Originally Posted by
RubberDogPoop
To check your MLW climb gradient on one engine, have a look in FCOM OPS section under "Approach with Engine Failed". Its gives an OAT and pressure altitude maximum to achieve gradients from 2.5% through 7% (Only at max landing though).
I imagine your OPT (if you have one) will throw out the calculation if unable at the given weight (this may be company selectable option??). Options would be to raise the minima (HKG has a 2.5% grad. minima listed for example), or to fly the engine out departure profile (if there is one), or land elsewhere.
Hope this helps.
Thanks for your answer.
The only table I can find in my FCOM, which also was referred to me by the technical section of my company, is the "go around climb gradient", which has only the "go around flaps 20" part and nothing else.
The OPT cannot do that unfortunately. It has the option to input a G/A clb gradient, but only for a "normal operation" with flaps 30 or 25, not 20.
Originally Posted by
wiggy
The answer lies somewhere in your FCOM and/or QRH where hopefully you should find a table cunningly labelled “ Go-Around Climb Gradient......”
Broadening the question slightly the fact you use the word "obvious" is interesting, because I guess whether it is obvious to use F30 or not might boil down to local/training department policy
FWIW we approach this question the other way around, so to speak: because of possible issues with performance on a SE Go-Around our "obvious answer" when running that checklist is very much one of "choose Flap 20”, unless there are compelling reasons such as stopping distance to use anything more.
If we have to use Flap 30 (e.g. contaminated runway, etc) and that compromises climb gradient then the solutions would be the sort of things RubberDogPoo has come up with.
Thanks for your input
As above, this table exists but helps only to say if it will be ok flaps 30.
And for the second part, you are indeed totally right. I probably saw the "if perf permits" as a way to say "this is preferential if possible", but there is no reason for that
To explain a bit more:
On that simulator training, we couldn't get the answer to that.
So I wrote to the technical office (a service in my airline you can write to if you have technical questions), and their answer basically confirms that it's not posible to know the G/A gradient with flaps 20 and you just have to use your "airmanship" to decide...
So I'm wondering if something is missing in our documentation, but it seems not as they asked Boeing and were told that there is no way to know it...