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29
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3 answers
Why does the DC-10's horizontal stabilizer have such a pronounced dihedral?
If you look at this picture, you'll see that the horizontal stabilizer has a very pronounced dihedral in comparison to the wings. Could somebody explain in a simple way why? I understand that a dihedral wing makes an aircraft more stable on the roll…
user13197
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Why doesn't the aviation industry use SI units?
This is a followup to What is the measurement system used in the aviation industry? and related to this question from History.
I can understand the arguments as to why adoption of SI units would not make sense for the general population, but…
asheeshr
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Are the fastest moving pieces of a jet engine supersonic?
A jet engine is composed of fast moving pieces. Those pieces are moving into an airmass different form the ambient airmass the aircraft is flying into.
The turbine pieces are spinning quite fast, thus its blade tips may be moving at a supersonic…
Manu H
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Why are most weapons in AC-130 on the left-hand side?
Lockheed AC-130 gunship is a heavily armed ground-attack aircraft variant of the C-130 Hercules transporter. The plane is manufactured by Lockheed and converted by Boeing.
Why are most of the guns in AC-130 installed on the left-hand side (but not…
Him
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29
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4 answers
How does a coaxial rotor helicopter achieve yaw?
Without a tail rotor, how does a coaxial rotor helicopter achieve yaw control? Does a coax have to bank in order to turn?
The link goes to wikipedia's article, and down a ways it says:
Rotational maneuvering, yaw control, is accomplished by…
DrZ214
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29
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4 answers
What is Cost Index?
I'm not sure if it's just in Boeing aircraft, but I've heard that Cost Index has something to do with flight planning but have no idea what it is.
What is it for and how is it calculated? (I'm happy for the simple version of the calculation if it's…
Greg
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Why does cabin air have to be dehumidified?
When air is piped in from outside and into a pressurized cabin, it is also dehumidified in the process. All airlines provide beverage service on even short-haul flights to combat the dryness of the air. Why is it necessary to dehumidify cabin air?…
Garrison Neely
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How does a Mach Meter determine the speed of sound at a given altitude?
By my understanding, the Mach Number at a given altitude is calculated by dividing IAS by the speed of sound at that altitude. So how is this speed of sound calculated to display the Mach Number on the Mach Meter? Does the Mach Meter share the same…
shortstheory
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29
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Is passenger weight distribution important on a commercial flight?
This is something I've wondered about for a long time. On really large airplanes, like a 747-400 or A380 for example, I would assume that the weight of the passengers on board is a significant to the flight characteristics of the plane. And it…
Jae Carr
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9 answers
Why do some fighter jets have two pilots while others have only one?
Why do some fighter jets have two pilots, while some have only one?
For example the newer fighter jets such as Dassault Rafale, Eurofighter typhoon etc. are mostly with single-seat, but two-seat models of these jets are also available.
anshabhi
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4 answers
Why did an iPad software failure cause a return to the gate?
I was amazed to read this which implies that a software failure on iPads caused departing flights to return to the gate.
I used to be an avionics engineer up until a point before the current generation of consumer electronics and now develop "field"…
Simon
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What is the difference between Boeing 73G, 73H and 737?
I found a data source, where Boeing 737 could be encoded with the following values - 733, 734, 735, 738, 73G, and 73H; Boeing 767 with values 762, 763; Boeing 777 - 772, 773, 777.
Any idea why such coding is used? Is it some standard to encode them…
LA_
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What are the major causes of parachutes failing to work?
What are the top causes of a parachute failing to work?
For "parachute", I mean primarily sporting parachutes, such as used in skydiving, but information about military (paratroop) chutes, ejector seat chutes, etc., would be useful.
For "failing to…
Roger Lipscombe
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Aircraft pilot's seats: what is the notch for?
If you do a Google or Bing search for "Aircraft Pilot Seat" then choose images, you might notice a large number, perhaps majority of them, have a notch cut out of the front of the seat. What is this notch for?
Notches are circled here:
Original…
CGCampbell
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Why do we use pylons to mount the engines on jetliners?
This question focus on jet airliners.
The De Havilland Comet's engine were mounted inside the wing, the Concorde's engines were mounted underwing (as many jet engines) but without pylon. It seems jet airliners' engines are now mounted on pylon. That…
Manu H
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