texts:
I don't know anything about planes (mechanics,electroinics,etc...) so bare with me (and the long post)!

In the USA

With ADS-B coming due in a few years, more GA are implementing their planes with ADS-B Out. They will call approach (who knows nothing about it) and in-turn they call us (center) for the answer. Or if they want to be "nice" they just have the pilot dial our frequency and the GA pilot will ask us (not fun sometimes).

All the GA pilot wants to do is verify with "FAA" that their ADS-B is working (center can see that it works, we have a button to toggle on and off). Once we tell them yes/no they are off the frequency. Sounds simple!!

The issue is Center, Tech-Ops, Supervisors.... don't know anything about ADS-B verification. I've taken upon myself to learn this in hopes to inform other controllers.

Questions~~~

What equipment do you have to have for ADS-B?
 Mode A/C transponder only or do you also need Mode S too?
Is ADS-B tied into Mode S or are they completely 2 different components?

Do you need a Mode S transponder to fly? (I think from what I read Part 121 ..commercial you do, but not required for GA if inside the US)

Does the ADS-B get registered to the N number or the air frame (not sure how you split that up)

What is an Example of an ADS-B "code" ? ....to clarify...If it is registered to the tail number, I would assume you have to register a specific "code" to tie the 2 together.

Is the ICAO hex number the same as the ADS-B number/code?

The reason I ask these question is for processing. A GA will call up and we will attempt to put in a flight plan mid flight (they pop up vfr and we try to work this out together) I tell them I need to give them a code to identify them and start a flight plan. I feel like when everything is entered, I am still missing something that needs to be entered to make sure the computer is aware the plane is ADS-B equipped. If it is tied to the tail number, once I create flight plan mid flight, it should auto acquire whether it is ADS-B equipped with no extra info input.

I ask about ICAO hex because I see some ADS-B equipped GA with hex numbers in the system and some do not have hex numbers but still verified ADS-B equipped. I want to know if they are both needed!!!

I also see Commercial flights with no hex number in the system too but I assume they all should.

Thanks, ZOB controller


texts: How do bearings in a jet engine keep water out when it's been cleaned?

texts: When a jet engine is running, it's generally immune to any liquid in the incoming air as the liquid would have been evaporated in the compressor. However, when the engine is being cleaned for carbon deposits, cleaning solution mist is injected is fed to the inlet, and the water would have the chance of entering the compressor bleed. Is there any special design in the bleed path to keep the water out, or the water simply couldn't get past the labyrinthine seals around the bearings?


texts: Why do some fighter jets have two pilots while others have only one?

texts:
Why do some fighter jets have two pilots, while some have only one?

For example the newer fighter jets such as Dassault Rafale, Eurofighter typhoon etc. are mostly with single-seat, but two-seat models of these jets are also available.


texts: What is the typical length of a Transport Category Aircraft Maintenance Manual (# of pages)?

texts:
This FAA publication contains the following image:

The numbers it lists translate to some very long manuals:

1998: 43,071,266 pages/2,532 manuals = 17,010 pages/manual
2008: 184,068,439 pages/5,500 manuals = 33,467 pages/manual

This seems like a lot. 33,000 pages printed out is nearly 11ft on a shelf (that's 3+ meters for those of you not using medieval units)!


texts: Is C.G. of wing itself in line with hang point (hang glider)?

texts:
Where is c.g. of hang glider wing,at hang point ,in front or behind hang point?
Is control bar "neutral" when glider is at rest and there is no wind or flip backward or forward?
At 0:45 control bar  lay at seat,slightly "nose heavy," so  this  wing c.g. is somewhere in front hang point(but to me seems very close to hang point,bar is almost neutral)

here is wing c.g.  excatly at hang point


texts: Does altimeter setting affect the vertical guidance in a LPV approach?

texts:
I had assumed during a WAAS approach when the GPS is in LPV mode, both lateral guidance and vertical guidance are generated from GPS/WAAS signals and the pitot-static system should have no effect on its vertical guidance. This is in contrast with LNAV/VNAV approach, where the vertical guidance comes from the barometric system, the same source as altimeter.

However, when I read RNAV (GPS) Z RWY 30 @ KHAF, I will get a different DA if I use a different altimeter setting. So, why does altimeter settings matter to the DA in an LPV approach?


texts: Why didn’t AFR4590 use heavy in its call sign?

texts: https://aviation-safety.net/investigation/cvr/transcripts/cvr_af4590.php shows that AFR4590 didn’t use heavy in its call sign even though Concorde had a MTOW greater than 300,000 lbs.  Unlike BAW, AFR didn’t have a specific Concorde callsign, so why did they not say heavy:


texts: Can I get an FAA restricted ATP certificate with 1000 hours total time?

texts:
I have an FAA Commercial Single-Engine certificate with 260 hours total time and a Bachelor's degree in Electrical Engineering issued in Indonesia. I have an Indonesian Passport and I'm working as a copilot flying DHC-6 Twin Otters in Indonesia. I'm planning to get a restricted ATP certificate in the USA but there's a question.

Is it possible to go and get a restricted ATP in the USA after flying 1000 hours TT on DHC 6 Twin Otter in Indonesia?


texts: What is "established" on an RNAV approach?

texts:
I was looking at the RNAV (GPS) RWY 6 at 12J.  Thinking about my descent profile, I wondered when I could start my descent from my transition altitude if I was told to maintain an altitude until established.

For example, if the controller told me to "maintain 4000 until established," would I start descending after crossing the IAF and tear-dropping into the hold?  Would I start descending on the inbound leg?  Or, would I start descending after leaving the IAF inbound on the approach?

Edit:

This question assumes that a hold-in-lieu-of-procedure turn is required.  The question, really, is if a controller says "maintain 4000 until established," when can you start descending?  Can you descend as soon as you cross the IAF?


texts: How do I calculate this question? mass and balance

texts:
If we start with $Total\ Weight = 2,850\ lbs$ and $CG = 101.67\ in$, then add $400\ lbs\ @\ 97.8 in$, then how much would the Center of Gravity move?

How can you calculate this?


texts: Do airline pilots identify failed engines in the same way as light aircraft pilots?

texts:
Do the two old adages of light multi-engine flying, namely "Dead foot, dead engine" and "Raise the dead", still apply when flying transport-category aircraft?  Or do airline pilots need to rely on their engine instruments in order to figure out which engine's kicked the bucket?

For those who aren't familiar with those memory aids, they are from page 12-21 (186 in PDF versions) of the FAA AFM:

  There are two time-tested memory aids the pilot may find useful in dealing
  with engine-out scenarios. The first, “Dead foot–dead engine” is used to
  assist in identifying the failed engine. Depending on the failure mode, the
  pilot won’t be able to consistently identify the failed engine in a timely
  manner from the engine gauges. In maintaining directional control, however,
  rudder pressure will be exerted on the side (left or right) of the airplane
  with the operating engine. Thus, the “dead foot” is on the same side as the
  “dead engine.” Variations on this saying include “Idle foot–idle engine” and
  “Working foot–working engine.”

  The second memory aid has to do with climb
  performance. The phrase “Raise the dead” is a reminder that the best climb
  performance is obtained with a very shallow bank, about 2° toward the
  operating engine. Therefore, the inoperative, or “dead” engine should be
  “raised” with a very slight bank.


texts: How was I able to just plug in my headphones and listen to ATC and pilot chatter?

texts:
I was travelling from Mumbai to Newark Liberty Intl on United Airlines 49, a Boeing  777-200. I was sitting in the economy section, last row, last seat to the plane's left, basically, I was literally the passenger on the last seat of the aircraft.

When I sat down, I plugged my earphones into the headphone jack and I could hear the conversation between ATC and the pilot, all I had to do was just twist the and hold the jack in a certain position. I could hear them talk to Mumbai ATC, the Islamabad ATC, Kabul ATC, even up to Iceland. My question is, how is this possible? What could have happened? Did the pilot or the airline know about this? Should I have told them about this? Is it illegal to listen to this chatter? Can this happen next time I travel or was I just lucky?


texts: In F-16 the pilot or FLCS , use the rudder to address the adverse yaw effects in direction of roll during an aileron roll? or opposite way?

texts:
Is the  rudder moving by FBW in direction of roll or in the opposite direction?

I understand that the rudder is used due to the ARI system (ailerons - rudder interconnect), but don't have any idea how much or in what direction it is used throughout the process ?


texts: What is the selection algorithm in f-16 stick LVDT?

texts:
In a reference:
https://www.nasa.gov/centers/dryden/pdf/88102main_H-1344.pdf
page 67 (71 of pdf file) in Table 12,

it is said that the signal selection algorithm from the redundant LVDT of stick in f-16 is GCAF which means good channel average plus monitoring for a fourth input. What does this sentence exactly mean? I know the meaning of good channel average but what is the meaning of good channel average plus monitoring for a fourth input?


texts: Are the A380 engines interchangeable (given they are not all equipped with reverse)?

texts:
I have noticed that the A380 only uses the two engines closest to the fuselage to reverse thrust to brake. Are all four engines the same (i.e.: could they theoretically swap engine 1 and engine 2) or are the inside ones different from the outside ones?

In general, would the outside ones have reverse capabilities if they were installed on the inside or are they different types of engines?


texts: How is metal fatigue detected in an aircraft?

texts: There have been many accidents involving metal fatigue. How do the engineers, maintenance team, etc. know if an aircraft has metal fatigue? What is done to "minimize" metal fatigue or repair it?


texts: Are we changing the angle of attack by changing the pitch of an aircraft?

texts:
For example:

if I pitch the airplane up, but also increase power and am able to maintain the same speed, then no, the AoA hasn’t changed, although it may have varied in the transition between one situation and the other. And yes, I’ll probably be climbing, although there are exceptions, becuase…
if I pitch up, slow down, and maintain the same altitude, then undoubtedly the AoA has increased. Flying slower reduces the amount of lift generated. An increased AoA gets that back so I can maintain the altitude.

Can someone explain these situations why exactly are they producing different results in AoA?

Can someone explain these what is going on in terms of forces?

Please explain in reference with these forces ( in the pic )


texts: Why increase or decrease rudder when using elevator in turns?

texts:
In normal 30 degree bank level turns, instructors teach students that if you are to correct your altitude you also need to change your rudder input.
Why is that?

For example if you are descending in your turn you are to pull the elevator and also lessen your rudder input. And if you are climbing in your turn you are to push the elevator and push more rudder.

