Originally Posted by
Emmerson Bigs
Yeah, listening to the recording again, they were already in the stall before they would have had a chance to do what I suggested.
It's possible they could have messed up with the clean up maybe throwing in some bank with the power coming back for level off, but the speed issue you mention doesn't make sense.
At about a 766 MTOGW departure, Vref is about 185 KIAS and clean maneuvering speed is usually about 265 KIAS (Vref 185 + 80). At 265 you're well above the red "zipper" and usually sitting just above the amber foot.
Min maneuvering speed for flaps 1 is Vref+60 - 245 KIAS with a limit speed for flaps 1 of 265 KIAS
MMS for flaps 5 is Vref+40 - 225 KIAS with a limit speed of 245 KIAS
All those speeds give the standard 1.3G margin.
20 knot spread in both cases. I don't know where you're getting the 3 knot thing. You can fly very comfortably with flaps 1 or 5 after a Max GW takeoff at 245 or 225 and still be 20 knots away from over-speeding the flaps.
Oops, didn’t clarify that properly in my original post. The max speed of the current flap setting, and the min maneuver for the following flap setting are that close. Flaps 5 Max is 245, and min maneuver for flaps 1 at MTOW is usually around 245. So if you retract flaps early to keep from hitting the zipper, but don’t have the trending airspeed it’s not hard to end up below the min maneuver. Normal case wouldn’t be that big of a deal, but couple that with being distracted or something not being programmed correctly and could lead to issues