Crj 200 Hydraulic/engine Quest.?

[dueguard1]

During t/o after V1 the #1 engine quits, As I understand all three hrdraulic systems are still pressurized.....is 1A still pressurized by 1B...or is something else backing up 1A??

Also why is it you will only get the "Hyd Lo Press" Messege until after the flaps go to 0 degrees? And will 1B Still be backing up 1A after flap retraction??

 

[JJ2U]

1B Is run off IDG #2 so it will still run.

1B in the Auto mode will shut off when flaps go to 0 degrees that's why the QRH makes you turn the pump on instead of auto.

 

[Edge540]

During t/o after V1 the #1 engine quits, As I understand all three hrdraulic systems are still pressurized.....is 1A still pressurized by 1B...or is something else backing up 1A??

Also why is it you will only get the "Hyd Lo Press" Messege until after the flaps go to 0 degrees? And will 1B Still be backing up 1A after flap retraction??

If #1 quits, 1A is a goner unless you have some serious windmilling (something like 280 knots?).

When engine 1 dies in this configuration (flaps out of zero), 1B takes over to power hydraulic system 1. Also remember that this disables 2B, as the #2 IDG is powering 1B.

In this situation, with the flaps OUT of zero: 1B will be operating. When the flaps are brought up, to zero, this turns off 1B because the switch is in AUTO. Turning the switch to the ON position, as your QRH will tell you to do, will turn it back on. No pump = Hyd Lo Press

 

[dueguard1]

1B Is run off IDG #2 so it will still run.

1B in the Auto mode will shut off when flaps go to 0 degrees that's why the QRH makes you turn the pump on instead of auto.

So Is 1A backed by IDG 2 also?

 

[dueguard1]

Tambien! Thanks Guys!

 

[Edge540]

So Is 1A backed by IDG 2 also?

1A = Turned by engine.... ie Engine Drive Hydraulic Pump
1B = Electric motor turns hydraulic pump.

1A, 2A = Engine Driven
1B, 2B = Electrically Driven

3A, 3B = Electrically Driven

 

[JJ2U]

1A = Turned by engine.... ie Engine Drive Hydraulic Pump
1B = Electric motor turns hydraulic pump.

1A, 2A = Engine Driven
1B, 2B = Electrically Driven

3A, 3B = Electrically Driven

Pretty good. But more to it than that.

1B = Electrically Driven by IDG 2
2B = Electrically Driven by IDG 1

 

[JJ2U]

So Is 1A backed by IDG 2 also?

You might be a little confused. 1A and 2A are Engine Driven pumps. But Engine #1's Generator runs Hydraulic Pump on 2B and Engine #2's Generator runs Hydraulic Pump 1B.

 

[flyboyike]

So Is 1A backed by IDG 2 also?

No, it's not backed up by anything except for 1B. 1A is only by the engine through the accessory drive. If the engine stops, so does the accessory drive and with it the affected A pump.

 

[Poahi]

Great discussion - I'd just like to add one point. The "B" pumps are actually powered by their assigned AC Bus. 1B is powered by AC Bus 2, 2B is powered by AC Bus 1 and 3A is powered by AC Bus 2 while 3B is powered by AC Bus 1.

Normally, in the event of a Bus fault of, say, AC Bus 1, you will lose Pump 2B and 3B.

Here's why I say this: Let's say you lose engine 2 on takeoff with the APU running. No problem - drive on. Run the checklists and land at nearest suitable airport. The load for AC Bus 2 is being fed by the APU gen and you turned on the 1B pump. Then, for more excitement, after a minute or so you get a AC Bus 2 caution message (from an AC Bus fault). This automatically takes the APU gen out and now, the entire load is being powered by IDG 1. If this overloads IDG1, it will take itself offline and guess what? The little honda trolling motor pops out adding to the excitement. Now you have 1A and 3B.

 

[Mongolikecandy]

Here's why I say this: Let's say you lose engine 2 on takeoff with the APU running. No problem - drive on. Run the checklists and land at nearest suitable airport. The load for AC Bus 2 is being fed by the APU gen and you turned on the 1B pump. Then, for more excitement, after a minute or so you get a AC Bus 2 caution message (from an AC Bus fault). This automatically takes the APU gen out and now, the entire load is being powered by IDG 1. If this overloads IDG1, it will take itself offline and guess what? The little honda trolling motor pops out adding to the excitement. Now you have 1A and 3B.

This is why I hate orals.

 

[JJ2U]

Great discussion - I'd just like to add one point. The "B" pumps are actually powered by their assigned AC Bus. 1B is powered by AC Bus 2, 2B is powered by AC Bus 1 and 3A is powered by AC Bus 2 while 3B is powered by AC Bus 1.

Normally, in the event of a Bus fault of, say, AC Bus 1, you will lose Pump 2B and 3B.

Here's why I say this: Let's say you lose engine 2 on takeoff with the APU running. No problem - drive on. Run the checklists and land at nearest suitable airport. The load for AC Bus 2 is being fed by the APU gen and you turned on the 1B pump. Then, for more excitement, after a minute or so you get a AC Bus 2 caution message (from an AC Bus fault). This automatically takes the APU gen out and now, the entire load is being powered by IDG 1. If this overloads IDG1, it will take itself offline and guess what? The little honda trolling motor pops out adding to the excitement. Now you have 1A and 3B.

Almost correct but no. It say's that in the manual but the pumps are not being powered by the AC Busses. They are load sheding pumps and are hard wired to the opposite IDG. So when you do loose an engine and IDG, you loose the opposite side B pump. However, you are correct to state that the respective AC Buss on the dead engine will be powered by the opposite side IDG.