texts: Can I work on my own airplane without formal mechanic's training?

texts:
Suppose I am not planning to be a career A&P mechanics, but would like to get some hands-on skills for airplane maintenance, for reasons of both cost and hobby. Say my basic goal is to perform tasks from as simple as tire replacement, instrument replacement to avionics installation and troubleshooting. My goals may be progressive. The aircraft for maintenance is self-owned or owned by share. The ownership and operation of the aircraft is within US.

Can I work on my own airplane? Since I'm not certified for mechanics work would it be OK that a certified A&P endorse my work is standard-compliant?


texts: How does ATC deal with a crew who is not capable of a clear pronunciation?

texts:
It probably is common guesswork to think that in nowadays' World we all speak English no matter what our mother tongue is. This should be even more the case with Civil Aviation, where everything is in English and the staff is hired also based on its linguistic capabilities, yet the question arises:

How does the ATC deal with a crew who is not capable of a clear pronunciation? The opposite might also happen.

What to do in such cases?


texts: How does one resume a VNAV climb in a B737 NG after being instructed to level off at an altitude below the Cruise altitude?

texts:
I am referring to a Boeing 737NG.
Assuming I am on a VNAV climb but I am instructed by ATC to climb only to an altitude lower than my FMC Cruise altitude.
After leveling off, how do I resume my VNAV climb to my FMC Cruise altitude after I am cleared by ATC to do so?
I obviously have to set my FMC Cruise altitude in the MCP Altitude window, but as VNAV is already engaged from before ans is the active mode, will the aircraft start climbing automatically, or do I have to disengage and re-engage VNAV by pushing the VNAV button OFF and ON again?
Or, alternatively, do I have to press the ALT INTV button to resume the VNAV climb to my FMC Cruise altitude?


texts: How do I clear an aircraft to exit a hold?

texts:
I'm learning ATC and one question is worrying me..

How do I tell a pilot to exit a hold and continue inbound...

Eg: pilot has entered hold and done one orbit.
and started the second,
and I want the aircraft to turn again 180 degree on inbound.

Basically how do I tell an aircraft to break out the stack, and continue flight plan.


texts: Is it possible to bluff one's way to the flightdeck like in Catch Me If You Can?

texts:
I was watching some clips from Catch Me If You Can starring Leonardo DeCaprio as Frank Abagnale.

I was wondering- If brought a ticket on an airline today, came dressed up like a pilot, would you, be able to sit in the cockpit? (assuming pilots are normally allowed to jumpseat in that jurisdiction) Say you come onboard the plane and present them a fake ID at the door. Is there anything to prevent this from happening, or are we still as vulnerable to this type of trick like in the movie?


texts: Are there any cockpit indications when an engine has separated from the aircraft?

texts:
On this answer, there is a comment that asks if there is an alerting alarm of some sort when an engine falls off an airplane.

Is there a direct alarm from the engines specifically saying "You lost an engine" to warn that an engine has fallen off from the aircraft?


texts: Who has authority over stadium TFR exceptions in VFR flight?

texts:
I fly in the Bay Area. I sometimes like to fly over SF through the San Francisco Class B. If I am in contact with Norcal Approach and in their airspace, I can ask them for an exception and they can authorize it. But, I could also be talking to the tower, and could also be talking to Oakland Tower.

All three of the following agencies have authority over sections of airspace that overlap with the stadium TFRs at the Giants stadium (see image).

Oakland tower (class C)
San Francisco tower (core class B)
Norcal approach (outside core class B)

My question is: which of these three agencies have the authority to grant me an exception to the stadium TFR?

(Image is SF TAC with TFR plotted by Foreflight.)


texts: What is the maximum take off climb angle of a Boeing 737 MAX?

texts:
This video is making its rounds on social media claiming to show a 90 degree vertical take off:

One can not tell from the video alone what the angle is.

Does anyone have a third party reference for the actual angle for this video?
What is the maximum angle for a Boeing 737 MAX with typical passenger load?
What is the maximum angle for a Boeing 737 MAX especially configured to maximize the angle?


texts: On a modern Aircraft like the A320 or B737, is it possible to disable computer interference with the control inputs of the pilots?

texts:
One more question due to the recent and unfortunate events in the case of the second ever B737 Max 8 crash.

As far as I know, the first of the two crashes was caused by the MCAS System, that overwrite the inputs of the pilots as a faulty reading of an angle of attack sensor indicated a stall (that was not actually happening).

Knowing (rather, having an idea of) what a difficult time pilots have in such situations I wonder if it is at all possible to stop the aircraft from executing such maneuvers.

I know that on an Airbus A320, there is different flight laws. While during "Normal Law" all the various protections the A320 has are active (Stall protection, overspeed protection, bank protection with all their proper names and so on), they are not active in "Direct Law". There are two more levels between "Normal" and "Direct" (namely "Alternate" and "Abnormal Alternate"), but let's ignore them for this question.

I have never flown an A320 in real life and lack the training any A320 pilot goes through, but in the Simulators I have flown (not talking FSX here!) you could "exit" out of "Normal Law" by turning off the flight computers on the overhead, like the ELAC, FAC and SEC, and go into alternate or even "Direct Law".

So the question is: is this actually possible on a real A320 as well? And is there a similar method on a B737 (Max 8)?


texts: Will control surfaces on a plane be less efficient at a higher altitude?

texts:
I may be wrong but I learned that control surfaces depends on the air flow to work properly, and that airliners have a higher cruise altitude because of the less dense atmosphere, improving the fuel efficiency.

But that got me thinking:

Will control surfaces on a plane be less effective at a higher altitude because of the less dense air?
Do modern airliners have a workaround to solve this problem?


texts: Has there ever been a sideways H-tail on an airplane?

texts:
I've seen several aircraft with 2 vertical stabilizers and 2 rudders. This could be an H-tail like the B-25 Mitchell or the A-10 Warthog, or something more sleek like the Su-27.

However, I got to thinking, are there any airplanes that have 2 sets of horizontal stabilizers and thus 2 pairs of elevators? This would be a sideways H-tail. I guess it would be sort of like a bi-plane, but in the tail only.

Do these exist somewhere? Why or why not?

Experimental planes are okay.


texts: Can I land my aircraft on the grass next to the runway at a public airport?

texts: The pavement is hard on my tires, so I prefer to land in the grass.


texts:
I am currently working on my private pilot license and am using a headset from the flight school.  I am coming up to my first solo and thinking about purchasing my first headset.

There are many different types of headset on the market, so what should I look for in a headset, and how do I go about picking the right headset for me?


texts:
I'm reading about a helicopter crash that happened yesterday in New York City. The helicopter landed in the East River and apparently inverted. The pilot was able to escape, but all five passengers died.

I'm having a really hard time processing the following quote from the CNN article:

  "One of the most difficult parts of the rescue were that five people were tightly harnessed," Fire Department of New York Commissioner Daniel Nigro said. "People had to be cut out."

How can it be that the passengers didn't undo their harnesses? I can't understand why their harnesses were still on. What are the regulations regarding the safety briefings and harness designs for open-door helicopters?


texts: Does preheating fuel before it reaches the turbine result in a performance improvement?

texts:
Preheating fuel before it reaches the combustion stage was first proposed several decades ago as a way to improve mixture, fuel economy, and to reduce emissions in car engines.

One example of this method being used in aviation was the Polish jet trainer PZL TS-11 Iskra. Overlooking mechanical complications which may be introduced by using fuel preheating (including vapour lock), does this method have any measurable benefits in aviation in terms of performance or fuel efficiency?


texts: How do I keep my home address private following new aircraft registration?

texts: I'm looking at filing out an 8050-1 for a new airplane in the US and the FAA is asking me for my name, and address. My concern is that once I register these bits of information, specifically my home address, become publicly available. So I'm wondering is there anyway of registering an aircraft tag in a way that keeps that information private? Are there any proxy registration services that exist for this purpose?


texts: What pieces of evidence do investigators have access to in the MH17 crash investigation?

texts:
In September 2014, Dutch investigators published a preliminary report for the MH17 crash. I understand they based there report on radar records, CVR, FDR and photos and thus can only say the flight goes as expected until multiple impacts from unidentified projectiles came from outside the plane.

I thought it was easy to identify those projectiles based on fire traces and chemical analysis on remaining wreckage, but it seems they were not able to do such analysis.

So my question is: what evidence do they have to perform their investigation? If they have wreckage, how can these be pieces coming from the aircraft? Based on the pieces they recovered (and ignoring the political background due to the Ukrainian situation), what kind of conclusion can be expected?


texts: How can I reduce the Short Period frequency of a Pitch Hold Auto-Pilot while maintaining stability?

texts:
I am working on a  Pitch Hold Auto-pilot for F-104, which has the following damping characteristics;

which clearly shows that it has degenerated and unstable phugoid mode. well, I made a SAS which consists of 2 loops / Feedbacks.
1) The angle of attack feedback to increase the Cm alpha or static margin of the aircraft
2 Pitch rate feedback to dampen the short period mode.
but it has eventually increased the natural frequency to almost 365 rad/s as shown below,

but this frequency is not according to the handling qualities as it should be less than 3 rad /s.
what feedbacks should I try so that all the states are stable as well as desired handling qualities can be achieved?
states are velocity, angle of attack, pitch, pitch rate.
Simulink Model of SAS:

Root Locus of the outer Loop:

How can i decrease the frequency to the desired range keeping it stable and keeping in mind that it was unstable first.
Also, with not much decrease in damping as it should be greater than 0.5.(short period mode)
Phugoid mode >0.04


texts: How do designers determine the altitude profiles of neighboring procedures for deconfliction purposes?

texts:
I am interested in studying ICAO's Continuous Climb Operations design strategy, however I have some trouble understanding how the procedure designers take into consideration the traffic flow from neighboring arrival procedures, in order to avoid conflicts with their proposed departure procedure (optimized for continuous climb).

Doc 9993 (Draft version) states:

  1.1.5.3 Traffic Avoidance. In the most optimum situation, a departure route should be designed in such a way that there is no restriction that prevents an aircraft continuing its optimum flight profile. Both, the arrival (STAR) and the departure (SID) should be de-conflicted laterally or vertically. This optimum situation may not be reachable and therefore a balance must be found between the arrival and the departure routes.

