^^^ Exactly.

So can someone explain about the isolation valve going from closed and back to AUTO?

In the absence of other indications such as loud noises or excessive vibration, when determining if an failed engine has suffered severe damage or has just flamed out and may be restarted look at three things:

 

1. Was there a fire indication?  If so don't even think about trying a restart.

2. Is the engine turning?  If it flamed out there should be N1 rotation.  If the N1 is indicating zero the engine has seized up.  Don't even think about trying a restart.

3. Do you have oil quanity?  If the oil quanity is showing zero it probably seized up from lack of oil.  Don't even think about trying a restart.

 

If there was no fire, you have N1 rotation and it still has oil in the absence of other compelling evidence it would be a good candidate for a restart attempt.

So can someone explain about the isolation valve going from closed and back to AUTO?

 

You close it to prevent the other bleed from being contaminated in the event of an engine fire.  Once the fire is out you put the isolation valve back to auto so bleed air is available to both wings for anti-ice.

Joe the man, Thanks alot its all about fault finding i suppose - Look, Listen and feel for any airframe vibration. So if there is no engine fire do you still close the isolation valve at the first step through the QRH?

So if there is no engine fire do you still close the isolation valve at the first step through the QRH?

 

Yes.  Just follow the checklist, don't try and get ahead of it. 

Hmm ok lets take a look at it. First it says close the isolation valve so the pack thats operating or that good engine side will go to HIGH. But later on it says

 

 

13 ISOLATION VALVE switch

(after the fire has been extinguished) . . . . . AUTO

This ensures bleed air is available to both wings if wing anti-ice is needed.

 

It then proceeds to return it to AUTO when the fire is out. Why can't we just keep it at AUTO if there is no FIRE...

Hmm ok lets take a look at it. First it says close the isolation valve so the pack thats operating or that good engine side will go to HIGH. But later on it says

 

 

13 ISOLATION VALVE switch

(after the fire has been extinguished) . . . . . AUTO

This ensures bleed air is available to both wings if wing anti-ice is needed.

 

It then proceeds to return it to AUTO when the fire is out. Why can't we just keep it at AUTO if there is no FIRE...

 

Because the whole point of the QRH is that you follow the procedure, exactly. A non-normal situation is not the time to "YOLO" it (as one of my pilot mates puts it) and start second-guessing the QRH and making stuff up on the fly.

 

There will be no ill effect from closing the isolation valve, whether there is a fire or not. Who knows, maybe there is a fire but you aren't aware of it, or the thing might burst in to flames whilst you're carrying out the procedure. Either way, you just close it, work through the rest of the procedure, and then if you are satisfied there is no fire, you place it back to AUTO when the QRH tells you. No big deal.

 

Could you get away with leaving it in AUTO if there's no fire? Probably. But it's poor discipline, and if you're prepared to start making it up for one procedure, chances are that when you get a different failure further down the line you go in with the mindset "ah, that looks OK -- we'll just ignore that step" -- only to find later on that you've missed something critical.

So lets say you have an engine fire i'm pretty sure you'll be jumping straight to the isolation valve and closing it but prob after discharging the fire bottles on the affected engine. So that YOLO may go out the window.

If you had an engine fire, you'd do the memory items, which I suspect will be very similar to the B747 items:

 

Thrust Lever (affected engine).....Confirm..............IDLE
Fuel Control Switch (affected engine).....Confirm............CUTOFF

Engine Fire Switch (affected engine).......Confirm............PULL

If FIRE ENG displayed:

Engine Fire Switch (affected engine)........Rotate to the stop and hold for one second

If after 30 seconds FIRE ENG remains displayed:

Engine Fire Switch (affected engine)..........Rotate to the other stop and hold for one second

 

Then you call for the checklist.

Yep memory items above 400agl are the same! And then the reference items when flaps up and the plane is under control. just to reinforce..

 

 

Indications of an engine fire, impending engine breakup or approaching or exceeding engine limits, should be dealt with as soon as possible. Accomplish the appropriate memory checklist items as soon as the airplane is under control, the gear has been retracted and a safe altitude (typically 400 feet AGL or above) has been attained. Accomplish the reference checklist items after the flaps have been retracted and conditions permit.

So lets say you have an engine fire i'm pretty sure you'll be jumping straight to the isolation valve and closing it but prob after discharging the fire bottles on the affected engine. So that YOLO may go out the window.

 

This is exactly what you should not do.  You should never "jump" to anything.  Even with an engine fire you don't rush things.  Take your time, accomplish the memory items and follow the approiate QRH procedure.

 

The AirAsia ATR crash is an excellent example.  They rushed things and shut down the wrong engine and ended up dead.

Yeh exactly disregard my message and whoever reads it. My SOPs call NO ACTION BELOW 400agl except raise the gear and silence the bell. 400agl do the memory items!

Can you manually unlock the engine fire switch with the override and pull in the NGX

Yeh exactly disregard my message and whoever reads it. My SOPs call NO ACTION BELOW 400agl except raise the gear and silence the bell. 400agl do the memory items!

 

SOPs vary but ours specifies 400 feet AGL as a minimum, not an absolute.  Typically we won't do anything until we have accelerated to the UP bug and the flaps are at zero. By that point you are around 1500' AGL.  The exception would be if the engine is surging and causing controllability issues.  In that case it's best to get the memory items done at soon as you can.

Ok cheers. Question joe - when would you start using rudder trim to give your leg a break is 4-5 units ample?

 

Also do you have to use little aileron in the sim unless you done it in real life...? I find in the NGX using small blips of aileron to keep wings level and on track.