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1500 questions
60
votes
1 answer
What is significant about the number 8069 ft?
On a sectional chart legend, the airport icon with a solid magenta or blue disk is labeled as "Hard surfaced runways 1500 ft to 8069 ft in length". This seems like an extraordinarily arbitrary number to use as the upper limit before a different…
PJNoes
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60
votes
2 answers
Why do airplanes have rounded windows?
Why are the windows of an airplane usually rounded at the edges?
anshabhi
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59
votes
9 answers
Why not mount airliner jet engines above the wings?
It seems that most airliners put the engines below the wings, i.e. the Boeing 7*7 series and the Airbus A3** series. This requires long (heavy) landing gear, and the engines are close to the ground which may cause damage to the engines (ingest…
dotancohen
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59
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3 answers
What are these things hanging off the trailing edge of the wing?
What are these things hanging off the trailing edge of the wing?
I've seen them in almost all of the aircraft I've flown in, and can't remember if they're exclusively Boeing or Airbus.
zundi
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58
votes
6 answers
Is a winglet better than an equal span extension?
Is there indisputable evidence that a winglet improves performance over an equal span extension? Please note: I am only interested in L/D improvements.
Winglets do improve roll performance, that is not what I am looking for. Also, if span is…
Peter Kämpf
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58
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2 answers
What is the difference between a turbofan and a turboprop engine?
I'm not an aircraft expert and I just realized that there are two different terms - turbofan and turboprop. I always had them combined in my head as a term for a large jet engine (like you would see on a 747). Apparently this is not the case though.…
David says Reinstate Monica
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58
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4 answers
Why do airplanes use MAYDAY when in danger but ships send SOS?
I thought SOS means "save our souls", but apparently it doesn't.
But ships send SOS when in danger and they used Morse code. Why do airplanes use MAYDAY?
Squareoot
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58
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6 answers
How can this aircraft be stable/maneuverable?
The new wave of electric VTOL aircraft concepts (Joby Aviation, Zee, Lilium, Airbus A$^3$, etc...) has produced some audacious unconventional designs.
Now my question, is how Lilium's concept can be stable and/or maneuverable, given the following…
mezzanaccio
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58
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9 answers
Why was the P-51 Mustang not adopted by the U.S. Navy?
I've heard from many WWII aviation hobbyists and WWII vets that the P-51 was essentially the pinnacle of U.S. piston-engine fighter design; it was fast, maneuverable, long-range, well-armed, allowed superb pilot visibility, etc etc.
So, why did the…
KeithS
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58
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4 answers
Why are the F/A-18 rudders deflected in opposing directions during takeoff?
Looking at some videos and photos of F/A-18 Hornets and Super Hornets taking off from carriers and from airfields, I recognised that the left rudder is pointing right, and the right rudder pointing left.
Here's a picture:
Why is that? Are there…
jklingler
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58
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8 answers
Even after years of research, why are planes unable to keep passengers alive in case of a fiery crash?
Aviation dates back to the 18th century, and since then tremendous research has been put into making aircraft safer and more efficient. Though these efforts have resulted in better aircraft, why are they still not strong enough to keep the…
anshabhi
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57
votes
13 answers
Have any large aeroplanes been landed — safely and without damage — in locations that they could not be flown away from?
And, what was done with them subsequently?
Daniele Procida
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3 answers
Did we get closer to another plane than we were supposed to, or was the pilot just protecting our delicate sensibilities?
Yesterday, April 28, 2019, I was flying on Alaska flight 557 from LAX to PDX.
About an hour into the flight (near the California/Oregon border) I was looking out the window and saw a jet travelling the opposite direction from us. It was travelling…
Aric TenEyck
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2 answers
What are these engineers doing sitting on a large format drawing of B-47s aircraft?
This answer about solid-jet-assisted takeoff links to the page B-47 Jet-Assisted Take Off (JATO). An image there took me to a collection of historical aviation images, apparently from a LIFE Magazine archive.
Browsing there led me to the image…
uhoh
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3 answers
Could a Dyson fan scale up to be used as a bladeless aircraft engine?
Dyson has been making bladeless fans for a few years now that accelerate a consistent stream of air without exposed blades.
If this concept were applied to aircraft engines, it could potentially reduce the number of bird strikes, engine…
Geoff
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