts: Do they just call 911? Or is there some special unit that’s specifically trained around disasters and rescue?


texts:
I just wonder why F16's have anhedral tail wings?

Is it kind of a design choice to increase maneuverability by compromising stability?


texts: Is there an official method to do pre-departure briefings?

texts:
We're using our simulator more at university, and while I might try to do a departure briefing (weather, route, etc.), it ends up fairly unstructured. None of us students have any formal qualifications and we are doing this for enjoyment, although we are keen to do it as authentically as possible.

FAA has an example online, that I gather is maybe be a bit overdone:

I've searched around for a recommended (check)list to go through for pre-departure briefings, but come out empty handed.

Is there such a document endorsed by either the EASA or the FAA?


texts: What is the difference between targeted airspeed and selected airspeed?

texts:
Are Targeted Airspeed and selected Airspeed the same thing?

And can someone explain in what cases managed airspeed or pilot selected airspeed would be used, i.e. for different flight phases/situations etc.?


texts: Why is the JAC VOR an Initial Approach Fix for the KJAC VORDME Rwy 19 Approach?

texts:
See the attached KJAC VOR/DME Rwy 19 approach.

QUESTION: Why is the JAC VOR an IAF for this approach?

There isn't a procedure turn to use this VOR as a functional IAF,
and the twin peaks (13,770' & 12,695' plus 7,139') should be enough to disuade you from trying while IMC.

The FAA Instrument flying handbook defines an IAF as:

Initial approach fix (IAF). The fix depicted on IAP charts
where the instrument approach procedure (IAP) begins unless
otherwise authorized by ATC.

The chart doesn't indicate radar contact required. I don't see any other route from the VOR JAC IAF to establish one's self on the final approach.
Hence the question on why the reason for labeling the JAC VOR as an IAF for this approach?


texts: Has Jeppesen announced plans to stop supporting the Microsoft platform for Flight Deck Pro?

texts: I heard a rumor around the water cooler recently that Jeppesen plans to drop support for Microsoft and have continued development of Flight Deck Pro EFB software only available on Apple. Has anyone seen anything that could confirm or refute this?


texts: How to demonstrate that an elliptical circulation distribution can be induced by an elliptical chord distribution?

texts:
I intend to demonstrate that a wing with an elliptical chord distribution, without torsion ($\alpha(z)=\alpha=\text{const}$) and constant section ($\beta(z)=\beta=\text{const}$, and $a_{2\text{D}}(z)=a_{2\text{D}}=\text{const}$), can induce an elliptical circulation distribution.
Well, for an elliptical chord distribution, the chord is defined by:
$$c(z)=c_C\sqrt{1-\left(\frac{z}{s}\right)^2}$$
where $c_C$ is a constant.
On the other hand, the circulation distribution is defined by:
$$\Gamma(z)=\frac{1}{2}a_{2\text{D}}V_\infty c(z)\left[\alpha+\beta+\alpha_i(z)\right]$$
So, by substituting $c(z)$ on $\Gamma(z)$, we get:
$$\Gamma(z)=\frac{1}{2}a_{2\text{D}}V_\infty \left[c_C\sqrt{1-\left(\frac{z}{s}\right)^2}\right]\left[\alpha+\beta+\alpha_i(z)\right]$$
which can be written as:
$$\Gamma(z)=\Gamma_C(z)\sqrt{1-\left(\frac{z}{s}\right)^2}$$
where $\Gamma_C(z)=\frac{1}{2}a_{2\text{D}}V_\infty c_C\left[\alpha+\beta+\alpha_i(z)\right]$
So, to demonstrate that an elliptical chord distribution can induce an elliptical circulation distribution, we would also need to demonstrate  that $\alpha_i(z)=\alpha_i=\text{const}$, to make $\Gamma_C$ a constant.
I don't know how to do this last step. How would you do it?
Note that:
$s:=$ semispan of the wing,
$z:=$ transversal coordinate of the wing, it goes from $-s$ to $s$,
$\alpha:=$ geometric angle of attack,
$\alpha_i:=$ induced angle of attack,
$\beta:=$ symmetric of the null lift (geometric) angle of attack,
$a_{2\text{D}}:=$ airfoil lift coefficient slope,
$V_\infty:=$ freestream airspeed.


texts: What is the visual difference between turbine fans and compressor fans?

texts: How to identify that a given fan is a compressor fan or a turbine fan, just by visual inspection? Also, can visual inspection of a fan help in identifying the compressor/turbine stage i.e. if the fan is from a High Pressure Turbine/Compressor blade or Low Pressure Turbine/Compressor blade?


texts:
The people from cruiser-feeder started a project called RECREATE.

