Originally Posted by
User7861
Excuse me if this was already mentioned before, but I have to ask:
Nobody seems to be disturbed about the fact that the Unreliable Airspeed memory items include two performance settings only, and none of those are suitable for an initial climb after take off.
80% 10 degress pitch is the one with flaps extended and gear up. Starting actions at 400 AGL would mean that somewhere around 1000' these values would be set if I happened to follow the memory items without thinking.
So then what? What about high terrain and MSA?
Why is there no initial thrust and pitch setting for take off?
My personal game plan would be to keep the take off thrust and an initial pitch somewhere 14-16 degrees up until MSA or in case of VMC to an altitude where I'm absolutely sure that there will be no terrain threat, then set the 80% 10 deg.
Can anybody here show me what am I missing? Is there any of you here, who would consider setting that pitch and power right after take off? Is there even any data about the actual climb rate at MTOW for that setting?
No, you are not missing anything. I sent my Fleet Manager a long list of items that I felt were deficient in the current Airspeed Unreliable NNC, this being one of them. One of the more significant problems is that once you have stabilized the aircraft, there are all kind of ancillary system effects from a bad AOA or airspeed input, and the QRH doesn't do a good job of discussing them. He said that they would forward them to Boeing along with a bunch of other material they had been collecting, but he said not to expect any definitive answers soon. I suspect all correspondence with Boeing is being vetted through legal.
To answer your specific question, the consensus among folks I've discussed this with is to maintain takeoff power and 15 degrees nose up until reaching 1000', engine-out acceleration altitude, or obstacle clearance as appropriate. At that point, set 80% and 10 degrees and work the checklist far enough through to determine the good airspeed system before you retract your flaps. If you are in an area that requires special routing for terrain, follow whatever company procedures you have for engine out maneuvering. Keep in mind that 80% N1 on two engines is better thrust than one engine at MCT. This procedure also works for a Go-around/Missed approach from low altitude.