Turning towards dead engine?
 

Hi There

I am a student ATCO and there has been some discussion lately about not turning a twin engined aircraft left if the left engine has failed or vice versa.

Is there any truth in this?

Regards

GB

Yes, you want to turn into the live engine. Reason being that if you bank/turn the other way, you might not be able to level off again.

See the yaw/slip thread in this forum for a lot of discussion on and around the subject.

Regards,
Fred

Forget about it, bull....

Those days are gone.

regards

This often rears its head as a topic. I think the current theory is that on a modern jet airliner it doesn't really matter, but on lighter piston twins (with very little excess power) then it has more bearing....

It is very true that most modern aircraft are disgned with enough rudder authority for this not to be an issue. However those people who fly older twin aircraft should remember the rule and live by it, or they may just die by it!

Miles Magister
An old timer trainer

Surely it depends on airspeed. If flying at blue line (I think this is the sort of aircraft you mean) then it would be wise to turn into the live engine, although by the definition of blue line speed you should have enough control authority to turn either way. You may find that you have to reduce the maximum bank angle used during the turn, and be wary of bleeding off the speed in the turn too.

If flying near high ground you may have no choice. I think common sence and airmanship have a large part to play in this discussion. Not to mention handling skills. If flying a light piston twin (PA 34 for example) then it is probably wise to practise engine failures regularly as they can be quite demanding to handle well. Certainly seem more difficult to deal with than an engine failure on an airliner.

Maybe DC3 or mosquito pilots would argue this point more strongly in favour of the "turn into the live engine" theory. I dunno, unfortunately never flown either.

Not a DC3 or Mosquito pilot, but if having been a Canberra pilot qualifies me to answer questions on Asymmetric (Canberra pilots can always spell it right!) here's mine.

This question always used to come up, from ATC folk wanting to be helpful. We always told them not to worry. Provided the aircraft has sufficient speed, and is starting from wings level, the turn either way is equally easy. Reversing a turn away from the live engine into a turn towards the live engine is a bit more difficult, but only in that it is slow reacting.

I understood from the 'ancients' that the question dates back to the old, powerful, wartime twin pistons where propellor torque was an additional complicating factor. I believe this was the reason why they requested no turns towards the dead one. It would have been too easy to overbank and lose it.

There's also the phrase "unable to comply". But if both options are available, why not go with the one with the most margin?

Besides, a stressed out GA twin pilot with barely enough power remaining to keep aloft might not have the extra capacity to question ATC directions or realize the possible consequences until too late. Even though this forum caters primarily to the big iron, there are others in the sky.

Regards,
Fred

PM
 

KeithL check your PM's please.

JackOffallTrades,

From DC3 through to B777 and all types between, there's not a jot of difference in turning into / away from the 'dead' engine, provided that the appropriate minimum speed was respected, and all manoeuvres contained within the normal envelope.

The argument becomes valid on a 4 engined aircraft with 2 out on one side, or on a DH84 Dragon where the live engine had to be throttled back to retain directional control.

As ft has suggested, "unable to comply" covers a multitude of sins.

Or you could just reduce the power...
 

On my ME checkride (Seminole) the examiner wanted to see steep turns left and right with an engine shut down.

No big deal.

But if it ever became a big deal in different airplane you could simple reduce power on the operating engine, regain directional control and fly home.

No big deal either way.

If you fly at an appropriate speed, greater that VMCA (but preferably V2 plus a bit (how technical!) in Take Off configuration or VFTO clean) then turns are possible in both directions. The angle of bank at such low speeds will generally be restricted to 15 degrees, thus giving a larger turn radius than normal but the pilot decides which direction. Fly less than the appropriate speed and the aircraft decides...