However, even if one makes the assumption that an IAP has a somewhat self-explanatory altitude profile, at least where the glide slope interception begins, this is clearly not the case for STARs. There are charts which do not provide a starting altitude for their depicted arrival procedures, something that makes the estimation of the aircraft's altitude during the route traversal even harder. On top of that, there are arrival procedures that do not have any altitude constraint at all, such as GATBY ONE.

Anything that could point me into the right direction would be more than welcome.


texts: If cleared to cross a runway and expedite but are slow to get away, are you obliged to stop?

texts: Suppose ATC says "Big Jet, cleared to cross runway 36, expedite" and you acknowledge "Cross runway 36, wilco, Big Jet". As you start to move forward  you immediately realize that you are unable to go as quickly as you expected (perhaps there's an incline or a gust of wind -- I'm not sure what's plausible). At the point you realize this, you can still hold short the runway. Are you obliged to stop and reply 'unable' or is that ill-advised?


texts: What’s the steepest possible descent for big commercial jets?

texts: What’s the highest descent rate, an A320/737/A380/younameit can achieve in safe controlled flight and how do they achieve it? E.g. can those jets do side slips to have a steep approach angle (maybe not for final) if they need to land ASAP, for example for a medical emergency / rapid descent due to pressurization problems?


texts: What are capabilities of small Airplane in general?

texts:
In general what can i expect of small, 4-seat, light airplane? I am specifically interested in the Pipistrel Panthera, though general responses would be appreciated.

What is usual range of that kind of plane?
What is the worst weather under which it can fly?
How expensive is to fly internationally with that kind of plane?
What is the procedure and usual cost for example if I fly from Rome to Prague, what border control checks can I expect? How and what kind of taxes related to that particular flight would I pay?
If a plane is declared to have range of 1900 km, what is practical range in practice?
If regular service for an airplane is declared to be after 7000 km of flight or X hours of flight, what has to be done usually in those services? Changing of oil, changing of filters?? How expensive usually is that?
Anything else you think is important to know about possessing and airplane of that type?


texts:
Related question:  Do fly-by-wire flight controls in airliners provide artificial feel?

Icefire, by Judith and Garfield Reeves-Stevens, contains the following passage:

  When the engineers develop a new plane, they like to give the pilots something familiar to work with, so they adjust the computer controls to feel like a plane the pilots already fly and like.  The Tomcat's one of those jets.  Solid, dependable, every test pilot's flown them.  So every new fly-by-wire plane feels a lot like a Tomcat.

Now, let's face it, this is a book featuring the main character stealing, and making off with, a Lockheed SR-72, so I'm not expecting everything to be a model of technical accuracy, but there could be a rock of truth in the middle of this snowball of fiction.

Are NATO fly-by-wire fighters designed to feel like F-14 Tomcats?


texts: What are some alternative benefits to electric propulsion?

texts:
The context I am asking is regarding if electric motors could ease the fuel cost, take off weight, or runway length if they were set up in 'hybrid' configuration with regular hydrocarbon engines.

If so, could potentially a military aircraft (IE, F35) have any weight savings or feature benefit of having an electrically boosted STOVL/VTOL system? Any fuel savings over regular flight? And of course, would this make sense at all from an engineering standpoint, today or ten years from now?

I am not asking the ability of electrical propulsion systems to replace the current main prop or jet systems, but rather to the alternative capacity that they might offer in other auxiliary or backup uses.


texts: Is it illegal for Joe Public to listen to ATC in the UK?

texts:
I recall that in the UK (unlike in the rest of the world) we have a law forbidding the listening to of air traffic control, dating back a century, to the days of paranoia over spies!

What is this law, exactly? Is it illegal for a member of the public to listen to live ATC in the UK? Are there any exceptions?

It seems like something of a grey area, but some sources claim that listening to a delayed feed (or historical recording) works around this law; is this true?


texts: How can I tell if an aircraft (N-number) is already equipped with an ADS-B transponder?

texts:
Is there any database that contains this information?

This question asked how many aircraft already have one. Here I am asking how can I get which contain it.


texts: Why do military jets seem to always take off using the afterburner?

texts:
I was wondering. At different places I heard that civilian airplanes often (or even most of the time?) take off at less than 100% thrust.

For example a question that tackles this is here:
Is it possible that derated thrust takeoffs are safer than normal takeoffs?

This makes a lot of sense to me.

However, whenever I see videos of fighter jets taking off (from normal runways, not from carriers), they always seem to use the afterburner. But surely they must have plenty of power to get to take-off speed without them, so doesn't this waste large amounts of fuel unneccessarily? What are the considerations for doing it?

Or is this just a "filter bubble" impression I got, because it just looks cooler and whenever those planes are filmed they know that they are and thus do it for the show?


texts: Why would flares be fired into the air after a flight lands?

texts:
On Monday 23rd September at about 14:30 BST my plane landed at London Stansted. Soon after landing, while the plane was at the end of its deceleration, I noticed what appeared to be two flares or fireworks shot about 50 ft into the air above the grass to the right of the runway (I believe it was runway 22).

What on Earth could that be about? The flight was Ryanair FR587 (and the plane's registration was EI-DYL if anyone is interested).


texts: Is there any way for the baggage carrier to add some fake luggage?

texts:
For the sake of a story that I am writing, is there any way that a conspiracy luggage carrier could add some luggage to given aircraft?

Specifically:

Is there still a man power used for the purpose of transporting luggage from the check-in to luggage trolley?
If yes, how do any of them know which luggage transportation belt they are supposed to deliver particular luggage to?
Are man present at all anywhere in the luggage sorting and transportation zones or is this today a fully automated process?

I am asking about a large international airport / Heathrow, if that matters.


texts: How long can passengers survive after ditching in the ocean?

texts:
Assuming Malaysia Airlines Flight 370 ditched in the ocean, and surviving passengers and crew were floating around in their inflatable vests, how long could they survive?

Is there data about the longest survival under such conditions?

There are a few examples of people surviving for months in tiny boats, but there they could gather rainwater and catch fish, obviously impossible in just a lifejacket.

Edit: although I mentioned a specific flight and lifejackets, the question is intended to be general for ditching in the ocean.


texts: What would happen if the wing of a supersonic plane goes into the shock wave from the nose?

texts:
What happens if the wing of a supersonic plane goes into the shock wave from the nose?

A plane have this shock wave at the nose going back at an angle, but it also have shock waves going back (in the same angle) from the intake or the joint between the wing and the body, shocks that do go over the wing.

Since the wing can live with that, why is it then a problem if they go into the shock wave from the nose (which I have always learned)?

In case anyone want to know, then the question arose when an friend and me discussed chock-cone angles, and the the X-29 seem to have an angle between nose and wing-tip that relates to the angle a schock will have at M1.8, the plane´s top speed.

-And the same seems to be the case with many other fast planes.

-By the way, I chose thát image as the angle of the schock is higher than the angle of the leading edge of an F-18.

I haven't been able to find a better image than this, I believe it is an F-18 with pretty straight wings:


texts: What is the 'arm' at the rear of the X-29?

texts:
In this image of the Grumman X-29, there is an 'arm' just above the exhaust nozzle leading forward and, apparently, attached to the right side of the fuselage. What is this and what is it for?

Source: Wikipedia X-29 Article

I realize this is an experimental aircraft, but it doesn't look like sensors (like the probe off the nose), it looks more like a structure for lifting the plane.


texts: What is the purpose of this loop in a taxiway?

texts:
This image is of Mariscal Sucre International Airport near Quito, Ecuador.  (Official site / in English)

What is the purpose of the loop in the taxiway plainly visible in this image?

From Google Earth (with the contrast punched up a bit)

Addendum

To respond to the comments to jwzumwalt's answer, I really don't think the hills and mountains to the north of this airport are an operational concern.  See below image:

Source plus my copy-and-paste extras

The airport's elevation is 7900 feet (verified by Skyvector), the first ridge in jwzumwalt's 2nd image is 6.4 miles distant from the north end of the runway and lower in elevation, and the second ridge is 8 miles distant but only 500 feet higher.  Distances verified by Google Maps.

If an aircraft can't comfortably clear a ridge 500 ft above the airfield in eight miles, well then that's a whole other issue. :-)

But, I do like jwzumwalt's answer.  Thanks!


texts: What inspection packages commercial airliners follow which make them more reliable than a C-130?

texts:
The Hercules C-130 get unserviceable often due to various technical issues. This causes the flight to be aborted (ground or air abort) due to avionics, propulsion, airframe or electric problems. I know that the three level of maintenance include 'O' (organizational or 1st level), 'I' (intermediate or 2nd level), and 'D' (depot level). USAF work cards are followed in all these inspections/maintenance.

I was wondering why commercial airliners, which no doubt are flying more than the C-130s, are rarely seen aborting a mission and diverting to a place other than the destination. Is there a different procedure or plan or work package followed by the commercial airliners which make the flight more reliable?


texts: Why was this Twin-Otter Take-Off unsuccessful?

texts: Watching this video I was asking myself, what was the error or cause of this unsuccessful take-off?


texts: What is the difference between VFR Flyways, Corridors and Transition Routes?

texts:
What is the difference between:

VFR Flyways
VFR Corridors
VFR Transition Routes

I can find a Flyway chart on the reverse side of the TAC chart and also Transition Routes in the TAC chart. But where can I find a VFR Corridor chart? I Googled it, but there’s nothing.


texts: The Socata TB-family wikipage lists the TB-9 and TB-10 as having "spatted undercarriage". What does that mean? From the pictures it appears to be a normal tricycle-gear-setup so I assume it's not referring to the layout of the landing gear.


texts: Can a Private pilot fly a company aircraft for business purposes if he is not being paid?

texts:
I understand that if you are carrying passengers and getting paid, then you have to have a commercial license.

What about this scenario? I have a PPL (Private Pilot License).  My friend owns a company that owns a plane.  If I fly him and/or his employees around, and am not being paid for the time and just doing out of the goodness of my heart, is that okay?


texts: What is the difference between aircraft integration and assembly?

texts:
I have never had a clear understanding of the difference between aircraft assembly and integration. My understanding is that putting together the airframe alone is assembly and putting together the avionics and other systems in order to get the aircraft flight-ready is integration. I'm not sure if this alone captures the difference. It would be great to have inputs regarding this.
Thanks in advance!


texts: How close to the envelope and the ideal was US1549 on ditching in the Hudson?

texts:
I assume that for "water landing" an airplane should be configured for the lowest possible stall speed, and then flown to that speed before impact to minimize the energy to dissipate on impact.

