Spanair accident at Madrid

[misd-agin]

This post doesn't address this incident specifically because what occurred, or didn't occur, isn't known as of right now.

Comments on flying and aircraft configuration have been asked. Some comments -

1. An a/c without flaps will accelerate faster because a clean wing(no LE slats/TE flaps) creates less drag while accelerating on the runway.

2. Post #733 shows the stall speed/configuration/wts graph. LE slats typically lower stall speed on commercial jets approx. 30-40 KIAS while ALL the TE flaps reduce the stall speed approx 20-30 KIAS(airspeed to non-pilots). For this case it looks like a clean wing would stall approx. 40 KIAS faster than a Flaps 5 T.O. configuration.

3. Someone asked how far it would take to accelerate to a safe speed without slats/flaps? Answers based on Post #733 data - You would have to accelerate approx. 48 KIAS(40 KIAS + 20%) to have the same safety margin that a typical takeoff has.

4. In ground effect(basically within one wingspan of the ground) a/c will be able to fly at speeds lower than stall speeds out of ground effect PROVIDED precise AOA(angle of attack) control is used. Trying to increase AOA(ie typical rotation after liftoff) or exiting ground effect can make an a/c that was once flying completely unflyable. Doing both, AOA increase and exiting ground effect, compounds the problem. Air Florida 737 KDCA and NW DC-9 KDTW crashes are examples of a/c that 'fly' but can't stay airborne due to AOA/ground effect problems.

5. V2 or V2+10 is typically very close to clean stall speeds. Should this situation(inproper T.O. configuration) occur staying 'on the deck' and acclerating on the runway, or in ground effect, can be a lifesaver. (sim experience from reenacting DL 727 KDFW T.O. crash and NW DC-9 KDTW crash, both with no slats/flaps extended)

Again this is not commenting on this incident since the facts aren't known at this time.