Is this because of you are tightening your turn when pulling elevator and therefore you are starting to skid and therefore you need to lessen your rudder to compensate. And if you are pushing the elevator you are doint the opposite starting to slip and therefore you need more rudder.

Or is there some other explaination to why you need to do this?

EDIT:

Hi,

no I think you have misunderstood the question.
They do not teach to use the rudder to compensate for pitch/altitude.

They teach properly to use the elevator. But they say that when you make a change with elevator to a higher nose you don't need that much of rudder than before. And when you use the elevator to push nose down there is more need of rudder.

The rudder change is just to compensate the need due to change in configuration. Not to use it to change the altitude.


texts:
I was surprised to see geese flying some 200 ft above my aircraft at 2000 ft MSL.

I obviously would like to avoid them but I am based too close to the New York City Class B, where there are much bigger, heavier, and faster birds:)

In order to avoid having to get clearance from ATC, I need to fly under the layered minimum altitudes by a safe margin of the upside down cake of the class B airspace.

What is the minimum recommended cruising altitude to avoid bird strikes?


texts: Why do you never see any other planes in the sky whilst flying?

texts: I was just wondering as I passed the airport this morning why, whilst we are flying, do we never see any other planes nearby? There must be millions of planes and millions of people flying each day, I appreciate the sky is massive but these planes must follow roughly the same routes so how is it that they never seem to pass by any other aircraft?


texts: Does asking for deviation due to weather give ATC any leeway for reducing separation between aircraft?

texts: When needing to deviate due to weather, does asking for deviation "due to weather" give ATC any leeway in terms of aircraft separation?


texts: Is constant air pressure maintained inside the fuselage?

texts: I just heard it somewhere but I'm not sure about it.   If it is, then why don't they build airtight fuselages?


texts: Is there a preferred wind direction for a helicopter in hover?

texts:
When hovering, how does a pilot deal with wind direction? As when landing is it preferable to point the nose into the wind? Is this a primary consideration for the pilot considering that he may need to maintain visibility on something, such as during a rescue or a news operation?

And is wind direction more of a factor when hovering in or out of ground effect?


texts: What medications may pilots take while flying?

texts:
We all get sick, suffer from allergies and sometimes chronic issues.  It is not safe to fly while on some medicines or in some cases, for some time after taking the medicine.

How do I know what I can take and still fly?  What resources are out there to check if a specific medicine is compatible with flying (AOPA, FAA, etc)?  Is there a comprehensive list of what I can and cannot take?


texts: What is the typical procedure if an engine fails during a vertical takeoff?

texts: My understanding of VTOL aircraft (correct me if I am mistaken) is that the plane accelerates vertically until it's a bit off the ground, at which point the thrust is slowly vectored horizontally, and when it's finished, the plane has enough speed to produce sufficient lift. So, what happens if an engine fails before the plane has enough speed to lift itself? I'm asking about both single and double engine planes, for example the F-35, Harrier Jump Jet, or Yak 36.


texts: Is there a way to get the original data used to create performance charts?

texts:
I want to create a flight planning software for GA. Just as a prototype for the time being. The performance data and info about the planes should be stored in various databases.

When I go through flight manuals like the CESSNA 150, I get a lot of tables which I could convert into a database, but where do I get data which created these charts e.g. the range profiles?

Is this data available somewhere? Or are there databases available to be used?


texts: Cross Country flight: what do I have to consider concerning radio communications?

texts:
I'm tasked with developing part of a cross country flight plan to cap off my ground school class. Among my group, I am handling the radio communications and regulations. However, I was not provided further details, and came here to gain a greater understanding of what I need to accomplish. Specifically, the trip is to fly from Aspen, fly by Capital Peak for the view, and then land in DIA (KBDU-KASE-KDEN).

As far a radio communications go, I imagine I need the frequency of each of the listed airports, but is there anything else I need to consider?

Edit: Further Information:

I'm flying N370SP, a Cessna 172S Skyhawk SP. I pick up friends (190, #320) and luggage (35, #60).


texts: What is the history of the aircraft logbook?

texts: I need to know when the mandate to maintain a logbook started. Was it a US requirement, or was it from another regulator in the world? Did the aircraft logbook start at the same time as the pilot logbook?


texts: For designing a runway, what are the largest cargo airplanes in use?

texts: I am working on a project where I have to design a runway for large cargo planes and I need to know what kind of planes I should assume would land there.


texts: How can a pilot deal with a magneto failure?

texts: As I know, the engine is independent from the electrical system, and it is supplied from magnetos. However, how can a pilot deal with a magneto failure? And also, when one magneto fails what problems can occur?


texts: Is there an API to get real-time FAA flight data?

texts:
I have been using an Android app to track flights. Their information is pulled from their own proprietary database, and some (with 5 minute delay) from the FAA.

I was thinking about making an app that would do this as well by pulling from multiple data sources.

What are some good APIs, either paid or free, that gives you near realtime data of flying aircraft?


texts:
How often does an aircraft make a mayday call?

I assume when confronted with an emergency on board, they will first deal with it, and not waste time contacting any one who would not be able to help anyway. And when they have time for such a call, there's no emergency anymore.

So, when does making a mayday call make sense?


texts:
Apart from covering the landing gear leg, the Yehudi also increases the wing root cord which allows the build height for the root to increase for the same wing relative thickness. This is useful as the wing has its highest stresses in this area, it is where the wings bending moment is at its highest (leehamnews.com).

I don't understand the text in bold. Apart from landing gear 'packaging'. What are the advantages of the Yehudi? Aerodynamic or otherwise.

(commons.wikimedia.org) An early jetliner without the Yehudi.

I'm also interested in the etymology.


texts:
I've been recently introduced to the world of mini aircraft, specifically, quadcopters - building them, flying them, calibrating them (apparently, it's such an important point that it deserves its own place on the list :) .

I'm about to finish building my own quadcopter (as soon as I can get a power distribution board - hard to find, it seems), and my hands are itching to try and fly it as soon as possible. I've learned a lot about how planes / helicopters / quads fly while in the process of building one. But maybe I haven't not learned enough about it, and was hoping you can help me with one question I have.

I think I've learned enough about the types of propellers used in these vehicles, power requirements, controllers, calibration, and whatnot. While searching about these things on the net, and asking a few friends about their experiences, a thought came into my mind:

Wouldn't be nice if I could, basically, scale all the components of this small, 330mm vehicle I'm building, to make something bigger?

I mean, bigger as in big enough to carry one, maybe 2 people around ?

Can I really say "hey, let's build a frame X times larger, with stronger materials, lets get 4 motors X times bigger, let's use 4 X-sized variable pitch propellers" and so on and so on, and actually be able to build a quadcopter able to carry people in it?

(Yes, yes, I know I'm basically saying "let's build an actual size helicopter, but with 4 propellers instead of one".)

Do you think this is a feasible approach to build such a thing? Is it even remotely possible? Have you had any experience doing such a thing? Any comments will be highly appreciated.


texts: Are seaplanes allowed to taxi in residential areas?

texts:
There's a small pond/lake behind my house. A sea plane was just going around it. It was very loud and got like 10 feet from the shore. It's just going in circles and won't take off and leave.

This is at the tiny town of Elbow lake, MN. There's a small airport here, Elbow Lake Municipal (Y63). If you look at the links, you can see it's near a small lake, and there is a large peninsula on it that comes to a point.

It's so annoying. How can they do this, so close and in residential? Isn't there some regulation to prevent this?

Note: The town of Elbow Lake, MN should not be confused with the body of water, Elbow Lake located some 70 miles NNE. That lake does have a seaplane base (M49), but that area is entirely unrelated to this question.


texts:
Under 14 CFR 91.3 ---> "In an in-flight emergency requiring immediate action, the pilot in command may deviate from any rule of this part to the extent required to meet that emergency."

Under which circumstances will that imply that the PIC deviate from Part 91?

Could it imply that Wx minimums won't apply?

Could it imply that Minimum Altitudes no longer are required?


texts: Why did the Boeing 787 switch back to separate IRS systems?

texts:
The Boeing 737 uses two independent IRS systems (see also Why are there two IRS switches on the 737NG?):

(source: 737 NG FCOMv2 (11.10.21 - Flight Management, Navigation - Controls and Indicators))

and the Boeing 747 uses three independent IRS systems:

(source: 747-400 FCOMv2 (11.10.9 - Flight Management, Navigation - Controls and Indicators))

For the Boeing 777, they switched to a single ADIRU:

(source: 777 FCOMv2 (11.10.10 - Flight Management, Navigation - Controls and Indicators))

The reasons are explained in this answer to the question How many Inertial Reference Systems are on a commercial aircraft?:

  Fast forward to the Boeing 777, the pilots only have one such unit: the ADIRU, or Air Data Inertial Reference Unit. The ADIRU by itself is a fault tolerance unit - within this unit, there are multiple gyroscopes and accelerometers. In the past, when multiple redundant units are provided to the pilots, there were instances where the pilots had trouble identifying the malfunctioning unit or switched to the wrong unit, and the plane crashed. Now there is only one unit, and the redundancy mechanism is auto-managed.

This makes perfect sense to me and should have improved safety. But I was surprised to find that the Boeing 787, which is in part based on the 777, switched back to two separate systems:

(cropped from source)

Question: Why did they change back? Was there something wrong with the 777 ADIRU?


texts: What is the lighting technology behind the Dreamliner's dynamic interior lighting?

texts: The flights that I've been on in the Dreamliner (and also Virgin America), have dynamic overhead cabin lighting that provides nice mood lighting, helps alleviate jet-lag, and is otherwise very pleasing to look at. What is the technology behind this? The closest technology I've seen that can offer dynamic light coloring is phillips hue lightstrips.


texts: Is there a rule concerning the offloading of a missing passenger's baggage?

texts: Is there an International Rule under which the baggage of a passenger is offloaded in the case that he/she fails to report at the departure gate 15 minutes before boarding time?


texts: Is there a preferred turn direction for helicopters?

texts:
If I have a requirement to fly a helicopter in a circle or racetrack over a point of interest that's stationary or moving relatively slowly, is there any reason to prefer left or right turns?

I'm not concerned about visibility and I'm not asking about turns in a landing pattern: I'm asking if - all other things being equal - there's any mechanical, aerodynamic or procedural reason that pilots would prefer to turn in one direction over the other.


texts: What RA will be generated if intruder traffic is at our level in TCAS II?

texts:
If the other traffic is at the same level, and neither climbing or descending. Will the RA say "CLIMB" or will it say "DESCEND"? How will it be decided and what are the possibilities?
Assume:

Mode S is not available
Only one aircraft has TCAS

Will it be random?


texts: Why is the A330neo more efficient than the A350 on shorter routes?

texts:
For A330neo Wikipedia page, is written:

  A330neo enables profitability on shorter ranges where the longer-range A350 and Boeing 787 aren't optimized.