What is that configuration for a plane like the A320?  E.g., full flaps?  Was UA1549 so configured?
How close did UA1549 get to the stall speed before impact?  If I understand this answer then the A320's fly-by-wire protection would not allow a pilot to stall the airplane, meaning that the Pilot Flying could pull full aft to nail that speed (without either pilot calling airspeed to avoid a stall, which I assume would be the procedure for a plane without a self-protection computer).
Was the ideal pitch for a power-out water landing known by the plane and/or the pilots?  Normally we "pitch for speed," and it would seem an unlikely coincidence for the stall pitch to match the ideal impact pitch.  Which pitch was higher?
If impact pitch was higher did the Pilot Flying have to account for this, flying above stall speed in order to permit an increase to impact pitch immediately before impact?


texts: How may I verify WAAS channel number on G1000?

texts:
Take RNAV (GPS) Y RWY 36L and RNAV (GPS) Z RWY 36L at APC for examples,

All fixes and routes in the two approaches are similar.
The noticeable differences that I observe are minimums and WAAS CH number.

So some questions:

(1) How may I know which approach I am able to shoot? (or which WAAS channel is available?)

(2) Is the WAAS channel number automatically selected when I load the corresponding flight plan in G1000?

(3) ILS vs LPV: For an ILS approach, I may tune the localizer frequency and get both horizontal(CDI) and vertical (Glide Slope) information, without loading the flight plan. Can I get something similar with an LPV? I mean to get the LPV glide path guidance without loading any particular approach (set the WAAS CH number for instance?).


texts: Can anyone identify this tri wing twin engine WW1 plane

texts: Can anybody identify this WW1 or earlier plane? This tri-wing plane has two engines, most others I have googled have only one.


texts: Which kind of display are used on commercial aircraft?

texts:
There are many kinds of display (LED, LCD, PDP...).
Which type is used in the in-flight entertainment system on commercial aircraft?
And which kind of display is used in the electronic flight instrument system?


texts: If I fly both Part 135 and Part 91 in a 24 hr period, which regulations apply?

texts: I was wondering if there is a regulation if you fly both part 135 and part 91 in the same day which regulations do you follow?


texts: How is a traffic pattern oriented, entered and exited?

texts:
If you've received traffic entry instructions from Heathrow Tower (sim) to fly left downwind for runway 9L, does that mean to be to the left of runway 9L (for a right-turning traffic pattern, where downwind is north of the runway) or to enter a left-turning traffic pattern? I ask because the latter would take you over runway 9R/27L and I'm unsure whether this is a problem or whether it's ok because of the difference in altitude between a plane in 9L's downwind and 9R's/27L's final/upwind.

Also, if you've received clearance from runway 9L to depart north, should the departure be done from the traffic pattern? E.g. you take-off, turn crosswind, turn downwind then turn base and depart the airspace? Or should you continue straight until you've left the airspace, then change course?


texts: What DAL level is IFE software certified at?

texts: An inflight entertainment (IFE) system has software for the computers and for the seatback displays. What DAL level is the software classified at?


texts: Could someone help me understand the mathematics involved in Elliptical cross section fuselage that are used in A380. Also how double bubble cross sections are calculated.


texts: How should an aviation novice evaluate 'flight experience' or 'flight training' services?

texts:
Some companies offer a service wherein a complete novice may take a flight in a small aircraft, sometimes as a passenger, sometimes 'taking the controls' under the close supervision of an instructor. Examples of this include:

Spitfire Flight Experiences
Fly a MiG-29
Laser dogfighting

How should a novice, who has little or likely no flight experience at all, evaluate whether an offer such as this is:

Safe, within reasonable bounds (ideally the same safety precautions that a well-run national aviation regulator would require for full-time student pilots)
Legal, again within the remit of the regulations that would apply in that particular country
Reasonably likely to offer what is claimed i.e. where 'taking the controls' is advertised, that this would constitute actually manoeuvring the aircraft and that this would be legal and proper within the regulations


texts: What does the "BA/" stands for in this ATIS?

texts:
LTBA ARR
  ATIS V
  0920Z EXP ILS DME APPCH 05 BA/ FOR RWY 05 TRL 110 AFTER VACATING RWY CONTACT 121.8 WIND RWY 05 340 DEG 07KT VRB BTN 310 AND 020 DEG VIS 9999 FEW/02000 FT BKN/03000 FT T 21 OP 15 QNH 1017 NOSIG
  END OF ATIS V


texts: How is the climb/descent performance affected by wind gradient?

texts:
I am exchanging opinions with other pilots concerning climbing and descending with a wind gradient, and I'm facing strong opposition... In my opinion, a plane trimmed for S&L flight, if it encounters a headwind with a positive gradient (wind getting stronger with altitude) will gain altitude, since–because of the gradient–it will harvest some of the wind energy. In other words, part of the energy of the wind will be converted in potential energy of the airplane.

When descending in a tailwind with a positive gradient, things will take place in reverse: the plane will lose altitude, since a part of the potential energy of the plane will be transferred to the moving air, resulting in an increased KE of the wind...

Is my theory correct?


texts: Why are the wings of some modern gliders tadpole shaped?

texts:
Why are the wings of some modern gliders tadpole shaped, rather than teardrop shaped? An example is the Schleicher ASG 29. Or did they just add a flat plate at the trailing edge for the flaps and ailerons?

Source: flickr.com


texts: How does the Boeing 747 smoke evacuation work?

texts:
(source, inset source)

I recently watched Mayday's dramatization of UPS Airlines Flight 6.

Then I recalled the Boeing 747 having a SMOKE EVAC handle.

How does the system work?
Why wasn't it used to better allow the crew to see? Or was it used but didn't work?


texts: Does the Airbus A350 have an Automatic Emergency Descent System?

texts:
In 2009 Airbus went public with a new feature in the Airbus A350, an Automatic Emergency Descent (AED) System.

The system would detect a rapid depressurization and, after a defined waiting time, would initiate an automated descent if the pilots failed to respond to the respective alert (i.e. in case of pilot incapacitation).

I found some presentation slides from 2015 on the topic but haven't heard anything on that system since. Does anyone have additional information: is it a standard feature now on the A350, is it optional, or was it not pursued any further? If not, for what reasons?


texts: Is there a way to avoid exhaust fumes when landing?

texts: I've taken a few hours towards my private pilot's license and each time we land I've smelled this plume of engine exhaust that we seem to fly/roll through just as we're touching down.  I must be sensitive to the fumes because I usually end up with a slight headache after a few minutes.  I haven't asked my instructor yet (because he may think I'm nuts) but is there any way to avoid this short of holding my breath?  I'm flying in a Cessna 152 for my training.


texts:
Yesterday, there was an off-topic question on Space.SE, asking if a ramjet-missile could place itself in orbit. Impossible for a ramjet, obviously, as it requires a high speed flow of air and is too slow to reach orbital velocity.
However, this got me thinking about a ramjets altitude limitations:
How high could a ramjet-powered aircraft or missile possibly go? And how does the speed the jet is traveling at effect the highest possible altitude?


texts:
What is hinge moment?
Why in the process of calculating it we must calculate the coefficient of hinge in 2D?
Why the distribution of airfoil thickness at 90%, 95%, and 99% of the line should be considered?
Why is the line used for his (cf= line form hinge line to trailing edge) (cb = line from hinge line to leading edge) using a perpendicular line with Λ_(1/4) wings?


texts: About ramjet efficiency in supersonic speed. Is there an optimal speed?

texts:
I know there is an optimal speed for ramjet.

This are the results of my research.

The reason the efficiency increases with supersonic speed to an optimal value then decreases is related to the combustion speed.
The burn flame in the combustion chamber propagates at subsonic speed.
When the air is compressed the speed of intake airflow falls subsonic while flowing into combustion chamber. However, when the air speed in the combustion chamber matches the flame advance speed, then the flame remains stable inside the combustion chamber and the top efficiency is achieved.
At higher speeds the airflow still needs adjusted to match the flame propagation speed. This means the compression has to reduce the speed to the airflow to the same subsonic value, while dealing with even stronger effect generated by shockwaves. There is a maximum flow rate through engine that still maintains the maximum subsonic speed of the flame propagation. Anymore air resulted from higher speed will push the front of the flame into the exhaust nozzle which in turn pushes the expanding exhaust gas outside of the nozzle, with loss of thrust.


texts: What is the three-light indicator on carrier-borne airplanes?

texts:
(YouTube)

The above three-light forward facing indicator can be seen on most (all?) nose landing gears of carrier-borne aircraft.

What is it called? I suspect it relays the angle-of-attack / E-bracket position to the landing safety officers (LSOs).

If that's true, I still don't understand why since the planes are already tracked by radar (e.g., the SPN-42/46 radar) and deck cameras pointing down the glide slope. And the same information is shown to the pilots, which they already use to fly the correct AoA.

Do the LSOs keep it insight using their binoculars? Or does the same deck camera system image-process the lights?


texts: Why is paragliding not an old invention?

texts:
Paraglider looks like a rather simple device for me. It does not have a complex engine that needs lots of technology to be built. It also does not need a powered aircraft just to be launched. Looking from the side I have an impression that it can cover serious distances along the ridge under right wind. While it is not convenient to have the airways bound to mountain ridges, it could still have had uses like patrolling borders or similar.

I am surprised, why the master that could build a bow, or possibly sails for the ship could not build a paraglider many years ago. What are the reasons why the paraglider is relatively recent invention? Is there something complex about is I am not aware of?


texts: Have there been fully pneumatic aircraft?

texts:
Have there been any passenger aircraft that used pneumatics for all of their on board systems that required force actuation, such as:

landing gear;
wheel brakes;
nose wheel steering;
propeller brakes;
passenger door operation?


texts: How does the critical Angle of attack changes with Increasing Reynolds Number?

texts:
I am simulating NACA 2415 Airfoil for different Reynolds Number i.e. 2 million,3 million and 4 million on ANSYS Fluent. The difference between the critical Angle of attack is quite vast. For the 4 million Re number, I am getting a critical Angle of attack close to 46 degrees which seems to be very weird and looks incorrect to me.
Any explaination of how different the critical Angle of attacks would be for the above mentioned Reynolds Number?


texts: What is this abandoned airport between Montague and Rothbury, Michigan?

texts:
It appears to have had two intersecting paved runways, each very roughly 2000 feet long (give or take); the one that runs closer to north-south is still legibly numbered as runway 17/35, but the other runway is in much worse condition (suggesting that it was closed some time before runway 17/35), and its pavement is too broken up for me to make out the numbering.  Runway 17/35 has considerably larger turnaround areas at both ends than the other runway does.  There is a cleared strip extending for approximately 400 feet past the southern end of runway 17/35.

