Take off and landing?
Thread Starter
Joined: May 2004
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From: Manchester
Take off and landing?
When a aircraft takes off does it want to take off into the wind or with the wind blowing in the same direction? Surely if it take off with the wind blowing in the same direction this is more fuel economical or is this not the case?
What about landing?
If anyone could answer these questions asap i would be most grateful.
Thanx.
What about landing?
If anyone could answer these questions asap i would be most grateful.
Thanx.
Joined: Oct 2000
Posts: 8,266
Likes: 1
From: Berkshire, UK
Aeroplanes preferably take-off and land into wind.
For them to take-off consistently with the wind would require much longer runways.... and what happens if the aircraft needs to turn towards its destination against the wind?
They land into wind so that it provides braking, otherwise (again) very long runways would be necessary.
For them to take-off consistently with the wind would require much longer runways.... and what happens if the aircraft needs to turn towards its destination against the wind?
They land into wind so that it provides braking, otherwise (again) very long runways would be necessary.
Joined: Jun 2004
Posts: 48
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From: UK
It's all to do with the speed of air over the wing. If you need 100 knots of air flowing over the wing to get airborne and you've got 20 knots of headwind the aircraft only needs a groundspeed of 80 knots to get airborne i.e. less runway needed. Conversely if it had a 20 knot tailwind it would need to achieve a groundspeed of 120 knots to get airborne... longer take off run.
Joined: Jul 2003
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From: N55' 56' and a wee bit west
Aircraft don't want anything, they are machines.
Pilots want to takeoff and land into the wind, with all other things being equal, for all of the good reasons give in the previous posts.
Pilots want to takeoff and land into the wind, with all other things being equal, for all of the good reasons give in the previous posts.
Joined: Mar 2001
Posts: 223
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From: Toronto, Ont, Canada
an,
> Surely if it take off with the wind blowing in the same direction this is more fuel economical or is this not the case?
I'm not sure about the fuel economy, good question. Is more fuel used from ground roll/tire friction, than low altitude flight?
Economics aside, the reason is more to do with safety, and the amount of rwy used, as well as a lower groundspeed at liftoff being safer.
When the plane is airborne and actually flying, then yes, a tailwind will increase the groundspeed and the flight will be more economical, than a constant headwind.
But as BZ explained, the aircraft flies as a result of the airspeed, therefore the stronger the headwind, the lower the groundspeed, less runway used and better climb performance (relative to the ground). And a lower groundspeed while taking off or landing is also much safer, as the aircraft is easier to handle and to stop if necessary.
>What about landing?
Same as takeoff, if the headwind were ideally exactly opposite the rwy direction, the strongest possible constant headwind would be ideal. Unfortunately in the real world, strong winds are a) usually not perfectly aligned with the rwy, causing crosswind/directional problems and b) are often very gusty, to the point of "windshear", which is extremely dangerous.
Here's a link to a great site with more details on how planes fly :
http://www.av8n.com/how/
Mike
> Surely if it take off with the wind blowing in the same direction this is more fuel economical or is this not the case?
I'm not sure about the fuel economy, good question. Is more fuel used from ground roll/tire friction, than low altitude flight?
Economics aside, the reason is more to do with safety, and the amount of rwy used, as well as a lower groundspeed at liftoff being safer.
When the plane is airborne and actually flying, then yes, a tailwind will increase the groundspeed and the flight will be more economical, than a constant headwind.
But as BZ explained, the aircraft flies as a result of the airspeed, therefore the stronger the headwind, the lower the groundspeed, less runway used and better climb performance (relative to the ground). And a lower groundspeed while taking off or landing is also much safer, as the aircraft is easier to handle and to stop if necessary.
>What about landing?
Same as takeoff, if the headwind were ideally exactly opposite the rwy direction, the strongest possible constant headwind would be ideal. Unfortunately in the real world, strong winds are a) usually not perfectly aligned with the rwy, causing crosswind/directional problems and b) are often very gusty, to the point of "windshear", which is extremely dangerous.
Here's a link to a great site with more details on how planes fly :
http://www.av8n.com/how/
Mike
Last edited by mstram; 27th July 2004 at 22:48.
