737NG/your EGT goes above the limit ,which QRH should you execute?

[b744FPEK]

engine severe damage or engine limit?

i am kind of confused here ,cuz,even those examiners' opinion are not in common here in my company .

some may say "you should see if the aircraft is shaking.if so ,then you should do the severe damage ,and if there is no shaking and the other engine parameters stay normal ,u should just do the engine limit "but some others believe once the EGT goes above the limit ,there could be a damage inside the engine and to prevent it get worse ,you should follow the engine sever damage QRH ,which you should shut down the engine by memory items.

wish to get some info from other pilots here ,thanks in advance.

[Checkboard]

Normally you look for TWO indications to confirm severe damage. I would reduce power to idle, and if the EGT continued consider shutting down the engine from the engine limit checklist.

[shlittlenellie]

Engine limit or Surge or Stall: Engine indications are rapidly approaching or exceeding limits.

How long does the EGT have to exceed the maximum in flight EGT before it is considered to be severe damage? Boeing guidance suggests that severe damage should be accompanied by vibration to indicate such.

It's logical to consider engine limit first as the actions are appropriate. If the EGT drops with thrust lever retardation then it is a better first response than launching straight into severe damage and instant shutdown.

[lomapaseo]

A few EGT over limits go all the way to melting out the turbine blades if the fuel is left on for minutes.

in this scenario with no turbine blades left the engine just windmills without exhibiting severe damage symptoms on the way down. The cabin crew will likely call complaining of flame in the tailpipe and after that most cockpit crews will shut off the fuel.

Not a big deal to the flight but damn expensive to repair.

[bubbers44]

Being spring loaded to shutting down an engine doesn't make sense. Reduce power to keep parameters normal, land and write it up. Taking a generator and engine off the line should require a very good reason. Especially if you have only two engines. That is what I have always done. Wasn't it "Fate is the hunter" the movie where the fire warning went off with a spill so they shut down a perfectly good engine?

[sevenstrokeroll]

I agree with Bubbers 44. (and yes, it was the movie version of "Fate is the Hunter").

I was in a jt8d powered B737-200 and the temp went high on one engine. I looked at it (as NFP)....and said: HUH. I told the copilot to FLY THE PLANE and I reduced power on the engine until it was in normal ranges. With only that problem I wouldn't consider shutting anything down...half an engine is better than none.

As it happens I also lost the CSD on it and disconnected that. Placed the APU on line to replace the lost gen and returned for a landing at KBWI. I always take off with APU running for just such a situation!

It turned out there was a crack in the engine case which allowed hot gas (vapor) to impact the CSD raising the temp. (also lost a great deal of engine efficiency) It was an unusual situation. When we got to the gate, (overweight landing) the mechanics swore up and down that nothing was wrong with the engine. It took a major inspection to find the problem and they replaced the engine, due to the case crack and not the over temp, which was very, very brief and minor. (auto throttles!!!).

There was never any reason to consider engine damage/seperation checklist. We did Engine over temp/over heat check, overweight landing check. We didn't even declare an emergency. Though when ATC wanted us to sequence behind someone else, I said a firm NEGATIVE.

oh well.

[de facto]

I always take off with APU running for just such a situation!


Seriously?

A few EGT over limits go all the way to melting out the turbine blades if the fuel is left on for minutes.

I thought the CFM 56 could take up to some 40C above engine limit temp for over up to 5 mins without damage to the engine..

[sevenstrokeroll]

defacto

yes...why not...a bit more fuel. you are most exposed during takeoff to more potential problems and why not be ready.

on super great weather days, with excellent long runway airports I might make my exception.

and in this version of the 737 we sometimes use the apu to allow a ''bleeds off'' takeoff for better load lift

[de facto]

Wouldnt that add to what can go wrong?(APU problems)..
You are two pilots with 2 gens,so why not let the PF fly while the PNF start the APU as you well did in the event you described earlier?.

Is your airline ok with this personal procedure?(decreased APU life/increased cost/fuel..)

APU for bleeds off t/o is the normal procedure for all 737s.


I agree with the answer of Post #3

[sevenstrokeroll]

wouldn't that add to what would go wrong? sure

and leaving the plane in the hangar makes things really easy too.

[de facto]

Why would you leave the aircraft in the hangar if it is serviceable?
Is there something I am missing here?
Are your 737-200 operating that close to EGT limits that you use bleeds OFF t/O
on a regular basis?

[lomapaseo]

I thought the CFM 56 could take up to some 40C above engine limit temp for over up to 5 mins without damage to the engine..

Depends on where the flame is.

EGT is like sitting in your easy chair next to a roaring fire in the fire place. If a log rolls out next to your feet you're going to get burned in spite of the room temp still being the same.

[misd-agin]

1. engine limit. autothrottles off, reduce power, shutdown if other, or continued problems.


Bleeds off takeoff only for additional lift (pax, cargo, fuel). At most airports it is not done. High, hot, or short runways? Yes.

APU running for all takeoffs is not procedure and only a few Captains do it. Last time I saw it done was probably 20 yrs ago.

[Sciolistes]

some may say "you should see if the aircraft is shaking.if so ,then you should do the severe damage ,and if there is no shaking and the other engine parameters stay normal ,u should just do the engine limit "but some others believe once the EGT goes above the limit ,there could be a damage
The QRH is clear and unambiguous. There is no need to listen to what some say when the current symptoms match the condition statement of a non-normal checklist.

I thought the CFM 56 could take up to some 40C above engine limit temp for over up to 5 mins without damage to the engine
The answer is in the AFM. For the 3C-1 you have 20 secs below 10deg overheat to correct before you get an EGT warning.

[framer]

"you should see if the aircraft is shaking.if so ,then you should do the severe damage
This is not good advice, what if it was an engine stall?
Boeing has put out a bulletin describing this exact situation, according to the bulletin, there have been many cases of crew shutting down an engine when they should have run the limit surge or stall cx list.

[de facto]

The shaking bit comes from the QRH description of one of the clues to identify a severe damage just as the 'engine' vibration clue is used to help in identifying an engine stall/surge...

engine certification (CFM flight ops support)

Overtemperature test
Demonstrate, by engine test, the ability to operate for 5
minutes at 42°C / 75°F above declared limit (N1, N2 at red
line) with post-test inspection showing engines parts within
serviceable limits.