West of the intersection of the two runways, there appears to be a dilapidated apron, with taxiways connecting it to both runways; immediately north of the apron, there is what could be the remnants of a collapsed hangar, or could be something else entirely (there is another area of junk just to the southwest of the apron).

Google Maps link to location of the former airport here.

Google Maps screenshot showing the mystery ex-airport:


texts: Can the wing stagnation point be bled off and used for laminar flow control?

texts: The stagnation point at the leading edge contains slow-moving, slightly compressed air. This sounds ideal for laminar flow control. This slow air will create little losses in ducts, and it's pressure allows it to be blown out of slots to reenergize the boundary layer, while at the same time removing contamination - a MAJOR issue for laminar flow today. Is this true?


texts: Why does this 757 have a propeller engine attached to the fuselage?

texts:
I saw the following photo of a Honeywell Aviation Services Boeing 757-225:

If it's not a fake, the airplane has a propeller mounted on a pylon on one side.

What's the purpose of such strange design? Why does it need a propeller engine, if it already has two jet engines? Or is it a permanently deployed RAT?


texts: What does “Ground loops are costly. Fly them until they stop” mean?

texts:
In one of the earliest scenes of William A. Wellman's 1942 film Thunder Birds, a sign can be seen in a room of a USAAF base (some relax or briefing room, apparently), which says:

  Ground loops are costly. Fly them until they stop.

I am not entirely sure about its meaning. I know what a ground loop is, but in what sense “Fly them until they stop”? Is it an advice not to use brakes too soon after landing?


texts:
I've been looking for this topic on the internet but I don't have enough concrete answers. Suppose we have a plane with dihedral and it has a suddenly swinging to the right (watching from the nose of the plane), so the right wing goes down. I'm trying to understand why the right wing generates more lift than the left wing when it has a sideslip. I have seen in some sites that the sideslip induces a flow from the tip to the root and this makes the right wing increase locally the angle of attack, hence the lift of this wing increases too.

But, why the right wing increases the angle of attack? I think it couldn't be possible because the sideslip flow is in a different plane respect the mainstream.


texts: Why do multi-engine privileges not propagate down to single-engine?

texts:
From this answer, privileges of single-engine and multi-engine are separated. A pilot who obtained his PPL on a single-engine and his CPL on a multi-engine is not permitted to exercise his commercial privilege on a single-engine airplane. To do so, he must past another CPL exam on a single-engine plane.

Why is this do? I see no reason why a pilot who can operate a multi-engine airplane safely is incapable of doing the same in a single-engine. Training in a multi-engine would include an all-engine-failure scenario, which would be similar in single-engine.


texts: Writing Research: What stick sensation would you expect in an Su-15 with a total hydraulic flight system failure?

texts:
The title pretty much says it all. I have a very specific research question in relation to a writing project I'm working on.
The main character is in an Su-15 performing low flying military training, and has a total hydraulic flight system failure (which I understand is extremely rare) and crashes into the side of a mountain. I envision moments before, the pilot pulling back on the stick as hard as he can, with no authority, or give in the stick, resulting in the plane smashing into the mountains ahead. However, I'm not entirely sure this would have been the case and need to be as accurate as possible for this project.
Thanks


texts: Differenciate- the motion of "Nose-up trim" and "Nose-down trim"

texts:
I wanted to understand a part in ‘Take Off” where the study starts to explain “… the airspeed for best rate of Climb.”
I am a little confused about the (how to) of pushing the wheel forward to relieve forward pressure
 (nose down trim) -or- Rotate the trim-wheel back towards you to relieve back pressure (nose up trim).
 Is the motion in opposite of when pushed down, nose up trim and vice versa to that motion?

Hope I am explaining it articulately and its comprehensible.


texts: Does ATC provide ILS frequency and course setting for the runway in use?

texts:
I'm just from FSX background and not familiar with real procedures. In real world situations, when the pilot is vectored to the runway, does the ATC provide the pilot with the runway frequency and course setting or does the pilot have to know these already from somewhere (logs, FMS, etc)?

I mean in a real world case does ATC say for example "Expect ILS runway 24 left" or do they tell the pilot the nav frequency and course setting too? Or does the pilot obtain the setting for approach like the FSX GPS?

If possible please provide me with a sample communication for landing between ATC and Pilot. (Really curious)


texts: What's the function of the plate behind the wheels of the Pilatus Porter?

texts: Anyone knows what's the plate behind the wheel of the Pilatus Porter for?


texts: Might a large commercial jet dump fuel if an engine were on fire?

texts:
In my mind this seems like a bad idea for a lot of reasons, like the dumped fuel lighting on fire itself, or perhaps leaving fuel vapor in the wing tanks (which may be even worse than regular liquid fuel) or even just because if you do put the fire out you would now have a new emergency.

But, I've been wrong before.  Perhaps it would actually help put out the fire and being forced to glide would be an improvement over an engine fire, right?

So I thought I'd simply ask the experts.  Might a large commercial jet (like a B747, A380, etc) dump it's fuel if an engine caught on fire in order to starve the fire of fuel?

PS- For the sake of this thought experiment, pretend the fire had robbed the engine of the ability to cease fuel flow to it...  Unless that really makes no sense, in which case please feel free to call me on it and that can be the answer.


texts: Are these questions really on the FAA Glider Commercial written test?

texts:
I'm currently working on my Commercial Glider rating and for the written, I am using a popular test prep package.  The package allows the specific selection of Commercial Glider (vs Airplane, Helicopter, etc.)  Indeed, their glider question bank has 639 questions, whereas the Airplane and Helicopter question banks have 881 and 727 questions respectively.

So I was surprised to be presented with several questions that I wouldn't have expected glider only pilots to have to know.  For example:

I am also a PPSEL, so I was able to answer this, but I've never come across a glider with a VOR installed, and I frankly am not sure how useful one would be.

I was even more surprised to find this question:

Why would this be on any Commercial written test (let alone the Glider commercial?).  An instrument rating is NOT required for any commercial rating AFAIK, and certainly not for a Glider commercial rating.

So my question is, is this just a mistake in the test prep software, or are these types of questions actually on the Glider Commercial written test?


texts: I am planning to build a large-scale LEGO airlier with most parts functional. Doing a little looking at pictures and research I see that commercial airliners have an underwing body that houses the flap track guides. How do they work mechanically?


texts: Is pilot alerted of any physical or structural failures?

texts:
Current crew alerting system messages, I believe, are displayed basing on the software detection of the failures basing on the sensor information.

What kind of structural failures can occur to an aircraft in flight? (I know one case an engine got separated and communicated to pilot as just 'engine fail' instead of 'engine broken or something that might indicate a physical disconnect'). The had me wondering what other structural failures are possible when in flight. When I say structural failure, I am talking about a physical disconnect, bent, etc. Is there a (remote) chance that a structural failure can be caused in an airplane.
If at all a structural failure occurs in the middle of flight, is there any mechanism to let pilot know about it.


texts: How does washout increase static pitch stability in subsonic swept wings?

texts:
How does washout increase static pitch stability in subsonic swept wings, more specifically in slow moving aircraft (eg. ultralights), 15mph to 60mph?

I understand washout is used to delay full stalls ( at least in unswept wings), but isn't pitch stability related to cg and centre of pressure?

See picture below of a european designed Archon SF1 rg ultralight with swept wings and retractable landing gear. Mid engine single prop is shown forward of the twin vertical tails.


texts:
High Speed Flights

  2.36 - When receiving an ATS surveillance service, certain ex-military aircraft types have been granted a CAA exemption from the
  Air Navigation Order requirement to fly at an IAS less than 250 kt
  below Flight Level
  100. In order to alert the controller to this higher speed profile, pilots of exempted aircraft shall, on initial contact, prefix the
  aircraft callsign with ‘FASTJET’ or ‘FASTPROP’ (depending on
  propulsion type), e.g. “Kennington Radar, FASTJET G-ABCD request
  Deconfliction service”.

  Use of this prefix shall be confined to initial contact with ATC
  agencies for periods of flight during which operations at airspeeds in
  excess of 250 kt are intended. Once acknowledged, it will not normally
  be necessary for pilots to use the prefix in subsequent transmissions
  until making initial contact with other ATSUs.

Source: Manual of Radiotelephony, Edition 2016

What is meant by Deconfliction Service?


texts: How do I paint an airplane with an electrostatic paint gun?

texts:
I have a Cessna 150 which needs a paint job. As I have experience in painting objects with a spray can, and also in stripping airplanes, I am thinking to paint the Cessna myself.

What are the considerations required for this job? I would enjoy the experience and I'm able to get it prepped and ready. What would be a good electrostatic paint machine for this job? And how can I practice before painting the aircraft?

Note, I know the paints are different, I've heard of something called Imron, as well as Epoxy paints that harden and set.  Suggestions on that would be welcome too.


texts:
Is it possible to briefly summarize how a commercial plane navigation system operates to a layperson (e.g. a passenger)?

The aircraft takes off, reaches a certain altitude, and then lands perfect on a runway somewhere else.

How does the navigation system affect this?

How do pilots know where to go and where to land?


texts: What are the landing stall speeds of a Cessna 172?

texts:
I understood from Why is stall speed listed in a POH? that the Cessna Skyhawk POH lists stall speeds for specific conditions due to a lack of AoA indicator. However, what's unclear to me is what the stall speeds actually are.

Page ii

In page ii of the Cessna 172 POH it lists 48 KCAS for the Flaps Down, Power Off-configuration:

Page 2-5

Then on page 2-5 it lists the white arc spanning 40 - 85 KIAS, with Lower limit is maximum weight Vs0 in landing configuration.:

According the V Speeds Wikipedia page Vs0 is Stall speed or minimum flight speed in landing configuration. I understand that KCAS is not the same as KIAS, but this is quite a significant difference.

