NTSB Hearing

[Lear70]

The APU LCV was probably in the right position, however due to switch position logic, it will not open when the 10th stage switches are pushed in. The 10ths fail closed so they will indicate closed with the switches pushed in, but the LCV will not open. I dont know if the engines were damaged, so it might not have even mattered.

Not quite.

Yes, they fail closed. However, by the time the crew was trying to restart using the Starter-Assist procedure, the APU was started and AC power was established, plus the APU was giving a source of bleed air. In this case, the electrically-activated-pneumatically-actuated APU LCV would indeed have opened.

They tried to relight BOTH engines, #2 first, then #1 during the event but they were "core locked". http://www.alpa.org/DesktopModules/ALPA_Documents/ALPA_DocumentsView.aspx?itemid=1616&ModuleId=1316&Tabid=256

Neither engine was going to restart. Good S.A. would have at least given them a fighting chance at dead-sticking it into SGF... *sigh*

And you're right... I don't think the company is impressing the NTSB board which is probably comprised mostly of individuals with 180+ IQ levels and at least a modicum of common sense.

 

[CRJ puppy]

Why on earth did they deploy the flight spoilers at F280 and leave them deployed? (accidental deployment?) That totally cooked their glide!

 

[PCL_128]

Why on earth did they deploy the flight spoilers at F280 and leave them deployed? (accidental deployment?) That totally cooked their glide!

They didn't deploy them. They "floated" due to the loss of hydraulic pressure. I think Bombardier said they float at about 6 degrees and the ground spoilers float at about 1 degree. It's just a result of losing hydraulics to all but the essential flight controls.

 

[bige2000]

My understanding of this system is that the APU LCV interlock system will prevent the LCV to open if the actual switches are in the on position, being pushed in. If the LCV is open and you push in the L10 or R10+isolation valve the LCV would close. The interlock protection is based solely on the switch postion on the panel, not the actual valve position. If the 10th stage switches are pushed in, the normal flight position, the LCV should not open. So the APU is on but no bleed air is entering the 10th stage manifold, until the 10th switches are turned off. Has anybody ever tried to start a CRJ on the ground, or in the sim with the 10th switches in the on position?

 

[Oakum_Boy]

The engines flamed out because the AOA was ridiculously high. No air = no combustion. The wings all but washed out any airflow back there. This was no fault of Bombardier or GE, just dumb pilots with no business flying that jet. Sorry but try flying any airplane outside the envelope and you will probably die. Sorry to be soooo blunt and politically incorrect.

 

[FlyChicaga]

Very sad indeed. But I will say, I'm sure we all have learned quite a bit from this accident. I know I have at least. Makes one think.