  However, for the concept with fuel transfer from feeder to cruiser (civil air-to-air refuelling operations), the results of our collaborative research indicate a fuel burn reduction potential on isolated aircraft level between 11% and 23 % for a typical 6000 nautical miles flight with a payload of 250 passengers.

That sounds very good, doesn't it? I answered this question about civil air-to-air refuelling with the cruiser feeder concept. A User said:

  with the Breguet equation it is easy to see that the savings are modest.

And:

  This concept will never be certified

They even created a high-realistic simulation environment in which they tested the refuelling-process with real pilots as you can see in this video.

The feedback from the pilot is very good and promising that the concept might become real.

I'm curious why the savings are modest, because the planes can reduce the fuel burn from 11% to 23% and why this concept will never be certified.

Can the cruiser-feeder concept become real? That a feeder pumps fuel to a cruiser after he took of?

When does the use of the feeder burn more fuel than it saves?

What could stand in the way to make the RECREATE Project become real?


texts: Why are ARINC labels are transmitted LSB first?

texts:
Why are ARINC labels reversed before transmitting them to destination and the LSB (less significant bit) is transmitted first:

Actual label = 0x58: 0101 1000
Transmitted as label = 0x1A: 0001 1010

Is there any particular advantage over formal transmission and label reversed transmission?

Also all systems are designed for odd parity. Why is that?


texts: What is the maximum angle between an airplane and runway centerline when touching down at a crab angle in a crosswind landing?

texts: What is the maximum angle between the airplane's heading to the runway when an airplane is being landing sideway due to crosswind?


texts: What would have been the other stops of Amelia Earhart's ill fated last voyage?

texts:
Having just watched Amelia - A tale of two sisters, I wondered whether, had she landed successfully on Howland Island, what, or where, would the remaining subsequent stops for the rest of her equatorial journey, in 1937, been?

Were there any other stages that would have been as equally, or more, dangerous, and liable to failure, or was the stage at which she tragically failed the most dangerous of all of the journey's stops?

This image from the Wikipedia page, Amelia Earhart, implies that she would have flown on to Honolulu, but the text doesn't state that fact explicitly:


texts: Do pilots switch their cell phones into airplane mode?

texts: I think that my question is pretty self-explanatory. I‘m interested in both general-aviation and commercial jet pilots.


texts: Why are digital autopilots better than analog?

texts: I've heard many people say that a digital autopilot is better than its analog equivalent. How do the two differ in design and the way they control the plane?


texts: How did the F28 have such a good L/D ratio?

texts:
The second link given on a Google search for "Breguet Equation" is to a PDF document from MIT.  On page 7 of this document is a chart showing L/D ratios for various commercial aircraft (turboprop, regional jet, and "large aircraft") plotted against the year the aircraft entered service.  Below is an image of this chart:

What appears to stand out (at the top of the chart) is the Fokker F28 aircraft.

From an engineering and operational perspective, what enabled that aircraft to have such a high L/D ratio?

Also, I thought that the F50 / F70 / F100 aircraft had the F28's wing (or an evolutionary version).  Why didn't these aircraft have an equally good L/D ratio?


texts: Which antenna on an commercial airline airplane is used for the transponder (SSR)?

texts: On the 767-200 image I see no SSR antenna, but since that TCAS uses the transponder I guess that are sharing the same antenna. Am I right ?]1


texts: Why are lower VHF frequencies used for towers?

texts: So, why are usually lower VHF frequencies (around 118MHz to roughly 120MHz) used for towers and higher frequencies (around 130MHz to 136.975MHz) for ACC? What is the advantage of using lower frequencies for towers and higher for ACC since the wave propagates as a line of sight in both bands, that is, the maximum distance of the radio wave should be the same regardless if the frequency is 118MHz or 136MHz?


texts:
I've read a few times that such-and-such a plane is an "all-weather" aircraft, for example:

  The McDonnell Douglas F/A-18 Hornet is a twin-engine, supersonic, all-weather, carrier-capable, multirole combat jet.

