Posts: 383
Joined: Fri Sep 17, 1999 12:04 pm

Two Hands On Throttles

Wed May 24, 2000 5:45 am

I’ve seen footage of airliner takeoffs filmed inside the cockpit. During throttle-up, both pilots sometimes operate the throttles simultaneuosly. Why is this done? Can this operation be performed by only one pilot?

Thanks for any answers.

RE: Two Hands On Throttles

Wed May 24, 2000 6:34 am

To prevent the throttles from slipping backwards...
Posts: 2442
Joined: Sat Feb 26, 2000 6:18 pm

RE: Two Hands On Throttles

Wed May 24, 2000 6:42 am

I don't know about other companies, but at Sabena we work as follows:
During take-off the Pilot Non-Flying keeps his hand on the throttles till V1 to retard them in case of an emergency. When V1 is reached, he has to remove his hand from the throttles so he can not have the reflex to retard them thus making the plane slow down on a part of the RWY that isn't long enough for that.
The Pilot Flying has both hands on the controls at all times during the take-off.
I don't see why the pilot flying has to have his hand on the throttles. Maybe it's just something like a harmless reflex from a nervous pilot you've seen.
Posts: 534
Joined: Fri Feb 18, 2000 6:07 pm

RE: Two Hands On Throttles

Sun May 28, 2000 5:24 pm

Last thursday, I saw a programme on the Dutch television, called Cockpit, and it was about a 747-200F captain. On take-off the captain, who was the flying pilot, kept his hands on the throttles as did the flightenginieer. As from V1 the pilot put both his hands on the controls.
Most of the time this is how it goes. The flying pilot keeps his hands on the nose steering wheel until about 60kts and his hands on the throttles until V1. The copilot kees his hands on the controls until 60 kts, to keep the nose down, and does not touch the controls as from the flying pilot has them on the controls (as from 60 knots when he does not hold the nose steering wheel anymore as the rudder became active). I thought this was the way it always went but at Sabena it seems to be different. I think it to be rather strange that the pilot who is not flying is keeping the throttles as that pilot is at that moment not really in command.

Posts: 8103
Joined: Mon May 24, 1999 1:12 am

RE: Two Hands On Throttles

Sun May 28, 2000 5:41 pm

The main reason is that these older aircraft aren't fitted with autothrottles that can be used on the ground. The flight engineer sets the power watching the forward engine instruments (between the pilots). He may make several adjustments as the aircraft rolls down the runway - there is no way the Pilot Flying can watch the engine instruments while flying a successful take-off. On 747-400s, 777s etc, the throttles still move but the power setting (EPR) is in the computer and the precise setting of the engines is automated. The Pilot Flying will still feel the throttles juggling under his hand, but it's the autothrottle doing it, not the trusty flight engineer. The same applies in flight, the flight engineer used to reach forward every so often and change the position of the throttles, now the autothrottle does it. Bummer, I prefer three-person flightdeck crews.

The Sabena technique is an odd one, but obviously must work, or an airline of the stature of SN wouldn't do it! In normal (non-SN!) operation, the Pilot Flying, to absolutely clarify this, removes his hand from the power at V1 because that is the point at which it is too late to stop on the runway. Whatever happens after V1, the power is staying where it is cos you're taking off, alright?!
fly Saha Air 707s daily from Tehran's downtown Mehrabad to Mashhad, Kish Island and Ahwaz
Posts: 534
Joined: Fri Feb 18, 2000 6:07 pm

RE: Two Hands On Throttles

Sun May 28, 2000 6:46 pm

Apart from your (and thank you for it) info related to the auto throttle, that is what I meant but you.