View Full Version : Take off and landing?
animalmagic1984
15th Jul 2004, 10:19
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.
HEATHROW DIRECTOR
15th Jul 2004, 10:29
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.
Bol Zup
15th Jul 2004, 11:03
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.
Old Smokey
24th Jul 2004, 06:13
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.
andyb79
25th Jul 2004, 00:44
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.
Good, if rather cynical answer.
Old Smokey
26th Jul 2004, 15:58
I apologise for the cynicism. I've been extensively reading the lengthy debates (in other forums) regarding Pilotless aircraft.
I felt sufficiently motivated to make the point that 'Man is the master'.
incubus
27th Jul 2004, 10:53
I felt sufficiently motivated to make the point that 'Man is the master'.
Don't tell Woman :D
...except in the past with a few Airboos FBW models.:uhoh:
mstram
27th Jul 2004, 22:28
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