This is quite intriguing and a rather odd thing to specify.

A fighter that couldn't be operated in for example rain (perhaps because it might dissolve, rust or leak) wouldn't seem to be much of an asset to one's air force.

Similarly, I would not expect a supersonic fighter to be unable to deal with gusty winds, or a heatwave, or really, anything else the weather might be expected to throw at it.

What sort of jet would not be an "all-weather" aircraft?


texts: What happens to Cessna electric flaps that are moving when power is lost?

texts:
On final in a C182T you move the flap control arm from 20 to FULL, and when halfway there, the breaker pops (or BUS1 fails, a wire falls off, etc.)

Does the flap stay where it is, slide back to 20°, slide back to UP, or something else? Perhaps the question is “are the stops mechanically significant?”

Would the answer change if instead of blackout it was a brownout? I.e. the motor is still trying to run, but doesn’t have all of its normal oomph.


texts: How can I find out if the FAA has ever sanctioned a pilot?

texts:
Is there any easy way to check to see if a CFI or commercial pilot has had past problems with the FAA?  The question came to me after an old thread in one of the aviation forums pointed me to this crash report:  https://www.wfsb.com/news/waterbury-flight-instructor-among-killed-in-ny-plane-crash/article_06e41c00-d066-11e8-a98c-7beca823cc54.html

The report says the pilot had had several enforcement actions against him, including having his CFI certificate revoked for falsifying logbook entries.  My guess is his two passengers would have liked to know this before going on their fatal flight.  The FAA certificate database only shows his ratings, not the enforcement actions.  Where else could they have looked?


texts: What is a SAAAR / RNP AR instrument approach?

texts: I understand that a SAAAR / RNP AR is a "special" approach and that special approval is required to even get the approach plate, but what exactly is it?  Aspen is an example of an airport that has one.


texts: Can motorjets be a viable means of propulsion?

texts:
A motorjet is a very early type of jet engine where intake air passes through a compressor driven by a separate piston engine, and is then mixed with fuel and burned to provide thrust. They were used in a handful of designs around the time of World War II, but fell out of favour when gas turbine metallurgy had advanced to the point where it was feasible to drive the engine compressor from a turbine in the exhaust stream without having to rebuild the engine every few flights; all else being equal, a motorjet, requiring an entire second engine to drive the compressor, is heavier, and, thus, has a lower thrust-to-mass ratio than a turbojet or turbofan. Are there any situations where a motorjet would still be a better choice than a turbojet or turbofan?

I can think of a few maybes:

Aircraft using fuel that produces refractory oxides when burned (such as boron-containing fuels and most organometallics), or operating in air heavily contaminated with particles of same (such as volcanic ash clouds), as these are very hard on turbines unless the exhaust gas temperature (EGT) remains high enough to vapourise these oxides all the way out the tailpipe; a motorjet has no turbine blades in the exhaust stream to suffer ill effects from this (unlike a turbojet or turbofan), does not need an onboard supply of oxidiser (unlike a rocket), and produces reasonable thrust even at zero airspeed (unlike a ramjet).
Aircraft with very severe length restrictions, as a turbojet or turbofan's compressor(s) and turbine(s) all have to be in line with one another, whereas a motorjet's compressor motor could be stacked vertically above the compressor and combustion chamber.
VTOL aircraft, where the torque and gyroscopic effects from all that heavy, rapidly-spinning turbomachinery can cause control problems while hovering or moving at very low speed (due to the control authority of aerodynamic control surfaces being very low at very low airspeeds, and nil at zero airspeed), as pointed out in this comment by Peter Kämpf on an answer to one of my earlier questions.


texts: How does a partially covered air intake affect the thrust of a propeller ?

texts:
does a partially covered air intake of a ducted propeller significantly affect its thrust?
If so, will it be like 10 or rather 90 percent less thrust ?

Thanks for your answers!