Question: what is the actual stall speed for a Cessna 172 while in landing condition and what do these two data points in the POH mean?


texts: What were those multiple flights leaving London night of 29th Aug 2019?

texts:
First time post here, please let me know if more detail needed (and which tag would suit it best).

I live in Essex UK, in the evening normally see lights of planes on approach to the London airports.

This evening (29 August 2019) from 21:00 BST / 20:00 UTC I have seen lights of planes flying away from London in large numbers (at least 30 when I started paying attention).

They were in groups of about 5, then another group following not far behind. They appeared to be heading in an easterly direction away from London.

Could someone help to shed some light on this? Have lived in this area for 15 years and never seen anything like this.


texts: What is the busiest route of Turkish Airlines in 2017?

texts:
What is the busiest non-domestic route of Turkish Airlines:

in terms of passenger number,
in terms of number of flights performed per year?

Is there a database that I can look for such kind of statistics for all other European airlines?


texts: What are the missions of high-endurance aircraft?

texts: What have been the missions of some notable high-endurance aircraft -- ones that can stay airborne for several days. Obviously, high-endurance missions have refueling, food, and human factors concerns that have to be addressed; what have been the missions that necessitated high-endurance aircraft?


texts: Why do we no longer have a navigation officer on modern commercial flights?

texts:
In the olden days there used to be a navigation officer in commercial airlines who had the tasks of navigation and radio communication. But, in modern commercial airliners there is no navigation officer.

Do the pilot(s) take the additional responsibility of radio communication and navigation? Or is the navigation part now done by onboard computers and systems?

If the electronic navigation system fails, are there any backup plans? Are physical maps and a compass then used to determine the direction and position?


texts:
Were planned release dates skipped in 2020 for the VFR sectional charts for Juneau Alaska and Dutch Harbor Alaska?
On February 3 2021, the FAA's "Raster Charts" webpage listed a March 26 2020 date for the latest edition of the Juneau sectional, and a February 27 2019 date for the latest edition of the Dutch Harbor sectional.  These dates seem unusually old.  (And interestingly, at that time, the links to those editions didn't even work.)
There was a rather significant airspace change at PASI at Sitka Alaska (which is located on the Juneau chart), effective November 5 2020, which appears to coincide with what should have been a planned release date for this chart.  The E2 Class-E-to-surface airspace at Sitka was changed from an "L" shape with arms to the northwest and southwest, to a nearly circular shape with a very large rectangular E4 Class-E-to-surface "extension" projecting toward the northwest.  As of February 3 2021, the current VFR sectional products available online still showed the old airspace configuration, while the new airspace configuration could be seen by going to the  LAANC map and typing "PASI" in the search window and enabling the E2 and E4 layers.  (Images of each attached below-- screenshots taken February 3, 2021.)
It seems odd that such a major change in airspace configuration would not have been covered by new edition of the VFR sectional chart.  Was a release of the Juneau chart planned for November 5, 2020, and then skipped for some reason?
Bonus: if so, for what reason?
The rather low "edition numbers" shown on the current edition of the FAA's "Raster Charts" webpage for many of the Alaska charts does suggest that they generally been released only about half as frequently as most other charts.  So maybe these long intervals have been planned, or at least did not come as a surprise.
Basically, in a nutshell, this question can be re-stated as "Did the latest editions of the Juneau and Dutch Harbor VFR sectional charts prior to the 2-25-2021 update show an 'expiration date' that was earlier than 2-25-21?  And if so, why was the previous planned update skipped?"
A note in closing -- The FAA's "Aeronautical Chart Bulletins" webpage is currently a good resource for seeing a list of significant changes that have occurred since the last publication of any given VFR aeronautical chart.  Also, as of February 3 2021, this webpage indicated that the Dutch Harbor chart was actually last updated on Feb 27 2020 rather than February 27 2019, so the 2-27-2019 "latest update" date on shown on the "Raster Charts" webpage on 2-3-21 may have been a typo.  That doesn't change the basic thrust of this question-- was a planned update in 2020 missed?


texts: What infrastructures are required for airlines to send PNL messages?

texts: There are lots of information about Type-B messages sent by airlines on IATA website but they have not stated under what communication systems (cable, teletype, intranet, internet, etc.) these messages are exchanged. What are these systems?


texts: How to calculations deviation on a magnetic compass and effect of it?

texts:
I am told to do self study and mainly for the part of the formula reading and i did some research and don't understand a single thing that i read online http://opac.vimaru.edu.vn/edata/EBook/Magnetic%20Compass%20Deviation%20And%20Correction.pdf. I also not very sure what is the effect of deviation have on the compass. Can someone pls help.Thank in advance.

P.S. I did it with zero knowledge of aviation as i just take this course.


texts: Why isn't the airspeed indicator the primary instrument for power during a constant speed climb?

texts:
I am studying the primary and secondary IFR instrument designations. I understand that the primary instrument is the one that closest represents your target value, and is normally the one gauge that isn't moving on the panel during the targeted maneuver (for example, in a constant rate turn, the Turn Coordinator is stabilized on a value after entry is completed and becomes primary).

I fly a variable pitch prop, and I think my confusion might be a result of not flying a constant speed propeller.

Take a look at the item in red:

Question:

Can someone explain why the CS Climb power primary isn't the airspeed indicator?

If you are stabilized on your airspeed, wouldn't airspeed dictate the power setting you want to maintain? If you change pitch, the airspeed drops/rises and the power is changed - doesn't that make the airspeed indicator primary?  I have been taught to set power (on entry) and then monitor airspeed to make pitch adjustments. This makes the idea of a power primary confusing in stabilized descent/climb.

This seems like a confusing way to have to learn the material as I don't find I have to think about this while flying to effectively control the airplane...


texts: How much actual difference does fixed pitch propeller make in takeoff distance?

texts:
So it's possible to buy fixed pitch propellers which are either optimised for takeoff or for top speed. I guess most airplanes have a compromise.

Considering a training aircraft like a Cessna 152, what would be the difference in Ground Roll and Total to Clear 50ft obstruction between different props?

As an example the Ground Roll and Total to Clear 50ft Obstruction  at 20 deg C for a weight of 1670 lbs at Sea Level is listed as 755 and 1390 feet respectively. How much numerically  would they change with different props?

Please note this is just a hypothetical question. I'm not in the market for propellers!


texts: Can TCAS cope with situations involving more than two aircraft?

texts:
Most of the information I've seen about TCAS talks about only two aircraft being involved.

It's pretty unlikely, although far from impossible that situations involving three or more aircraft may arise.

In such situations is TCAS expected to detect the situation and offer sensible advice still? Or are all bets off and a series of confusing and conflicting advice the most likely outcome?


texts: What is defined as "day VFR" under EASA rules?

texts:
I received a document where it it specified that the flight relevant for such document can only take place in "Day VFR" conditions undear EASA regulations.

Is this connected to VMC? What does EASA defines as "Day VFR"?


texts: What is the ratio between time in the air and time on ground for an aircraft?

texts:
I suppose it may be different from an airline to another.
Given the maintenance, the time to load/unload the aircraft, the time the aircraft is grounded because there is no flight scheduled (e.g. at night), how many time an aircraft actually spend on ground compared to the time it spend in the air?


texts: When taking passengers, what should I do to prepare them?

texts: What kinds of stuff should I think about in terms of taking other passengers flying in a small airplane?  Many potential passengers have never been in a small airplane.


texts: Why do light taildraggers swirl uncontrollably on runways in a simulator?

texts: When a pilot chooses to run at a speed way above its takeoff speed on the runway in a simulator without taking off, the plane begins to skid and spins 360 uncontrollably around the yaw axis, what is the cause?


texts: Is it possible to calculate lateral acceleration from pitch/yaw/roll rates?

texts:
Can you calculate an aircraft's lateral acceleration from the aircraft's yaw, pitch and roll rates? If so, how?

This is to implement a digital slip indicator.


texts: When not cleared straight in for a VOR approach, how is this type of procedure executed?

texts: You are flying to the GDM VOR on a 097 heading. The ATC clears you for the approach, but does not specify straight in. The procedure turn is marked by the barb and specifies remaining within 10nm. My assumption is that you would fly a procedure turn style course reversal, using the altitude of 3000 within 10nm, fly the 277 back course, then fly the procedure turn inbound. I would assume most times ATC would just clear you straight in however is there any documentation of this style of double PT/unpublished course reversal procedure?


texts: What are the advantages and disadvantages of a double bubble fuselage?

texts:
Double bubble is mostly used for Cargo Aircraft with 2 intersecting circles which is in other words: they are 2 floor which are used for more space for freight and also passengers. this type of fuselage mostly used in the past by some small airlines but today they are only used for cargo. i wonder to know all the things above mentioned by me are right or not?
and the other question is that what ARE advantages and disadvantages of A380 fuselage? and how it is designed that able to carry a large number of passengers although its fuselage is not double bubble?


texts: Can Savannah be stalled with agressive yoke pull?

texts:
My friend fly ultra light Savannah, 2 seats plane,wings dont have slats ,it has vortex generators at leading edge.
He says that he cant stall plane with agressive yoke pull (I talk about speeds above stall-speed).
My question is this really true,why airflow dont separate from wing at high AoA and cause reduction in lift and sudden drop in altitude when pull yoke as fast you could?
He says plane just starts climb an that is what happend.


texts: What is a "departure" in the context of flight testing / maneuvers?

texts:
I was reading about the F-35 flight tests and it mentions a "departure" at a couple of places.

What does that word mean in this context? I understand spins and stalls but what's a "departure"?

  AF-2 was the first F-35 to be flown to 9g+ and -3g, and to roll at
  design-load factor. Departure/spin resistance was also proven during
  high angle-of-attack (AOA) testing which eventually went as high as
  110 deg. AOA

  Pilots really like maneuverability, and the fact that the aircraft
  recovers so well from a departure allows us to say [to the designers
  of the flight control system laws], ‘you don’t have to clamp down so
  tight,

(Wikipedia Lockheed Martin F-35 Lightning II article)


texts: Do helicopter rotors have anti-ice systems like propellers and wings?

texts: Icing disrupts the aerodynamic qualities of wings and props, is there a similar danger with helicopter rotors?  Are there de-icing systems to prevent this?


texts: Why are no HAPS (High Altitude Platform Station) solar planes of a biplane design?

texts:
HAPS are fragile due to weight constaints, e.g. NASA’s Helios. Biplanes are more robust.

