texts:
By MSgt. David N. Craft [Public domain], via Wikimedia Commons

How does a flight or squadron communicate when radio silence is in effect?

If one pilot spots an unexpected target or danger, how is it communicated to their flight?

Rocking the wings? Kicking the rudder? A gun burst? What are the different non-verbal ways of communicating in such scenario?


texts: I am looking to sell this instrument, but it has no part numbers or any other identifying marks other than it says "Kollsman" on the back.  Anyone know what it is and what it might be worth?


texts: Is there a way to get descriptions of great circle routes?

texts:
Given that I am blind and love to know where I'm flying over, is there a online service that describes a great circle route in text form? e.g. in a format like this:

  A great circle from CYVR to LTBA goes NNE over British Columbia,
  Alberta, Northwest Territories and Nunavut, passing over Arctic bay in
  the northernmost part of Baffin Island. Then across the middle of
  Greenland, crossing the Atlantic to Norway then Sweden, passing abut
  30 miles west of Stockholm. Then across the Baltic Sea and over the
  Kaliningrad Oblast, which is the small exclave of Russia that sits
  between Poland and Lithuania. Then across eastern Poland, western
  Ukraine, Romania, the very corner of Bulgaria, across the very western
  edge of the Black Sea and arrives in Istanbul from NNW.

(thanks to @TomMcW who left this in my previous question).

This way I can stop asking these great circle questions here.


texts: Are Sophisticated Planes with Multiple Computer Interfacing Safer to Fly than Traditional Aircraft?

texts:
I passenger travel short haul flights to the carribean islands every month for business. I typically fly on an Embraer E190 or Airbus-320...I feel confident on the 190, I suppose I like the standard control wheel/yoke and  from a craft size and technology level standpoint, it just feels like a manageable piece of equipment. But on the Airbus, I just can't warm up to the joystick control. It doesn't seem natural; which provokes my question.

Given that all pilots are simply human, how in the world is it possible to have a comprehensive knowledge of all of the sophisticated computers and electronics that are required to interface to fly a plane safely? It seems to me that in truth, pilots have just enough knowledge to operate these new planes and systems under normal conditions and the moment a malfunction occurs it becomes a race to a safe landing with only troubleshooting guides to help understand what is happening and try to offset it long enough to get the plane safely of the ground.

This is a broad stroke assumption, but it seems that the simplest of a breach can affect the operation of another and pilots are reduced to a guessing game to keep systems operating normally; which is not very comforting. Isn't it better just to get back to the basics and avoid these overly complex computers?


texts: Is there any part of a flight where the pilot would pitch down?

texts:
Would the pilot ever pitch down (even slightly) during a flight, or would he/she simply reduce power to reduce altitude?

This question is not similar to Why do airplanes lift up their nose to climb? (asked by Chris) for it the reasons aircraft pitch up. This question is looking for an answer that explains if and when a pilot pitches down during a flight to reduce altitude, the very opposite of the question of @Chris.


texts: Twist optimization for a low speed aircraft

texts:
I'm currently designing an aircraft with the following specifications-

s=1.8m^2, AR=7-8, trapezoidal planform with a taper ratio of about 0.45, a load of 25KGs and a cruising speed of 13-15m/s.

I'm barely getting any improvement in drag reduction or tipstall delay after testing twists upto -4deg.
A twist of -3 is delaying tipstall by about 0.7deg while reducing Cl by 0.08 in xflr.

Is a twist even necessary for my model?

Also I've read that a twist optimizes drag reduction and lift distribution for a single aoa in non-elliptical planforms.
Should this angle be the aoa for the Cl I get for my cruise speed?

Also how would my planes angle of incidence depend on the twist that I select?


texts: What stops a pilot from flying VFR and going IFR?

texts: Even if the pilot is instrument rated, what stops them from doing it anyway? I’d imagine in certain situations where danger is approaching, it may be best to switch to IFR, it can’t be that hard to rely on your instruments to get through a cloud? Would controllers know if you switched from VFR to IFR and this could get you in trouble or something?


texts: Why does Boeing use a trim wheel in the 737 and not their other products?

texts:
Why does Boeing use a trim wheel in the 737 and not any other products?

Is the trimmed state for the 737 just more important than in the 777? Or even 747?

It gives the impression that a secondary control for the trim (If the power to the pitch trim motors have been cutout) is extremely vital, seeing it features two fold out handles that are located 90 degrees apart, so a pilot has good leverage at any point in the rotation to their desired trimmed state.

I take it that this style of a trim system is implemented in the 737 for a good reason, so I’m curious what makes this “style” the perfect fit.

On the 747, and 777 it almost seems that once power to the pitch trim motors have been cut-out, there isn’t a way to manually move the stabilizer? I’m very aware that I could also be 100% wrong, but why not have a trim wheel in all products? Or vice versa?


texts: • Why fly from east to west takes longer time then flight form west to east and does this apply to both hemisphere?


texts: What is the typical aircrew for a cargo flight?

texts:
What is the typical aircrew for a civilian (not military) cargo flight? From my limited web searches, it seems that there would be three crew members:

Pilot
Co-pilot (I assume there must always be minimum of two people in the flight deck, in case anything happens to the primary pilot)
Loadmaster, a crew member responsible for loading and unloading cargo, and for assuring load balance during the flight.

Are these indeed three minimal, required crew members for a cargo flight? Are there any others that are required or optional? What is typical for a long haul cargo flight, and what is typical for short haul. (Rather than precisely defining how many hours is long haul or short haul--I'm not even sure--I'll leave that open for the answerers, since I'm really not sure what to expect.)


texts: What course should be taken to make estimated calculations?

texts:
(skyvector.com)

When I want to calculate the leg time from GIJ to CRL going along the airway J554, at say FL190, I know that I have to calculate the ground speed first, but in order to do that, should I take 082° magnetic course, 087° magnetic course (reciprocal of 267° from CRL), or should I enter in the CX-2 flight computer (Plan Leg) an average of them?

What I would normally do is to enter in the CX-2 flight computer the true course (calculated with a plotter) in order to get the ground speed; but I want to know if it is correct to get the true course by converting the known (shown on the chart) magnetic course by adding or subtracting to it the magnetic variation, whatever be the case.

In this case the magnetic variation around GIJ is 1W and the magnetic variation around CRL is 3W, so the true course of the GIJ - BENJO - CRL leg would be 81° and 84°, am I correct? Once again I get confused without knowing if I should take true course 81°, 84° or an average of both.

In the explanations given in the FAA book ATP Test Prep, relative to the nav questions in the performance chapter, the course to be taken, is sometimes the magnetic course that corresponds to the beginning of the leg, other times it is taken from the end of the leg and other times it is an average of the leg's initial and ending magnetic courses.


texts: During multiengine training, are pilots taught how to use the throttles for control?

texts: The use of a multiengine aircraft’s throttles for steering and pitch control is critically important should the aircraft’s primary flight controls fail or severely malfunction; are pilots nowadays taught this potentially-lifesaving skill during training for a multiengine rating?


texts:
I know it means “I have understood the instruction and will comply.” However, any instruction that

is a clearance,
concerns runway use or
contains altitude/level, heading, speed or squawk code

should be read back. And that seems to cover most instructions.

So what is an instruction, but does not require a read-back and may be instead answered by just ‘wilco’ (+ callsign)?


texts: Why do solar planes have many small propellers instead of fewer large ones?

texts:
Many solar planes, like NASA's Helios (pictured above), NASA's Pathfinder, and to a lesser extent Facebook's Aquila employ the use of many small motor propeller sets instead of one or two engines like most planes. Why is this?

Smaller motors tend to have slightly higher power density, but aren't the relative losses higher on the smaller airfoils of these propellers?


texts: Water salutes by the fire crew are regulary done for certain events like plane retiring, or an new airplane delivered and much more. But where does it come from? And why should the fire service do a water salute even if they don't really care about a pilot retiring?


texts: Is it legal to compensate a CFI for more than 8 hours of his services per day?

texts:
A CFI can only log 8hrs of in-flight dual given in a 24hr period (FAR 61.195).  In my scenario, a CFI is required to be aboard a plane to satisfy insurance requirements.  This CFI will put in a 17hr day, all of it in a plane that a non-student customer is flying as PIC.  The customer has a valid medical, is current, and is appropriately rated in category and class.

The CFI might (or might not, he doesn't need the time) log a few hours of dual given to complete a checkout with this customer but then just sit there for the next ~15hrs staring out the window as the ground slides by and the customer racks up the hours he needs.

At the end of a very long day the CFI hands the customer a bill for 17hrs and is rewarded about as handsomely as a CFI can be rewarded.  The CFI walks away with a fat stack of $20s and maybe 3hrs in the logbook.

Has the CFI broken a rule?


texts: Why do some commercial flights start off unpressurized?

texts:
In this video, the B738 starts takes off without the plane's pressurization system engaged.  The video specifically notes that the craft is being pressurized fairly soon after the takeoff has happened.

Is this because of the icing conditions they had on the ground?  Or is there another reason why it would take off unpressurized?

Screen capture for the extremely busy:


texts: Why are heavy flaps better than just a bigger wing?

texts:
Flaps increase lift during landing and T/O. But when retracted, they do nothing. The space needed to stow the common fowler flaps can't be used for anything else - fuel or structure. Extended flaps are thin, making them need more material to maintain stiffness. Moreover, they transfer their loads through the wing, instead of directly to the fuselage.

So, why do we use flaps instead of just scaling the clean wing up?

Is it because of concerns over cockpit visibility during landing? Can't we use video cameras do display the bottom during high AoA?
Is it because the extra lift - and drag - is unwanted? We can simply increase the cruising altitude without changing the cruise speed.
Is it because (for fowlers) the chord reduction really is that beneficial?  The larger wing volume for fuel leaves more space in the fuselage for everything else. And since the span does not change, induced drag does not increase.
Is it because slotted airfoil, as in many modern flaps, are not good for cruise? Surely we can add slots to the airfoil, and add mechanisms to seal them for cruise.


texts: How would one calculate the thrust-to-weight ratio for a minimum turn radius?

texts:
I'm looking to calculate the T/W from the minimum turn radius while level, as well as the load factor while banking, and the wing loading W/S

I plan to plot the thrust to weight ratio against wing loading given the inputs mentioned above.


texts: What is the method to find the resonance frequency of a PowerFlow exhaust?

texts:
I asked a related question about PowerFlow Exhaust systems, which produced another question for me: How do they go about finding the resonance frequency so they know how long to make the exhaust pipe?

