CRJ200 question
 

Fuel pump boost questions...after the engines are started on the CRJ does the fuel pump boost light go off or does it stay on ??? I am studying the regional jet course and i am confused on the part on the before start flow where it says to push the L & R fuel boost pumps on and 2 white lights should come on indicating on...but on the after start flow it says verify that the fuel pumps are on but the fuel panel should be dark..can anybody verify this..thanks

They go off. They are "on" but only energize in a low fuel pressure condition

Once the engine has been running for 15 seconds the light goes out. Remember the Bombardier's Dark Panel theory...

They(the lights) should be off with the engine's running. Think of them as in an "armed" position. When the pressure in the fuel line drops (I think it is below 9 psi) both boost pumps will come on and so will the lights and the status messages L (R) BOOST PUMP ON (not sure of the exact wordage)

ok thanks for the responses

yes, what everyone else said

Thanks for the endorsement. hahaha.......just teasing you man...

CRJ200- "Dark Cockpit Concept"...if everything is engaged and working correctly, looking up at the panel should be relieved by seeing no lights...

This is the problem with the dark cockpit concept, everything is on but not on. Hard to understand at first but then it eventually makes sense. To further confuse you, on the ground, pressing a boost pump button actually activates both boost pumps even if you didn't press the other boost pump. Whenever the on is illuminated it's just means the pump is on but there's not enough fuel flow in the system for the pump to go into stby.

To further confuse the Boost pump issue, I once got a "L Fuel Low Press" caution message, neither boost pump came on, and the engine did not flame out. I'll let you scratch your head about that. And no, I don't believe the fuel pressure switch is like the oil pressure switch (pressure readout vs warn msg)

Trufactor,

It's been 7+ years but I'll try and answer this for you. The CRJ like most modern cockpits works off the dark cockpit principle. That means when all systems are powered and you are at the end of the runway ready for takeoff, the cockpits dark. Any light on would signify there is a non-normal condition. Not necessarily abnormal, just non-normal.

In the case of the boost pumps, when selected prior to engine start the pumps come on when pressed in and the lights are on to signify they are working. In this case, it is a status message which means that the system is letting you know its not normal for the boost pumps only to be on but they are working. The reason they are status lights is because the boost pumps are only used until there is sufficient fuel pressure from the engine driven pumps and primary ejectors to take over the load. The engine driven pumps boost the fuel pressure to around 800 psi whereas the electric pumps are around 50 psi I think. That's why if you lose an engine driven pump the engine fails no matter how many electric pumps are available.

The electric pumps only exist to provide positive pressure to the engine driven pumps and augment the primary ejector. The primary ejector has no moving parts and is simply a siphon. Once you get suction from it, it stays on until you stop the flow. At some point during engine start, the primary ejector gets enough suction pressure to take over the load from the electric pump. The system senses this and the electric pump which was selected on, goes into a standby mode. If for any reason, the electric pump senses low pressure to the engine driven pump, it turns on to ensure positive pressure to the engine driven pump.

Since the electric pump is in standby, you don't have any lights on. The only reason you would get an electric pump light following engine start is if there is a primary ejector failure, or an engine is shut down.

Its been awhile but hope that helps. I spent a lot of time on the RJ years ago. IMO, it was the most challenging plane from a systems standpoint to learn. Once learned however, its hard to forget and is a very straight forward airplane. Good luck. You will enjoy it.

Let me know if you need any help with AUTOXFER FAIL.

The engine should still run because of the suction from the EDP. However, the only reason the other boost pump wouldn't come on if I remember is if you manually select the L Boost Pump Off in this case. However, since you didn't do that I have no idea why that would happen.

Motive flow! Baby; Motive flow!:cool:

That's one of the better avatars that I've seen in a while.

Now let’s not confuse the issue.

Let’s see, L(R) FUEL LO PRESS master caution illuminates at 5 psig to indicate that a low fuel pressure condition (at the engine inlet) has been detected. During which phase of flight and under what conditions did you experience this?

And… to reply to other posts…

Just to be clear, there is no AUTOXFER FAIL caution, advisory, status, or other message if that is what you were getting at. L(R) XFLOW SOV FAIL or XFLOW/APU PUMP master cautions are related to “failures” of the automatic crossflow operation.

