17
$\begingroup$

This video shows a 727 apparently rotating too soon.

The take-off run starts at 2:00 minutes and at 2:11, you can see the yoke is pulled back by the elevators rising.

It seems to me that this is no mistake and that the early pull, held until the main wheels leave the ground and accelerating with the nose wheel held off, is very deliberate.

Is there a solid operational reason for doing this?

Improve this question
$\endgroup$
6
  • $\begingroup$ @KorvinStarmast. I might have missed something but I can clearly see the 3rd engine and there are 727 variants with winglets. $\endgroup$ – Simon Nov 21 '16 at 22:21
  • $\begingroup$ The first video link and the second are not the same. I clicked on "this video" and saw a 737 from the rear. I clicked on 2:00 and found a 727. My mistake. $\endgroup$ – KorvinStarmast Nov 21 '16 at 22:24
  • $\begingroup$ @KorvinStarmast All three links are to the same video and the edit history shows that the links have never been changed. $\endgroup$ – David Richerby Nov 21 '16 at 23:03
  • 2
    $\begingroup$ The only reason I can think of offhand would be that the airplane had a nose gear shimmy, and the flying pilot elected to stop it by getting it off the runway early. Of course, any such shimmy should be written up for maintenance attention. $\endgroup$ – Terry Nov 21 '16 at 23:07
  • 1
    $\begingroup$ @Terry, I think it's much simpler: just a jigit showing off. It's Azerbaijan Airlines! $\endgroup$ – Zeus Nov 22 '16 at 11:15
13
$\begingroup$

enter image description here

It's a 727 take-off technique used on unpaved surfaces.

Glimpse of the real deal here.

Possibly an old-timer was showing someone how it was done. Or someone was doing a recurrent for it.

It's to avoid nose gear damage if it hit a rock, or damage to other parts if said rock/debris were to be deflected. Also to avoid digging the nose gear into the soft field—reducing the rolling friction.

Improve this answer
$\endgroup$
3
  • 6
    $\begingroup$ There is one more consideration, which makes early rotation almost universal for unpaved runways: because the rolling friction is much higher, it becomes more optimal to unload the wheels with whatever lift can already be produced. Aerodynamic drag will rise, but the overall balance will be better. $\endgroup$ – Zeus Nov 22 '16 at 2:28
  • 1
    $\begingroup$ I did think about a soft field take-off but I'm not convinced. It seems almost reckless to demonstrate one where one is not required. A failure of engines 1 or 2 or a main wheel tyre burst or other asymmetric event would have given that crew a lot more trouble than they would already have. $\endgroup$ – Simon Nov 22 '16 at 8:30
  • $\begingroup$ @Simon in that case, the pilot could use control inputs to counter any "asymmetric event". $\endgroup$ – fabspro Jan 31 '18 at 21:55
2
$\begingroup$

This is a take off maneuver which allows the aircraft to take off at the minimum speed possible, called V2min. It presents the best possible airfoil attitude to the air to generate lift at a low speed.

You can see the same thing being done with the Airbus A380 during its flight testing.

Improve this answer
$\endgroup$

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.