I guess I'm interested in the technical aspects of it. What formula do they use? Do they have special equipment?

I think it's interesting that they now offer a "short stack" for some mods:

  “Classic” or Short Stack? The Classic is our original design from
  1999. It is the “ideal” tuned length for this engine. Everybody loves the performance, only a mother (or an engineer) could love the looks.
  So, we came up with a compromise: The Short Stack is virtually
  indistinguishable from the stock Cessna exhaust and will give you
  about 85% - 90% of the performance gain of the Classic in a much more
  attractive installation.

Is this one of those instances of the 80-20 rule (approximately)? It seems interesting that a similar length gives you 85-90% of the gains. I'm guess then, that it's not just about the length of the new exhaust, but also the width?


texts: Why do airliners have "pressure bulkheads"?

texts:
Image source: FAA

What part of the fuselage aft of the bulkhead would leak pressure? Or is it just there to reduce stresses?

How does a DC-9/MD-80/90 incorporate aft bulkheads when there's a staircase in the way?

(Image source)


texts: How does vertical separation work above FL400?

texts:
The information mentioned in "Jeppesen Airway Manual" is that after FL400, fight levels are FL430, FL470, FL510 for the 'even' FL's column.

Normally, I would expect every level divided by a thousand feet to be usable (FL410, 420, 430, 440 and so on). Why is this not the case above FL410?


texts:
Why does the Boeing 787 have fewer cockpit windows? The 787 has only 4 cockpit windows, whereas other airplanes have 6. Here is a comparison between the 787 and 777:

^ 787
V.S.
777 v


texts: Conducting a Precision Approach on a Non-Precision Runway - What are my limitations?

texts:
Let's take ILS, for example.

As stated in the FARs, the minimum RVR for a CAT I ILS approach would be 2400ft (1/2 SM) for a runway that does not have TDZ and Centerline Lighting. So, that is one limitation for such a scenario.

A couple more would be the limitation to the visual references available under 91.175 of the FARs.

Can you think of any other disadvantages if one were to conduct a precision approach on a non-precision runway?


texts: Is there any way to estimate the weight difference between a trimmable horizontal stabilizer and a fixed tailplane?

texts:
I am trying to estimate the benefits of using a trimmable horizontal stabilizer (THS) instead of a fixed tailplane. In my model I use a T-tail (Sh~30 m), and I can trim the aicraft in every condition so the main reason to go for a THS would be aerodynamic efficiency.

I've estimated the drag reduction but I'm having huge problems estimating the weight increment of the system.

Please, could someone shed some light on this? I've checked a lot of references but still couldn't find anything clear.


texts: Can you broadcast a very low power nav vor signal in air?

texts: Are there any FCC restrictions on broadcasting a test nav signal on 108.0 in the air? Or perhaps on other nav frequencies that can be received within the navigation band?


texts: Is there a standard place to find detailed wiring circuit and component information for different aircraft?

texts:
Today I was looking into the systems that are affected by the STDBY ATTD (#1 and #2) circuit breakers in a SR22 and I accidentally stumbled upon something that I find very interesting and I've been searching for some time now.

In the Wiring Manual (WM) chapter 91-00 I found a really big table with circuit load charts. For example: GPS 1 has a 1.12 A current drain at 28 VDC.

Now here come my questions:

Will I be able to find this information in all Wiring Manuals in chapter 91-00? According to the ATA chapter list, chapter 91 is just for charts. Do all aircraft manufactures have a circuit load chart at chapter 91-00 or is it just Cirrus?
Is there a standard place in the manuals where I can find the power requirements of each component for any plane or manufacturer? I'm interested in a manual name and a chapter preferably.


texts: If a shoulder harness becomes INOP in an aircraft certified before 1978, is it still required equipment?

texts:
So we fly a 1973 Piper Archer, with shoulder harnesses installed from the factory. The question is:

Would the shoulder harness becoming INOP (jamming & not coming loose) ground this airplane or could you fly without it, since the FAA required shoulder harnesses as of 1978 (or some other year...?)?


texts: What software is used for aerodynamic wing shape optimization?

texts:
I can see lots of research articles around aerodynamic shape optimization of airfoils and wings like this MDOlab program. But all stuff like that don't seem to be available for a simple customer. Personally I've not seen where I can buy or download it. The only programs for that purpose that I've managed to find are:

Tosca Fluid (not adapted specifically for the airspace industry)
ANSYS Adjoint Solver (probably OK, don't know yet)
This Python code coupled with XFoil, but it's primitive and only for airfoils, not for wings.

Somebody know some accessible software for shape optimization of airfoils and wings for an ordinary engineer, but not for scientists or programmers?


texts: What keeps certified GA aircraft from being affordable?

texts:
A personal (pipe) dream of mine is to own a new aircraft, but the costs for certified GA aircraft is borderline outrageous. A new Cessna 172, considered an entry level aircraft, can go for well over \$250,000 new. The Icon A5, an entry level light sport goes for about \$190,000 for the base model.

Not discounting the engineering process or tooling required, but what really keeps the price of these aircraft so high? Is it possible that a company could bring an aircraft to market that is comparable to the A5 below the \$100,000 mark? I find it hard to imagine that a company couldn't take an aircraft like the SeaRey, certify it, and get it out for a reasonable price.

So the question is, what are the factors that make certified GA aircraft so expensive, especially for established companies like Cessna, Piper, or others? Does the mere presence of an FAA certification command a premium price?


texts: What exactly are "suitcase handles" in a cockpit?

texts: I was watching Seconds From Disaster about Alaska Airlines 261 (the one with the horizontal stabilizer issue) and at one point the copilot tells the pilot to "try the suitcase handles". Is that pilot slang for something or did I maybe hear it wrong? (Seconds From Disaster uses actual cockpit recordings for the recreations, so I don't think it's made up or anything.)


texts:
If I understand correctly, when a plane transitions from takeoff roll to being airborne, it is not something that happens "by itself" when the airspeed is high enough, but is caused by deliberate pilot input somehow.

Which control surfaces are involved in causing the plane to lift off?

Is it an ordinary nose-up movement of the elevators? That is, the elevators create negative lift that pushes the tailplane down, which makes the entire aircraft pivot around the main gear and increases the wings' AoA enough to create lift that takes the plane off the ground.
Or is it something that increases lift with unchanged attitude, such as a symmetric aileron movement, or an additional flaps extension? And then after the plane is airborne it is rotated to climbing attitude?

The descriptions I can easily Google up point towards 1. However, while that makes perfect sense for tricycle gear I don't see how that would work with taildraggers. Pushing down on the tail would just increase the downward force on the tail wheel rather than change the AoA.


texts: What does the ASDE-X ground radar unit look like?

texts:
Above is a picture of a primary / secondary surveillance radar combo (top is secondary, bottom is primary).

What does the ASDE-X radar unit look like in real life?


texts: Do I need to call Clearance Delivery for IFR Practices when taking off from a D airport?

texts:
I have the following question:
If I am going to practice IFR approaches under VFR, do I need to contact clearance delivery for that or it's enough to contact ground and state my intentions?
I would deffinetly contact clearance delivery on a C airport, but I am not so sure about a D airport. For sure I will contact clearance delivery if the practices were under IFR with a filled IFR plan.


texts:
So Uncle Bob just died and left me 3.14 million dollas.  Or else I hit the lottery, or what have you.  Whatever the case may be, I've decided that today is the day I buy myself an airplane.  Harrison Ford has one and by God I want one too.  This means that I need a mechanic.

We can assume that I don't already know any mechanics (For the purposes of the question, we can assume I soaked my home in Cristal, tossed flaming $100 bills at it until it burned down, and then moved to Beverly Hills, away from all the little people), so:

How do I find a mechanic or maintenance shop to keep my privately-owned aircraft airworthy?


texts: What are the failure rates for piston, turbine, and jet engines? (If more subdivisions of "engine" are necessary to make the data useful, please point them out).


texts: Is there a way to approximate the best glide speed for maximum glide distance in a headwind during flight?

texts:
Flying at an airspeed corresponding to an aircraft's maximum glide ratio in calm air will maximize the distance covered for a given altitude (AGL).  But in a headwind, the horizontal velocity would be reduced by the headwind velocity and the maximum distance at that airspeed would be correspondingly reduced.  At an extreme case, if the headwind is greater than the best glide speed, an aircraft would move backwards relative to the ground if it flew at best glide speed.  But an aircraft could always pitch for a greater airspeed into the wind an achieve some forward distance even if the headwind was greater than the best glide speed.

My question is how to determine the best "penetration" speed if one is forced to try and glide for maximum distance into a headwind?  And can this be approximated in flight?

I am mostly interested in small GA aircraft that might be considering a forced landing, so time is of the essence.  A corollary question would be above what headwind speed is it best not to try for any distance and only consider landing in the downwind direction.  I understand that maximum range would always be downwind, but for some small headwind speeds and enough altitude, an upwind landing location might still be practical.


texts: What winglet airfoils are used on the Boeing B737?

texts: I would like to know what airfoils are used for the Boeing 737 winglets.


texts: When is a fuel pump needed on GA aircraft? I am a flight simmer and have noticed that you can leave the fuel pump off and start/fly the aircraft. When would you use the fuel pump?


texts: Why are the windows of an airplane usually rounded at the edges?


texts: Is the climb rate different for short-haul flight and long-haul flight?

texts:
A short-haul flight does not spend much time in its cruise level (let's say less than two hours). Thus, it is important to rapidly reach the optimal flight level and I think this kind of aircraft should be optimised to climb. On the opposite, on long-haul flights there the climb and descent reprsent a tiny portion of the whole flight. The aircraft should then be optimised to consume as little fuel as possible during cruise, even if climb rate is less important. That's why I wonder if my thinking is right and if there are significant differences in climb rate between short and long-haul aircraft.

Related thinking: On average, does a short-haul flight descent more rapidly than a long-haul? I think not as this diving has no reason to be related to climb/cruise performance and all commercial aircraft are made to use the same airports with the same approach pattern; but that's only an assumption.