BOOST PUMPS. Breakdown L(R) Fuel Boost Pump Switchlights:

Pressed In – For engine starts, both boost pumps are activated (“ON” light illuminates). With engines running, (“ON” light extinguishes with sufficient fuel pressure), boost pumps remain armed and automatically come on when low fuel pressure is detected in any engine feed line. Switchlights show ‘ON’ when pumps are operating.

Pressed out – The boost pumps are disarmed.

INOP light illuminates when:

1. Low boost pump pressure (engines off),
2. Boost pump not armed (engines running), or
3. Has failed.

WOW... simple question has turned out dozens of VERY detailed and correct answers. Gotta luv systems... But yeah Motive flow! Better start hitting the books myselfs again incase my Loft turns to a PC.

My comment about AUTOXFER FAIL was kind of a joke not related to anything fuel but electrical. I remember a lot of guys were confused by AUTOXFER FAIL and AUTOXFER OFF back in the day. Again though, this is all from memory from a long time ago. However, it shows you how much they made you know back in the day to think it's still with me. There is very little I remember about the 737-200 but a CRJ I can talk all day long. Many a late night candle was burned for the airplane when in initial and upgrade.

I can never be the first on to answer these questions

Another question for you CRJ guys...ive looked through my study guide and could not find the answer to this and you guys were a lot of help on my first question...when taking off it says to select TOGA and set N1 70% power for takeoff..does selecting TOGA mean flipping a switch or what exactly does it mean??? thanks in advance

2F5, 4A1- k i'm good for the checkride.

200 has 2 buttons on either side of the thrust levers that, when pressed, bring up the FD for TO/TO or GA/GA. On takeoff it brings up FD, TO/TO on FMA, completes a runway update for the FMS, and off you go.

The TOGA switches are located on the top of the thrust levers, on the sides where your thumbs would naturally rest, so they can be activated without having to remove your hand.

(the 70% thrust is just a starting point for the addition of takeoff power....if the configuration warning systems detects something out of place, it'll set off the config warning when thrust>70%)

HAHAHA Better study up on smoke.

Hit TOGA then reset your command bars to 10deg. HATE doing that on the roll.....

How do you reset your command bars to 10deg? Do you do it with the pitch wheel? We arent even allowed to use the FD for T/O because our bars just go straight to 15deg... Then again, this is the same company that doesnt allow FO's to do the T/O when the wx is less than 500/1.. :rolleyes:

Someone managed to over-rotate a 200 a few months ago (not sure who) so we got a bulletin telling us to set 10 degrees instead of 15. Once the TO/GA button is pushed you just roll the pitch wheel till you get 10. It is a royal P.I.T.A. and I still haven't figured out how many clicks to get it exactly right first time. I usually set it holding short, you can do it anytime but you have to remember to do the runway update.

Ya, well you can do the runway update on the FMS. Ive gotten so used to flying departures to 10K feet raw data that I could care less about the FD anymore...

Had a captain show me this trick... Hit TOGA, move up one click on pitch wheel, then put your thumb at the top and go all the way down twice. This will set 10 degrees every time and you can do it taking the runway.

Or just runway update and don't use the FD. 10 degrees is only "required" when using FD.

Awesome!!!!!!

Simply out of curiosity anybody know who the over-rotating culprit was?

I've wondered that too, I thought it was just somebody at my company, but from the looks of it, Bombardier must have issued some kind of warning bulletin about it because everyone is doing FD 10 or no FD from what I can tell.

Can we blame it on Mesa? :D

Yes, please.

I flew with a CA in the training department who told me it was from Bombardier, and it was the result of somebody over rotating a Challenger.

A... Mesa Challenger... :D

...flown by JO

I believe a couple of accidents led to this. The first was a CRJ-200 in China which crashed after taking off with ice on the wings and over-rotated. The second was the Challenger crash with Dick Ebersol form NBC sports.

Doesn't change the fact that it's a stupid procedure.

You could be right but I thought both those crashes occurred in 2004 and the new procedure was handed down in April/May of this year.