3407 ntsb #4 pilots configured the aircraft's flaps and landing gear for landing q400 at Buffalo

This is last in a 4 series audio of NTSB update on 3407. The final report on the 16th follows, yet is similar in info. The NTSB may take months combining the data for official report.
The de-icing system was turned on 11 minutes into the flight by the crew, who discussed significant ice buildup on the aircraft's wings and windscreen shortly before the crash.

Following this, the pilots configured the aircraft's flaps and landing gear for landing. Immediately, the plane went through severe pitch and roll oscillations, and the aircraft's stall-protection systems activated, which included a stick shaker and stick pusher, which tried to push the nose of the aircraft down in order to gain airspeed and lift. The crew then attempted to raise the gear and reset the flaps. At some point during this chain of events the autopilot disengaged itself. The plane pitched up at an angle of 31 degrees in its final moments, before pitching down at 45 degrees. It then rolled to the left at 46 degrees and snapped back to the right at 105 degrees. Occupants aboard experienced forces estimated at nearly twice that of gravity. Witnesses on the ground claimed to hear the engines sputter just before the crash.
more info about the plane at www.q400.com

A deep stall is a dangerous type of stall that affects certain aircraft designs, notably those with a T-tail configuration. In these designs, the turbulent wake of a stalled main wing "blankets" the horizontal stabilizer, rendering the elevators ineffective and preventing the aircraft from recovering from the stall.

Category:

Travel & Events

Tags:

• 3407
• NTSB
• flaps
• q400
• deep
• stall
• turboprop
• T-tail
• propwash

[bethpage89]

"Flaps set to 15" wasn't mentioned.

"They commanded the flaps to 15...."

"They commanded flaps 15......The flap handle.....got back to the 10º notch--we think--because all we see on the flight data recorder is the flaps got to 10º. They didn't get to 15º."

[bethpage89]

pythos1:

The power had been back at or near idle in order to slow down for the final approach, but after the stickshaker activated and the automatic pilot disengaged the pilot promptly powered up and pitched up drastically--before the stickpusher activated.

A stickpusher offers only about 30 pounds of force; the pilot was able to overpower it easily.

[pythos1]

so what you are saying is there was a delay on the part of the pilots. You did hear the power was reduced, which is another action to be done for tailplane icing. You are not getting that I do not think it was actual T.P. icing. I am saying the pilots were fooled into thinking the plane was encountering this situation, due to this stupid and unnecessary system.

[pythos1]

The stick pusher is a device that should be removed from all aircraft that are meant to operate in icing conditions. It is unnecessary. From what I have heard the stick pusher in fact provides a lot of resistance to being pulled back. It is a dangerous system and can give a pilot the wrong signal. Check out the Nasa video about tail plane icing. The stick pushes imitates these movements.

[bethpage89]

I didn't defend the stickpusher.

[bethpage89]

A stickpusher pushes the yoke, but the yoke doesn't move forward if the pilot doesn't let it.

Flaps up was selected at 22:16:36. The upset began before at 22:16:29.

[pythos1]

Are you even a pilot?

What does a stick PUSHER do?

When the stick pusher activated was when the stick moved forward. Did you even listen to the report. The term "flaps set to 15" was mentioned at least twice. The flaps never reached that position due to them being quickly retracted at the moment of upset.

Why do you defend a stupid device as the stick pusher any way? I as a pilot need no such device. I need a stall horn, or stick shaker.

[bethpage89]

Flaps 15 degrees was never selected.

The "upset" was the pilot drastically pitched the deck angle from 9 degrees to 20 degrees. That was before the stickpusher activated.

The stick moved forward? When?

The back pressure applied in a tail stall is to get the nose back up where it belongs. They didn't have that problem. The nose began too high at 9 degrees, and the pilot pitched it up drastically to 31 degrees.

[pythos1]

That is exactly what they did. You don't have to be in level flight to have a tailplane stall, you can have it happen at an angle. The stick pusher gave the impression the tailplane was stalled. The system has no other indicating system dealing with the activation of the system. It is did, this may not have happened.

[pythos1]

As I have said, I do not think there tailplane icing or stall. But the plane gave all indications of such. The stick moved forward. There is no other indication of the stick pusher activating such as a light or horn. The pilots were tired after three legs. Their "recovery" was reduce power, return flaps to previous setting, and hauling the gear up. These are the recovery procedures for tail plane stall. They THOUGHT they had a tail plane stall.