EDIT: OK, the quantity of fuel is quite important. I suppose an aircraft designed to be heavier (long-haul, carrying lots of fuel and payload) is equipped with more powerful engines and thus if it is lighter than designed for (lets say a B777 or a A330 used on short-haul flights), it climbs faster than the same aircraft in a long-haul flight. But the long-haul aircraft is designed to make long-haul flights. Maybe I should have asked if there is a significant difference in climb rate between short and long-haul aircraft at their maximum operating take-off weight.


texts: How can I plan a VFR flight through controlled airspace, without knowing what instructions ATC will give me?

texts:
I'm currently planning a VFR flight from KFRG to KDOV. Due to airspace restrictions in this area, I plan to contact NY Approach and request flight following. If all goes well, then I believe I will get transferred from center to center and eventually be handed off to KDOV tower where I will land. Happy Days.

What I'm worried about is that somewhere along the way the controller will drop me with the dreaded words "radar services terminated". Say this happens between KEWR and KPHL, what do I do? Fall back on GPS/VOR? How does one create a VFR navlog for such eventualities?


texts: Does a powered aircraft fly faster when in a head wind or with a trailing wind? The question revolves around the head wind should provide 'better' lift, and trailing winds have very little to 'push' against.


texts: Where is the best place to perform a run-up at a busy airport?

texts: If you wait to perform a run-up at the end of a taxiway at a busy airport you will probably not make many friends.  Some airports may have designated run-up areas or have runways designated for general aviation but at those that don't would it be acceptable to do a run-up on the ramp before you taxi?


texts: What are approach control's expectations regarding weather information for flights to satellite airports?

texts:
I have never passed through class-C airspace without intending on landing at the primary airport.

If the flight is conducted under VFR, and I am planning on landing at a satellite airport to the primary class-C, will approach control expect me to indicate that I have ATIS information from the primary airport, that I "have numbers" for the satellite airport landing destination, or that I have both weather station information sets?

What about just passing through their airspace with no intent to land nearby? Do they still expect that you indicate receipt of ATIS information?


texts: Could an aircraft 'hide' in the aircraft shadow of another aircraft without being detected or noticed?

texts:
I just finished reading an interesting post where the author suggests that the missing Malaysian Airlines flight 370 could have 'hidden' under the cover of Singapore Airlines flight 68 to fly to a covert airstrip.

I've read multiple thrillers where submarines have hidden behind the acoustic signal of large cargo vessels to mask their sound over sonar arrays, and this (at least in the book) sounds plausible. I also read another book where a bomber (flying under the identity of a commercial jet) masked a business jet to get it into an area without detection. Naturally, both examples are taken from fiction, but I'm wondering:

Would there be any hints now in retrospective to suggest they were being followed? Their transponder was off of course, but I'm wondering if for instance there might be some radio interference or static from such as large aircraft behind them? Are there every any issues when refueling aircraft do this sort of thing?
What is the resolution of radar? Would one be able to notice the two blips on the screen unless they were literally under or beside each other, or would it still appear as one dot on secondary radar if say they were 200 meters behind and below?


texts:
May an ultralight vehicle pass directly above KEGE at 9200 MSL at 1600Z with no prior authorization without violating FAR 103.17?

http://vfrmap.com/?type=vfrc&lat=39.643&lon=-106.916&zoom=10

The A/FD entry for KEGE says "AIRSPACE: CLASS D svc 1400–0200Z‡; other times CLASS E."

There is more to this question than meets the eye-- KEGE appears to be an oddball case.  More detailed descriptions of the airspace descriptions at KEGE, including the page numbers for these airspace descriptions in the FAA's "Airspace Descriptions and Reporting Points Documents" JO 7400.11C, are given in this related question Can the Class-E-to-surface airspace near Eagle County Regional airport KEGE be ignored when the tower is open?

Please note that this is NOT a question about:

Whether an ultralight needs prior authorization to fly in the airspace above the surface footprint of E4 "extensions" such as at KNYL or KMFR, as per Which parts of class E airspace can an ultralight (part 103) fly in without prior ATC authorization?
Whether an ultralight needs prior authorization to fly in the airspace above the surface footprint of the rectangular projection of E2 airspace at KEGE-- this rectangular projection was the subject of another related question Can the Class-E-to-surface airspace near Eagle County Regional airport KEGE be ignored when the tower is open?
Whether an ultralight needs prior authorization to fly over the ceiling of Class D airspace in a case where the E2/E4 airspace designations have been assigned in a more conventional manner, with the footprint of the E2 airspace fully coincident with the footprint of the Class D airspace, such as at KMFR or KNYL http://vfrmap.com/?type=vfrc&lat=42.374&lon=-122.874&zoom=10
Whether an ultralight needs prior authorization to fly in Class E airspace in general


texts: Does an NVIS filter attenuate or pass the near-IR wavelengths?

texts:
If I put an NVIS (Night vision imaging system) filter on an electronic display which is installed in cockpit then will that filter 'Attenuate' or will it 'Pass' the 610-930 nm near-IR wavelength of the display device?
How will this filter helps the pilot to view in daylight as well as in low light at night?


texts: Technical factors to consider for retrofitting aerial refueling for commericial aircraft

texts: What are the factor that need to be taken into account to retrofit and an airliner like an a330 or 777 or maybe even a business jet like a global 5000 to an aerial refuelable (receiving) aircraft. Is it even possible?


texts: Is the phrase "going missed" standard in the US?

texts:
The use of the phrase "going around" is specified by ICAO Doc 4444 as the phrase to use when we're aborting the landing and heading for

another lap in the traffic pattern if we're on a visual or VFR approach, or
the appropriate missed approach procedure if we're on an instrument approach

However, in the US, I often hear the pilot saying "going missed" when breaking off an instrument approach. Is this standard phraseology in the US, or another one of those non-standard phrases which have gained footing? The 7110.65 only mentions the instruction "go around" (which incidentally is analogous, traffic pattern if visual, missed approach if on instruments), but doesn't say anything about the appropriate pilot phraseology. I couldn't find any reference in the AIM (chapter 4 section 2) either.

(I also often hear just "missed approach", which I suppose would be appropriate when checking back in with approach, but not with the tower, although feel free to clarify that for me as well)


texts: How to reproduce NASA/Langley airfoils for general aviation with long chord lengths?

texts:
I have scaled a NASA/Langley LS(1)-0413 airfoil to a 90 inch chord length, and now the trailing edge is 0.5in. Any longer chord length would have a larger trailing edge thickness.

  (90in*(0.0071-0.0016)=.495in)

This doesn't seem right, I have not witnessed a non-supercritical airfoil with a trailing edge larger than a .25in.

First off, do long chord length wings using the low and medium-speed airfoils have thick blunt trailing edges?

Secondly, if medium speed wings don't have blunt trailing edges how does industry taper the trailing edge? Is it assumed they will be rounded off, or sanded to a point? Should one remove from the bottom concave surface or remove from the top surface? Both will alter the exit angle of the airstream.

Thirdly, is there an ideal length chord for the NASA/Langley low and medium-speed airfoils, e.g. do they really only apply to a 36in chord lenght? Does scale matter?


texts: What does the altimeter indicate if it's at a certain elevation

texts:
The purpose of the altimeter is to show the pilot the altitude and the pressure above a fixed level. It uses barometric pressure and is 29.92Hg in ISA conditions.

What I dont understand is, how can this be extrapolated to be used in a situation where there is an elevation. For example, say the airplane is in a static position in an airfield at code EGNX, 52°49′52″N 001°19′40″W that has a 10 foot elevation. What would the altimeter indicate in such a situation.

Edit: Added a starting position


texts: What is the difference between slice, segment and leg?

texts:
I have heard of the terms slice, segment and leg. Since I am a newbie in travel industry, I would like to know and understand the basic differences between the three.

Could someone please explain the three, using some kind of example?


texts: Why might a Cessna 208 need a FAR Part 23 waiver?

texts:
The capacity of the Cessna 208 is stated as 9 passengers, or up to 14 with a FAR Part 23 waiver. FAR Part 23 states that it applies to any aircraft with "more than 10 occupants and that is intended for use in operations under Part 135" (commuter or on-demand operations).

What part or parts of Part 23 require the C208 to have a waiver?

Is it common for waivers like this to be issued for the C208 or in similar situations on other aircraft?


texts: Has a fixed-wing aircraft ever been built that featured multiple turbines powering a single propeller?

texts: Has a fixed-wing aircraft ever been conceived, prototyped or built that features multiple turbines powering a single propeller? The concept of a twin-engine aircraft with a single propeller is intriguing to me. Picturing something like a Pilatus PC-12 with two engines under the hood and a single prop might have some advantages. I come from a fixed-wing background and know little about helicopters, but if something exists I suspect it is a rotor wing.


texts: In the ARINC specification, why is baro altitude (label 204) measured in Knots?

texts:
I am currently designing a system that reads the baro altitude (on label 204) from an LRU. Ultimately in my software I would like to display the baro altitude reading in real-time using a graphical interface. In doing this, I'd like to have the units of measurement next to the reading. However I am having a bit of trouble in deciding how to display the units of measurement.

In the ARINC specification (attachment 2 "data standards"), label 204 (baro altitude) is listed as having units of knots. Is this an error, or can altitude be in Knots?

I am referencing ARINC specification 429 part 1-17, mark 33 digital information transfer system (DITS) published in May of 2004.


texts: Could the Grumman G-21 Goose be started by punching the instruments?

texts:
In the 1985 movie "Commando", John Matrix (played by Arnold Schwarzenegger) initiates engine ignition simply by punching the cockpit dials after several failed standard attempts.

Could this ever result in the engines starting in reality?


texts: What is the lightest weight operational jet/turboprop fighter ever deployed in combat?

texts:
Since the beginning of WWII there was been a trend towards larger fighter aircraft. In about 1960 the United States continued with larger fighters (F4, F100, F111, F15) but also started a branch of very small light weight fighters (F105, F16, Tucano, etc).

What is the lightest weight jet/turboprop fighter any nation has ever deployed in actual combat?

Epilogue: I learned more from this discussion than I expected. As I recall, at least one South American country used the BD5J but it never saw combat. That's why I included the combat stipulation. - Thanks for the answers...


texts: Where to find the various cargo hold dimensions and volumes of transport aircraft, such as the A330-300?

texts:
What are the dimensions of the cargo hold on the Airbus A330-300? (In order to check the usable space for containers or baggage.)

