PPRuNe Forums - View Single Post - Shortfield Tips
Thread: Shortfield Tips
View Single Post
Old 27th March 2006 | 20:39
  #21 (permalink)  
Tinstaafl
25 Anniversary
 
Joined: Dec 1998
Posts: 4,282
Likes: 6
From: Escapee from Ultima Thule
The technique specified in the manual in all nosewheel light aircraft I've flown is something like:

* Configure the a/c as required
* Hold the a/c on the brakes while applying full power. Confirm that the correct RPM & MP is achieved.
* After brake release accelerate & rotate at the speed specified in the chart to achieve Vtoss by 50'
* Retract gear & flap as scheduled
* Climb at Vx until clear of obstacles.

If you choose to accelerate beyond the specified speed(s) you will have a reduced t/o performance. It's a fallacy to think that doing so improves take off performance OR is necessary to avoid operating behind the power curve. Unlike jets, light a/c aren't behind the power curve after take-off & during climb out.

If they were then rotating at a faster speed would improve performance unless the limiting obstacle is very close - in which case the manufacturer would want to include such things in the performance chart to maximise their claims for the aircraft.

If you rotate at a lower speed than specified then you risk being behind the power curve & reducing take off performance. Some a/c have sufficient power to do this and still improve the take off performance. You lose handling quality protections & buffers built into the scheduled speeds however.

There are considerations & techniques that can be used that are outside the manufacturer's manual but try explaining to the insurers & the CAA if you stuff it up & damage the a/c...
Tinstaafl is offline