Emergency Turns after Engine Failure at V1

[Overseasaviator]

My query goes to all those performance experts out there.

I used to fly under the FARs but now under CAA regs (if this is relevant). On similar aircraft, one set of take off performance figures stipulated an emergency turn in the event of an engine failure at V1 from certain runways and yet the other does not, stating a climb straight ahead in the event of an engine failure.

I have no doubt that both companies would try to take off with the maximum payload possible but I do not have the figures to make a direct comparison.

Any performance experts please throw in your two penny worth!

Wishing all a Happy New Year

[GlueBall]

"...emergency turn in the event of an engine failure at V1 from certain runways..."

The answer is embedded in your statement:
When taking off in a Heavy at a place like Kathmandu or Quito it is not possible to maintain runway heading without contacting terrain.

[john_tullamarine]

Overseasaviator,

(a) I presume that you are looking at two different operators' approaches to the same runway/airframe/engine/operating rules takeoff ? Not much good if we are comparing apples with oranges.

(b) Often there are multiple options available to the ops engineering assessment

(c) A lot will come down to the attitudes of flight management personnel and company/Type SOP philosophies.

(d) The observed difference may have a lot to do with different splay requirements .. ie with a narrower splay a curve might be feasible while a wider splay brings in a critical obstruction which makes the exercise a no-go...

[mutt]

We generally produce turn procedures to increase takeoff weights by avoiding obstacles in the straight out path. I dont know of any regulation stating that we have to do it, its purely a case of economics.

Mutt

[m&v]

Two different proc' off the same runway??The only diff'would be the climb gradient /weight.Couple of dept's in the Canaries posed a problem until 'we'acquired different 'charts'stipulating the 'immed turn over the water'escape...Naturally only 15degree bank until 400'
Cheers:)

[john_tullamarine]

m&v,

Obviously there are runways where no special procedure is needed and others where only one way out exists.

For runways with moderate problems, though, there is no reason at all why two ops engineers shouldn't come up with two different procedures for such runways ... sometimes a procedure designed to drag the last kilo out of the takeoff is deemed too workload intensive or navigation critical and a simpler procedure will be adopted for the cost of a bit of weight .... horses for courses and, to a large extent, a matter for company compromise between flight standards policy and the beancounters.

I would be VERY wary about pinching other operators' procedures unless you are VERY sure that the aircraft AFM data is identical and that you know ALL the subtle details of a particular operator's techniques ...

[mutt]

Morning J_T,

I would be VERY wary about pinching other operators' procedures unless you are VERY sure that the aircraft AFM data is identical and that you know ALL the subtle details of a particular operator's techniques ...

We will generally look to see what others are doing, i.e, left or right turns, but then produce the procedure using manufacturers software and an obstacle filtering program.

Mutt.

[john_tullamarine]

G'day Mutt,

No problem with an ops engineer such as your goodself ... using an idea and then doing the hard yards to make sure that it is kosher and appropriate .. but I have seen more than a few pilots over the years just pinch another operator's procedure without so much as a fleeting thought as to whether it might be remotely relevant to what they are doing ... and I don't think that that is a good way to go .....

[m&v]

Couldn't agree more about the LEGALITY of using other charts -once approved by ones regularity Authorities(the home nation in a wet lease issue)...Pilots talk and 'learn'about a better way-Co's look into it,for acceptance.(Jepp's versus the 'Nordic charts??)..And as you say all the different types of 'one'aircraft(A320),all are trying for the last kilo uplift...
cheers

"but your Honour, it looked good to me"

[Overseasaviator]

Thanks to all you performance experts for your contributions.

Glueball: in basic terms, my question is why does one operator specify a turn and another not in the case of an engine failure from the same runway in an identical aircraft?

john_tullamarine: as per the above, you are correct in (a), I am not comparing apples and oranges, just similar apples from two different suppliers! However, your answers do throw light on the query.

mutt and m&v: thanks for your contributions.

As I readily admit, performance is not my top subject but I am a little the wiser now!