I'm looking for the internal dimensions of the hold with its subsections in the Airbus A330-300, i.e. length, width and height. What are they? This is in order to understand how much space there is and and how it's divided for standard containers or for baggage in bulk configuration.
I'm looking the value of volumes of the parts of the hold, too.


texts: How many cabin crews are needed for an A350-1000?


texts: Best glide speed vs. best glide angle? Maximum glide range?

texts:
I have some open questions regarding best glide in a descent:

I understood, that there is a best glide speed. This best
glide airspeed occurs at the highest lift-to-drag ratio (L/D). This best glide speed is normally given in the operator's manual of the aircraft.

Is it true, that this best glide speed is given in terms of indicated airspeed IAS and hence is independent of the elevation?

What about the sink rate when flying at best glide speed? I have seen hodographs where the sink rate is given over airspeed. (Diagram taken fom Taken from: Coombes, Reachability analysis of landing sites for forced landing of a UAS)

Is this again inidcated airspeed IAS?

As we all know, the TAS decreases with decreasing elevation when maintaining a constant IAS. For navigation with respect to earth's surface I need ground speed GS which is directly related to TAS via the wind speed (which we can assume to be zero for the moment)
To determine the glide path angle I suppose, that the ground speed and the sink rate is relevant.

Supposing, the best glide speed is IAS contrary to true airspeed TAS, how can I determine the glide range?

What is the resulting flight path angle when maintaining best glide speed? Does it change with decreasing elevation?

My intuition tells me, that when flying at constant IAS, the flight path angle should get steeper with decreasing elevation.

Is this assumption true?

Every reference to clarify these questions is welcome.

Currently I try to implement an autopilot for an emergency landing assistant that maintains a constant flight path angle during gliding descent. This enables me to exactly determine the distance traveled when I know the starting and the end elevation which in turn allows to do a proper path planning. My gut feeling tells me, that in this case I don't make use of the maximum possible gliding range as I have to start with a too steep flight path angle at high elevation to maintain this constant till the ground.

Is there any good idea how to predict the distance traveled when only knowing the start and target elevation?

Thanks a lot and Cheers,

Felix


texts: How do the wings connect to the centre wing box?

texts: First of all does the centre wing box form part of the fuselage as it's in the centre of the fuselage? Secondly how does the wing spars connect to this centre wing box to hold everything together?


texts: Can a CFI endorse a BFR flight review through real-time video including the flight portion?

texts:
Context: To minimize the heath risk during pandemic, many CFIs, especially senior ones, are not comfortable to conduct instructional flights with students in a narrow cabin. In the meantime, many pilots are due soon for flight reviews (BFR), but still within the 24 calendar month valid period.
For the ground portion of the flight review, a remote video call should make no difference with respect to regulation compliance. So the remaining of the question is for the flight portion,
Is it regulation-compliant to let a CFI to endorse me while the CFI is on the ground while I am going solo for the flight? There will be real-time videos, which cover the flight instrument panel, my maneuvers and cockpit outside views, broadcasting to my CFI in real-time, as well as recorded for post-flight verification. The CFI will be able to communicate to me in real-time through a hand-held radio, and will watch my takeoffs and landings near the runway, just like what happens on a first solo.


texts: Why is "Affirm / Negative" used instead of "Yes / No"?

texts: Does anyone know why we use Affirm and Negative in RT, rather than Yes and No? I assume it's to prevent confusion with accents and other languages - but Yes and No sound very different to me!


texts: What special airspace exemptions are granted for civilian fighter jets?

texts:
How do civilian fighter jet operations arrange airspace usage for conducting flight tours? Do they use military operation areas? If they fly into class A can they perform maneuvers, or do they need to stay below class A? One such operation is migflug.
When flying in airliners cross country I look out the window and think what it would be like to experience flying around and between cumulonimbus clouds in a jet fighter, but doubt ATC would allow it. It got me to wondering how the civilian jet tours handle airspace and speed restrictions.


texts: How to define quarter-chord sweep angle for a cranked wing?

texts: I have the values for surface area, span, aspect ratio, and quarter chord sweep angle, etc., for a general trapezoidal planform. So, I changed my wing to a single cranked wing such that surface area and span doesn't change. Therefore, parameters like root chord, tip chord, etc., changed. Now, for the, cranked wing how to define quarter-chord or half-chord sweep angles?


texts: What to do with excess fuel before flight?

texts: I've read that it's recommended to store a plane with full fuel tanks to prevent water contamination.  Some small general aviation planes, however, would exceed their maximum gross take off weight with full fuel and just two adult passengers of average weight.  One option, of course, is to fly with less than a full fuel tank.  This seems like it could be a problem if 50 gallons of fuel need to be dumped which cost the pilot $300.  My question is: what does a pilot do with the extra fuel that needs to be discarded before the flight?


texts: Do intermeshing rotor helicopters have a swasplate? If no, then how do cyclic and collective controls work?

texts: Looking at the Kaman K-Max and H-43 Huskie, it looks like they rely entirely on rotor flaps. How are they controlled?


texts: How may one notify the FAA of the apparent flaw in the airspace design at KEGE?

texts: Several questions and answers have addressed the design of the airspace around KEGE.  The situation is perhaps best summarized in this answer -- Can the Class-E-to-surface airspace near Eagle County Regional airport KEGE be ignored when the tower is open? .  How may one notify the FAA of this apparent flaw in the design of the airspace?  Note that this is not a charting error, but rather an apparent error or omission in the way the airspace has been designated, as described in the "Airspace Designations and Reporting Points" document JO 7400.11C.


texts: How is maximum payload determined in the payload-range diagram?

texts:
What determines the maximum payload weight, as seen in the horizontal line of a payload-range diagram? I understand that

$ OEW + W_{fuel} + W_{payload} \leq MTOW$

but what's stopping me from just putting in 10lbs of fuel, enough to taxi across the apron, and therefore have a maximum payload weight of MTOW - OEW?


texts: Is ETOPS satisfied solely by range circles?

texts: Consider a scenario where an airplane is operated on an ETOPS 180 route where the ETOPS alternate is open, available and above minima, but there is terrain between the route and the airport which makes it absolutely unreachable. If, in that scenario, an engine failure or decompression alternate is available but more than 180 flying minutes away, and enough fuel is carried to reach it while satisfying the terrain clearance requirements, would that flight be legal (not: practical, safe, desirable - only legal!) according to EASA/FAA regs? In other words, is ETOPS satisfied solely by looking at range circles around available airfields, or are there additional considerations required (not: prudent, desirable - required!) by regulations?


texts: Could a variable sweep aircraft also use negative angle?

texts:
Variable sweep on fighter aircraft is a bit out of fashion, but seems to a worthwhile option to adjust the wing to the current speed and needed lift. All this is bought with complexity and weight of the system.

Would it be possible to build a variable sweep aircraft that goes low speed and in a dogfight into a forward swept wing configuration like the Su-47 and high speed in a rearward swept wing?

Image of Su-47 credit to Wikipedia (Leonid Faerberg)


texts: What are the effects of the tilted lift vector in a banked plane?

texts:
I want to clarify the effects of the change in direction of the lift vector caused by banking in a plane.

Banking rotates the lift vector creating a horizontal component. I have read that some effects of this horizontal component are as follows:
1) It acts as a centripetal forcing inducing circular motion in the plane.
2) It generates sideslip such that in dihedral planes there is an increased angle of attack in the lowered wing, and a decreased angle of attack in the raised wing. This generates a restoring moment facilitating roll stability.

So my questions are as follows: How does the horizontal component of the lift have both a centripetal effect and a slide slip effect? (A more general question) In a banked turn under cetripetal force, what causes the change in the heading of the plane such that its longitudinal axis remains facing the relative wind?

Perhaps I have somewhat answered the first question with the second: initially under the centripetal force the plane does not yaw to have its longitudinal axis aligned with the new air velocity vector and therefore sideslip occurs? I am not sure, please let me know.

Thanks


texts: How should I request an IFR approach at the end of a VFR flight?

texts:
Here's the scenario:

The flight starts night VFR, with broken ceiling at destination (class C airspace) and expected to improve according to the pre-flight abbreviated briefing. I'm IFR certified but prefer to stay VFR to dodge icy clouds along the way.

Now I'm about 15nm from my destination, talking to approach control, and the ATIS calls the ceiling overcast: it's apparent I'll have to file IFR one way or another. Approach is busy, but not overwhelmed.

What is the best way to handle this situation on the radio? I have the ATIS, picked an approach and have a squawk code (advisories):

a). Do I ask approach directly for the IFR clearance, and what is the officially sanctioned phraseology? Also: do I have to cancel IFR when I'm on the ground/see the runway, i.e., is the clearance to descend thru the layer and shoot an approach a 'real' IFR flight plan?

b). Ask approach if I can change frequency to FSS, file with them, then return to approach to pickup the clearance (and cancel when on the ground/view of runway)?

c). Other?

I did read How do you request a "pop up" IFR clearance?. In my scenario I have the time to call FSS, there is no emergency, I'm on flight following and could complete (b) if that's the best way to go.


texts: Jet engines: are they owned by the airline or just rented?

texts:
For commercial jets, the engines are complex parts of the aircraft, are the most expensive components, and must be carefully maintained.

Source

When a company buys an aircraft, do they also own the engines, or are they still the property of the engine manufacturer? What happens when an engine must be exchanged?


texts: Electric Airplane - Hybrid / dual type engines how would that work?

texts:
If you have an airplane with electric propellers for take off and landing and you have a turbofan/jet to reach higher speeds for cruise.
For example, electric propellers can go to 250mph and turbofan to 550mph

Do you switch off the electric propellers or leave them on ?
Do they work in conjunction ?
What is the effect on the propellers when the turbofan reaches 550mph ?
Is the thrust added if both engines are working ?


texts: How much effect does the ground have on flight control when flying low?

texts:
In this awesome video, shot at the "Mach Loop" in Wales, F-15Cs fly down the valley, then cross a ridge very low to the ground. While it's difficult to tell from the video just how low they really are, they seem to be fairly close. How much effect on flight characteristics do the pilots feel as the ground comes up to meet them, then falls away?