For what reasons it is true?

A330 and A350 have almost the same size, weight and passenger capacity (the undeveloped A350-800 should be also more similar), and also engines are very similar, the same family Trent 7000 vs Trent XWB.

I thought that with almost similar planes, the bigger difference for calculating range could be only the fuel capacity (surely bigger for A350), but efficiency (in terms of lower weight due to advanced materials, lower fuel burnt due to new engines technologies) could be an "always true" concept.

So, why for shorter routes A330neo is more efficient than A350? Could not be enough to have an 350 with lower fuel capacity (in case shorter length) and maybe reduced engine power (the opposite of higher power in A350-1000) thanks to reduced weight?

I found this similar question, but I think that mine is more focused to general concepts because I'm asking also "what makes an aircraft more optimized for longer/shorter routes.


texts: How is the range/fuel computed when there is a 3-hour difference for the same route?

texts:
I am not a pilot. I recently took a trip SIN-SFO 14 hours (tailwind) and SFO-SIN 17 hours (headwind), flying United.

According to the Dreamliner Wikipedia page, the 787 range is 7,635 nmi (14,140 km), where the distance SIN-SFO is 8,447 mi.

How is the range rating computed? In the example above, there are 3 hours difference in flight time for the same range.
What is the difference in fuel consumption on the two trips (rough average)?

According to 'How does wind affect the airspeed that I should fly for maximum range in an airplane?':

  If you have a headwind, the longer you stay aloft, the more you are carried back, so you better hurry up. With a tailwind, it helps to slow down because now the wind is helping you to cover even more distance.

*

SFO = San Francisco

SIN = Singapore


texts: How to find capture area of an engine inlet?

texts: I tried to relate intake pressure recovery in terms which do not involve efficiency of an inlet and capture area, i was able to formulate pressure recovery without intake efficiency but now i need to find a way to formulate capture area of inlet without without use of intake efficiency and pressure recovery is it possible ? if yes please share.


texts: Where can I find info or techniques on calculating the influence of a duct on the thrust and efficiency of a propeller?

texts:
I am trying to run numbers on a concept VTOL fixed-wing aircraft, and I am looking at having fans or props positioned inside the wings, (which would therefore make the wings relatively thick for a fixed-wing aircraft). Naturally this would see the fans/props enjoying the benefits of a duct, but with minimal downsides such as the need to add weight/material as the wing is already going to be there.

I am using Blade Element Theory to trial propeller dimensions/numbers to see what kind of sizes I would need to achieve the VTOL (if I can minimize the radius of the VTOL fans then I can the wings thinner or with a smaller chord), but I don't know of any way to estimate the influence that the duct would have on the final thrust/power values.

If there is a rule of thumb for this, or a database, or some equation or anything, that would be a great help!


texts: What are the fonts used in MCDU screens?

texts:
All MCDUs (and other screens) I've seen share a very similar, if not identical, set of fonts - a monospaced, sans-serif, very clean and easily readable font, often in two vertical sizes at the same horizontal pitch. What font is that? Do different instrument/airplane makers have their own? Do airlines standardize on one across their fleets?
FAA's Advisor Circular 25-11b (https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_25-11B.pdf) makes some recommendations on fonts.
Also, http://www.b737.org.uk/fmc.htm has screen photos where the pixels are discernible, presumably from an early 737 model. There isn't a name, but there is enough unique features for it to be identified, if it has an official name.


texts: Why does the elliptical wing planform have two different types of curves?

texts:
Generally, I have seen that the planform of an elliptical wing consists of two different types of elliptical curves
The elliptical curve towards the leading edge has a lower value for semi-minor axis and the curve towards the trailing edge has a higher value of semi-minor axis
What is the reason for such a geometry?
(Image is attached for reference)


texts: Why do GA pilots in Europe operate N-reg (US) aircraft?

texts:
When I read articles or blogs online about GA flying in Europe I get the impression that it's not unusual for European GA pilots to have FAA licenses and fly N (US) registered aircraft.

I've never seen any numbers mentioned so I don't know how common this really is, whether they hold only FAA licenses or also European ones etc. But in general, as a European GA pilot, what is the benefit of operating an N-reg aircraft rather than a locally registered one?


texts:
An autobrake is a type of automatic wheel-based hydraulic brake system for advanced airplanes. The autobrake is normally enabled during takeoff and landing procedures, when the aircraft's longitudinal deceleration system can be handled by the automated systems of the aircraft itself in order to keep the pilot free to perform other tasks - Wikipedia

How does the aircraft "know" when is time to activate the autobrake
systems on a rejected takeoff and landing?
Does it apply full brake to all the aircraft's wheels?
Is it really used by commercial jets?


texts: How do pilots maintain level flight after launching missile?

texts:
I saw, on National Geographic, two well built navy guys lifting a comparatively small missile to be attached on wings of an F-18 Super Hornet.

So when one missile on left wing is launched doesn't it drastically shift CoG of jet? Who copes with this shift

Computer & other stuff internally adjusts the zero position of flight controls to attain level flight. In this case what is the basis of detecting shift in flight control made by pilot - the old zero or the new zero?
The pilot by shifting position of flight controls, using hands & feet, in non-zeroish positions to maintain level flight despite changed CoG. If yes, isn't it detrimental to pilot's performance in a dog fight?


texts: Why can't this blended wing body trijet airliner fly?

texts:
I was told in this other question this aircraft was not real, and that it could not fly in this design.

I'm now interested in knowing what would prevent it to fly, from an engineering point of view. It looks great... why is it so obvious this cannot work?


texts: Is smart phone's GPS accurate enough to calculate airplane speed?

texts:
Around seven years ago, I did airplane speed measurement. I activated the GPS on my tablet and I monitored the speed, especially when the airplane touched the ground (runway). I found that the airplane touched the ground with speed 420kph, which it was fast enough. The measurement was probably not 100% accurate, but I could feel that the airplane was landing and touched the ground quite fast.

My question, how accurate is measurement with GPS, especially using GPS installed on smart phone? If I need to calibrate, how to calibrate?

Edit:
The airplane was Boeing 737. Not sure the series.


texts: What does "Clear Of Clouds" mean in reference to Class B Airspace in the United States?

texts: Does "clear of clouds" mean you cannot touch a cloud or does it mean that that Class B airspace must not have any clouds in it?


texts: What are all the US airports where E4 "extensions" change to E2 and become part of a larger E2 "surface area" when the tower closes for the night?

texts: Of all the US airports with part-time control towers and with E4 "extensions", in which cases are the airspace definitions written so that the E4 "extensions" change to E2 and become part of a larger E2 "surface area" -- which also includes the airspace that was Class D during the daytime -- when the tower closes for the night?


texts: Why isn't the wing span of a certain airliner longer with the longer fuselage versions?

texts: The Boeing 737 next generation models (700,800,900ER) all have the same wingspan at 117ft 5 in. Why doesn't the wingspan increase with bigger and longer models? With the 737-900 wouldn't you need a longer wingspan than the 737-700 because of the extra weight you would be carrying and you need more lift to support that extra weight.


texts: What could cause the Boeing "Pickle Fork" issues?

texts: The Boeing 737-NG has been in the news recently regarding cracks discovered in the "pickle fork" assembly which transfers loads from the wings to the body of the aircraft.  The "pickle fork" was supposed to last the lifetime of the air frame (90,000 cycles), but cracks were discovered in airplanes with less than 30,000 cycles.  Could the cracks be due to an "over G" situation where turbulence or a hard landing could have caused the airplane to exceed its load limit, or is this likely due to a design flaw?


texts: Does lift-to-drag vary with anything beyond geometry?

texts:
The basic equations for both lift and drag show dependency on $v^2$, air density and some constants. At a glance, Lift to Drag ratio should depend on nothing else than plane geometry. Although I realize in aerodynamics things are rarely that simple - and so, I wonder how constant these constants actually are?

In particular - let's say we use a very efficient air-augmented rocket engine (so thrust doesn't degrade with air pressure) of a moderate thrust, sufficient to achieve take-off and a modest climb rate. We also somehow manage to shield the airplane from overheating. As it climbs, air density drops, speed rises - could it reach orbital speed eventually? Or will it encounter conditions where it can neither accelerate to gain more lift, nor climb to reduce drag?


texts: How does PF or "pilot flying" and PNF or "pilot not flying" affect logging?

texts:
How does PF or "pilot flying" and PNF or "pilot not flying" affect logging for pilots operating in a two-pilot environment?

Here are some granular examples...

How should actual instrument be logged? Should a PNF be able to log actual time if they are monitoring during instrument conditions?
How should landings be logged? Should a PNF be able to log landings they were not at the controls for?
How should approaches be logged?

Any insights are appreciated. This question is in reference to FAA regulations only.


texts: Is it safe to fly ultralights at 6-7 weeks pregnancy?

texts: Are there regulations or official guidance regarding pregnant women flying ultralight aircraft at 6-7 weeks pregnancy (amenorrhea weeks)?


texts:
Reviewing the ILS 7 approach at Barrow (PABR) revealed something I have never seen before:

Now, I saw the note (and diagram) in the upper left corner, so I was able to infer that this is a "grid course" but I still have no idea what this is.

Is there anyone on Aviation SE that knows and can explain?


texts: What is this ring-shaped device behind this DC-8's jet engine?

texts:
What is this ring-shaped device behind this Douglas DC-8's jet engine?

(YouTube)


texts: Who decides what measurement units are used for altitude, and why is there no standard?

texts:
I know that some countries (Russia and China for instance) use meters to measure altitude while the rest of the world uses feet. Why isn't this standardized around the world?

I guess all modern cockpit instruments nowdays offer both unit system measurements, but this must be creating some confusion for pilots.

Who decides which measurement units should be used for aircraft altitude? The airlines? ATC? Each country?

Why are both units of measure used?  Are there any pros or cons with using meters?


texts: What were DJI drones spying on? What data did they capture?

texts:
In late 2017, it was claimed that DJI (a very popular Chinese drone company) was working with the Chinese government to spy on the United States via their drones, or their drone controllers, which are owned by many Americans. This claim was made by the Los Angeles Office of the Immigration and Customs Enforcement Bureau, which cited "moderate confidence" in their findings. This led the military to discontinue the use of DJI drones.

