Whats the trick to work out an adjusted apprach minima given a reduced missed approach performance gradient?
I'll give it a go in explaining it.
Missed approach gradient: 2.5%
Find out what percentage your aircraft can do from flight manual. Let's call it 1% for argument sake.
Line up 25 on outer scale with 10 on the inner.
Now here's the tricky bit. Figure out the altitude that you have to climb from MDA to MSA/LSALT etc. Eg) MDA: 500ft, MSA: 2000ft. Therefore 1500 ft to climb.
Find 15 on the outside and read the number on the inside...which is 6. This means that with an engine out you'll only be able to climb 600ft. Therefore you'll be 900ft (1500-600) below the altitude you should be.
Add this deficit....900ft to your minima to get your new MDA/DA. In this case 1400ft.
You'll get much quicker with a few examples on your own. It's also an extremely good idea to have an approximate engine out percentage climb gradient as there won't be any time to fiddle around with a flight manual should it happen while you're up there,
The other option available is to declare an emergency and continue to the original MDA or below it.
If anyone finds an error with the above, please feel free to correct me.
