PMDG 737 fuel leak

[berdim99]

Hi Guys.
I have a question about the fuel leak and the PMDG 737.
I had a fuel leak about 10 minutes after take-off (left tank)
After that I turned off the left tank fuel pumps and headed back to my departure airport.
I didn't turn on the fuel cross-feed (I think that was wrong of me).

But , when the left fuel tank totally emptied, BOTH engines failed, and I couldn't start them in the air, and crashed....

My question is - Should a fully empty fuel tank shut down BOTH engines?

Thanks...

[Ceemosp]

IMHO it's a case of bad modeling.

Let's look at the scenario: Fuel settings were each individual fuel tank feeding it's respective engine - correct?
No crossfeed or both engines being fed from one tank ?

You switched off one fuel pump (that of the tank leaking) and what should have been happening was an immediate drop of fuel pressure
and loss of power (depending how/where the tanks are located up to a complete loss). Later on - when the tank was empty and you didn't
switch the fuel settings - this engine should have stopped while the other carries on to run (as it still has fuel).
Both engines stopping could only be possible when both don't get fuel BUT that can't be the case with the settings you mentioned.

The correct procedure for your situation (not knowing the 737 POH by heart) I assume to be feeding both engines from the good tanks and
transferring fuel from the leaking tank over to the good ones.

I need to try that myself and see how "f*cked" up the fuel management of the PMDG really is

Regards
Carsten

[Mac]

Technically no, but it depends on what your fuel management settings are.
It just so happenes that (on doing a test flight for the FSP world tour, leg 4) right now, my 737-700 has developed a fuel leak in the right wing.
It's actually my second attempt at this leg before going online, since the first time I had a window crack and cause a rapid decompression
I'm going to sell this aircraft and go round Boeing field browsing for a replacement.

Anyhoo, this is my OH settings, and the engine display. With cross-feed on or off, both engines are operating fine (if a little slanted).


I might need the cross-feed on when the centre tank is drained, since it's the only one feeding both engines, assuming the left tank is for engine 1
only. I'll let you know when I get to that stage

I hope that sheds some light on the situation
***
Also forgot to mention, you can re-start the engines mid-flight (don't know if you were too low level to do it in time or just couldn't get them started). In the Abnormal Procedures PDF you'll find a section titled 'Loss of thrust of both engines'. If you follow the instructions in that you should be fine. Worked for me at least :

Condition: Loss of all thrust on both engines accompanied by illumination of both ENG FAIL alerts.
ENGINE START SWITCHES FLT
ENGINE START LEVERS CUTOFF
EGT decreasing:
ENGINE START LEVERS IDLE
APU START and ON BUS
Do not wait for successful engine starts prior to starting APU.
If neither restart is successful and N2 is below 11%:
WING ANTI-ICE SWITCH OFF
PACK SWITCHES OFF
APU BLEED AIR SWITCH ON
IGNITION SELECT SWITCH BOTH
EITHER ENGINE START SWITCH GRD
APU BLEED AIR SWITCH OFF
ENGINE START SWITCH FLT
THRUST LEVER ADVANCE
GENERATOR SWITCH ON
PACK SWITCH AUTO
Start Second Engine

Post Edited ( 12-21-06 02:02 )

[berdim99]

Thanks for the detailed replies.

I did in fact forget the cross-feed, plus my start switches where on OFF and not on CONT; maybe that way one or both engines would stay on.

As for the mid-flight engine restart - I did try that, but it didn't work, never mind, I'm a little smarter now and will handle such a malfunction
better next time.

Thanks again.

[Ceemosp]

OK, here's the way I handled it on my FFS 340



With this configuration I transfer fuel from the leaking right tank to the left tank - while still feeding both engines from their respective tank.
You need to watch the fuel gauges to make sure the right tank is not running dry.


After the left tank is topped up, Connector Valve is closed and the right fuel pump switched off - X-feed ON and this way both engines are
fed by the left tank (as only the left fuelpump works)

Note: The Saab is configured in a way that crossfeed means Left tank feeding BOTH engines as well as Right tank feeding BOTH
engines when both fuel pumps are on AUTO. It may well be simulated differently with your Boeing