My question is - What specific information could be gleaned from these drones? I would presume navigational data, but perhaps video and audio could be recorded? The data that was collected, what benefit would it provide to China?

Regarding the above, my only assumption would be that the Chinese could track military operations that DJI drones were used in, but I'm not sure if this is accurate, or the only potential purpose. I'd be appreciative of any well-sourced answer.

LA-ICE Analysis


texts: What do aircraft accident investigators do in between incidents?

texts:
Consider aircraft accident investigators in your average first- or second-world nation. Something like the US NTSB, the French BEA, the Canadian TSB, the Australian TSB, ... (whichever you happen to be most familiar with is fine)

Now, most of the time, aviation ticks along nicely. Aircraft take off, aircraft cruise, aircraft land. Aircraft are checked up and maintained. It's not like you are going to call in an accident investigation team for a hard landing or a broken light bulb.

Yet when something does happen (especially in a known location) that warrants an investigation, investigators are on the scene quickly, not uncommonly within hours of an incident.

Considering how long investigations can take to complete, it seems likely that multiple teams would be needed, so that one can be brought in quickly without unnecessarily disrupting any ongoing investigation. (Aircraft incidents do, unfortunately, happen more often than once every several years, especially in large countries with significant amounts of air traffic.) On the other hand, incidents happen rarely enough that it seems to me, most of the time, a large number of such investigators would basically be sitting around just waiting for something to go wrong. That doesn't seem reasonable, so...

What do these people actually do while aviation pretty much just works?


texts: Does every single aircraft have a unique registration mark or number? If, for example, 2000 Boeing 777 units were produced, do they have their own registration number? And how is that registration number regulated? Who keeps the number? What is that registration intended for?


texts: What do these white on red words indicate on a London Heathrow taxiway chart?

texts: What do the words in white block capital letters over a red background denote on this aerodrome chart of LHR?


texts: Why don't passenger planes move back by their own means before taxiing?

texts: As far as I know, passenger planes needs a puller/pusher truck to go back in the land. But why they don't go back without truck assistance?


texts: Which American twin tilt-rotor aircraft is this a scale-model of?

texts:
What aircraft is this model?

(photos: own work)


texts: What is the most carbon-efficient way to take off in a passenger plane?

texts:
Consider two possible flight paths for a jet passenger plane; the first is a slow climb, held low over 20 or so miles to avoid other flight paths, the second a more rapid climb over 10 miles to the capacity of the plane rather than restricted.

It has been said to me that the more rapid climb will reduce CO2.
But logic to me is that the rapid height gain will burn more fuel and so increase CO2 production (or perhaps are the 2 not linked I wonder).
I would appreciate being put out of my mystery on this?


texts: What do you need to do to bring a 737 Max back in service after 6 months in storage?

texts:
What kind of maintenance has to be performed on an aircraft if it has been stored for 6 months?

For example, do fluids need to be changed, have the tires become flat, etc.


texts: As a student pilot can I fly solo hours from any airport?

texts: I am researching flight school because I am very interested in getting my PPL. I live in DFW I just graduated from college and money is tight. So I am saving money to get the PPL. I know the bulk of the cost is paying someone to train me. My question in regarding the privileges you have as a student pilot.


texts: Why does the US Marines continue to fly the AH-1 Cobra, retired by the US Army in the late 90s?

texts:
My father flew Bell AH-1 Cobra for the United States Army in the late 1970s and a young man in my daughter's USN winging class (July 2017) was being assigned to Camp Pendleton to fly Cobra's for the United States Marines.  From talking to my father and reviewing the Cobra wiki page, it appears that the Army retired the Cobra in the early 1990s.  However, it seems the Marines have continued to fly the Cobra, though AFAICT, they seem to have moved to the twin Super Cobra:

I am aware that other attack helicopters followed the Cobra and that the Army adopted the AH-64 in the mid 1980s.

What's not clear is why the Army retired the Cobra but the Marines continued to fly it.  Or, perhaps another way to ask this question would be, why does the USMC favor the Cobra over the newer AH-64?


texts: What kind of cable is used to transmit signal from flight control computers to actuators?

texts: I am a student and have been researching about ARINC 629 and AFDX. In b777 fly-by-wire system, what kind of cable is used to transmit analog signal from Actuator Control Electronic (ACE) to the respective electrically-controlled actuators? What kind of bus cables/connectors are used in ARINC 629?  What about in AFDX? Does AFDX use fiber optics?


texts:
easy question: When creating a list of regulations (and the documents that show compliance with those regulations) that apply to our STC, if one of them has been canceled, would we continue to use that regulation+Amdt basis or the successor regulation?

The install is assumed to be non-significant based on 14 CFR 21.101, so we're using the cert basis on the TCDS.


texts: Which regulation requires me to report entering a hold?

texts:
I have seen in many bulletin boards that a pilot is supposed to report upon entry into a holding position.
I can find that reporting nowhere in the regulations .
I can find in the regulations where a pilot must report leaving a hold at expected clearance time,  and at that time he is supposed to report time, altitude, and position, and the fact that he is leaving the holding position.
Where in the regs does it show that you must report upon hold entry?


texts: How to measure thrust produced from combustion chamber of Gas Turbine Engine?

texts:
I'm conduction a scale model experiment of thrust production in combustion chamber by using different types of fuel source.

Comparing the thrust produced by using hydrogen gas, kerosene and petrol.

Specific energy:

Hydrogen gas = 142 MJ/kg

Kerosene = 42.8 MJ/kg

Petrol = 46.4 MJ/kg

What are the instrument to be use for measuring thrust output of the combustion chamber through combustion of the fuels?

What values do we measure? (eg. airspeed at output of combustion chamber/ temperature/ thrust)


texts: What options are there in Canada for treatment of severe depression and anxiety for pilots?

texts:
I'm a Canadian commercial helicopter pilot, and I've been struggling with severe depression and anxiety issues since childhood.
I'm very good at faking it, well, good enough that I've been able to lie on my medical in order to get it. Initially I had a 'good reason' to, I thought that my depression issue had something to do with not being fulfilled in life and that maybe following my dreams would sort it out. Because that was the only thing I hadn't tried yet, besides chemical treatment.
Well, it hasn't. In fact, its become abundantly clear to me that its entirely a chemical issue. Its not an issue of environment, job, friends, family, its not an issue I can talk about because there is no reason in the first place. I need actual prescription treatment.
It's entirely independent of my life, which I have no complaints about. Gradually its gotten worse. I took myself off of flying duty when the suicidal ideaton started up again, and have been unemployed since as I cant even get out of bed before 4PM most days, not fit to fly in the least.
Ever since then I've been treating it with cannabis, which has had quite satisfactory results, the daily life-is-pain levels have descended from a steady 8 to a solid 4. But as everybody knows that's not sustainable with aviation drug tests, as well as obviously illegal to continue. I've done lots of research into my options for treatment that wont end up throwing my career away, but maybe its just the depression talking, but all of them see like rather optimistic and shit gambles to me. Every non chemical option i.e, shrinks, supplements, getting outside, exercise, has fallen flat entirely. TC does say on their site that they have some program for treatment, but my interpretation of it is that the goal is to have you off the medication before returning to flight, not to have you able to stably take it during, which in my case sounds like a recipe for disaster as I feel it'll just come back.
I'm seriously considering just hanging up my helmet for good and just accepting that until the issues are sorted out fully, which may be never, that I'll have to pursue another career. I don't want to, I want to be a pilot. I don't want to be a washed up former pilot, because I don't know if I'd ever get over that. But I'm killing myself slowly doing it, so I have to do SOMETHING.
Has anybody ever faced a similar situation before, or have any ideas?
Because all I can see options wise right now is; A, throw away tens of thousands and an entire career to get treatment, and possibly never get over that. Or, B, continue lying on the medical and keep going, but effectively torturing myself.
I don't know what I'm expecting asking an anonymous forum this, but I don't have anyone else to ask aviation related questions and I despise working with shrinks.
PS:
Also, don't be that guy, or any variant of that guy, who goes, "Well you shouldn't have become a pilot in the first place then!", because there's always that guy. I know. Tell me when you've got a time machine to make that piece of advice worth anything.


texts: Speaking in terms of health for the ears and eardrums, would earplugs that form an airtight seal be dangerous to wear in flight due to cabin pressure changes? What about in the event of a rapid depressurization? And does it make a difference in which phase of flight they're first put on (before take off vs when in cruising altitude)?


texts: Why does the F-16 canopy have a K-shaped 'latch'?

texts: Why is the F-16 canopy latch (the yellow painted part) shaped like a K? It's a very funky shape, and I'm wondering if that functions as more than just a latch.


texts: Which GPU (Graphics Processing Unit) is used to generate the graphics for avionics?

texts:
I guess it isn't the GTX 1080Ti.

But which GPU(s) has the Boeing 737-NG for example? How does it differ from a GTX 1080Ti (cost: around €800), or Quadro P6000 (cost: around €7100)? How many GPU's are required? And what is the cost of one single GPU-Module for a 737?


texts: Do autopilots force the aircraft to fly over certain coordinates?

texts:
As part of a project I'm doing I plotted the flight paths of about 2000 flights around the globe, I noticed over both the North Atlantic and Pacific that there is a pattern to the flight paths:

You should be able to see Europe on the right and the USA on the left. Why is there such a common pattern in the flight paths? They all seem to cross every 10 degrees longitude and 1 degree latitude. Is there any explanation for this?


texts: Could reduced-lift wingtips allow an airplane to generate less wake turbulence?

texts:
Would it be possible to weaken the wake vortices generated by a large aircraft (which can be dangerous to smaller aircraft behind the large aircraft, and are the limiting factor determining how closely aircraft can be safely spaced in the air) by shaping the tips of its wings so that the lift generated (and, thus, the amount of air deflected downwards) by the outermost portion of the wing drops off gradually to zero, instead of abruptly transitioning at the wingtip from “lots of lift, lots of downward-deflected air” to “no lift, no downward deflection of air”?