Simon


texts: What kind of flight termination measures are taken for supersonic aircraft?

texts:
Having recently read  an article that hyper-sonic airplanes carry enough energy that just flying into some target makes them as powerful as some missiles and I wonder if the supersonic planes have been around for so long, what measures were taken if they misbehaved or went out of control. I've heard of crashes with pilots, but what about terminating the aircraft mid-air after getting the pilot to safely eject. With more UAVs and drones being used, what measures are taken to terminate the flight of such a system in case of a loss of control? I know of such measures for rockets but am unaware for flights.(Commercial ones have FAA guidelines or other national ones to follow)

P.S. Are there any books on such design or discussions about such situations. Please recommend.


texts: Would a de-aerating fuel tank have any benefits?

texts:
I know turbine engines (bearings) are cooled by oil jets and that when oil is scavenged from the bearings it is more of a mist than a liquid, hence the need for various types of de-aerating this mist to produce oil once again. So is there a need for fuel de-aerating? Especially in fighter jets, because they maneuver a lot, will this cause the fuel to churn in its wing, causing the fuel pump to suck in a lot of air?

As an add on, I read from multiple sources tanks in wings can operate in high-g situations simply by having multiple fuel ports leading out of them. I find this a little confusing. Let's say a fighter is dashing, so all the fuel in its tank is rushing to the rearmost part of the tank. If this tank has a front and a back fuel port, and they are being sucked by the same pump, will this result in something like a 50/50 fuel/air mixture? This has to be dealt with, or the combustor will hiccup, or even worse the flame will back travel into the fuel line and bust it open, am I right?

PS: I know all about baffling, so please don't include this in your answer, thanks!


texts: What is the size of toilet or septic tanks in various planes?

texts:
This question, led me to wonder, how big are the tanks that hold poo. I had seen a BBC video, showing how they empty the tank on an A380 at Heathrow, can't remember the capacity.

Also, what about planes like Cessna etc, do they have toilets?

In an emergency can the tank be emptied, in case it overweight, i.e. above the Maximum Landing Weight?


texts: Is there any latest List of CAT IIIB airports in the world?

texts:
Recently I had my very first CATIIIB experience at my own homebase (VILK) and since then I've been keen to know more about this most advanced landing system we have in the aviation as of now and given its such a costly instrument and its maintenance is no easy feat I was wondering how many airports around the world may have this technology..does anyone have any data ?
Thank you


texts: Do interceptor squawk codes suppress TCAS RAs?

texts: Some parts of the world reserve a discrete squawk code for use by military interceptor operations (in the NBCAP, code 7777 is used for this).  Does this squawk code, or some equivalent value, suppress TCAS RAs from other aircraft, or is turning off their Mode A/C/S transponder replies the only way an interceptor can avoid triggering a TCAS RA from a TCAS-equipped aircraft?  Is some sort of Letter of Agreement used to keep track of interceptors in areas where transponding is mandatory but interceptors cannot squawk during intercepts, or during intercepts outside of primary radar coverage where the interceptor is unable to squawk?


texts: Factors to be considered when re-engining aircraft

texts:
What parts of the aircraft need to be adjusted / refitted / added when fitting new (different type) of engines?
Also what what kind of re-certification regarding airworthiness etc. will be necessary?


texts: What are these three indentations on the SBD's wing?

texts: I was looking at pictures of WWII planes and noticed that the SBD Dauntless had 3 indentations towards the tip of the wing. What were these for?


texts: Areodynamics of ancient flying machines. Did they really worked for them?

texts:
If any modern day aerodynamic scholars by chance  gone through rig vedas of hindu mythology. It has been described like below.

  "jumping into space speedily with a craft using fire and water ...
  containing twelve stamghas (pillars), one wheel, three machines, 300
  pivots, and 60 instruments."

Reference from: https://en.wikipedia.org/wiki/Vimana

Is there any scientifical proofs that those aerodynamic principles would have worked for them or just a myth?


texts: Why are winches not used for towing commercial planes up?

texts:
In this video a glider is pulled up by a winch on the ground, like this:

(Source)

I would say you could apply the same principles with bigger planes, possibly even using sustainable energy sources.