Although biplanes have high drag, HAPS only need to move slowly because at their operating height the wind speed is less than 50 mph, and to maintain station they only need to overcome that.


texts: Why this huge discrepancy in flight times?

texts:
I was looking at return flights from London - Azores islands and was astonished to see the huge difference in flight times, both flights are via Ryanair:

out: 3 hr 5 min
return: 4 hr 45 min

I am aware of differences due to wind conditions/jet streams and routes etc but for the return flight to take >50% longer really surprised me. What is likely to be the cause of this?


texts: Is there a legal minimum stop time between 2 legs?

texts:
This question is restricted to airliners transporting many passengers (let's say more than 20).

Between two legs, airliners stay at the boarding gate for a limited time, sometimes less than an hour. The stopover duration at the gate is typically dictated by the time to refuel and disembark/embark both freight and passengers. I understand the cost-saving logic behind the decision to make this operation as fast as possible.

However, in a competitive market, safety may not be compatible with shorter turnaround times. No pilot would irresponsibly compromise safety by leaving the gate without fulfilling their safety and security obligations, but I wonder if there is a minimum turnaround time imposed by regulation to avoid downward pressure on turnaround times?

EDIT:

let's focus on the fastest and simplest scenario: no crew change and no refueling (the crew took enough fuel to make several legs)
I don't want to be restricted to one legislation or one part of the world. The question is: does any regulation exist to require such a stop time?
I just thought that technically, brakes should be cooled down before the next take off roll.


texts: What spacing is needed between aircraft parking stands?

texts:
I'm doing a project where I have to design an apron for a general aviation airport (ICAO type 2B). The airplanes have to park in angled nose-in parking, or angled nose-out parking.

What is the required separation between two stands? I think that the dimensions of one stand depend on the turning radius of the airplane that is supposed to use the stand, but I don't know where to find this angle for every airplane...

I'm looking for any data or other relevant information.


texts: Can two Airlines have the same ICAO code but different IATA codes or vice versa?

texts:
We are trying to import all the Airlines into a Table.
Plan is to Update existing Airline Data if not present then create it.
For this we needed an unique way to identify the Airlines.
Is ICAO+IATA an unique identifier or is it possible to have Airline without IATA or ICAO code?


texts: Are military and jet pilots given any extra training before entering commercial aviation if yes, then how?

texts: Because a jet pilot is habitual of flying super sonic aircraft, which can possibly go in any direction and do many maneuvers, which commercial aircraft can't, are they given any special training before entering commercial aviation?


texts: What organisation owns intersection names?

texts:
I understand that five letter intersection codes (such as WARPI, PAPPI, KUBBS, ROSLY, ZALPO, ...) are unique in the world.

However, their names don't comprise a national prefix (as aircraft tail number do, or airport codes do), which would allow to delegate name bookkeeping to the individual countries's aviation authorities by prefix.

Therefore, a single, international organization has to somehow own and disambiguate all the intersection names. I would expect the ICAO to be that organization, but I haven't been able to find any resource mentioning that.

Help?


texts: How to scale the data of a wing aspect ratio to correspond to the case of another aspect ratio?

texts:
I am reading "Fundamental of Aerodynamics " by J.D.Anderson Fifth edition. If you got the book, go to chapter 5, page 440 and 441. If you don't have the book then here you go: https://avionicsengineering.files.wordpress.com/2016/11/john-d-anderson-jr-fundamentals-of-aerodynamics.pdf  (page 465 and 466 of the pdf file).

I don't know how to insert the respective values of $C_{D,2}$ and $AR_2$ from figure 5.21 into Equation (5.66). How can we obtain the graph in figure 5.22 ? I am stuck at this point, can you help me out ?


texts: Do aircraft tyres have inner tubes? Modern small single-engine turboprops to the largest Jumbos. If not, did they ever have inner tubes? And if so, why were they discontinued?


texts: How to calculate optimal prop diameter, pitch, torque and power coefficient given required thrust?

texts:
this is my first post here, so bear with me if this isn't the right place. I'm coming here from Stack Overflow, and this seemed to be the most relevant Stack Exchange for my question.

So, I'm building a multicopter (quadcopter, preferably, due to it's relatively simple design) on a scale that's more-or-less never been done before. I've decided to funnel all the money I made over the summer into this project, and I've just begun the planning stage.

I've worked out that I need about 2500 Newtons of thrust: enough to move 180 kilograms (about 80kg for the person and 100kg for the electronics, maybe more) at a rate of ~4.5 m/s^2 more than standardized gravity—13.888 m/s^2 in total, to be specific. I'd need approximately 750 Newtons of maximum force on each rotor, as my experience with building and coding (from scratch) an Arduino flight controller has taught me that the upper motors often need to work much harder during x and z movement than they would during standard y elevation.

Some other notes:

I'm pretty sure that π * diameter-in-cm * rpm / 6000 must be <340.29 (Mach I). Maybe I should be using a turbofan? Especially considering the next note...
The diameter of the rotors shouldn't exceed 30cm for convenience purposes. I.O.W. it can't be too big or else lugging it around would be a hassle.

Fuel source will (hopefully) be batteries, most likely an array of LiPo cells in series and in parallel (probably something like 10x10), each cell containing about 10,000mAh.

I struggle to continue from this point. I haven't the slightest idea as to how to pick a prop design that is most efficient for this project. My question for Aviation is this:

  Given a required maximum sustainable thrust of 750 Newtons, a mass of about 180kg, and the assumption that maximum velocity of the craft is slow enough that air resistance and other drag is pretty much irrelevant...

  How would I be able to calculate the optimal prop diameter, pitch, Kp (power coefficient), Kt (torque coefficient), as well as optimal number of blades and optimal manufacturing material? Or, would a turbofan be more optimal?

I wouldn't be surprised if your first thought was something along the lines of "this is ridiculous." Some may even suspect me of being a troll. I can assure you, I am highly committed to this project. My flight controller is insanely stable, and I believe it would be worthwhile to test its abilities on a build that is more heavy, powerful, and top-heavy than most multirotors ever built.

Could you guys point me in the right direction?


texts: Is this a reasonable way of thinking about an auto-rotation?

texts:
Related to this question.

My instructor described an auto-rotation as:

Entry.  Lever down, stick back, pedal in.
Fly normally, with a little tweaking of RRPM to keep it in the green, until about 50 feet above the ground.
Perform a quick stop.
Perform an engine failure in the hover.

I can see the logic in this but, all of the autos that I have done have been far too busy to think about it like this and all the ones I've done to the ground have been run-ons so step 4 was not an option.  Without significant extra training and experience I would not even contemplate a zero-zero landing so in practice, I will probably never get to test the theory.

Is this a valid way of thinking about the manoeuvre?  I'm not suggesting that anyone does anything other than what they were taught, just thinking about how these four manoeuvres roll into one.


texts: Why do aerobatic planes have symmetrical wings?

texts: Besides the fact that symmetrical wings fly the same inverted as upright are there any other reasons why aerobatic planes prefer symmetrical wings?  Can symmetrical wings achieve a higher critical angle of attack?  Does the large ailerons on aerobatic aircraft have anything to do with it?


texts: How does the control-board on small drones govern their flight?

texts:
I saw this YouTube clip for a light weight drone, under a few ounces, with very impressive maneuverability. They used styrofoam for frame and taped the rotors and battery and the control chip to it. It maintains the balance, controls the four motors, pitch and yaw, lift and thrust, basically pilots the drone.  And can do automatic stall recovery or aerobatics?

It seems like the most complex part of these drones, gyro, accelerometer, balance, aviation and navigation (all packed on a tiny board), is the most easy to make and cheapest part!

Can somebody explain to me how the this small flight command center feeds the controls of rotors? Does it have any sense of right side up, gravity? Can it sense the wind by measuring the drift?


texts: Why at some airports/airfields you need to fly a non-standard circuit/pattern?

texts: Why at some airports/airfields you need to fly a non-standard circuit/pattern, what are the specific reasons for this and what are the differences between them while flying?


texts: Does the cannon of the A-10 deliver more thrust than the engines do?

texts:
The A-10 Warthog is built around a 30 mm cannon that fires depleted uranium rounds, 65 of them per second.

I heard from someone who worked on the flight controls a long time ago, that when the cannon is fired it provides more thrust than the engines. Is this true? What are the effects of this?

Update

The original question was answered by @Gypaets: thrust of the cannon is comparable to thrust of one engine. The wikipedia article on the GAU-8 cannon mentions that effects of thrust of the cannon are well accounted for by placing the firing barrel at the centre line of the air frame. Ron Gordon's answer reveals some interesting side effects from spooling the cannon up and down when operating - the aircraft bucks. It's a big cannon.

Image source


texts: Why don't air-cooled radial engines use fuel to cool the oil?

texts:
Having read up on WWII air-cooled radials, one thing that struck me is how frequent is the mentioning of external oil cooler overheating, or the need for armored boxes around it, and some even venture to say the so-called air-cooled radials are in reality oil-cooled radials.

This got me thinking. Since the oil in turbofans is cooled by fuel flow, why isn't this the case for radials? Is this because the fuel flow is insufficient, or the oil too thick, or some other reasons?


texts: How did the Caproni Ca.60 electrical communication system work?

texts:
On the wikipedia page for the Ca.60 it says:

  The two nacelles also housed a cockpit for one flight engineer each, who controlled the power output of the engines in response to the orders given by the pilots by means of a complex system of lights and indicators located on electrical panels.

I would like to know more details of how this system worked, such as what the function of the switches were, and what was communicated with the lights.

If nobody knows how this particular system worked, maybe we can infer how this worked from similar systems used in the past, if any existed?

There is a picture of the remains of this panel on the wiki page. Here is another picture that I found. Any ideas?


texts: How to use airport panel information on sectional chart?

texts:
In the Chart Supplement, the airport information includes the chart on which the airport is located. It also includes a panel on the chart where the airport is located. How can I use this panel information? Sectional charts don't appear to have panels.