Diagram of what I’ve got in mind:

This would come with a slight efficiency penalty (equivalent to slightly decreasing the length of the wing), but could still be useful in some situations despite this (such as high-frequency operations by a mix of heavy and less-heavy aircraft in heavily-congested airspace, or large numbers of takeoffs and landings by both heavy and light aircraft on closely-spaced parallel runways), and the reduction in lift generated by the wingtip would offset some of this penalty by reducing the upwards bending force on the outer portions of the wing (and thereby reducing the amount of material needed for stiffening this part of the wing).


texts: Was the adoption of conventional tailplanes as 'everyday aircraft' inevitable, or are there other designs that can be just as good?

texts:
I originally asked a variant of this on Worldbuilding.SE, but they didn't seem to like it. So I apologize if it's out of place even here.
I ask, because I've been forming in my head an alternate history or two that would logically involve a completely fresh start to aviation; no Wright Brothers, no Otto Lilienthal -- the entire world looks slightly different on a political map.
Because the world is different, it would be lazy of me to just import elements of our timeline without understanding why things developed the way they did. Our world, in general, appears to have rolled with canard planes and later adopted the tailplane for just about every conceivable function for fixed-wing aircraft.
That alone seems to imply that the tailplane is the superior choice to any other design, but is it really? Or was it just a case of technological and economic inertia?
Since 'superior' can be subject to opinion, I'll try to narrow down some criteria:

The design has comparable advantages in stability, lift production and maneuvering.
The design has comparable economic advantages; it doesn't necessarily require more time and resources to build and maintain.
The design does not (necessarily) incorporate concepts that require an advanced and well-developed understanding of fixed-wing aerodynamics. These would be among the early aircraft designs, or at least a short time into successful flight, so things like vortilons, fly-by-wire, etc. would not be present.

There are definitely plenty of wacky creations like Burt Rutan's Quickie, the V-173 and Miles M.39, but I'm sure there are good reasons none of them ever became popular...right?


texts: What is the reason for setting flaps 1 on the ground at high temperatures?

texts:
Yesterday I've seen an A320 standing at the gate with flaps 1. While this question answers, why the flaps should be up, is there any reason to retract the flaps to 1 instead of up?

In addition it seems to apply only in high temperatures (30°C, and rising yesterday). As well in this pilot eyes video the FO confirms the temperature (31°C) before setting flaps to 1 as they taxi to the gate.

I've seen this only on the A320 (yesterday) and on the A330 (in the video). Does this apply only on Airbus aircraft or as well on others?


texts: Why would an airplane tip backwards during unloading?

texts:
I flew on JetBlue Flight 1011 BOS-ORD today, 2017-01-14. At the arrival gate, after 2/3 of the passengers had deplaned, a flight attendant asked us to stop and wait. He told us that the pilots were concerned that the plane was "tipping" to aft. I overheard the pilot say that the front landing gear was fully extended. The pilot also mentioned that they had "never seen anything  like this," that there was no cargo on board, and that the baggage handlers had 30-40 bags remaining at the rear of the plane. After about ten minutes, we were all allowed off.

Why would something like this happen?


texts: How are VORs oriented near the magnetic poles?

texts:
I noticed on SkyVector that, for example, the Resolute Bay VOR (YRB) and Baker Lake VOR (YBK) seem to be oriented in such a way that the 360 radial is pointing in the direction of true north (and I don't think the variation is anywhere near zero there).

I know VORs are supposed to be oriented according to magnetic north, but is it common practice close to the magnetic poles to have them point true instead? If so, is there any way to tell if a particular VOR is doing just that, except looking at the chart and noticing that the small arrow is pointing north rather than off to one side?


texts: How is an out-of-trim condition (in relation to weight distribution) detected on the ground?

texts:
My question relates to Captain reports Out of trim
and
this answer.

How is an "out-of-trim" condition like the one mentioned in the linked question detected on the ground? I.e "out-of-trim" in the context of weight distribution or balance of the aircraft and not control surface trim.


texts: Why does weather radar not report some precipitation?

texts:
Not sure this is the right place for this, but how come I look at the radar sometimes and, despite it clearly raining at my present location, it doesn't show any precipitation? Example is right now at KEWR, it's raining. I can verify that by standing outside. But looking at the radar from several sources (NOAA, weather.com, several iPhone apps) there is nothing on it.

I know about the whole tilt thing but KEWR has a terminal radar quite close as I recall most airports do.


texts: What causes fuel gauges to be untrustworthy?

texts:
I went on my first flight yesterday (Cessna 152), and I was told not to trust the fuel gauges and to check fuel levels manually. The instructor said that the only fuel gauge reading that I can trust is a 0.

Why is that exactly, and what can be done (or what has been done/studied) to improve their accuracy? Is there some fundamental technical limitation that makes better accuracy difficult to achieve?

Do automobiles have more or less the same issue, or is the inaccuracy more prevalent in aircrafts?


texts: Due to the corrective calculations being ground-based, does the reliability of WAAS degrade with increases in altitude?

texts:
Since the WAAS system utilizes stations at known, fixed locations on the ground to make determinations for positional correction, is there a loss in the precision or validity of that correction with an increase in altitude?

If there is, how does it scale?  Is the loss in reliability of the correction linear, exponential, is it simply a negligible degradation, etc?


texts: How can I calculate turbofan efficiency as a function of turbine inlet temperature?

texts:
I know that increasing the turbine inlet temperature (TIT) increases the overall efficiency of the jet engine. So I wanted to find the overall efficiency as a function of TIT. I used the equations from this website. But the efficiency seems to go down as I increase the TIT. I have attached the pictures of the functions I used to get the graph.

I assumed a compressor pressure ratio of 30, a fan pressure ratio of 1.5 and a bypass ratio of 8.

stages of the cycle the way I defined it as
1-2 is inlet
2-3 is compressor
3-4 is combustor
4-5 is a turbine
5-6 is afterburner(I didn't use it so 5 and 6 are same)
6-7 is the nozzle

I have also found another picture from this website that showed the similar result with efficiency going down as TIT is increased

Can someone please tell me what I did wrong? Or if you can provide a similar graph with similar assumptions that would be great.


texts: How much lift must a helicopter rotor produce?

texts:
How much lift must a typical helicopter rotor produce? For example, consider the rotor of what seems to be a common helicopter: the Robinson R22. Is the lift produced equal to one of the following:

The weight of the helicopter;
Double the weight of the helicopter; or
Simply some value greater than the weight of the helicopter?

For example: for a 700kg helicopter, what maximum lift will the helicopter rotor need to produce?


texts: What is a "sidestep landing" in an instrument approach?

texts: I have never seen a sidestep landing on an approach plate. What is a sidestep landing and when I can chose this approach?


texts: How fast can pushback tugs actually go? (maximum possible speed)

texts: For school, I'm doing a project where we choose a topic about anything, ask questions, and learn about it. I chose my topic as fuel efficiency of airplanes, and one of the things I want to research as part of that topic is fuel efficiency of planes on the ground and see if we can cut down fuel burn at airports. While I was exploring that sub-topic, I thought about tugs and if they are capable of going faster than 30 kts. If they are, we can use them more than just for pushback and potentially cut down on aircraft fuel use.


texts: Why are sidestep ILS minima not used in EASA-land? (specific example: EGKK)

texts:
If you are not aware, London Gatwick (aka EGKK) has a setup with a primary air carrier runway and a backup runway immediately next to it, such that only one runway can be used at a time.

The main runway 8R/26L (South) has full HIALS (ALSF-2 in FAA parlance) with CAT III ILS as well as RNAV (LNAV/VNAV, no SBAS/LPV) and plated SRA non-precision approaches; however, the backup runway 8L/26R (North) only has RNAV and SRA approaches, and no ALS.

Similar runway configurations in the US (KEWR aka Newark Int'l is similar save for having a crosswind runway) allow what is called a sidestep ILS procedure, where the main ILS is flown to higher (nonprecision) minima and then a maneuver is executed on short final to "slide" over to the other runway after visual contact with both runways has been achieved. From AIM 5-4-19:

  5−4−19. Side−step Maneuver

  a. ATC may authorize a standard instrument
  approach procedure which serves either one of
  parallel runways that are separated by 1,200 feet or
  less followed by a straight−in landing on the adjacent
  runway.

  b. Aircraft that will execute a side−step maneuver
  will be cleared for a specified approach procedure
  and landing on the adjacent parallel runway.
  Example, “cleared ILS runway 7 left approach,
  side−step to runway 7 right.” Pilots are expected to
  commence the side−step maneuver as soon as
  possible after the runway or runway environment is
  in sight. Compliance with minimum altitudes
  associated with stepdown fixes is expected even after
  the side−step maneuver is initiated.
  NOTE−
  Side−step minima are flown to a Minimum Descent
  Altitude (MDA) regardless of the approach authorized.

  c. Landing minimums to the adjacent runway will
  be based on nonprecision criteria and therefore higher
  than the precision minimums to the primary runway,
  but will normally be lower than the published circling
  minimums.

Why has the UK not published similar minima for Gatwick's ILS?  The existing OCHs for the secondary runway RNAV approaches are in the 650' range -- if the Newark ILS sidestep minima are any indication, it'd be possible to obtain lower minima for a sidestep approach to the EGKK secondary runway than are currently available from the RNAV or SRA approaches, and it would require no new navaids to be put into service.

Are sidestep approaches verboten in JAR-land? Is there some terrain or obstacle factor that I'm not seeing that makes a sidestep ILS approach into EGKK problematic or not desirable relative to the current RNAV approaches to the secondary runway?  Or can the ICAO/CAA format for approach plates not represent sidestep minima?


texts: Can hang glider hover straight into wind and keep same position?

texts:
Isnt resultant force allways  pointing slighlty backward at every wing,so why hang glider is not push downwind by the wind?
From theory that cant be possible,so does wind somehow coming at him at angle from below? ground seems flat,maybe slightly angled..
(Is it easy what his doing or that can do only very very skilled pilots?)
Can he penetrate continusly forward into wind direction in zag-zag motion,first straigt up and then down-forward or maybe with dynamic soaring like birds do?


texts: How is health monitoring of large aircraft engines and components done?

texts:
How is online (in-flight) and offline (between flights) health monitoring of large aircraft engines and other essential components done?

As far as I have been told, there are a lot of measured channels (at least for engines), but:

what exactly is measured?
How are the data evaluated during flight?
How are the data evaluated on the ground (from long term point of view or after/before failure)?

EDIT: You can consider Boeing 747 or 787 as a large aircraft (to narrow down the question as requested).


texts: Where can I find airfoil data for the Beechcraft 1900D tail?

texts: I am creating a CAD model of Beechcraft 1900D from images for a project. So far most info is available in http://www.users.on.net/~grypen/b1900d.html except the airfoil used by the tails. I have searched extensively and wasn't able to come up with any data. I am new to this and may be unaware of popular sites for these kinds of data. Any help is much appreciated. Thanks!


texts: What is this metal plate below the door?

texts:
What is this metal plate for?

