PPRuNe Forums - View Single Post - B777 eng inop NNC: flaps 30 or 20 with G/A gradient?
Old 14th May 2019, 09:24
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Romfour
 
Join Date: May 2019
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Originally Posted by RubberDogPoop

FWIW our reference is OPS.29 (not that I expect it to match yours) and gives max temps and PA for both a F20 and F5 go around. I’d be surprised if a customer would elect to not have that info available.

I’m with wiggy, starting point would be F20 unless runway length/stopping performance was in question.
Thanks.
What is OPS.29? Can it be found anywhere online?

For information, here is the answer my airline got from Boeing when asking about a question similar, which actually doesn't answer at all about the flaps 20 / GA Flaps 5 question.
As XXX (airline) has stated, the Go-Around climb gradient is not used in the Non-Normal Configuration landing distances calculation since there is no information available to evaluate the go-around climb gradient for each failed system configuration. That is, there is lack of source data. The go-around gradient capability could actually be determined by doing another OPT landing calculation without selecting the NNC because the 'ENGINE SHUTDOWN' NNC with landing flaps 30, for example, is essentially the same as the approach climb gradient with landing flaps 30. Additionally, the 'Engine Inop Go-Around Climb Gradient' table presented in the Performance Dispatch (PD) chapter of the FCOM-QRH can also be referenced. Please be advised these data only represent the particular point in the go-around maneuver at which the assumptions provided exist. For example, for the attached 777-300ER/GE90-115BL table, the conditions are Flaps 20, Gear up, packs on, wing anti-ice off. Corrections are presented for packs and anti-ice variations, but otherwise these data do not represent any other condition or configuration.
​​​​​​​Thanks
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