Turning a twin

[PeterThePilot]

Sirs,

I am an inexperinced Student Pilot.

I am curious as to the correct procedure for turning a twin engined aircraft during taxi.

Take for example a 737 type.

Does one use differencial braking when turning or does one apply higher power to one engine?

I.E. if I was taxying a 737 and wanted to make a sharp turn to the left, would I apply more power to the right engine? Or is it simply a case of turning the nose wheel?

I would be greatfull if someone among your good selves would explain these things to me.

[OBK!]

You are encouraged to use a mixture of differential thrust and turning the nosewheel. Differential breaking can heat up the breaks during taxi, and prior to takeoff, makes them less responsive and effective, i.e - requiring more distance should you abort takeoff.

Say you wanted to do a moderatley steep right turn in the seneca, you would approach at a fairly slow speed (walking pace), then coming into the turn you would point the nosewheel in the direction of the turn, reduce thrust on the right engine and increase slightly on the left. Just before lining up, bring the right engine upto the left engine to equalise the power, centre the nosewheel and then bring both throttles down together to maintain speed.

Hope this helps.

obk

[Maximum]

PeterThePilot, on the B737 assymetric thrust or differential braking are definitely not recommended. So all you do is turn the tiller (down at your left hand when sitting in the left seat) which turns the nosewheel and turns the aircraft. Limited nosewheel steering is also available through the rudder pedals, although the tiller will override any rudder inputs to the nosewheel. Simple!:D

[rightbank]

It really depends on the type of aircraft. If the aircraft is equipped with a steering tiller then except when possibly manoevering off stand (if not getting pushed back) or other similar tight spots, when a combination of differential braking and opposite engine may also be used, all steering is soley via the tiller.

On a typical light twin not fitted with tiller steering, then a combination of rudder (linked to the nose wheel ), differential power and differential brake may be used.

On very old twins, usually taildraggers with cable operated brakes and no direct steering to the tailwheel, then a lot of differential power may be necessary at times, especially if the cables have stretched out of adjustment and the brakes are less than ideal. Whilst taxiing such an aircraft in a strongish X-wind a fair bit of differential power may be even be necessary to taxi in straight line.