(source)

You can also see it here:

(source)

Is found on many aircraft so what is that piece of metal right there?


texts: How do pilots calculate the temperature to put Into the FMS for an FLX takeoff?

texts: I recently read an article about derated takeoffs and I understand the concept, but how do pilots know what temperature to put into their FMS if they want an FLX takeoff? Some people say it's a rough estimate like ~50-60 C, but is this true? If it is gauged by some external factor, what is it?


texts: What is causing these "corners" on this F-104 V-n diagram?

texts:
In this V-n diagram for an F-104 (source: this Wikipedia link), on the left-hand edge of the flight envelope, what is causing the "corners" that we see at the following points? (Numbers are approximate)
30,000', 375 knots IAS, and 5 G
40,000', 295 knots IAS, and 3.1 G
50,000', 230 knots IAS, and 2 G
60,000', 180 knots IAS, and 1.25 G
70,000', 140 knots IAS, and 0.95 G
Do these points simply represent the "corners" of what performance is possible while still maintaining horizontal flight at a constant airspeed (i.e. while maintaining both altitude and airspeed), and if more engine thrust were available, these "corners" would move higher up and to the right, continuing to follow the stall speed curves?  I.e., do the actual stall speed curves continue upward from the corners following a path that is more or less continuous with the lines below the corners?
(Note-- re the last data point--  a G-loading of less than 1 is obviously incompatible with constant-altitude flight-- but the data point still could have mathematical or theoretical significance -- e.g., if the aircraft weight decreased by 5%, then the aircraft could maintain constant altitude.)
Wouldn't it be theoretically possible for a pilot to operate well outside the illustrated envelope, say, by pulling 4G at 340 knots IAS at 40,000'?  Am I correct to assume that this could be done without stalling the aircraft, but the aircraft would be losing either altitude or airspeed continually?  Because it is on the "back side" of the thrust-required curve?  Whereas that would not be the case for a point further to the right, on the other side of the illustrated curve?
If the actual stall speed curves do in fact continue more or less smoothly upward from the "corners", this would imply that if, theoretically, we were setting a "maneuvering speed" to protect the aircraft from exceeding 6G's, it would need to be at about 430 knots IAS at 20,000' (the "cornering speed" shown on the diagram), but it would need to drop to about 380 knots IAS at 30,000' -- well outside the envelope of the figure as drawn.  Is this in fact the actual situation?
Is this particular diagram really as much about achievable performance as about protecting the aircraft from excess loading, at least in the positive-G part of the flight envelope?
Is it therefore not strictly accurate to call this particular diagram a "V-n diagram"?
Related ASE questions and answers--
(Q): In this F-104 V-n diagram, why does the stall speed (in terms of IAS) decrease with altitude in some parts of the flight envelope?


texts: What are the major differences in operating the Boeing P-8 Poseidon and Kawasaki P1 in the maritime patrol aircraft role?

texts:
What are the advantages and disadvantages of the P-8 Poseidon and Kawasaki P1 in the maritime patrol aircraft role? They were made for the same role, but they are different. The P-8 is something like converted from a civilian design while the P-1 is military-purpose built. What does that mean? What does the different number of engines mean for missions undertaken by these aircrafts?

P-8 Posiedon (left) and Kawasaki P-1 (right)

(source)


texts: Does installing a PTZ dome camera outside the aircraft violate any FAA rules?

texts:
I want to install a big PTZ camera at the exterior of the plane like A380 which can give the pilot a clear view while landing or taxing.

I have gone through a similar question but it doesn't give any specific answer though. Can I attach a camera to the outside of my aircraft in the USA?

My question is: if its going to be a permanent part of the aircraft and not a GoPro type, can it be included by the Manufacturer themselves?

I am not sure if this kind of exterior object is going to affect the aerodynamics of the plane. I got confused when an aerospace engineer told me it can affect the plane and can create some issues whilst in the air.
I would like to get clarification on this matter.


texts:
I've been looking at the SEA-TAC VFR map, and something caught my eye...

On this map one can see that the SEA-TAC airport has a class B designation in a strange inverse-rhomboid  shape, surrounded by, depending on the direction, class C or D airspace.
This is confusing to me, and I am looking for clarification.
Specifically:
There is no Ceiling or floor stated for the class C space. What are the proper ceiling/floor elevations for the class C airspace?
There is also no ceiling or floor for the class D space. What are the proper ceiling/floor elevations here?
The center of the map also says "see NOTAMSs/SUPPLEMENT" for class D eff hrs. I didn't get any supplement with this digital map.. where would I find this information?


texts: What's the difference between "HAND OFF" and "HAND OVER"?

texts:
I think "HAND OVER" is a whole process of transfering radar idenrification between 2 controllers, and "HAND OFF" is a term used by the transfering controller(not receiving controller) when doing HAND OVER.

Am I right?


texts: Why is a rectangular wing with winglets not better than an elliptical wing?

texts: Why is a simple rectangular wing with winglets not better than an elliptical wing in terms of induced drag and produced lift?


texts: what's the difference between priority and sequence valve in aircraft?

texts: What roles do they play during retraction and extension of a landing gear ?


texts: What is the runway holding short line on Taxiway B between B2 and B3 at KFAT for RWY29L?

texts:
At Fresno Yosemite International Airport (KFAT), I was instructed to taxi to RWY 29L via B11, B from Signature Support. When passing B3 and approaching RWY 29L end, I noticed there is one holding short line between B2 and B3 and the next one is on B2, I was confused where to hold short for the instruction (hold at the first anyways).

The one between B2 and B3 seems extra, but it is a double-solid-double-dashed line, which is also shown the Google Map the same I observed. I am wondering how this can well-define a runway protection area? Meanwhile, the first holding short line (the one between B2 and B3) does not mark which runway it protects. I also suspect it should have been ILS protection marking instead.

Google Map Link to KFAT Airport

FAA Airport Diagram for KFAT


texts: Does landing in extreme weather conditions require any different or special training?

texts: Is there any special training, relating to land under extreme weather, such as snow storms, contaminated runways or ice conditions?


texts: Where can you join a STAR & STAR Altitudes?

texts:
Do you have to join a STAR at a transition or can you join it at any point?

For example, coming from the south, can I join the DODJE5 arrival at FZT rather than AEX?

DODJE5: https://aeronav.faa.gov/d-tpp/1908/06918DODJE.PDF

Also, if I were to fly this in a standard GA prop aircraft, would the MEA looking numbers (ex. 5,000 for FZT -> CQY) be required?


texts: Is fuel moved around during flight on a passenger or cargo plane? If so why? Is balance an issue?


texts: Are cockpits waterproof to prevent spills

texts: Are cockpits waterproof, i.e. designed with the fact that a pilot might spill  a hot or cold drink over the instruments by mistake?


texts: Why do some military jets have needle-like structures at the nose and others don't?

texts:
I have seen some military jets have a needle-like structure at the nose and some others do not have that. Lockheed SR-71 Blackbirds have that structure and Lockheed Martin F-22 Raptors do not, why so?

(Image Source: www.aviationexplorer.com)

(Image Source: www.wikipedia.com)


texts: What are the process involved in tire rotation during long term storage?

texts:
During Covid-19 crisis in 2020 a lot of planes are grounded for a long time. Tires of parked planes can develop flat spot hence the need to keep these tire rotate. What are the processes involved regarding tire rotation during this time?
Is the plane towed 100 feet every week or rotate each tire 45 degree every day or something else?

Aircraft with tire marking.

Source: https://www.facebook.com/media/set/?set=a.1908245919474139&type=3


texts: Is landing without engine power routinely feasible?

texts: Considering that airplanes are very noisy, could one routinely land them with the engines turned off, gliding onto the runway? Could the engines be started fast enough for an emergency situation?


texts: I need to clean my aircraft's windows - what do I use?

texts:
I need to clean my aircraft's windows what do I use?

Note: I hope this is not a "subjective" question, as I don't want to put a potential harmful substance on my aircraft's windows and as a new aircraft owner, I would think this would be a logical question.


texts: Could the filming of the 747 in "Awakenings" have taken place during the 747 flight testing?

texts:
In the 1990 film "Awakenings", the main character Leonard awakens after suffering from a catatonic illness for 30 years.

There's a scene where Leonard watches a 747 landing in New York at JFK. This is considered to be an anachronism/continuity error in the film, as the film takes place in the summer of 1969 and the 747 didn't enter revenue service with Pan Am until early 1970.

However, I know that the prototype 747 first flew in late 1968, and my guess is that by the summer of 1969 several aircraft had been produced, and flight testing was ongoing.

My question is if there's any 'plausibly deniable' way Leonard, in the world of this "based on a true story" yet finally fictional movie, could have actually spotted a non-revenue service test flight 747 landing at JFK in the summer of 1969?

I'm more wondering along the lines of if I were transported back in time to the summer of 1969 and hung around JFK, did pre-revenue 747s ever land there? Or did all testing prior to its introduction with Pan Am occur in controlled environments where it wouldn't be observable by the public?


texts: How to calculate bending moments and shear forces on a wing?

texts:
I am trying to create a MATLAB script to plot the Bending Moment Diagram (BMD) and Shear Force Diagram (SFD) as a function of spanwise distance, x, along a wing from the wing root (x=0) to the wingtip (x=b/2).

I will be considering the case where the lift generated by the wing is 2.5 times the weight of the wing (so n=2.5).

The three main forces I plan to consider in this analysis are:
1) The weight of the engine (Point load)
2) The weight of the wing (uniformly distributed load)
3) The lift generated by the wing (bell loading distribution)

My question is this: how can I set up an equation for the bending moment and shear force as a function of spanwise distance, x, despite a non-uniformly distributed load being considered in combination with a point load and a uniformly distributed load?

The classes I have taken at college have only covered BMD and SFD for uniformly distributed loads, so I am a bit confused as to how to go about setting up a numerical model for a non-uniform load.

Thanks a lot.


texts: How to calculate the Lift Coefficient for the A320?

texts:
I'm trying to figure out the lift coefficient of an A320.

What I'm doing is the following: during cruise, the lift is equal to the weight of the aircraft ($mg$) so that I used the cruise table taken from the FCOM to get the speed, the wing area is known ($122.6 m^2$) and I calculated using a tool online the air density at FL290 (29,000 ft).

