Aborted MP Takeoff

[gwelo shamwari]

A question for the seasoned ones here please....

When performing a max performance takeoff in a confined area, what would be the best course of action if you start to run out of power - over torquing, droop in RRPM, etc. I have heard many different methods sitting around the coffee table and as being a youngster not quite sure as to what would be the best course of action. I know that getting in to this situation in the first place probably is a sign of poor planning, etc. but say one does get in to such a situation it would be very handy to know what works and what does not.

Thanks
TGZ

[eagle 86]

Get familiar with performance charts in RFM - usually quite conservative.
Departing from IGE:
select a flight path that will clear tallest obstacle by 10 feet,
select last safe hover point inside pad,
select abort point that will allow safe return to this point,
commence normal IGE departure (overarcing OK initially),
IF:
you can't maintain flight path OR not accelerating OR an engine limit is reached ABORT.

Departing OGE:
select lateral and for/aft markers to ensure climb is vertical,
last safe hover point is directly below helo,
abort point is anywhere above this.
IF:
you stop climbing vertically OR you reach an engine limit ABORT.
Level with top of obstacles you should have ROC>200fpm, some power in hand - if so continue departure (caution having adverse wind as you pop out).
I can't imagine many civvie ops where you would resort to overtorque/overtemp/bleed - as they say PPPPPP.
GAGS
E86

[eagle 86]

PS.
Bleeding MRRPM usually means a degradation of yaw control!
GAGS
E86

[Matthew Parsons]

Based on the title, I think you're looking for an abort procedure.

Like eagle said, first make the decision to abort prior to overtorquing or drooping Nr below limits.

After you make the decision, it really depends what your choices are. If there is only one spot below that is safe to hover IGE, then you'll have to descend to it. If you've made the decision early enough, maintaining current power and allowing a slow descent works fine. You don't want a rapid descent to start because the small power margin you've given yourself may not be enough to stop the descent. Remember that you will get an IGE power advantage eventually.

If there are other places to land/hover IGE then consider them before you take off. You should always have an abort plan, especially for a MP takeoff.

If there is a spot in front of you worth using, then I would descend vertically until I reach a point where a dive for airspeed and subsequent flare could be accomplished to that spot. This is a procedure you'd want to practice in an open area first, to gain the judgement.

Is this what you're looking for?

Matthew.

[212man]

..and if you really want convincing how important it is to abort and not press on regardless, look up the Madrid 206 crash video to see how not to do it:confused:

[CYHeli]

Think of where you are and how you got there. I know that you are talking generalities, that's all these are.
Is the altitude a factor? Do you normally work on the coast and today you find yourself at 5000'?
Did you come in early in the day and now it's stinking hot? Is the weather a factor? Could you leave more easily later in the day as it cools?
If you came in to pick stuff up and now you're too heavy, can you leave some of it behind and make two trips? I'd rather pay for the fuel for two trips than an engine rebuild!
Well said about planning, but if you came in to pick up firefighters and the flames are coming over the hill... you might just want to know how to get out.
One thing that I was taught was a one inch hover. The closer you are to the ground when you start your climb, the less power used to start with, the longer that you are in ground effect means the more acceleration that you are going to get as you climb.
Good question.