To clarify a couple of points from the comments, I'm interested in any effects on flight control that are caused by flying fairly low over that ridge and through the valley (to grandmother's house we go).


texts: How does EEC/FADEC recognize/anticipate engine acceleration/deceleration?

texts:
So I'm wondering, when the engine runs at idle and the pilot sets a higher thrust level, what exactly happens, that the EEC/FADEC recognizes, that I want to accelerate? My professor said, it's anticipating the upcoming acceleration through:

$TRA > TRA_{threshold}$
$pt_3 < pt_{3_{min}}$ (cabin bleed)
$N2/\sqrt\theta < N2/\sqrt\theta_{idle}$ with $\theta = Tt2/T_{t ref}$

I get that the TRA (throttle lever angle) is higher than my previous one, hence I just raised it. But why exactly would pt_3 be lower than pt3_min, and why is $N2/\sqrt\theta$ smaller than idle? That would indicate that Tt2 has increased.


texts: What are the actual uses of the APU? When is it used? When does it go off?


texts:
In the event of a plane crash such as MH17, and the flight data recorders (FDR, a.k.a. "black boxes") are potentially in the "wrong hands", is it theoretically possible to:

open the FDR and close it again without leaving traces?
alter or selectively erase data of the FDR?

In other words, can an FDR professionally be tampered with as opposed to purely destroyed for the purpose of hindering an investigation?


texts: How unusual is it for remotely piloted aircraft to fly through commercial or general aviation airspace?

texts:
According to the Phys.org article NASA flies large unmanned aircraft in public airspace without chase plane for first time:

Flights of large craft like Ikhana, have traditionally required a safety chase aircraft to follow the unmanned aircraft as it travels through the same airspace used by commercial aircraft. The Ikhana flew in accordance with the Federal Aviation Administration's (FAA) Technical Standard Order 211—Detect and Avoid Systems—and Technical Standard Order 212—Air-to-Air Radar for Traffic Surveillance.
[...] The Ikhana aircraft was equipped with detect and avoid technologies, including an airborne radar developed by General Atomics Aeronautical Systems, Inc., a Honeywell Traffic Alert and Collision Avoidance System, a Detect and Avoid Fusion Tracker, and an Automatic Dependent Surveillance-Broadcast capability – a surveillance technology where the aircraft determines its position via satellite navigation and periodically broadcasts this information so other aircraft can track it.
The flight took off from Edwards Air Force Base in California and entered controlled air space almost immediately. Ikhana flew into the Class-A airspace, where commercial airliners fly, just west of Edwards at an altitude of about 20,000 feet. The aircraft then turned north toward Fresno, requiring air traffic control to be transferred from the Los Angeles Air Route Traffic Control Center to the Oakland Air Route Traffic Control Center. On the return trip, the pilot headed south toward Victorville, California, requiring communication control to be transferred back to Los Angeles.
During the return flight, the pilot began a gentle descent over the city of Tehachapi, California, into Class E airspace—about 10,000 feet—where general aviation pilots fly. The pilot initiated an approach into Victorville airport at 5,000 feet, coordinating in real time with air traffic controllers at the airport. After successfully executing all of these milestones, the aircraft exited the public airspace and returned to its base at Armstrong.
"We are flying with a suite of sophisticated technology that greatly enhances the safety capabilities of pilots flying large unmanned aircraft in the National Airspace System," said Scott Howe, Armstrong test pilot. "We took the time to mitigate the risks and to ensure that we, as a program, were prepared for this flight."
Tuesday's flight was the first remotely-piloted aircraft to use airborne detect and avoid technology to meet the intent of the FAA's "see and avoid" rules, with all test objectives successfully accomplished.

At the end of the article:

More information: For more information on NASA's Unmanned Aircraft Systems Integration in the National Airspace System project, visit go.nasa.gov/2sx9VCn.

Question: While this was the "...first remotely-piloted aircraft to use airborne detect and avoid technology to meet the intent of the FAA's 'see and avoid' rules, with all test objectives successfully accomplished", (without a chase plane?) how rare is it for remotely-piloted aircraft to fly through US airspace where commercial or general aviation also flies without all those extra qualifications? Has this happened several times, several hundred, daily? Is it even more infrequent without a chase plane?

Click images for full size.
above left: "Aircraft maintenance crews at NASA‘s Armstrong Flight Research Center prepare the remotely-piloted Ikhana aircraft for a test flight June 12, 2018. The test flight was performed to validate key technologies and operations necessary for the Federal Aviation Administration's approval to fly the aircraft in the public airspace without a safety chase aircraft." Credit: NASA/Ken Ulbrich
right: "NASA’s remotely-piloted Ikhana aircraft, based at the agency’s Armstrong Flight Research Center, is flown in preparation for its first mission in public airspace without a safety chase aircraft." Credit: NASA/Carla Thomas


texts: What happens when you break the rules while flying?

texts:
In a car, when you speed, you get pulled over, probably get a ticket, and you might get points added to your license.

How are air traffic rules enforced? Are there patrol planes that make sure no one is going over the speed limit? I have always been curious about that.


texts: How can I calculate effective wingspan of a high aspect ratio model airplane?

texts:
I've heard of people talking of wingspan and effective wingspan.

Considering:

L = Lift Coefficient . 1/2 Rho . Velocity ^ 2 . Surface Area,

I understand that tip vortices increase drag, but do they reduce the effective wingspan of a wing?

How can this be calculated?


texts: Why no runway markings at south end of 18/36 at FRA?

texts:
Perusing Google Earth I just now noticed that the north/south runway at Frankfurt am Main Airport (FRA / EDDF) does not have the usual markings at the south end of runway 18/36 - no "piano keys" nor runway number.  These are present at the north end (see below screenshots).
Why are the threshold markings and runway designation number missing?

South end of 18/36 at FRA (from Google Earth)

North end of 18/36 at FRA (from Google Earth)


texts: What is that black pod on the left wing of a TBM?

texts:
What is the black pod on the left wing of a TBM?

(Source)


texts: Why max thrust without afterburner is called military power?

texts: The jets before the merge starts with military power, which means max thrust before ab.Why named that way?


texts:
Since the standard A330's nose-down body angle on the ground, the A330F uses a revised nose undercarriage layout to provide a level deck during cargo loading to overcome the issue.

What is the angle between A330 body and the ground?


texts: How can I calculate the fuel consumption of an Airbus 320-200 at various loads?

texts:
I want to know:

What is the fuel consumption of an Airbus A320-200 - 180 Seats, at 100% load factor for a distance of 2000 km?
What is the fuel consumption of an Airbus A320-200 - 180 Seats, at 80% load factor for a distance of 2000 km?


texts: How can air launched UAV's be decelerated?

texts:
I am working on disaster relief drones for a college project. I was thinking about having multiple set of drones launched from an aerial vehicle over the disaster prone area. That's when I came across a big challenge.

How would you effectively decelerate a UAV that is air launched from an aircraft which is flying at a much greater speed than the maximum allowable speed of the UAV?

The stall speed of the aircraft is much larger than the maximum speed of the UAV (assuming, it has to be a very low cost UAV and hence the idea of having a parachute for deceleration is not very effective).

I would be glad if anyone could suggest me simple and robust ways to do achieve this.


texts: How much pressure do boost and jettison fuel pumps produce?

texts: What is the pressure output of a (boost) fuel pump on a Boeing 767 and/or 777, compared to a heavy-duty jettison fuel pump.


texts: Is this scheme for a single-fan electric airship with a rocket-like geometry workable?

texts:
I am currently designing a vertical take-off and landing vehicle that uses a Tesla powertrain connected to an electric ducted fan. Please comment on if my thought process is sound on my feasibility analysis.

My initial mission goal is extremely modest to grease the wheels of my feasibility analysis and have a realistic utility in society (and for people in my sport, recreational/experimental skydiving).

The vehicle simply needs to lift itself and a 100kg payload (coincidentally the approximate mass of a skydiver with his parachute) to the altitude of 1 mile.

I think I need to calculate my total delta_v, but because I don't need a high speed (like an orbital escape velocity or something like that) I am not positive how to go about getting it without first understanding the maximum thrust from my system.

My current plan for determining thrust from the tesla-system: 1) identify maximum output of tesla battery and motor (lets say Model S P100D) 2) calculate maximum propeller size for #1 based on algorithms available in electric drone aircraft websites/forums 3) calculate potential thrust produced by #2 4) use #3 to determine if liftoff is possible carrying at least #1

My initial calculations are not intended to include all outside forces; I will incorporate these if it is in fact, theoretically feasible at all.

Based on information above as well as the weights of the battery, motor, and an estimate of a basic rocket-shaped frame, I can figure out if a basic propeller will work for this, or if I will need to incorporate an electric turbojet, which would blow up my budget for this.

It is also feasible I could have a combination of several motors / batteries attached to multiple propellers with something like a rocket sitting in the middle of an oversized quadcopter. Again, budget goes up considerably.


texts: What equipment is used by Boeing to convert the F-16 into an unmanned aircraft (QF-16)?

texts:
How exactly does this equipment convert the F-16 into an unmanned aircraft?

Is it possible to use this equipment on any other fighter (like the F/A-18 Hornet for example) in order to convert it into an unmanned aircraft?


texts: Why did the Beechcraft Starship use a delta wing?

texts:
From what i've seen delta wings are more appropriate to supersonic designs, and have poor lift/drag ratios at subsonic speeds. The Starship had a cruise speed of 300 kn, so what was the reasoning behind the wing design?

I know that the engine on the back/pusher configuration puts the CoG further back, so you would want to put the wings behind, but the Piaggio Avanti does the same with conventional wings.


texts: How to compare two SFCs, one in thrust, the other in power (both turbofans)?

texts:
I want to compare some recent turbofan engines in terms of fuel efficiency, particularly the PW535A and FJ44-4.

I found the SFC for the PW535A to be 0.44 lb/h/lbf. I couldn't find anything on the FJ44-4, except for an earlier model. The FJ44-3A has a SFC of 0.456 measured in kg/kW*h.

Firstly, how can I effectively compare these? I tried rearranging the units so they could immediately be compared but kept ending up with laughably different values.