The plane would not use its engines at all to get to cruising attitude (unlike a suggested catapult in a previous post), so this part of the flight would be "for free".
Using a back of the envelope type of calculation with 5% efficiency it takes 17000 litres of kerosine to lift a 747 to 10km (which agrees with this paper).

However, this would however cost at least (calculated below) 25km of towing line(s). If we use a UHMWPE fiber a 400g/m and 1.2 cm radius cable would be able to support 2x the 400kN thrust maximum output of a typical airliner.

Sure there are a lot of hurdles to overcome, but since some airports in cities cannot expand because of noise problems this seems like one solution.

Logistically this seems like a large extra challenge for the crew on the ground, but would this be possible?


texts:
Suppose that an enemy plane comes into our radar surveilled airspace, and that this plane is mimicking the signature of a friendly aircraft.

Can this tactic be recognized? Is there a way of counteracting it?


texts: Does the Piper PA-28 Cherokee have a limitation on its maximum lifetime flight hours?

texts: Is there a lifetime limit on the (airframe) flying hours of an aircraft (specifically the Piper Cherokee)?


texts: How can I know if the Garmin GTX 345 transponder supports modes A and C?

texts:
How can I know if the GTX 345 supports mode A/C?
I did not find a mention in the installation manual the capability of mode A/C.


texts: How far does an A320 travel horizontally while climbing to / descending from cruise altitude?

texts: I am trying to determine how far an A319, A320, and A321 travel horizontally while climbing to / descending from cruise altitude? Would anybody be able to help me calculate this?


texts:
Heathrow airport is one of the busiest airports in the world, one would assume most traffic there is reserved for commercial airliners because they carry a much larger number of passengers.

How many private jets land at Heathrow airport per day?

On a normal work day
On weekends.


texts: Is it possible to know why an airline operates specific equipment on certain routes?

texts:
I've spent far too long staring at flight tracking sites, and occasionally I think I'll notice some pattern in what types of aircraft a given airline uses for certain scenarios/routes.

For example, Delta seems to operate a lot of MD-88's on short-haul routes that other airlines would likely use ERJs or CRJs on. They also seem to use 757s on quite short hops (ATL to southeastern cities ~1hr away).

Another example would be why British Airways operates 747s to some cities, and 777s to others, and exactly how they decide where to use which aircraft.

Is there a good reference for figuring out the reasoning behind why airlines use a given aircraft for a given route? Or are there too many different factors and too much corporate secrecy to really know for sure?


texts: In case of emergency, is it possible (doable) to land a small propeller-driven aircraft on an aircraft carrier?

texts:
I was watching the Disney movie Planes with my younger brother, and one of the characters/planes perform a emergency landing on an aircraft carrier.

And that got me thinking...

In case of emergency, is it possible (doable) to land a small propeller-driven aircraft, like a Cessna 350 Corvalis on a military aircraft carrier?


texts: During WWII, what did internal bomb bays and turret layout look like on flying boats?

texts:
I am writing an alternate WWII story, and I was wondering if you fine fellows on this site could help me. I am trying to make a fantasy bomber version of the USN Boeing C-98 Clipper, AKA the Boeing 314 Pan-Am Clipper flying boat. My idea is that the Navy ordered more C-98's as new builds after being impressed with the performance of the Pan-Am craft, and a bomber variant was developed.

So, were there any WWII era flying boats that had internal bomb bays? The German Blohm & Voss BV 238 is listed on Wikipedia as having 'wing bomb racks' and 'external racks'. The later jet powered 1960's Martin P6M Seamaster has an internal bay, but could that have been done back in WWII, or was the technology to keep the doors sealed when the craft was sitting on the water not up to par in the 1940's? Could they have used something similar to torpedo tube door seals from submarines?