The result is that the lift coefficient is $0.03029$. Is it right for the assumptions given above?

Next, if I want to relate the $C_L$ with the Angle of Attack, what is the formula and the procedure?


texts: How could Airbus better tailor the A380 to the modern market?

texts:
I understand any company do things that give net profit. But, had not manufacturing newer engines that increase its Endurance and Range saved it from its decline?

Airbus had designed the A380 to carry as many people as possible so that airlines would be able to fly fewer flights. Instead of flying multiple flights between two cities, airlines could save money by flying just one A380 flight and cramming as many passengers into one plane.
What that would've meant, however, was fewer flights and less flexibility for travellers who don't want to rely on just one flight per day. Very few airlines used the model as intended and the A380 came too late as Boeing was already knee-deep in the 787's development by the time the A380 took its first flight.

Source
Though, bigger aircraft need more ground handling times and management. But with the oncoming innovations, it would have been decreased in future.
For example,
The Wheeltug
Video

As the electric power is used, it also reduces required staffs, cuts down time and Taxi fuel too.
And that may help the airlines too increase the number of flights.

The FlexSys Morphing Wing
Video

As the weight of hydraulics are removed here. This can also lead to higher fuel economy.

Hydrogen Fuel Cell Concept
Video1  Video2

It is nice that the Airbus is itself working on this concept for commercial airliners.
And it would had been nice too if it was implemented to A380 later too.

Reducing the wing span by folding wings on ground for smaller airports. (Though mentioned earlier) Improving engines for shorter Takeoff and Noise Reduction, etc. could help the airliners to reach more destinations with A380.
I want to know the practical feasibilty of introducing an A380neo. And how my above mentioned innoventions fail to be implied in A380? Also, could idling the outer engines thrust help in reducing the wake while landing or gliding, that eventually reduce the safety regulations and requrements for a "Super" aircraft (by this, I meant, will it lead to decrease the seperation required specially for Bigger Aircrafts)?


texts: What control issues did the X-1 have to overcome to achieve supersonic flight?

texts:
In Chuck Yeager's autobiography, he went into a little bit of detail as to why the X-1 was able to break the sound barrier safely where as the P-51D he flew during WWII could not have safely broken the sound barrier.  He mentioned it had to do with the controls... Something about flow separation, as I recall, and the elevator not working as a result in most aircraft before the X-1.

I was wondering if someone could explain this though?  What advances where made during X-1 development that made it stable at Mach 1?


texts: Why has the range of movement of the control surfaces changed over the past year?

texts:
During the annual inspection on our glider, we discovered that the maximum downwards extension of the right aileron (i.e. full left stick) was outside the manufacturer's tolerance. The measured value was 32mm and the manufacturer allows 40mm ± 5mm.

What are the possible causes of a change in the geometry of the system such that the ailerons no longer move in the range they did last year?

For reference, the glider is a 1983 Schleicher ASW19b, with standard l'hotelier control connections and aluminium push rods over bell cranks in the fuselage and wings.


texts: Other than a swing wing, what types of variable geometry have flown?

texts:
We're well familiar with swing wings, on small and large aircraft from both the east and west.

What other types of variable geometry have been tried?


texts: How long would the engine of a Tecnam P92 Eaglet run for with the fuel selectors turned off?

texts:
I'm wondering about a scenario where a P92 has been flying for at least 30 minutes or so, at say 4,000 RPM and 2,000' AGL at standard temperature (I'm not sure if these details matter). With both selectors on, you would then shut off both fuel selector valves. With no fuel coming through the lines, how long would it take for the engine to starve and stop working?
Flight manual for reference: http://www.whangareiflyingclub.com/wp-content/uploads/2012/10/P92-Eaglet-LSA-flight-manual.pdf


texts: Determination of a Joukowski airfoil chord (demonstration)

texts:
I'm currently studying Aerodynamics, and one thing that I noticed is that the maximum and minimum $x$ coordinate of the airfoils (which are necessary to compute the chord) on the transformed plane (let it be $z(x,y)$) correspond to the transformed intersection points of the circumference on the original plane  (let it be $\zeta(\xi,\eta)$) with the real axis. I don't find any proof of this statement, and so I tried to do it by myself. The problem is that it got too complicated to be solved analytically (too many different powers of trignometric functions). So I'm requesting someone to try demonstrate this too. I think that there's a simpler way to do it.
There's my introduction to the problem:

Consider the original circumference defined on the complex $\zeta$ plane:

where $a$ is the circumference radius, and $b$ the intersection of the circumference with the real positive axis, $\xi$. The parameter $\beta$ is the angle between the horizontal line and the line that links $\zeta_0$ to $b$. The center of the circumference is:
$$\zeta_0=-b\varepsilon+ia\sin(\beta)=-b\varepsilon+i(1+\varepsilon)b\tan(\beta)$$
So, this circumference is defined by:
$$\zeta=-b\varepsilon+b\frac{1+\varepsilon}{\cos(\beta)}\left(e^{i\theta}+i\sin(\beta)\right),\hspace{15pt}\theta \in [0,2\pi]$$

Now I need to show that for the Joukowski transform $z=\zeta+\frac{b^2}{\zeta}$ the $x$ coordinate (real coordinate on the plane $z$) has
a maximum on $\zeta=b$ (intersection of the circunference with the positive real axis) and a minimum on $\zeta=-b(1+2\varepsilon)$, (intersection of the circunference with the negative real axis).


texts: Airfoil and Wing Analysis for Transonic Speed (M = 0.85 and Re = 42 million)

texts:
I am working on a project where I have to design a plane which has to cruise at 0.85 Mach at 35,000 ft. While working on the wing design, I quickly discovered that 6 series airfoils, with a good amount of thickness ratio, have a low Critical Mach Number. So, I started exploring Supercritical Airfoils (SC Airfoils). F or doing analysis of SC airfoils can XFLR5 be used?

Moreover, Aspect Ratio and Sweep also influence Critical Mach Number.

Is there are a relationship that connects these three entities?

Lastly: is there a credible source that compiles the analysis of Transonic Airfoils (Supercritical Airfoil)?  (Similar to Theory of Wing Sections by Abbott and Doenhoff, which contains data for conventional airfoils)


texts: What do you need to know to fly a Cessna?

texts:
I've almost finished ground school and am about to start flight training.  I'd like to show up fully prepared, so am compiling a list of things I'll need to know to fly a C150.

I was hoping someone knowledgeable could point out anything I've missed.  One point specifically is checklists: I read a good article once by a military pilot who argued for completing all procedures from memory, then checking them using the checklist (hence the name checklist).  Is this a controversial approach?

The things I think I should know on day 1 are:

Vso, Vs, Vfe, Va, Vno, Vne; Vr, Vx, Vy
Procedures: Walk-around, pre-flight, emergency procedures, pre-landing
Airport: Taxiway layout, communications
Skills: Taxi, takeoff, turns, mushing, landing

Any other tips on how to best prepare myself before getting in the cockpit would be welcome.

Thank you.


texts: What is the relation between the boundary layer and lift of an aerofoil?

texts: Why do we try to reduce the thickness of the boundary layer over an aerofoil as much as possible if the boundary layer is responsible for creating lift?


texts: Is there a NOTAM code for solar eclipse?

texts:
Sun eclipses have some noticeable effect (e.g. drop in air temperature). Inspired from Eclipse Flights (xkcd) I'm curious if eclipses are notified as NOTAM or as weather notice. How?

Never seen such notification (but there are also few sun eclipses).


texts: Are landings easier during the day or at night?

texts:
When is it easier for a pilot to perform a "good" touchdown: during daytime or nighttime?

Considering typical flights for 737s to holiday destinations so mostly small airports with a single runway.

In the above, "good" is defined as a firm landing with both rear wheels simultaneously on the ground.

During the night the runway is brightly lit and all the guiding lights are clearly visible, but the actual tarmac is more difficult to spot. During the day there is flare from the sun and the lights are less visible but on the other hand the tarmac is clearly visible.


texts: What do aviation agencies do to make waypoints sequences more easy to remember to prevent navigation mistakes?

texts:
Inspired by this question.
What examples are there of waypoints strung together on airways or approaches which are funny or tell a story in order to help controllers and pilots reduce navigation mistakes?  I'm not looking for individual waypoint names, but connected waypoints.  For example:

WONZA JOLLY SWAGGY CAMBS BYLLA BONGS UNDER ACOOL EBARR TREES arriving from the West into Perth.
WEEEE WLLLL NEVVR FORGT SEP11 on the Freedom airway to Washington International.


texts: How can you find the best altitude for range or speed?

texts:
How can you select best cruise altitude (altitude for best range velocity) and maximum speed altitude?

The specific case is a turboprop aircraft of gross weight 8000 lb.


texts: How does retracting the gear affect weight and balance?

texts:
In many of the POHs, in the W&B section it is indicated that there is a moment change due to gear retraction. For example :
Moment change due to gear retraction +780 in-lbs.

Two questions :

If I understand correctly, to simulate a gear retracted scenario I only need to add 780 to the total moment (sum of moment for the empty weight, crew, passengers, baggage etc...) while calculating the W&B. Is that correct?
In the majority of the POHs the C.G. envelope limits are based on gear down (fwd and aft).I saw one aircraft where it states the aft C.G. for both gear down and gear up - does it mean there is a different C.G. envelope for each case?

The aircraft in question is CJ-6A, please note the footnote in the image below


texts: Do some airplanes have weighing scales on the landing gear?

texts: It seems to me that takeoff weight is an important piece of data, and if one had weighing scales between the wheels and the aircraft body, one could precisely determine it. However, searching the internet, there seem to be no scales and cargo/fuel/passenger weight is estimated by adding up what is brought on board. Why aren't scales common? And are there any commercial airplanes that have them?


texts: Did Boeing build airliners other than the 7x7 series?

texts:
What I mean by the 7x7 series is the 707, 717, 727, etc. I took this picture at the Pima Air and Space Museum in Tucson, Arizona.

What type of aircraft is this? Was it an airliner? I know that no 7x7 series aircraft was that small, so were there other airliners made by Boeing besides the 7x7 series?


texts: Which jet airliner types have had the fewest accidents per million departures?

texts:
Passenger jet transport is very safe, but are there any jet airliners with a lower recorded accident rate?