Furthermore, where might I be able to find data on the FJ44-4?


texts: Apparently, the Aviation Traders folks worked with EASA to define a special type of cargo compartment, known as a class F, during their work on Iron Maiden's touring airplane.  Just what is a Class F cargo compartment, and how does it differ in safety properties from the large class B compartments used on earlier combi configured aircraft?


texts: What is the correct name for clearance delivery at KSAN if the tower is called "Lindbergh Tower"?

texts: In the departure and instrument approach charts for KSAN, they reference Lindbergh Tower" for KSAN tower. Does this mean that we should be calling up "Lindbergh Clearance" to pick up our flight plan?


texts: Why are turbofan inlets leaned/angled forward?

texts:
(Image Source: Wikipedia)

Seeing that everything is radially symmetric (apart from the nacelle mount, naturally), I wonder why the inlet (the front part of the nacelle) is usually skewed?


texts: When is Class Delta Airspace not Class Delta?

texts:
Although there could be many examples, I'm using the KLCQ airport in this case. This is how the airspace stands:

In the CHART Supplement, it is mentioned that it's a "Class D svc other times class E".

I called the Airport Manager and he confirmed saying "Yes, we're a Class D during the time tower is in service. Other than that, it's Class E".

Questions:

1) Why does this airport not have a dashed blue circle like a normal Class D?

2) Since it's inside a Class E Transition airspace, shouldn't the airspace be Class G up to 700' AGL when tower is not in operation?

3) What is primarily required for an airport to actually be designated as a Class D airport - x amount of traffic, x amount services, x amount of weather reporting capabilities?

Why should this matter?

Weather minimums
Communications with ATC during arrival/departure
Etc.


texts: How can one approximately guesstimate wave drag?

texts: Wave drag is an especially high drag that affects supersonic vehicles above mach 1, but I've found it hard to find source materials to estimate wave drag. I'm looking at the transonic region till Mach 1.2 and so I'm looking to have an estimate about how I can design better for wave drag by estimating how it would affect my flight in the region mach 0.8 - 1.2.


texts: Do any commercial airline models have a parachute at rear to help in landings?

texts:
Some land-based fighter aircraft have a drogue-chute to help them slow down during landing.

Do any current models of commercial aircraft have a similar
mechanism?
Secondly, would such a mechanism help aircraft in making a better landing and reduce landing related incidents/ accidents?


texts: What does "POS ITERV WAS CHGD" mean on the ACARS page of a Boeing 737?

texts:
During the whole flight, the message "POS ITERV WAS CHGD" appeared frequently on the ACARS page of the MCDU (Multipurpose Control and Display Unit). The aircraft is a Boeing 737.  I cannot find any reference in the FCOM (Flight Crew Operating Manual).

What does this message mean and why does it appear?


texts: Will depression from 20 years ago prevent me from being an airline pilot?

texts: I was diagnosed with clinical depression at age 16 and was on prozac for a year.  During that time I coped and after six months I tried taking myself off the medication because I did not like the feeling of being medicated.  I have been free of this for nearly 20 years.  I have had no relapses, I have never been medicated since then.  I also attribute my falling into it in the first place due to lack of coping skills since I was so young, given my life experiences since then I don't know how I let myself "slip".  However, will this prevent me from ever becoming an airline pilot?  I have saved up the money to go....  Even if I get evaluated and given a clean bill of health does this doom me to be forever be thrown on the "reject" pile???


texts: Impact of hurricanes on flights that have to traverse affected areas

texts: Hurricane Florence is forecast to reach the US east coast soon as a very strong hurricane. This makes me wonder if hurricanes have a big impact on commercial flights that have to traverse the area affected by an hurricane?


texts: Can a helicopter mask itself from radar?

texts:
I have read somewhere that if a helicopter is traveling under 100 km/h and below 5 meters AGL then most radars will ignore it. From what I understand of this process, the radars can pick up things like cars and vehicles driving on the ground and thus need to ignore certain signals if they are traveling below a certain speed and height.

Is this actually the case, though? Does this also apply to military-grade radars?

Edit: This is not asking if a helicopter can fly under the radars coverage, but whether the helicopter can using techniques to notch its signal from being displayed as a contact on a radar operator's screen.


texts: Am I required to report an incident that isn't specifically mentioned in 49 CFR 830?

texts:
I have read an understand NTSB Part 830, and know that IMMEDIATE notification to the NTSB is required for aircraft accidents and the listed serious incidents. My question is, is there a requirement to notify the NTSB or FAA of an incident that is not listed in part 830? This is not a question about accident reporting, but specifically incident reporting for incidents that are not listed in the regulation.
Possible scenario: While landing at an uncontrolled field, the airplane loses directional control and departs the runway into the grass and the airplane did not receive substantial damage nor was there a serious injury or death.


texts: How to manage anxiety just before flying?

texts:
I am new to aviation and flying.
I have a one hour trip that is making me anxious and sleepless.

How can I manage the fear and is it safe or just like the news we hear on news?


texts: What was the first commercial aircraft to have a 'built-in' oxygen system?

texts:
(Source) Boeing 307 of TWA, the 307 was the first pressurized passenger aircraft.

The 307 (c. 1938) flew as high as 23,300 ft, lower than the jets of nowadays, and did not have a built-in oxygen system as evident by the picture above.

So what was the first passenger aircraft to have a built-in oxygen system, as opposed to carry-on oxygen?


texts: Why does an airspeed indicator not simply read TAS?

texts: If the airspeed indicator has inputs regarding air density (static port) and temperature. Why isn't Indicated airspeed from the indicator simply the same as True airspeed


texts:
A minority of the world, specifically Russia and China, uses the metric system in aviation. ATC will tell the pilots to "climb to 900 meters height".

How do pilots of international flights manage this? Do they request the ATC to provide altitude in feet, or do they perform the conversion manually and dial in the altitude in feet to the autopilot?


texts: The Concorde had a maximum speed of 2.05 Mach, carrying about 96-128 passengers. The Airbus A380 can achieve a top speed of 0.95 Mach with more than 500 passengers on board. This means roughly 5 times more passengers can be accommodated by compromising half of the top speed. So, why does speed lose out so much to capacity that it ultimately becomes unfeasible to operate a supersonic airliner?


texts: What aircraft can make these sharp 90-degree turns?

texts: I took this photo when I saw a plane make a crazy 90 degree turn. What kind of aircraft could do this? I have a plane finder app for commercial aircraft and this plane did not show, which is the first time that's happened.


texts: What's the inspection/repair procedure following damage from severe hail?

texts:
Delta 1889 was forced to make an emergency landing last Friday (August 7th, 2015) after being battered by hail in a severe thunderstorm.

The picture in the news shows the two leading segments of the windshield have been ruined and will need to be replaced.  The nose cone of the jet has been caved in.  Zooming in suggests that the sheet metal ruptured where it made contact with whatever it behind it.  If that's the case I'm assuming it's too damaged to just have the dents pulled out and will also need to be replaced.

Beyond the obvious damage, what else will need to be looked at before the plane is able to resume normal operations?


texts: Could a modified J58 jet engine be used commercially?

texts:
Could this mean for more fuel efficient supersonic commercial cruising?

If so in what ways would it need to be modified and how possible is this?


texts: How do airports handle traffic during emergencies?

texts:
What does ATC do when there is an emergency? This could be a tower or an ARTCC being evacuated or otherwise unusable.

How do they decide whether to close the airport/airspace?
What do they do with the traffic, whether they do or don't close?

On this related question, it turned out that Newark closed because of smoke in the tower.

Another user posted an interesting anecdote about another tower being evacuated, so I thought it warranted a question.


texts: What is the metal plating on the back of the A-6 for?

texts:
What is the perforated metal plating on the back of the A-6/EA-6 for?

Source: Wikipedia


texts: How is the serviceability of VOR unit part CI 215 checked?

texts:
In the VOR receiver we use two antenna, which are joined with the help of an assembly (part # CI 215), then the output of these two antenna is fed to RxR.

My question is: how do we assure the serviceability of this unit (CI 215)?

Means coxial cable inner lead should short with outer OR Not.
Both antenna Fitting point short with each other OR Not.
coxial cable inner lead should short with both antenna Base fitting point OR Not.


texts: How did the nose landing gear of JetBlue Flight 292 get stuck sideways?

texts: The nose landing gear of the Airbus A320-200 was jammed, but the tires were perpendicular to the fuselage. How did that happen?


texts: Is training required under §61.55 to move from PIC to SIC?

texts:
I am current as PIC in type on a jet requiring two crew members. I will be out of currency as PIC soon and my company wants me to move to SIC position when that happens.

Am I required to have training specified under 14 CFR 61.55 for SIC if I am already type rated in the aircraft?


texts: When an airship climbs the hydrogen in the ship's cells expand. Does this mean that when the airship descends the empty cells fill with air?

texts:
During WW1 a U Class Zeppelin had hydrogen cells that contained 55,795 cubic meters of hydrogen.
At sea level the cells were filled to 100% with hydrogen and this weighed roughly 4,500 Kilograms.  The cells displaced roughly 68,000 Kilograms of air and this difference gave the ship tremendous lift.
As the ship ascended to 5,000 meters air pressure would drop by 50% and the hydrogen would expand.  To keep the cells from popping the crew would release a significant amount of hydrogen.
However this is where I see a problem and I'm not sure how engineers solved it.
As the Zeppelin returned to sea level with hydrogen cells at only 50% full wouldn't it take on air in the now empty 50%?  The air is heavy and at some point the airship would come crashing down to Earth.  How did they solve this problem?


texts: How much fuel is used for the different phases of the flight of a typical airliner?

texts:
An Airliner flies from LA to JFK in 5 hours. In the first 30 minutes the plane climbs to about 30,000ft. For the next 4 hours the plane flies at about 30,000ft. For the next 30 minutes the plane descends to JFK.

What % of the total fuel used for the flight is consumed in each of the 3 phases  of the flight, i.e, the climb out, the cruise, the descent?


texts: What are these boxes built into the tails of some fighters?

texts:
In looking at European-designed fighters of the 4th and 4.5th generation, I keep seeing a common design feature; a box-like structure built into the tail, often in the top half or third. Some examples:

Saab Gripen

Mirage 2000 (this one's more complex and less box-like but the arrangement is very similar)

Rafale

Eurofighter Typhoon (this one looks markedly different, much lower and more like an intake)

Panavia Tornado (this one has two main protrusions from the tail, one much like the Typhoon's, the other more like the Gripens or Rafales)

SEPECAT Jaguar (you know what you're looking at by now)

What is this box? My best guess is some sort of avionics/sensor package, maybe RWR/missile warning. What's odd to me is that this box-in-tail arrangement is not seen on any relatively late-model U.S. or Soviet fighter; you'd think if the Europeans were onto something with this placement, the U.S. or Soviets would have tried it out at least once.