Could something like this have been done with the hull of a modified C-98 design, or would it not be feasible with 40's tech?
Also, how would turrets be laid out on a flying boat? I'm thinking this craft is a long-range strategic bomber like the Flying Fortress, but I think belly turrets would probably be out of the question if this thing is going to land on the water. Would it have low down turrets on the sides of the fuselage to attempt to compensate for this?
Thanks in advance for any help.


texts: How does flight duration affect the hourly fuel consumption in heavy aircraft?

texts: A 15 hour flight across the Pacific obviously requires more fuel than a 7.5-hour transatlantic flight.  How significant is the hourly fuel consumption increase due to the additional fuel carried at the beginning of the longer flight? Another way of asking the question would be: How much more more fuel do you need to carry (in a typical heavy plane such as the B747-400) for a flight that is twice as long?


texts: emergency and/or 7700 squawk database or API?

texts:
Is there an API or some database somewhere of aircraft that have squawked 7700 (emergency).  Where do mobile apps like FlightRadar24 get their notifications form?

I'd like to monitor when flight to/from/diverted to my local airport are involved in emergencies.


texts: How does changing the altimeter setting in the US and elsewhere compare?

texts:
I have been trying to track down an answer to this question and I stumbled upon this website. Apologies if this answer is already out there. I have seen the FAR regulation, 14 CFR 91.121 - Altimeter settings. Is it possible for an ATC controller in the US to give you "Descend and maintain 18,000' (Not FL180)" and thus you would need to change your altimeter setting to local upon reaching?

I also fly ICAO quite often and the same question would apply to the transition level. Could a controller give you, as example, FL150 is transition lvl and 13,000 is transition altitude, "descend and maintain 15,000'." Would you set the local altimeter once level at 15 or wait until cleared to descend below? The source I was looking for ICAO procedures was the ICAO 8168, PANS-OPS, Volume I.

My understanding is that you do not change your altimeter setting until you are cleared below the transition level. I hope my questions aren't too confusing. I appreciate any clarification.


texts: What is the minimum runway width for SSC Stratolaunch?

texts:
What is the minimum runway width for the Scaled Composites Stratolaunch vehicle?

Is this determined by the separation between its fuselages (and thus undercarriages), or its outer engines (to stop blast kicking up soil, and causing FoD)?


texts: How do I optimize a turbofan engine to fly lower and slower instead of higher and faster?

texts: I was reading something about someone who was doing this and I'm intrigued, but I have no idea what you actually do to optimize the engine to be better at lower altitudes and lower speeds?


texts: Is this legal for transportation in the US? (video in description)

texts: I wanted to make something like this, but I don't know if this is legal for transportation.


texts: Why do older airplanes have a wing on both the top and the bottom of the aircraft?

texts: The first airplane by the Wright brothers had a double wing. This concept continued through World War 1 and into the 1930s - why was this concept popular?


texts: How to navigate at night after a complete navigation systems failure?

texts:
How do pilots deal with incorrect navigation readings at night? How do they know where to fly?

At low altitude do they have to know the shapes of cities and villages?
At high altitude and speeds over an ocean, what is the procedure?


texts: How does aircraft weight affect the glide performance?

texts: Since the L/D ratio remains unaffected by the aircraft weight, will there be any effect to the gliding range?


texts: Are afterburners required to be engaged during catapult launch?

texts:
Is it required to engage afterburners during catapult launches from an aircraft carrier?

This answer mentions that afterburners are used for night takeoffs as per regulations, but not required during day takeoffs. Is this true? If yes, why?


texts:
If I, pilot, have to make a stop at the undesignated parking position for some reason, such as FOD or ground handlers crossing in the ramp area, it is mandated that I have to contact ATC to explain why I have to stop?

Is there any global reference that describing when flight crews have to make a contact with ATC?


texts:
Most commercial flights will have to taxi a short distance to the end of the runway, before actually taking off. But in an absurd, absolutely extreme case, what if that passenger plane could only taxi, not fly? How far would the plane be able to taxi before it runs out of fuel?

I imagine that the answer is in the ballpark of "many times around the world", given that passenger planes like a Boeing 777 or Airbus A380 hold tremendous amounts of fuel. However, since no plane has ever taxied until it has run out of fuel, I ask this question from a theoretical standpoint. I certainly wouldn't want to be on a plane taxiing the entire route from Los Angeles to New York!


texts: When/How may I replace the Turn Coordinator with an Artificial Horizon?

texts:
I've seen a few panel shots where the traditional turn coordinator has been replaced with a second artificial horizon, as shown below.

The benefits seem obvious - if my artificial horizon failed I'd certainly like to have a fully functional back-up rather than a turn coordinator with no pitch information.

