Higher Decision Altitude
I found this thread quite interesting so wanted to add in my (probably
mis-informed) opinion and questions.
I'm looking from the perspective of Light Twin Piston flying in UK, so unsure
if ponts relevent to other countries, jets, more than 2 engines, etc.
If an MEP cannot obtain, or exceed, a 2.5% climb gradient with one engine
inoperative then planing (as far as practicable) should be based on SEP
criteria:
eg:
- No (commercial) departure if cloud base is below 1,000' above
airfield - to allow for visual obstacle clearance in the event of an EFATO.
- Do not descend below 300' above threshold unless you are committed to land:
ie Runway in sight, Runway available, Stable Approach and Landing
clearance received.
This implies that with an engine failure the MAP would be further back, and
hence higher, along the FAT. So if a missed approach was initiated the
2.5% obstacle clearance surface would not be breached even with a climb
gradient of less than 2.5%.
Only time there might be a problem is if you are on an all engine approach
and you lose an engine whilst fairly low on FAT - However your chances here
are still much higher than if you were in a single engine aircraft to
start with.
So if aircraft not capable of 2.5% climb on one engine should you not plan
your approach to a higher Decision Altitude?