The F-15 has what I think is an RWR probe on top of the left tail, but the tail itself is pretty clean:

The F-16 does have a boxy construction flaring out at the top of the tail, but the front is clean:

The F/A-18 has some trailing-edge bulges but again very clean:

Su-27, ditto to the F-18 (it does have that big probe between the engines though):

MiG-29, same thing:

I could go on but you get the point, Soviet and U.S fighters seem to have passed on whatever this package is in the tail. So, what is it, why is the arrangement limited to European fighters (for the most part) and how do other regional designers accomplish whatever these do?


texts: Why does the takeoff N1 limit start to decrease below 30°C OAT?

texts: It's easy to understand why the takeoff N1 limit decreases with an increase in the OAT in the chart above; the engines get less dense air at higher temperatures, and less dense air means less engine power capability. But why does the takeoff N1 limit start to decrease with a decrease in the OAT below 30 degrees Celsius? For your information, the chart is an airport analysis chart for Boeing 737.


texts: Advantages in using a flight sim to prep for a private license?

texts:
I'm starting to save up to get my pilots license and I was thinking I might be able to do some amount of prep work by using a flight simulator.  That being said, I realize there must be some huge limitations to what I can actually learn, on my own, on a flight sim.

So, out of curiosity, are there good things to try practicing on my own in a flight sim?  There's got to be a few basic things that would make it worth my time...  Otherwise I'll just go back to flying around aimlessly like I usually do :).


texts: How does wind speed affect helicopter rotor speed?

texts:
So on the left it shows wind flowing with the direction of the rotor, yet it represents that it would reduce the rotor speed. I'm wondering how it does this, wouldn't the wind minimally help increase rotor speed by pushing it? Even if the effect was minimal to the point that it was neutral, why would it slow the rotor down?

If anyone could explain that would be great! Thanks.


texts: What design characteristics influence helicopter wind gust spread tolerance during takeoff and landing

texts:
Not considering pilot reaction time, what factors influence a helicopter's ability to survive high wind gust spreads (from any direction) during takeoff and landing?

I have considered:

Swash plate delay: assuming an example main rotor spinning at 600RPM, the rotor completes 10 rotations per second. If each control input requires 180 degrees of rotation to take effect, then fastest possible reaction time is an adjustment every 1/20 second.
Mass of the aircraft: a heavier aircraft will be moved a shorter distance by crosswind gusts. This reduces the likelihood a skid will unintentionally strike the ground during the earliest stages of takeoff or the final stages of landing (1inch to 3ft off the ground), which could result in the gust building under the vehicle and causing a  roll.
Rotor system: rigid and articulating rotor systems are not susceptible to mast bumping.

Questions:

How do you rank these factors in order of largest influence on surviving high wind gusts during takeoff?
Are there other factors I have not considered?


texts: How long does it take to get your official FAA certificate in the mail?

texts:
I'm asking this question because the only answer on the web right now is pretty old and I assume this is a common question. The above link refers to an FAA page that says:

  We are currently processing permanent Airmen Certificates for
  temporary certificates that were issued approximately May 3, 2015.

The above quote hasn't been updated in weeks.

How long does it normally take to get a new certificate in the mail?

Does it vary substantially?

Is there a better place than the above link to get an idea of how long a certificate will take to be processed?


texts: What should I do to resolve an incorrect birth date on my FAA medical certificate?

texts:
While taking my pre-solo exam, I noticed my medical has my birth date one year earlier than it actually is. I am expecting to solo tomorrow.

Would this error legally prohibit me from soloing until it is corrected?


texts: Does transport-type certification account for engine separation and its possible effect on hydraulic lines?

texts:
This question is inspired by the United Airlines Flight 328 where the No. 2 engine is damaged.
Some multi-engine aircraft are design to withstand the detachment of an engine while some are not. Boeing 747 is designed to operate after an engine detaches from the pylon. In 1993, Japan Airlines 46E successfully landed after the No. 2 engine detached from the aircraft (1) In El Al 1862 and China Airlines 358, the detached engine struck another engine. Those are outside of the design scope. On the other hand, the detachment of an engine on a DC-10 would sever hydraulic lines to the control surface as in the case of American Airlines Flight 191.
Many twin engine aircraft are certified with ETOPS so that in the event that one engine failed, the aircraft can return to an alternate airport within the certified time span. However, the ETOPS scenario listed by FAA only includes engine shutdown but not engine separation. (2)
Are there any twin-engine aircraft that are controllable after an engine separation?


texts: Why is the Boeing 747-300 not in service anymore?

texts: Doing a little doodling on flightradar24.com and Wikipedia, I saw that all the versions on the Boeing 747 except for the -300 version are used. Why is the Boeing 747-300 not used even though it is newer than the -100, -200, and SP versions?


texts: What is the ambient temperature used in RTCA/DO 160?

texts: I was going through RTCA/DO 160D for some work-related issue. I went through the whole document but nowhere does it define what the "ambient temperature" value is? In one place it defines +15 to +35 degrees Celsius as one of the parameters for ambient conditions. Does anyone know what is the value of ambient temperature, or it is generic room temperature of 20-25 degree C?


texts: How does the Pseudo-Satellite Zephyr land?

texts:
I don't see how the Airbus Pseudo-Satellite Zephyr solar plane can land safely.

It this video, it is "thrown" to take off, but no gear or something similar is visible. Will it just land on its belly?

This video shows, I think, landing footage, but only the runway is visible.


texts: What is the Beggs/Mueller emergency spin recovery technique?

texts:
I've always used PARE for spin recovery:

  Power to idle
  Ailerons neutral
  Rudder opposite the spin until rotation stops
  Elevator forward to break the stall

What is Beggs/Mueller emergency spin recovery, and why does it work?
Does it work in any aircraft?


texts: What is the fuel mass flow rate at stationary full power for the CFM56 5C2/3C1 engines?

texts: Does anyone know what is the value of fuel mass flow rate when stationary at full power for CFM56-5C2 or CFM65-3C1 turbofan engines? I am doing a work on engine performance and it seems that only information I can't find is the fuel flow rate at conditions above. I will be very grateful to someone who can help me.


texts: How accurate is an Inertial Navigation System

texts:
I was surprised to learn that an inertial navigation system even works at all; I'd expect that the integration drift would throw the velocity measurement off badly enough, not to mention the position. Other questions have asked about how these systems work, and the answers have explained that cross-checks with other measurements which give absolute position (e.g. GPS) improve accuracy.

But given a state-of-the art INS which operates in isolation (no interfacing with airspeed, GPS, etc) from takeoff, how much drift could we expect for, say, a normal transatlantic flight? Does this change if the aircraft flies through turbulence?


texts: What is the "No Step" flap thingy used for on an A320 engine?

texts:
There is a small plate sticking out of an A320's engine narcelle with "No Step" written on it. I tried taking a picture of it, which in retrospect didn't turn out as good as I wanted it to be, but I hope it helps:

Anyway, I'm wondering what it's used for? It's only on one side towards the aircrafts body and it seems to be too small to be an aerodynamic surface. I suspect it's used during maintenance?


texts: Are aircraft engines classified as DAL A or DAL B?

texts:
I am confused regarding the Design Assurance Level (DAL) of aircraft engines. I attended a seminar in which the speaker mentioned aircraft engines as being DAL level B; when we asked about it, he answered that it's not required by the FAA to have two engines running because an aircraft is capable of flying with only one engine. Hence, it's classified as DAL level B.

If I'm not wrong, the FAA states that an commercial aircraft should be able to fly with one engine with for at least 1.5 to 2 hours. So was the speaker right about the DAL classification?


texts: What is the history of the "Superbay" at San Fransisco International?

texts:
The Superbay is a maintenance hangar on the north end of the field at San Francisco International Airport, north of runway 28R and west of runway 19R. On the airport diagram it is not labeled, but next to fire station no. 2.

It is currently used by United Airlines and American Airlines for maintenance. Ground control refers to it as the "Superbay" when giving instructions.

When was the Superbay built? Did it have any uses before the current tenants? Where did the name come from?


texts: Are experimental aircraft exempted from the 2 year transponder and avionics checks?

texts: Experimental aircraft and LAS. The 2 year verification test for avionics , transponder and altitude encoder.  Are experimental aircraft exempted from this test or they must comply ?


texts: Is there any regulation on how often a private aircraft should be washed?

texts: Is there any regulation on how often a private aircraft, such as a Cessna, should be washed?


texts: What's the difference between FAA Part 61 and Part 141 training?

texts:
I've got schools with both part approvals in my area. I'm just interested in recreational flying, I'm not sure which part is more suited to my needs.

What are the differences I should consider before choosing one or the other?


texts: Why don't commercial aircraft have drag chutes for aborted takeoffs?

texts:
We were watching the program  Air Crash Investigation and there was an episode where it was too late to abort the take-off and the pilots had to attempt to climb still but since an abort was not possible at that speed.

My 5 year old son asked and I quote: "If the brakes don't have enough power to stop at that speed, why don't they use the parachute brakes?"

So why don't big jets have drag chutes to help with emergency braking if there is some margin still, but not enough for the tyre brakes to stop safely in time?


texts:
So up front, I'm aware of the high number of aircraft and environmental factors and how oversimplified my request is. After all, there is a reason that the aircraft manufacturers provide charts to calculate such things, and not hard numbers.

I'm looking for the average fuel burn rates for a Boeing 757-200 at MTOW during the first hour of flight, and then the same, the average fuel burn rate for the second hour of flight. If you have a range for each period, that be cool as well. If you need variables to run the calculation, I offer the following:

Field Elevation: 1,000' MSL

Temp: 59° F/ 15° C Altimeter Setting: 29.92 In-Hg/ QNH 1013 Final
Cruising Alt: FL380 Assume standard takeoff configuration and initial climb performance. Standard cruise climb t FL380 with no clearance altitude restrictions or ATC level offs

I think that's it, let me know if I forgot something.


texts: Can a plane fly backward if its propeller is in reverse?

texts: I would like to know if a prop plane, for example the P-51, could be able to fly backward. Is it possible through some trick like changing blade angle or reverse the prob rotation direction? It would have been hard for piloting, but is this theoretically possible?


texts: Why is UTC activation time referred to 30W in NAT-OTS?

texts:
I am reading the NORTH ATLANTIC OPERATIONS AND AIRSPACE MANUAL and I came across the following statement more than once during my reading:

  The activation time of the westbound OTS shall be published as 1130z
  to 1900z at 30W.