Here is the airport information for San Francisco International:

I understand that San Francisco stands for San Francisco Sectional Chart and H-3B and L-2F are for the IFR charts, but how can I use the 3B and A information?


texts: Can a captain fly in the right seat as SIC under part 129?

texts: Re a Part 129 air carrier that is short of co-pilots:  Can a pilot who usually flies in the left seat (B737 aircraft: non-US registry) as the Pilot-in-Command fly in the right seat as the SIC (co-pilot)?


texts: Do any manufacturers have plans to use turbojets in future aircraft? What is the state-of-the-art in turbojet design?

texts: Turbojets have largely been superseded by turbofans (or turboprops for low-speed flight). Are there any aircraft being planned that would use turbojets?  I'm also interested whether there has been any improvement in turbojet design over the last few decades.


texts: Can I fly under a Military Operations Area (MOA)?

texts: If a  a Military Operations Area (MOA) is designated from 10,000 to 18,000 feet, can I fly under the airspace without any permission?


texts: What is the effect of a taildragger on P-factor?

texts:
By looking an image of P-40 Warhawk with taildragger (and other vintage warplanes), one can conspicuously find the propeller disc of this aircraft isn't perpendicular to the relative airflow which induces P-factor.

Doesn't this design forces the aircraft to further left which causes difficulty for pilot to direct rudder to right?

Is this the reason why all the modern airliner's (including single engine aircraft like Cirrus SR22, Kestrel K-350) fuselage isn't made inclined?


texts: Was there any Hawker Trident installed cockpit voice recorder before BEA Flight 548 incident?

texts:
After BEA Flight 548 incident in June 1972, all British-registered airliners have mandatory cockpit voice recorders. The TV series Mayday claimed no voice recorders were installed in Hawker Tridents before the report of the incident was released.

9 months before BEA Flight 548, a Chinese Air Force Trident 1E (AP-ATL) crashed in Mongolia. Lin Biao, the second-in-charge in China, was killed as well as his family members in the incident.

The incident itself is still mysterious, but some source claimed that there were voice recorders in the cockpit and the chat inside the plane was recorded.  Many sources cited that the Chinese officers did not know the black box was installed, so the voice recorder was only installed by either Pakistan International Airlines (previous owner of the airliner) or by the manufacturer.

The question is : Were there any Hawker Trident installed cockpit voice recorder before BEA Flight 548 incident?


texts: What is the cockpit shown in this picture?

texts: What is the cockpit shown in the picture below?


texts: What's This Cable Connecting Cockpit to Vertical Stabilizer in Air Tractor AT-401?

texts:
This is a picture of an AT-401 Sprayer Airplane

I was wondering what's this steel-string stretching from cabin's windshield to the top of the vertical stabilizer
...


texts: Is Qantas holder of the world’s longest commercial non-stop flight?

texts: Is it Singapore Airlines or Qantas that is currently holding the record for the world longest non-stop commercial flight?


texts: Does a dual-rotor helicoptor like the Chinook transition from hover to forward flight differently than a single rotor helicopter?

texts:
I watched this video of an RAF Chinook taking off vertically and transitioning to forward flight.

I'm curious if the method for increasing lift to move forward, controlled by the cyclic in a single rotor if I'm not mistaken, is different when you have two rotors along the length of the aircraft. My untrained assumption is that to lift the rear of the helicopter and start moving forward, you would increase power or the collective on only the rear rotor.


texts: How much knowledge/experience can be transferred between different categories/classes of certification?

texts:
This question was originally going to be "Is it possible to earn an ATPL without also ending up with at least one airliner type rating?", but I thought I'd broaden it just a bit (hopefully not too broad).

Requirements for an ATPL in the United States include 1,500 hours total flight time with several minimums in various special conditions and as PIC, "applicable to the aircraft category and class". My question is basically, "what is the definition of 'applicable'?".

For instance, it is theoretically possible, and even useful, to obtain an ATPL in the ASEL class (so the answer to my original question is "yes"; you can earn the FAA's highest certification level without being signed off on anything close to the type of aircraft Southwest or Delta have in their fleet). You could get that license and fly Cessna singles for Ravn Alaska (formerly "Era Alaska" of Discovery Channel fame) or any of the other bush airlines around the country.

However, that represents a lot of flight time before you can even sit the written tests and fly the checkride; 1,500 hours total (250 as PIC), 500 of that XC (100 as PIC), 100 hours night (25 as PIC), and 75 hours real or simulated instrument time (no more than 25 hours in a flight simulator, 50 if you're training under Part 141), all in single-engine fixed-wings. If you then wanted to progress to multis and thus eventually become useful to a major U.S. domestic airline, you would have to start from scratch as a student pilot in the AMEL class.

... Or would you? That's the question; how much of your flight time and/or certification level in one class is "applicable" by FAA regs toward any other class of the same category at the same level of certification? It seems unfair for a pilot with a fairly high ASEL certification to have to start from scratch on flight hours just to fly a plane with floats, or more than one engine, or both. However, they are different classes for a reason; more, or at least different, knowledge and experience is required to taxi a float plane on a lake or to get a multi-engine plane off the flight line. So while there is definitely a lot of overlap between the four "Airplane" classes, it's not 100%.

How about applicability of flight time and certifications to other categories? I'm particularly interested in the "rotorcraft-gyroplane" class and the "powered lift" category, as these were developed as aircraft hybrids which AFAIK have a significant skills overlap with a fixed-wing aircraft. Does flight time in an autogyro count in any capacity towards flight time in a fixed-wing, or vice-versa? How about flying a Harrier? In 50 years when the Osprey makes its way to GA in come capacity, how would existing civilian airplane and/or helicopter pilots get rated to fly it (I hope not by amassing 1,500 hours in an Osprey)? How about something completely different? Even between a fixed-wing and a helicopter there's some overlap (though I'd imagine even the chief pilot of a major airline would be out of his depth in a B204).


texts: How do I determine the best altitude to fly for fuel economy?

texts:
If you fly low, air is dense so you can get more thrust from your engines, but you get more drag.
On the other hand if you fly higher you have less drag but the output of engine decreases as well.

So what's the optimum altitude to fly at, and how does one determine it?


texts: I was curious if someone could help me gather some more info on this aircraft.  I have looked it up in the FAA.GOV site and it does not match.  Is there a way to find out info on this plane that flew around the Springfield Illinois area around 1946, possibly before?  Also, this is a Stearman?  Is there anything else interesting or remarkable about this aircraft?  Thanks!


texts: Why do cargo aircraft still have floors?

texts:
Even with dedicated cargo aircraft built as cargo aircraft (rather than converted from a passenger-carrying configuration), the cabin is virtually always still divided into an upper and a lower lobe (which would, on a passenger aircraft, be the passenger cabin and the cargo hold, respectively) by a floor located a third to a half of the way from the bottom of the fuselage, drastically reducing the maximum size of the cargo that can be carried and making it much harder to transport round outsize cargo (such as, for instance, large high-bypass turbofan engines as are used on essentially all modern jetliners) by air.  Given that the essential structural members of a large modern jet are

the skin itself;
longitudinal longerons running the length of the fuselage just beneath the skin; and
circumferential frames encircling the fuselage just beneath the skin;

it should be possible to remove the floor, and thus dramatically increase the freighter's ability to carry very large objects, without significantly compromising the fuselage's structural integrity (the middle of the cabin would still be partially occluded at the bottom - or the top, or the middle, depending - by the center portion of the wingbox, but there would, nevertheless, be a considerable increase in the outsize-cargo capacity ahead of and behind the wings).  Why isn't this done?  Is the floor left in to facilitate possible future conversion to a passenger aircraft?


texts: Why is an ATC operational error called a "deal"?

texts:
Air Traffic Controllers who lose separation between aircraft call that event a "deal". Why?

When the Conflict Alert function was added to the computer system, it reported conflicts to the area supervisor.  Controllers came to know the feature as "Squeal-a-Deal", but no one could ever tell me why they're called deals.


texts:
I'm a US-citizen living in Japan, and the costs here are insane ($500 per hour). So I'm thinking to go to the US or Australia for my pilot's license, but how long am I'm going to need to live there? Could it be done in 2-3 months? Less?

This question discusses the cost of learning to fly, and it's mentioned that people often take a year (flying once a week) to see the hours. My question is: reasonably speaking, how quickly can someone get their license?  I'm not actually looking to go from "zero to hero" in record time, I do want to learn the material and enjoy the process. But wanted to have a rough idea of the lower limit so I can plan for the total costs (housing, time away from work).

If you need 40-50 hours of flight time, and you fly 2-3 times a week, what is the typical duration of these instructional flights?  How many hours can someone realistically book in a week (I hear flights get cancelled)?

In reply to the comment about individual ability… I have a high-IQ and have taught myself many things throughout my life. I'm a software engineer with 20+ years experience (created my first commercial software application around age 12), I've authored several top-selling Japanese language books, I taught myself photography and have two Page-One credits in the NYTimes, I learned freediving and 9 months later I won an event in a competition in Japan and ranked 11th nationally, etc. When I put my mind to something I'm focused and disciplined. How much does it really depend on my ability and how much depends on class hours and flight time?


texts: How do elevator servo and anti-servo (geared) tabs differ?

texts:
(Community work) Image shows tab deflection direction in relation to an upward deflected elevator.

How do elevator servo and anti-servo (geared) tabs differ in handling? How to decide on which tab to use?


texts: What will air traffic controllers do when radio contact is lost?

texts:
When a pilot loses radio contact with ATC, there are standard procedures to follow, e.g. squawk 7600, observe the traffic pattern, observe the red / green light gun.

On the other side, if a controller attempts to contact an aircraft and gets no response, what will they do? Assume that radar contact is not lost, or the controller is not equipped with radar.

