0
$\begingroup$

If a strong and fairly steady headwind was coming down the runway at just under the stall speed for a clean configuration/weight, what challenges would a pilot face? Or would it be fairly easy? Is this something that happens often?

Edit: This is the video that made me ask.

$\endgroup$
3
  • 2
    $\begingroup$ Just to confirm, the windspeed is just under the stall speed of the aircraft? Because for a light civil GA plane this would be a gale force storm. For an airliner or military jet, it would be hurricane force winds. Pilots don't fly in winds like that. It isn't taking off in a headwind that's the problem, it's taxiing without flipping over that makes it dangerous. $\endgroup$ Dec 23 '20 at 0:27
  • 1
    $\begingroup$ Here's an example of what happens in a strong wind near stall $\endgroup$
    – Ron Beyer
    Dec 23 '20 at 4:58
  • $\begingroup$ @MichaelHall It was pretty late at night when I asked this lol. $\endgroup$ Dec 23 '20 at 12:31
2
$\begingroup$

"Fairly steady" wind is the only wording that would make it even remotely considerable, with risks of being ground looped or blown over while taxiing.

One scenario may be a light GA plane taking off from a moving aircraft carrier.

Tricycle gear would be a tremendous advantage, as this would help keep the wing at a very low angle of attack to the wind. This allows the plane to remain on the ground during its takeoff run long enough to establish a safety margin in airspeed before the plane "rotates" to an angle of attack sufficient to generate enough lift to fly.

One must be aware, although this is doable, gusts make it extremely dangerous. Far better to wait for better weather.

Even with no wind, the safe rotation airspeed will be higher than the clean stall speed.

$\endgroup$
3
  • $\begingroup$ A taildragger would be just as able to keep the AoA down by simply raising the tailwheel off the ground. Perhaps even more so than a tricycle geared plane, prop clearance permitting. $\endgroup$
    – Jpe61
    Dec 23 '20 at 7:39
  • 1
    $\begingroup$ Yeah but forget get about trying to taxi in any direction other than directly into wind. $\endgroup$
    – John K
    Dec 23 '20 at 20:20
  • $\begingroup$ Oh absolutely 🤣 $\endgroup$
    – Jpe61
    Dec 23 '20 at 22:56
2
$\begingroup$

Robert has answered the question quite well, but I will elaborate:

Taking off into a strong headwind is not difficult as such, but as Robert (and John as well, in less subtle way :) pointed out, taxiing in strong wind, however steady it might be, is a real pain it the seat of the pants. Since the question is about taking off, lets assume the plane would (magically) get to the end of the runway safely. The takeoff itself would then be something along the lines of what can be seen for example in this video:

Youtube: STOL Competition - World Record Shortest Landing 9 Feet 5 Inches (Yes the title says "landing", but there are plenty of takeoffs to be seen)

Nothing special really, except you are airborne in a blink of an eye. What might be troublesome to an inexperienced pilot, is that the visual cues are weird, so airspeed would have to be monitored with great care as referencing the surroundings would be useless. Also: great wind speed at ground level guarantees there will be turbulence, so maintaining appropriate airspeed is critical, and lifting off the plane should be "decisive" to avoid being pushed back on the ground by shifts in wind. The question states a wind speed just under clean configuration stall speed, so you would not use flaps, since as soon as you would lower them, you would lift off.

As for the part of "Is this something that happens often?": No. Outside the realm of STOL contests, during normal operations: this does not happen. Regulations and POH limitations set aside, you just could not get on the runway in one piece.

P.S. It is worth noting that majority of STOL contest planes are taildraggers, so this gear configuration certainly is not a disadvantage when taking off or langing at windspeeds closing stall speed.

$\endgroup$
1
$\begingroup$

The main challenge would be the long walk back to the airport, assuming you could still walk, after your airplane was blown like a tumbleweed into the next county. In other words, it's simply not something you would even try. Only very experienced or foolish pilots will even go out in winds approaching 50% of stall.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.