Under what circumstances/conditions are these second horizon gyros acceptable as replacements?
Are there any drawbacks that I should be aware of if I'm considering installing one.


texts:
Hot air balloons are quite obviously carried along with the wind, so how can they be navigated?  Choosing the correct launch point relative to the desired landing point would seem to play a major part of this, but logic states that it is not always possible to choose the best possible launch and landing points.

Can a hot air balloon be "steered" by increasing or decreasing altitude, hence selecting just which wind it will be subject to?  Does the direction of the wind vary with altitude, and if so, how much?  How do balloon pilots know how the wind will vary at altitude if that is the case?


texts: Why isn´t TOGA thrust always 100% N1 or N2?

texts: It makes sense to me, that under normal circumstances the engines shouldn´t be pushed to their maximum, to reduce wear and tear. But why isn´t TOGA thrust, which is the maximum selectable thrust setting, not corresponding to the maximum possible thrust, thereby 100% N1 or N2 whichever is the limiting factor.(In the picture TOGA is limited to 88.9% N1)


texts: How much power is drawn by a turbofan to power its own compressor?

texts: In a modern commercial airliner how much percentage of its engine power is used to power its own compressor, the ducted fan and other ancillaries like the airconditioning etc? Maybe it can't be calculated with accuracy but I'm looking for at least an approximate figure.


texts: Is it okay to use magnetized tools on airplanes?

texts:
Let's say you stored your tools on a magnetic organizer in your toolbox, such as the one pictured.

Now you go and use a socket or wrench that is slightly magnetized. Have you done wrong?


texts: How does an aircraft turn while taxiing?

texts:
I know that an aircraft uses its own power (thrust) while taxiing to move forward. But how does it turn?

Do the front wheels pivot?
Do you simply apply more power to the left engine if you're trying to make a right turn?

If you do apply power to turn, how much power? Wouldn't it tip over the plane? And how do you do it on a single-engine or prop aircraft?


texts: Does aircraft allways rotate about center of gravity like weather vane about pivot point?

texts:
When gust of wind hit plane form side,does plane allways rotate about center of gravity like weather vane about pivot point or  CG as pivot point  is just "math areegment" for easier solve equation?
If one force(wind gust) act at body which is not at CG,body will translate and rotate,but center of rotation will not be at CG.
Because only rigid object in space far from other influences will rotate about its center of mass.
If does ,why plane allways rotate about CG?
(boats dont do that, but only differnce in air and water is  fluid density?)


texts: Do wingtip vortices really only form when airplane wheels are separated from the ground?

texts:
My GA theory textbook (which covers fixed wing up to and including EASA PPL) has some suggestions on taking off and landing light aircraft soon after large aircraft (besides avoiding it, if possible), intended to reduce the risk from wingtip vortices. These suggestions are to,

when taking off

...after a heavy aircraft taking off, to lift off at a point on the runway before the heavier aircraft lifted off
...after a heavy aircraft landing, to lift off at a point on the runway later than where the heavier aircraft's nose wheel touched the runway

when landing

...after a heavy aircraft taking off, to land as early as possible on the runway
...after a heavy aircraft landing, to land ahead of the point on the runway where the large aircraft touched down

When I asked about the why of these suggestions, the answer was that wingtip vortices form because the wings are generating lift, and when the aircraft's wheels are on the ground, the wings don't generate (or aren't generating) lift so no wingtip vortices form.

While that might be true in a "rule of thumb" sense, and a good generalization of these rules to serve as a memory aid, I want a bit more than that. The way I understand it,

Any airfoil will generate some amount of lift as long as there is ambient air movement around it; "lift" (as opposed to net positive vertical lift, which isn't being generated when landing anyway because the aircraft is descending) isn't something that suddenly starts being generated when one or more of the aircraft's wheels are separated from the ground
An aircraft can move at significant speed relative to the surrounding air even when all of its wheels are on the ground, causing likewise significant speed of movement of the wings through the ambient air

It appears to me that wingtip vortices should form at any time the aircraft (or rather its wings) is moving relative to the surrounding air; whether that's because the aircraft is standing still and there's a wind, or because there's no ambient air movement and the aircraft is moving, or a combination of the two. It also appears to me that the strength of the vortices should be in some way proportional to the amount of lift being generated.