EDIT: Let say a controller spotted a 7600. What's next?


texts: How does the idle mixture adjustment in a Stromberg NA-R9B float-type carburetor work?

texts: At what temperature should idle mixture adjustments be made in Stormberg NA-R9B float-type carburetor?


texts: How does the shift in aerodynamic center affect the performance of swing wing aircraft?

texts: I am trying to understand how a  variable sweep wing changes the aerodynamic center of a plane, and its effect on the plane's maneuverability. I also would like to know the importance of the pivot point as it somehow affects the center of pressure.


texts: Why can't horizontal stabilizers be longer than they are today?

texts: I've wondered this question because if the horizontal stabilizer is longer than that means more lift. My guess to this question would be the result of wing tip vortex strength on a longer wing


texts: Why do pilots refer to the Flight Service Stations as "Radio" in the the United States?

texts: When using an aircraft radio to call a Flight Service Station ("FSS"), why do pilots refer to them as "radio?" I understand calling control towers "tower", ground control "ground", Air Route Traffic Control Centers ("ARTCC") "Center", and so on, but why "radio" for a Flight Service Station? Why isn't it "Station?"


texts: I've always wanted to ask a pilot what a CRM was. Of course, I didn't really get lots of chances to ask pilots, no I thought of just asking here. What is a CRM and what does it stand for?


texts: What type of airspeed are wind speeds given in?

texts:
When you get wind speed from an ASOS/AWOS or from ATC, are those speeds in true airspeed? Are the instruments weighted for elevation?

Say you're on approach to 05R at MEX and you're given wind speed of 25 kt at 140° and the OAT is 35°C. Do you need to take density altitude into account to determine if it's safe to land? Or is there not enough of a difference to matter?


texts: What is the difference between en-route delays and airport delays?

texts:
ANSP performance is gathered an published online on https://ansperformance.eu. They monitor complexity, delays, efficiency and other operational data.

I also noticed they have two ways of describing delays with a formal definition:

En-route delays

  The en-route ATFM delay provides an indication of ATFM delays on the ground due to constraints en-route.

Airport delays:

  The Airport Arrival ATFM Delay provides an indication of ATFM delays on the ground due to constraints at airports.

My question is: What does this exactly mean? Are these different ways of describing the same delays? Or do they describe two different sources of delays.

One reason of my doubt is that both categories use the same classification, from A (accident/incident) - W (weather). Could someone shine some light on this?


texts: Why aren't there any jets with horizontal-stabilizer-mounted engines?

texts:
Looking at the spectrum of where jet aircraft put their engines, there are examples of almost every place that could conceivably used to carry a jet engine:

slung under the wings
buried inside the wings
on top of the wings
on the sides of the aft fuselage
in the aft fuselage
on/in the vertical stabilizer

Notably absent, however, are jets with engines having anything to do with the horizontal stabilizer.

Why aren't there any jets with engines mounted on/in their horizontal stabilizer?


texts: Are records of certificate actions available?

texts: Are there any online records that may indicate why a specific DPE may have lost qualifications recently?


texts: How much jurisdiction does the FAA have over military aircraft?

texts:
The FAA controls just about everything about civilian aircraft in US airspace in terms of regulation, certification, flight rules, etc. Do they have any authority over military aircraft beyond requiring military flights to communicate with ATC for safety and designating certain areas as military airspace?

This question addresses retired military aircraft in civilian use, and one of the answers to this question mentions a "Surplus military" category, but nothing about active military.  I'm asking about current, active military aircraft in terms of certification, pilot licensing/qualification, etc.


texts:
As far as static thrust, does a shrouded/ducted propeller outperform an un-shrouded propeller? It seems that the guide blades on the bottom of the duct would allow little more thrust to be extracted from the vortex the prop generates by redirecting the air flow. Also the duct seems like it could "focus" the propelled air (like a rocket thruster) resulting in better thrust.

(Source)

Of course I can see how an improperly implemented duct could really kill efficiency (creating more interference and turbulence), but what about a well designed one? And if they are better, why wouldn't we seem most propeller aircraft use them (what is the advantage about not having the duct)?


texts: How can I calculate the velocity of air drawn by a pusher configured propeller?

texts: I am attempting to construct a model plane using Custer channel wings. In order to calculate (or at least approximate) the lift generated I need to find the speed of the air through the channel due to the propellers. Is there an equation I can use to do this given pitch, diameter, rpm, etc?


texts: Why don't multiengine aircraft have to demonstrate spin recoverability?

texts:
(Building off this earlier question about spin-testing airliners.)

For normal-category aircraft1 in the U.S. (at least), only single-engine (or, in the case of some gliders, no-engine) airplanes need to demonstrate the ability to recover from a one-turn (or, if the aircraft is intended to be certified for intentional spinning, six-turn) spin.  This means that, for instance, the single-engine Cessna 208 (MTOW 3630 kg) has to be successfully recovered from a one-turn spin, whereas the much-smaller Piper PA-34 (MTOW 2155 kg) is exempt from this requirement solely by virtue of having a second engine.

There is nothing about multiengine aircraft that makes them inherently resistant to spinning compared to single-engine aircraft; indeed, if anything, it would be expected to make spins somewhat more likely (think "aftermath of botched or absent pilot response to an asymmetrical engine failure"2).  If, instead, the number of engines is being used as a proxy for the size and intended audience of the aircraft (as suggested in this comment on the aforelinked question), then I don't see any reason not to simply use a dividing line based directly on weight (especially since, as noted above, there are many large single-engine airplanes and small multiengine airplanes).3

Given all this, why aren't multiengine airplanes (especially small multiengine airplanes, such as the aforementioned PA-34) required to demonstrate spin recovery like their single-engined compatriots are?

1: Utility and aerobatic airplanes do have to demonstrate spin recoverability even if they have more than one engine.

2: Especially for multiengine tractor-propeller aircraft with wing-mounted engines, where, when flying at very low airspeeds, simply shutting down one engine or losing it to a mechanical failure can be enough to immediately stall its respective wing (due to said wing losing the air previously being blown over it at high speed by said engine's propeller).

3: Granted, even large multiengine airliners can find themselves spinning on occasion, something that (inadvertently) happened to (for instance) the first 307 and the first 737;4 however, I accept that an airplane requiring an ATPL and a specific type rating, not to mention a second pilot, is (by virtue of hopefully-good piloting) rather less likely (barring a major structural failure) to be placed in a spin than one requiring merely a PPL, and also that very large aircraft such as these are likely to become debris clouds if spun.

4: For the record, both the Stratoliner and the 737 were successfully recovered from their spins, although the former then almost immediately disintegrated in flight due to an overly-aggressive pullout from the subsequent dive.5

5: Hey, I can nest footnotes!


texts: Do I need a driver's license to get a PPL in Canada?

texts:
I've been searching on Google but there doesn't seem to be any results confirming or rejecting the requirement of a driver's license prior to PPL. It returns results for the United States, but that is of no use to me.

There is this question, but it doesn't address the having or not having a driver's license prior to PPL.

I have looked at the flight school (a),(b). Unless I am blind, there is no reference to this matter.

It seems like a very obvious question to ask, I'm surprised there is no reference.

If someone could point me to resources, or if someone obtained their PPL prior to driver's license could provide a briefing of whether this is an obvious requirement and I am oblivious to it or is it not a requirement at all.


texts: How do I find the magnetic bearing to the station in this question?

texts:
In my PPL trial test, I have the following question regarding an NDB:

  Consult Figure 3, Illustration 6. On a magnetic heading of 160°, the
  magnetic bearing to the station is:

  045°
  205°
  165°
  270°

  (See the attached figure, illustration 6)

Looking at the figure, I see a needle pointing to 045°. Therefore, I conclude that when my heading is magnetic north (as the heading of the aircraft is shown in the figure), the magnetic bearing to the station would be 045°. Consequently, I deduce that if I am heading 160° magnetic, then the bearing to the station would be 115° to my left, i.e. 360° - (160° - 45°) = 245°.

The reason I think this is because, as I am turning eastwards the magnetic bearing to the station will decrease until I reach a heading of 45° magnetic at which point the magnetic bearing to the station would be 0°. As I turn eastwards more, the magnetic bearing to the station would flip around at 360° and keep decreasing. I need to make a starboard turn 160° - 45° = 115° more to reach the desired heading 160°, so by that time the bearing would decrease from 360° by 115° to reach 360° - 115° = 245°.

Nevertheless, the test claims that the correct answer is 205° (which I'm guessing is, for some reason, calculated as 160° + 45°). Could you kindly explain what is wrong in my thought process or interpreting the ADF instrument?


texts: Why is the speedbrakes rate of retraction 25 seconds when used at speeds greater than 315 knots/.75 Mach on the A320?

texts:
While I was routinely reading the FCOM normal procedures I came across a note with regard to the speedbrakes retraction time going up to 25 seconds when we use them at speeds at or over 315 knots / .75 Mach.

Why is this ?


texts: I built this Airfix kit when I was younger, and don't know what it is. I'd love to know!


texts: How is wind direction reported (blowing from or blowing to)?

texts:
When the tower controller, the ATIS or a METAR says Wind 270, 15 knots does it mean the wind is blowing in the westward or in the eastward direction?

Is there a single convention used to express the wind direction?


texts: Is there a backup to fuel inerting systems?

texts:
I've heard it said many times that "everything has a backup" in commercial planes.

What about the fuel inerting system (injecting nitrogen in the fuel tank). Does it have a backup? Is it somehow failsafe all by itself?


texts: What is the typical value of maximum lift coefficient for aerobatic aircraft?

texts: I'm working on a conceptual design phase project for aerobatic aircraft (for university) and I can't seem to find any statistics about key aerodynamic properties (such as in the question), so I hope somebody here does know something about this subject?


texts: Can one fly up side down while a glass of water keeps full due to g-forces?

texts: If one makes a looping for example with a plane and the g-forces that the planes makes will keep the water in the glass, but if one is at the top of the loop is there still enough g-force to keep water in the glass?


texts: Does a 100 Hour Inspection Start Over Every Annual?

texts: If an airplane receives a 100 hour at 350 hours and has an annual at 400 hours, does the next 100 hour inspection need to take place at 450 hours or 500 hours?


texts: If a Boeing 707 hits turbulence that registers as +5 G on the FDR, would the 787 experience lower G forces due to the flexibility of their wings?

texts:
A 707 being a much older plane with relatively stiff wings compared to the 787. What percentage would the g forces be reduced on a 787 given its wing flex?

And yes, I mean if the 707 and 787 were flying through the exact same turbulence at the same time.


texts: Is there employment opportunities of becoming a pilot

texts: I am 18 years old and I want to become a pilot so bad .i got B grades in math and C grades in physics and geography.but my parents don't want me to be one since is hard to get employment of becoming a pilot.So am asking is there any employment opportunities of becoming a pilot