I hope some of the contributors remember earlier lessons in meteorology where we all learnt that in wind-shear conditions (and that includes high altitudes!) the exedence to one side will most probably be followed by one to the other side.
Now where would you rather be, too fast or too slow, bearing in mind that you have to report either?
Congratulations, 65% of you answered right, they would rather be on the fast side. I can hardly remember one incident where an airliner crashed having been too fast but two recent and spectacular accidents having been too slow.
With some engines a pull back to idle is not a good idea, on others it is less of a problem, so know your aircraft.
But to use speedbrakes at high altitude is a no go on my deck. For how long did you guys experience an incidental overspeed at altitude and level? Isn't the aircraft somewhat autostable and the increase in drag brings you back in due time?
The Mach shock wave increases drag and reduces lift, the autopilot or the pilot will initially keep the altitude, therefore the speed
will come back.
Extending the speed brakes will increase drag and reduce lift even more, the speed might come back more quickly, but the chances that the counter-shear will throw you into a subsequent low speed situation are greatly increased:
You are suddenly in an equally t&b-prone situation, but in a much more dangerous one.