Edit:

number of accidents per se is of course never a good indicator since it will always rise over the years and with fleet size. Accidents per flying hour skews towards long distance aircraft, since not many accidents happen during cruise. The most objective comparison would be the rate of accidents per million departures of the type.


texts: Are there any aircraft designed to operate between an altitude of 50-80km?

texts:
Aircrafts operating at high altitude falls into several categories:

Wings with high aspect ratio (Global Hawk, TR-1, Scaled Composite Proteus,...)
High velocity aircraft (Concorde, A-12, X-51,...)

Aircraft falling into those two categories cruise between 15km and 30km high.

Balloons (up to 50km high)
Suborbital aircraft (X-15, Space Ship Two), performing their mission between 80 and 120km high.
higher resides low earth orbit, and thus satellites which can hardly be qualified as aircraft.

I cannot find any aircraft designed to perform its mission at an altitude between 50km and 80km, which corresponds more or less to the mesosphere. Is there any aircraft designed to perform its mission into this 30km wide slice of atmosphere? What is the usefulness of this slice for aviation?


texts: Why are there different types of winglets?

texts: If all winglets serve the same purpose (to reduce vortex drag), why do different aircraft have different winglets? This question is not trying to get a comparison of the development of winglets/wingtips, with other aircraft components, as the question of @Manu H is.


texts: What are the limitations of using a single shaft between the compressor and turbine in a jet engine?

texts:
Question Background

I'm studying the internal structure and components of a turbojet. I can see there is a shaft between the compressor and the turbine, so that energy is mechanically extracted from the exiting gas and used to help the compressor rotate. You can appreciate it in the next image:

Question

I understand the shaft is there so that the turbine helps the compressor move. But this introduces a serious constraint: both the compressor and the turbine need to rotate at the same speed. Is this true in general? How is this managed when there are several shafts connecting several compressors/turbines? Are reduction boxes needed here or do they, in fact, move at the same speed? Is this a big deal, does it introduce any serious limitation/drawbacks regarding the exiting air power?

Just started studying jets, hope the answers are not very trivial.


texts: What exactly do "attempt" and "cycle" mean in these starter duty limitations?

texts:
Can someone please explain me this A320 Starter Duty Limitation in simple terms?
E.g. for the CFM56 Starter:

No running engagement when N2>20%
4 cycles of max 2 mins
Pause between
start attempts . . . . . . . . . . . . . . . . . .. . . . . . . . . 20
sec
Cooling period after 4 attempts . . . . . . . . . . . . . . . . .
. . . . . . . . 15min

Does it mean the moment I put Engine Master to ON till Automatic abort by FADEC in case of Automatic Start or Manual abort by turning the engine master and man start button off (limiting it to 2 mins) in case of Manual start = 1 Cycle. Then 20 Seconds gap. Then Next Cycle and so on and then say after 4 unsuccessful cycles I got to wait for 15 min.
But things get confusing between words Cycle and attempt. Since for another type of Engine it says

Auto start with up to 3 start attempts is 1 cycle.
Between
successive cycles – 20 seconds pause (for auto or manual ground
starts).
After 4 failed cycles – 15 min cooling period.

What is attempt and what is cycle? I hope someone explains it in real simple terminology.


texts: In a fighter jet, what is the average weight of the ejection system?

texts:
In the old days, pilots had only a parachute pack. (In the really old days they might not even have that.) They had to open the canopy manually and jump out.

Today, fighter jets have zero-zero ejection seats. They can save the pilot even at zero airspeed and zero altitude. They do this with solid rockets to eject the pilot upwards.

I would like to know what is the average weight of this system for a single-pilot fighter jet? That way we can compare it's weight to the total weight of the plane and see what fraction it is.

Really the weight would include only the rockets and explosive bolts on the canopy, and I guess the ejection handle too. It would not include the weight of the seat or the pilot, as those have to be there even without an ejection system.


texts:
I'm looking to visit the Grand Canyon this September. I fly an open-cockpit two-seater gyroplane - a Magni M16. Its ceiling is around 13k' and I'm not wild about trying to reach the top end of that. I'm confused by the SVFR rules on the special Grand Canyon chart and would appreciate some clarification.
If I look at the chart on Skyvector, I can see the allowed corridors and the SVFR area fine. Looks like in the east it's more restricted and for the Native American areas, you have to be above 14.5k' to fly over them (which rules them out for me anyway) but that I can use the Dragon and Fossil Canyon corridors down to 10.5k', which should work. The rest of the area I need to be at least 10k', at least over the Supai and Diamond Creek sectors.

So far so comprehensible. However, in the west, you have to avoid The Sanup tribal area below 8k' but then the rest of the area is either the same or higher than that! Do I have that correct? Looks like I could depart from 1G4 and fly due east over the Sanup area at 8k', then turn north and provided I followed the edge of the Pearce Ferry sector, I could stay at 8k' all the way to the Bar 10 airport 1Z1. Is my interpretation correct?

Thanks for any help and guidance, especially from anyone who's done this in a low power open-cockpit craft.


texts: Airplanes in static display at Whiteman AFB

texts:
After reading the post about B-2 sizing, I spend a couple of minutes on Google Maps looking at airplanes on the Whiteman AFB.

On runways, I think there are one B-2 Spirit, 3 T-38 Talon, and one AH-64 Apache.

On static display, I have spotted an F-111, one B-52 (north of the base), one A-10, one T-38, one B-47, and one B-29 at the south gate.

But there are also 3 more fighters at this location.

Center one seems to be an F-22 Raptor.

What are the two other ones? And is there any more static airplanes spread over this base?


texts:
I know that there are three type of wind, headwind, tailwind and crosswind.
What degree of wind direction can distinguish it? 30 or 45 degree?


texts: How the aircraft sense the sink rate during autoland?

texts: Radio altimeter is required for autoland, and the target of autoland flare mode is to reduce the sink rate to an acceptable sink rate at touch down， then how the sink rate is computed by the radio altimeter since radio altimeter just provides the height information rather than the rate?


texts: How well does a composite fuselage deal with lightning?

texts:
The metal fuselage of an aircraft, being highly conductive, protects occupants, interior components and fuel from the effects of lightning by conducting the electricity around them.

Some newer aircraft, such as B787 have a fuselage made entirely out of composite materials. The major portion of the 787 is made from carbon fiber plastic laminate.[1]  Although carbon fiber conducts electricity it has a higher electrical resistance.[2][3] Higher resistance means more heat generated by the material. And carbon fiber makes up only a percentage of the composite.

Has the composite material been found to have enough conductivity to deal with a direct lightning strike without damage to either the material itself or the contents of the plane? Or do designers deal with lightning strikes in some other way?

[1] Boeing 787 Systems Manual.

[2] Department of Physics
University of Illinois at Urbana-Champaign website

[3] Electrical and mechanical properties of electrically conductive polyethersulfone composites. Lin Li and D.D.L. Chung, 1991, State University of New York at Buffalo. [.pdf]


texts: What is this fighter-like plane with huge wings?

texts:
Can anyone identify this strange plane? It looks like they took wings from a bomber and put them on a fighter body...
What was its purpose?


texts: Airbus 320 "Data Position Monitor Page" Bias?

texts: What exactly do we mean by bias when it comes to calculating the FMGC position?


texts:
(B738 AFM, 0-2000 feet elevation, up to 27°C) Example of V1 increasing with weight.

This valid question came up the other day here in chat.

The heavier the aircraft, the harder it is to stop.

So why isn't V1 reduced to allow for better stopping?
How is the max weight / V1 determined for a specific runway?

V1 is the speed by which the decision is made to continue or reject the takeoff.


texts: Why is the wing bending so much in this video?

texts:
On a recent vlog, YouTuber CGP Grey mentioned how much the wing of the plane he was on bent. I understand that wings are designed to bend a little,  but what actually causes so much deformation?

Here it's a video of it:

Why does this happen?


texts: What are these strange clouds on the wing and how do they form?

texts: I am having a little trouble figuring out what these strange clouds are. You have a cloud forming off of a fighter jet when it breaks the sound barrier, but this is a different situation.


texts: What is the purpose of having different ILS categories?

texts: What is the difference between CAT I, II and III ILS approaches? I understand that the different categories are used in different weather, but what are the differences, exactly? Do flight crews have to act differently when flying a CAT III approach as opposed to, say, a CAT I approach?


texts: What is the function of the lower vertical fin on a MIG-23?

texts: I would like to ask about the function of the lower vertical fin in Mig 23 .


texts: Why do planes make landing approaches at significantly varying heights?

texts:
I live in NYC and my house is under one of the approaches for JFK. Im still about 15 miles away from JFK, so the noise isn't an issue 99% of the time. Once in a while however, especially if I'm outside, I notice that the plane is much louder and seems to be visibly lower.

Why is this? I'd figure with all the fancy GPS and radar systems planes and ATC have that the landings would be near identical, but this doesn't seem to be the case.


texts: What is the difference between Marginal VFR (MVFR) and Special VFR (SVFR)?

texts: I would like to know the difference between marginal VFR (MVFR) and Special VFR (SVFR), particularly when flying in the US airspace. What does each of them mean exactly?


texts: What is the purpose of a retracting cowl?

texts:
I flew yesterday in a SWA Boeing 737-300(?) in the seat next to the engine. Right after touchdown, I noticed that part of the cowl retracted back significantly (a few feet or so it seemed), exposing the engine body. The cowl closed back when the speed dropped to taxi levels.

What is this cowl retraction for? Is it part of the aerobraking?


texts: Vs1 is the stall speed in a specified configuration. What exactly is specified configuration?


texts: What are the advantages of a geared contrarotating turbofan?

texts:
I read that this would be the holy grail of jet engines:

Next Gen NB Engines : Contra Rotating Turbofan Fan

Why is this so and what problems are stopping us from doing this?


texts: What modifications need to be made on an engine that normally uses AVGAS to utilize it with MOGAS?

texts: Asking just out of curiosity. What modifications need to be made on an engine, e.g. Lycoming O-360, that normally uses AVGAS to utilize it with MOGAS?


texts: Why isn't the U-2 used for commercial purposes?

texts:
There are some companies that use decommissioned military aircraft for commercial high-altitude flights (for, say, tourists). Examples would be the MiG-31 and the MiG-29:

Why isn't the Lockheed U-2 used for such flights? Here is a two-seat version of the U-2:

( Image source )

Is the U-2 still secret? Or is it expensive to build?


texts:
This question is prompted by a recent news about a dog dying while transported in the cabin overhead bin for about 3.5 hours.

Are those bins airtight enough to cause death of a (relatively) small animal by asphyxiation? According to some pics on the internet, the dog in question was a French bulldog or similar.