CRJ-200 Fuel system

[DoinTime]

oh my GOD. Dorks, you must be from Fagship or Mesa (losers)

oh my GOD....Cøck Sucker, you must be from Skywest or CHQ.

 

[Rez O. Lewshun]

Alltheway... look up FAR25.

On a side note, I've picked up over the years the reason why on take off the XFlow Auto overide is switched to manual is each engine gets its own fuel souce.. not shared. An accident concerning a multi engine recip crashed because only one tank was contaminated but that contam fuel went to all engines. Not sure of the details or how true... but I believed it created an FAR. Anyone have more info??

Back to your question...... can good fuel in one tank cross over to the opposite side engine. I hate to think there is an engineer that would not allow a pilot to do that.......

Title 14--Aeronautics and Space

CHAPTER I--FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION

Part 25: AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES


Previous Section 25.954 Next Section 25.957 Contents of Part 25 List of all FAR parts


Section 25.955: Fuel flow.

(a) Each fuel system must provide at least 100 percent of the fuel flow required under each intended operating condition and maneuver. Compliance must be shown as follows:
(1) Fuel must be delivered to each engine at a pressure within the limits specified in the engine type certificate.
(2) The quantity of fuel in the tank may not exceed the amount established as the unusable fuel supply for that tank under the requirements of §25.959 plus that necessary to show compliance with this section.
(3) Each main pump must be used that is necessary for each operating condition and attitude for which compliance with this section is shown, and the appropriate emergency pump must be substituted for each main pump so used.
(4) If there is a fuel flowmeter, it must be blocked and the fuel must flow through the meter or its bypass.
(b) If an engine can be supplied with fuel from more than one tank, the fuel system must—
(2) For each turbine engine, in addition to having appropriate manual switching capability, be designed to prevent interruption of fuel flow to that engine, without attention by the flight crew, when any tank supplying fuel to that engine is depleted of usable fuel during normal operation, and any other tank, that normally supplies fuel to that engine alone, contains usable fuel.
​

 

[Alltheway]

ok thanks, I have never flown a jet, but I came across some crj material and just seeing diffrent systems and what not

 

[av8erab]

On the CRJ-200 fuel system is it possible to x cross feed fuel from one side to the other (TO both engines) in a unlikely event of lets see…..you right side engine driven fuel pump fails and also your right side electric boost pump. The fuel layout shows there is a connection between the two just after the left and right boost pumps. thx

If the high pressure engine driven fuel pump fails the engine will not run. Some of this fuel pressure is used for motive flow to operate the main ejector and scavenge ejector.

You had mentioned the "engine driven fuel pump" above.

This may help you prepare www.crjstudyguide.com

 

[atlcrashpad]

oh my GOD. Dorks, you must be from Fagship or Mesa (losers)

did you skip ground school? or is it just the 300 hrs. total time you have?

The problem is, to ask that question an open forum just doesn't make since. you must be joking or really stupid.

What doesn't make sense, is your spelling. Since you don't use spell check, you look like an idiot. Learn to spell or write in Ebonics.

 

[Lear70]

oh my GOD....Cøck Sucker, you must be from Skywest or CHQ.

Exactly. From "Airplane": "What an A*S hole".

One boost pump can supply fuel to both engines. On the other hand, one main ejector is only able to feed that side's engine due to a one way check valve that is not shown on the synoptic. My airline (PSA) does a daily check on this check valve on the first flight of the day by turning off both boost pumps once both engines are started. This is done to ensure that you can stop fuel to that engine in the case of fire.

Absolutely, positively, 100% correct.

If the high pressure engine driven fuel pump fails the engine will not run. Some of this fuel pressure is used for motive flow to operate the main ejector and scavenge ejector.

Also 100% correct.

Rez, I *think* you are trying to imply that the FAR's require that the engine WOULD be able to run in this scenario. If you are, you forgot one thing: the engine is NOT designed to be fed from "more than one tank", reference para. B that is bold typed in your quote. Each engine on the RJ gets fuel from only one tank - all the other tanks motive flow into the collector tank eventually and both the EDP and the motive flow pump supply fuel ONLY from the collector, i.e. ONE tank for each engine.

As AV8erAB said: if you lose the EDP (engine-driven pump), you lose the engine. Every turbine engine I've ever flown works like this from the King Air all the way to the 727/737, some because the EDP provides motive flow (Lear, CRJ), and some because the ONLY fuel supply line to the injectors goes through the EDP and a non-moving EDP means the vanes in the pump restrict the flow of fuel.

Most system INSTRUCTORS at PCL didn't understand the line on the synoptic page or the manual drawn between both supply lines on the CRJ fuel system enough to explain WHY it's there and how the check valve works, so about half the pilots flying it don't get it either - I did a LOT of explaining on that one little line to my F/O's who were eventually brave enough to ask why we did the check-valve test on 1st Flight of Day.

 

[n32jk]

It is soo much fun watching a bunch of low time losers bashing each other. What we really need to do is focus on unity in trying to fix a broken industry. When I see posts like these, it makes me glad I only have 10 years left.

Joe

 

[atlcrashpad]

Joe,
It appears you got sum catchin' up ta do. Start postin' bouy... Ten years left? Not much time ta post in order to catch up wif da General.

 

[Thermocouple]

If the engine driven pump fails, that engine quits period. The boost pump cannot deliver fuel pressure high enough to keep the engine running.

Forget about motive flow or anything else. The issue is the fuel control unit and injectors do not have enough psi to keep the engine running. Yes, the boost pump will still be able to supply fuel to the engine and at a more than adequate volume. But, you can still pump 2000 pph of fuel to the engine, but if the engine needs 100psi of fuel to run and the output of the boost pump is 30 psi, then it doesn't matter what volume of fuel you can pump. You are single engine either way.

When the engine quits, who gives a flying f**k about the theory of why it quit and won't restart. If you follow the QRH and then engine is still off, flying the fu**ing airplane safely to the ground.

Does Embry-Ridiculous not teach people how to fly airplanes anymore.

 

[dbert]

The EDP has three pump elements. Perhaps it’s unlikely but it’s possible to lose the one that provides motive flow.

One booshand, one main ejector is only able to feed that side's engine due to a one way check valve that is not shown on the synoptic. My airline (PSA) does a daily check t pump can supply fuel to both engines. On the other on this check valve on the first flight of the day by turning off both boost pumps once both engines are started. This is done to ensure that you can stop fuel to that engine in the case of fire.

I’m good with most of this, but you shut off the boost pumps with “both” engines running? What do you look for?