172
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Why does XKCD say that autogyros will crash if the pilot reacts to a stall as in a normal airplane?
That one thing is to unload the rotor too much (i.e. "push on the stick"):
From explainxkcd:
... Unfortunately, as soon as the rotor stops spinning, the whole aircraft falls like a brick ...
- 2,377
66
votes
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What operation is this aircraft performing?
The flight in question is most probably an evaluation/calibration flight for radio navigation systems at Ust-Kut. The aircraft is a Yak-40 special version designated for such tasks:
Aviamuseum - Yak-...
- 30.5k
61
votes
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Why aren't flights continued after losing a tire on rotation?
Blown tire - can't raise gear, shredded tire will not fit in the bay. ->
Gear down - much lower maximum speed and lots of additional drag ->
Both of those mean very poor fuel economy ->
Very ...
45
votes
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How and why can multiple people control the Boeing B-29?
In aircraft of this vintage, all the controls are mechanically interconnected. If the left-hand pilot's control yoke/ wheel moves, so does the right-hand pilot's. Likewise for the rudder pedals. ...
- 23k
42
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Why aren't flights continued after losing a tire on rotation?
That kind of thing would be a judgment call on the part of the crew (ultimately the capt) and would come down to what is the safest action based on the circumstances, with logistical/convenience ...
- 136k
37
votes
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Is there a tank priority sequence for using the fuel tanks?
Which fuel tanks are used in order of priority in aircraft?
What you're talking about, in large aircraft, is often referred to as the fuel burn schedule. Light aircraft generally do not have a fuel ...
- 39.2k
36
votes
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What time zone is used for operating an airplane?
The pilot (and the ATC) use the UTC (Coordinated Universal Time). The flight's departure and arrival are in terms of the local times at the respective airports.
As for data logging, the FDR/CVR ...
- 101k
32
votes
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Why do flight attendants on the 787 lock the dimmable windows at different phases of the flight?
On long-haul flights, most passengers will want to sleep, often including when the aircraft is flying through daylight. It's especially common on East-West long-haul flights for lots of people to want ...
- 19.6k
32
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Why aren't takeoff flaps used all the way up to cruise altitude?
The image below from this answer shows characteristics of airfoils with flaps.
As you rightfully concluded, lift ($C_{L_{max}}$) goes up with the deployment of flaps, but the drag also goes up and ...
- 8,272
31
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Why does XKCD say that autogyros will crash if the pilot reacts to a stall as in a normal airplane?
This is a well known problem with gyrocopters. The first answer was partially correct in that the problem was caused by pushing the stick forward and unloading the rotor. However, the problem wasn't a ...
- 466
26
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Why do pilots cut the reverse thrust below 40 km/h?
The question speaks of a very old 747 landing tutorial. And as such I take that to mean it would be of a 747-100/200 aircraft, and that's the reference point I'm answering from.
First, concerning the ...
- 39.2k
26
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Accepted
Are glider winch launches rarer in the USA than in the rest of the world? Why?
To expand on Quiet Flyer's answer, it's technical and economic at the same time.
Technical: Winch is limiting because you are deposited in the same spot over the field, whereas a tow, if the pilot ...
- 136k
26
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How and why can multiple people control the Boeing B-29?
Quiet flyer is right, here are some more comments to help.
The Pilot In Command (PIC) will advance the throttles for takeoff. The flight engineer's job is then to follow with setting the mixtures and ...
- 22.2k
23
votes
What are the effects of a rejected takeoff?
If an airplane is close to V1, the brakes - which have to absorb kinetic energy and dissipate heat - can get hot to the point where the tires automatically deflate, to prevent them from exploding. For ...
- 1,962
23
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Why does XKCD say that autogyros will crash if the pilot reacts to a stall as in a normal airplane?
I believe what the comic is referencing is Mast Bumping. Rotor blades are very flexible, and for a bunch of reasons, are free to pivot around the mast.(The shaft the blades are spinning around) In ...
- 239
23
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Accepted
How does aircraft valet parking work?
There are no keys to hand off. Most jets don't have any access controls - staff access trumps security.
Except on takeoff, large jets are preferably moved around the airfield by ground tugs, rather ...
- 30.1k
21
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What would be the challenges to taking off and landing a typical passenger jet at FL300?
These are the main challenges I can think of:
High takeoff and landing speed: To generate enough lift for takeoff in the thinner air at FL300 (gravity has almost not decreased, so required lift stays ...
- 58.3k
19
votes
Why aren't takeoff flaps used all the way up to cruise altitude?
This is a good question, and I don't feel the other answers get at the essential part which is:
Is it optimal to climb with the flaps deployed?
As with any optimal question, the answer relies on what ...
- 5,580
18
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What is the danger in the over-use of reverse thrust during ground operations when operating a turboprop powerplant?
One concern is Foreign Object Damage (FOD). More reverse thrust means more dirt is thrown into the air, which can then be ingested by the engine:
Damage to turboprop engines is not
as common as in ...
- 58.3k
18
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What is the danger in the over-use of reverse thrust during ground operations when operating a turboprop powerplant?
We used lots of reverse thrust in the C-130; it was normal to go to full reverse on landing, and also to use some reverse thrust in order to back the plane into or out of parking spots.
The two common ...
- 53.6k
17
votes
What are the effects of a rejected takeoff?
The outcome depends on the speed, aircraft, weight, and other factors.
If the takeoff is aborted at low speed (maybe up to 30-40kts), there may be no issues. The pilot would be able to vacate the ...
- 73.8k
16
votes
Why do flight attendants on the 787 lock the dimmable windows at different phases of the flight?
For takeoff and landing, @bianfable pointed out the answer. For longer flights across timezones, they set them to dark in order to not disturb passengers who would like to sleep.
And yes, I ...
- 391
14
votes
Can an airplane engine fire be extinguished without shutting down the engine?
I wanted to add to 757toga's answer.
In addition to being required to "pull" the fire handle before you can discharge the fire suppressant, which cuts off the fuel, hydraulics, electrical generation ...
- 2,639
14
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Can flaps on Airbus/Boeing airliners be deployed at high speeds during cruise, still?
There are protections against selecting flaps and slats during cruise in modern airliners.
For example, on the Airbus A380 there is a function to prevent extension of flaps 1 during cruise conditions:
...
- 58.3k
13
votes
Accepted
Why are parking brakes not used for parking jetliners?
Parking brakes are used by commercial aircraft at the gate if the ground crew can not set the chocks. The most common time for this to happen is during a lightning storm when ground crews are not ...
- 2,639
13
votes
Accepted
Why would the Speedbrake be required for such a long time on approach?
There are two reasons I can think of off the bat:
Its possible the controller asked them to hold a slow speed due to increased traffic ahead. The brakes may have been deployed to match the speed ...
- 102k
12
votes
Accepted
Can planned runway closures prevent a plane from leaving an airport?
There is actually a really good example of this...
In 1994 it was decided that the infamous Meigs Field would be demolished and turned into a park. (I say infamous because for all of us young flight ...
- 36.2k
12
votes
What operation is this aircraft performing?
It looks like a low pass, for unknown reasons but more likely a demonstration of some kind than an runway inspection. That's just a guess, of course, but I think it's the simplest thing that explains ...
- 72k
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