  The activation time of the eastbound OTS shall be published as 0100z to
  0800z at 30W.

You can find this quotes at page 175 of the link provided above.

Here is my question: if the activation times are expressed as ZULU time (therefore as UTC), why is it specified at 30W? As far as I know a ZULU time is referred to the Greenwich meridian and therefore at 0W. To me it sounds quite contradictory to express an UTC time by specifying a longitude different than 0.

What am I misinterpreting? What is the right interpretation of the quotes presented above?


texts: Do airline transport pilot trainees ever fly a passenger-less aircraft?

texts: Do airline transport pilot (ATP) trainees ever fly an empty aircraft? Consider the example where a pilot is under training to operate a 777. Would the pilot ever fly the real aircraft without any passengers? Or is training only limited to simulation?


texts: How do I know how to describe my position on the airport when I contact ATC?

texts:
When asking for taxi clearance, a pilot must include his location when contacting ATC. However, I'm not quite sure exactly how to state your position in the airport.

For example, I've heard some pilots say something such as "Ground, N123DB is southside by the tower, requesting taxi clearance," but I've also heard something like "Ground, N123DB is at transient parking, requesting taxi clearance." How do you know your location in the airport?

Obviously, I can look at an airport diagram and find out where I am, but how do I communicate this using proper terminology to ATC? Is it standardized?


texts: What's the profit margin for airlines between fuel cost per seat price per seat to the customer?

texts: I understand that there are other costs that go into the full price per seat, like maintenance, crew ect., but all I am asking about here is fuel.


texts: What does a white over red VASI indicate?

texts:
I have found the following mnemonic's to remember Visual Approach Slope Indicator combinations:

White over White, you're high as a kite. / you'll fly all night
Red over White, you're alright.
Red over Red, you're dead.
White over Red, unsaid / you're under head

What does White over Red exactly mean? Does you're under head mean your low? I can't seem to find it anywhere.

Mnemonic Src: https://en.wikipedia.org/wiki/Visual_approach_slope_indicator


texts: Which are the main aluminium alloys used in airliner construction?

texts:
The proportion of composites used in airliner construction has increased in the last decades, with the B787 and the A350 being the first ones with composites making up the majority of wing and fuselage structure. From Wikipedia:

  The 787 is the first major commercial airplane to have a composite fuselage, composite wings, and use composites in most other airframe components.

And

  The A350 XWB airframe will be made out of 53% composites: carbon fibre reinforced plastic for the outer and centre wing box (covers, stringers, spars), fuselage (skin, frame, keel beam, and rear fuselage) and the empennage (horizontal and vertical tailplanes).

The vast majority of aircraft in operation (A320, A330, B737, B777) still use aluminium as the main load bearing construction material though. Which aluminium alloys were used for the wings and fuselage of these aircraft?


texts: Is airspace more crowded on days following cancellations or a large number of delays?

texts:
I am looking at some data form the BTS and trying to understand some spikes in month to month Volume delays. From my understanding a Volume delay is due to the volume of airplanes, causing the ATC to manage more take offs and landings and therefore slowing down the whole process.

My problem is that for volume delays bts only provides monthly aggregates. So I have data with a spike for Volume but the number of flights on that same month is normal or sometimes less than average. So I am assuming that something is happening at the daily level that is completely lost in the aggregation.

This all boils down to my question. If we where to quantify the capacity of the airspace around say ORD and call it X and on average the airspace is occupied with N planes, such that N < X and airspace is operating at N/X capacity.

On days following mass delays or large number of cancellations, does the amount of planes in the airspace increase to alleviate the pressure of passengers who are behind schedule? or does the load factor simply increase?

For examples say that on average airspace at ORD operates at 75% capacity, then one day you have some event that causes a lot of delays and cancellations. Do the following days operate at say 90% airspace capacity to help relive that congestion? or do they still operate the same number of planes but those planes are simply almost guaranteed to be full.

All summed up, would a spike in delays for some reason other than plane volume result in a spike in volume delay in the following days as they deal with the extra passengers?

Sorry if this question is worded strange, I had a hard time putting it down in writing. If its unclear let me know and I'll try to clarify.


texts:
horizontal surfaces in airplane have small angle of incidence in general, Is it possible to have an angle of incidence for a vertical stabilizer?
Please help me to find it. Thanks!!


texts: Is one-sided thrust reverser deactivation still allowable?

texts:
While browsing the major accidents in the Aviation Security Network's database, I noticed that a couple of accidents seem to at least be aggravated by one-sided deactivation of thrust reversers. One-sided thrust reverser deactivation seemed to be permissible according to the respective Minimum Equipment Lists, yet the reports indicate that the crews have been caught off guard by the resulting asymmetric thrust after reverser activation during landing.

As some of the mentioned accidents resulted in a high number of fatalities, I wonder if the procedures and requirements regarding thrust reverser deactivation have ever been changed. How common is it for an airliner on a commercial flight to have thrust reversers deactivated asymmetrically nowadays?


texts: What would happen if put a jet engine behind another jet engine?

texts: Just curious. Would it do nothing, would it generate a massive amount of thrust? Would it even work?


texts: Could any complications arise if the two FMCs are using different OPS programmes, i.e U10.7 and U10.8A?

texts:
B737-300
FMCs ARE OF SMITH INDUSTRIES 2907a4/10-6225-003


texts: Why did this Cirrus deploy the parachute while ditching over Pacific Ocean?

texts:
In this incident near Hawaii, a Cirrus SR22 had fuel problems and deployed its airframe parachute.

My question is why did the pilot deploy the parachute rather than perform a "normal" ditching procedure in the ocean?

For reference, here's the video.


texts: Flying an amphibian with ASEL privileges

texts:
So I have an interesting scenario:

You hold an ASEL private pilot certificate in the USA with high-performance and complex endorsements. You also fly a Cessna 206 on a regular basis.

Given that all your certs and currencies are valid, are you allowed to act as the sole PIC of a Cessna 206 amphibian as long as you perform your takeoffs and landings on land only?


texts: How far ahead of the wing should a propeller be located for a UAV?

texts:
This question is asked in context of a fixed wing, Unmanned Aerial Vehicle (UAV), with a wing span of about 5m (16ft).

How far ahead of the wing leading edge should the propeller be located?

The propwash should have minimal effect on stability and should not adversely affect the airflow over the wing.

Can propwash be useful?


texts: How to fly an RNAV (RNP) approach with VNAV in a Boeing 737?

texts:
Let us assume you are flying a B737NG and you are cleared for an RNAV (RNP) approach which has several legs with different altitude crossing restrictions.

What do you enter in the MCP altitude window? The first, highest crossing restriction, and then keep repeating by entering the next restriction or does one enter the last and lowest one and let VNAV manage the step descents automatically?

If during this gradual VNAV descent procedure you have to use SPD INTV to alter an FMS commanded airspeed, does this "cancel" the VNAV profile, or will it adjust automatically to suit the new manually selected airspeed?


texts: how does recovering a plane from stall lead to exceeding the critical mach speed?

texts: Recovering from stall itself states that the aircraft is below stall speed. So how does recovering from that stall lead to exceeding critical mach.


texts: When does a pilot and when does a co pilot start/land?

texts: I am wondering if there are certain rules about when a pilot and when a co pilot starts or land a plane. As far as I understand a co pilot's job is to support the pilot. Do they talk to each other during the flight and decide that spontaneously or is the decision already done long time before a flight and how?


texts: Was NextGen simulated/tested against alternatives?

texts:
Researchers in aviation usually test systems in simulated environments to find out the pros, cons, challenges, etc. Now ADS-B is a key component of NextGen and its European counterpart. And I've seen papers/researches on applications than utilize ADS-B.
For the US, even shortly before the current pandemic, the Office of Inspector General was not too thrilled with NextGen, with the latest in a series of audits being announced in Oct of 2019. Based on earlier audits, the benefits will not be realized before 2025, and that was before the pandemic, and the latest audit is currently questioning the benefits:

Given concerns over the progress and benefits of NextGen, the FAA Reauthorization Act of 2018 mandated that our office study the potential impacts of a significantly delayed, diminished, or completely failed delivery of FAA's NextGen initiative.

Two years ago I asked, What benefits does Automatic Dependent Surveillance bring to continental ATC over Mode S? Of the pros noted, there were these two relevant to my question here:

ADS-B updates faster
ADS-B is cheaper

Since one of NextGen's big aims is boosting the traffic capacity, which is mostly limited by separation in the terminal environment, were alternatives tested? For example:

Sector limited radars (one per approach end) that would provide the faster update rates. (Radars that don't make complete revolutions.)
Its relative cost, i.e. equipping thousands of planes versus tens of super busy airports.

If no, were there [then-valid] reasons?


texts: Why does the thrust limit page display the thrust in percentage (« % ») and not in pound-force?

texts:
When the pilot sets the takeoff engines thrust on the Flight Management thrust limit page that displays on the CDU (or MCDU) interface, the selection will finally show as a percentage.

The direct consequence of this is that, « at first sight », the pilot does not know the exact thrust that the engines will develop in pounds-force.

Considering that all operators do not necessarily choose the same rating for a similar combination of aircraft-engine, does it mean the same percentage of takeoff thrust might provide different thrusts according to the operator?


texts: Do UL aircraft complying with LTF-UL need to copy an existing design pattern?

texts:
With my current pipe dream being to get physically involved in aviation
instead of only theoretically, I looked into the regulations for ultralight planes in Germany.

On multiple occasions in the LTF-UL regulation it is mentioned that in special cases the design inspection authority "Musterprüfstelle" needs to approve the aircraft.

This and the fact that most articles about building your own UL are referring to using existing design patterns "Muster" makes me wonder if it is even possible/feasible to design your own UL aircraft.

So the question is split into two parts:

Is it possible to legally design, build and fly your UL in Germany (complying with LTF-UL)?
Is it feasible to design, build and fly your UL in regards to the financial and time-killing aspect of the bureaucracy in contrast to using an existing design pattern?