Aterpeter,
I believe you and it makes sense.
"Perhaps Boeing advises 400' OEI vs 1000'AGL for normal ops because the aircraft will not meet the OEI performance requirements if flaps are carried to 1000'AGL? "
Gulfcapt,
Ok,from what i understand,if you have no obstacles in your take off path(ie you take off from an island and there is water left right and center:-) ) so your perf data will STILL give you a Minimum flaps retraction height of 400ft.
This is a legal requirement cause really you could accelerate at 200 feet...and this what i am interested in...is it the same for all states?(USA,Europe i know but what about Indonesia?china?UAE?).
I grasp the fact that your airline may impose a higher acceleration to be on the safe side...
Accelerating at 400 feet height will give you a clearance of 35ft of the obstacle....but beware of cold altitude corrections...
If there are however obstacles in your take off path(your perf analysis will give you a higher Minimum flaps retraction altitude,lets say 800ft),so it means if you lose an engine you need to climb to a minimum height of 800 feet before accelerating to be above the take off obstacle.
So airlines using a higher MFR height will be on the safer side (ie Runway perf gives you a MFR of (400-999ft).
For the Flaps retraction height you are limited by TOGA time.
Concerning if you are climb limited,it is another story, you may need to use improve climb speeds(to make the oei 2.4% gradient,VLOF to 35 ft dry runway),
which will give you the highest v1 for the runway used.
The scary part is that if you reject at V1, you will be very closed to the end of the runway...dont correct for low Qnh and you go ploof into the water....
"Unfortunately, Gulfstream has recommended for years that for normal takeoffs the profile is gear up, flaps up. I refuse."
Im glad you do..