Consquently, it seems to me that wingtip vortices should form at every point during the takeoff or landing roll (as well as taxiing and other movement on the ground) at which the aircraft is moving relative to the surrounding air, and increase in strength with (but not necessarily linearly with) the indicated airspeed of the aircraft.

It seems weird that the air flowing near the wingtips would somehow "know" anything about the position of the aircraft's wheels with respect to the ground, let alone that of any specific wheel (such as the nose wheel).

All that just as the lead-in to my question: am I missing something, or is this a case of the textbook (and teacher) presenting the simple case so as to not overwhelm students?


texts: What is the aviation term for what the navy calls "fire control system"?

texts:
The weapons systems, including computers etc, in a naval ship can be referred to as the Fire Control System. I'm not sure if FCS would be considered an appropriate acronym for fire control; I'm using to hearing FCS as Flight Control System.

Is there a specific aviation term equivalent to Fire Control System? If so, what acronym does it use (if any)?


texts: Why do some 2 seat fighters have side by side seating, while others have the pilots inline with each other?

texts:
In some multi seat fighters, like the F-111 Aardvark the pilots sit next to each other, like so:

While in other multi seat fighters (most of them it seems) the pilots sit with one in front of the other, like this F-15E:

Why do some fighters have the pilots in a line like that?  Is there an aerodynamic or performance advantage that comes with having them in a line?  Or maybe it's so they can have a bubble canopy, which perhaps affords a better view? It seems it would be easier to work together when they are side by side.

So why do some multi seat fighters have side by side seating, and others are in a line?


texts: What are the disadvantages (if any) of using a supercritical airfoil?

texts:
The title sums up my question pretty well.

I've searched all over this site, having read many of the questions and answers to various supercritical wing topics, but I haven't found any mention of disadvantages to using them.

Are there any?


texts:
I am aware that wind shear is the geostrophic wind between two pressure levels and am also aware of the catastrophic effect microbursts can have.

If informed, can the crew avoid wind shear? And if not, how do they deal with it?


texts: What is the "Brake to Exit" feature on the Boeing 777X?

texts: I have come across a new feature called BTE (Brake to Exit) on the 777X, but I am unable to find any documentation related to that. There are vendors who are working on this technology for the 777X.


texts: What is this red dashed line between door and cockpit window?

texts:
I noticed this dashed line located between the door and cockpit window on this 737-300 while boarding this exact aircraft at Ibiza airport. It seems to have text beside it but I did not have time to read it while boarding and it is too hard to read from the photo. Older photos of the aircraft with the same paint job do not have this suggesting that it was added recently. Wondering if it has anything to do with aligning air stairs or jet bridges. Does anyone know any other aircraft with a similar marking?

(Photo by Roberto Bianchi, source)


texts: How to calculate the thrust of a piston or turboprop engine?

texts:
This spawns from a related question. Propeller-drive engines (piston/turboprops) seem to always list their output in horsepower or kilowatts, which are units of power.

I want to know the engine's thrust instead.

How to calculate this?

I know propeller thrust depends on airspeed. What I want is an equation where we input engine power and airspeed (and maybe other parameters), and output thrust.


texts: Will talking about sleep problems with my doctor jeopardize my medical?

texts:
I am asking this for someone I know who's up in years but still under 60, and is a fellow pilot.  He brought this question up:

"I am concerned that I might have some moderate sleep problems - doubtful it's narcolepsy, and I've driven (and flown) safely for years and the worst is feeling tired.  My thought is to check on blood levels and maybe EKG stuff etc..  Perhaps there is something that's actually detectable.  Perhaps there is medication that reduces the tiredness.  If I go to a doctor and bring these up, will it jeopardize my medical?"

Your thoughts?  Appreciate your feedback - my friend is not an internet person at all :)


texts: Did factors specifically related to the concorde design influence the Air france flight 4590 crash?

texts:
This youtube video partially attributes the retirement of all concorde fleets to the airfrance flight 4590 crash:

Were the factors in this accident due to the concorde's design? Specifically, the tires of the concorde?