B737 Engine Surge followed by Overheat
 

Hello guys,

I got a question regarding a situation that I believe the BA B744 recently had out of Phoenix. But I would like to apply it to the B738.

If on take off you get engine surge/stall indications but also an overheat which memory item(s) would you suggest initiating?

My answer would be the Engine Overheat memory items.

Seeing as there are memory items for both the Engine surge/stall and also and overheat plus the engine fire, severe damage, separation. I would like to know your thoughts.

The times we’ve practiced engine surge during take off in the sim the pulsating yawing from the surges has made the aircraft a handful to control. So, retarding the thrust to get rid of that has been the first thing to do (even with the help of my colleague).

/With the usual caveat that the simulator may not behave as a real world event

I'd go with the following thinking, as it's on take off and I therefore assume you are climbing away not yet clean; i.e. close to the ground, perhaps.

The initial actions are the same, with the proviso that an OVERHEAT says close TL, whereas SURGE is reduce as necessary until closed.
Surge, if allowed to continue can lead to other damage. Overheat, if allowed to continue can spoil your day more. Surge is obvious, Overheat could be sensor, but it's not wise to consider that risk in such a position. There is no time to trouble-shoot.
For me I'd rather have the a/c under control in a constant thrust status, therefore close the TL. That allows me to control & trim the a/c for a constant thrust climb out. It is also less distracting for PM.
This leads me to opt for the OVERHEAT memory items. It solves both problems with prioritising the worse, reduce work load and make control simpler.
This supposes you're not going any where anyway.

Fly the airplane to a workable altitude then FIRE memory items and shutdown checklist.

I'm with RAT5 all the way. Disconnect A/T, smoothly retard TL to idle and then just concentrate on flying the aircraft, you'll either remove the surge, remove the Overheat warning or you won't. If you do, job's a good'un, if you don't it make PM's job easier. But first and foremost, get the thrust predictable, and the aircraft up and away safely.

I'm with RAT5 too :ok:

Well on that aspect of this it might be worth bearing in mind not all surges are the same and the sims seem to do seem to replicate “worse case”...

I don’t know if the PHX crew reported any handling issues but FWIW I’ve had a brief series of pop surge(s) on takeoff on a 744 .... hot, high and heavy.....and no, not the one referred to by the OP...

It was certainly noisy, and being at night visually impressive to all and sundry both inside and outside the aircraft and fore and aft of the wing, so just like the video, but our event probably lasted under five seconds. Symptoms on the flight deck: a few very, very, and only just perceptible tiny flickers to one of the EGTs, which even so always remained within limits, some minor jolts but little in the way of yaw or other control issues...

Given it was unclear to anybody on the flight deck ( we had a heavy) as to which engine was definitely involved and given whichever one had been surging auto recovered very quickly a team decision was made to leave them all running at takeoff thrust. I wouldn’t argue with any of the previous advice about checklist actioning, just caution any assumption that diagnosing the exact source of even a noisy surge will be easy, or caution any assumption that you will get the sometimes violent jolting and yaw effects that are modelled in the sims...

FWIW in our case the engine involved did go pop properly and in a terminal manner a few days later........

As wiggy notes, if an engine surges but quickly recovers and doesn't continue to surge, no immediate action is required (especially since, as wiggy also notes, it's often not obvious which engine it was). If it keeps surging then a controlled throttle retard is warranted when work load permits. But keep your wits about you and communicate with the PM to make sure you're addressing the correct engine (again, it's not always obvious).
There was a rather infamous incident at Boeing during the PW4000 development in the 1980s (I had several friends on the event flight). They were flying a prototype PW4000 engine on the Line No. 1 767 (VA001) - with a JT9D on the other wing. During takeoff from Boeing Field, the PW4000 started surging at about 50 ft. - un-recoverable surge. The pilot flying didn't say a word, but calmly reached over and retarded both throttles to idle :eek:. As the aircraft started settling towards the Georgetown neighborhood, the PM took control and slammed both throttles to the firewall - the PW4000 furiously barking the whole way before it was shutdown and they circled back around and landed.
That particular Boeing flight test pilot was demoted...

Thanks for the input guys, I guess my initial thinking was correct. In the sim when we practice our OEI manoeuvres, the problem is usually just one thing (overheat, fire, seizure) but reality is that there may be more than one diagnosis.

In the sim when we practice our OEI manoeuvres, the problem is usually just one thing (overheat, fire, seizure) but reality is that there may be more than one diagnosis.

Indeed. I wonder if airlines could be more imaginative in their recurrence programs. I used to find them distinctly lacking. Thankfully I've no direct experience of in-flight engine failures, but I suspect engine failures are often associated with more complicated reasons than a simple wind down. The sim exercises tend to be a simple distinction between failure & damage followed by SE handling & QRH action. Job done. I think the Qantas A380 engine malfunction & the BA loss of total thrust in volcano ash showed that the real world has never heard of a simulator and has a wicked imagination.

Reducing the throttle should correct, either or both the surge and the overheat. if it doesn't correct the overheat, expect the engine is lost completely until shutdown.

Hi,

It was a flight test, so I assume ballast tanks (filled with water) were installed to simulate passengers weight and cargo load. I don't know about the fuel weight. With that being said and I stand to be corrected:
a) Can this plane still climb with both throttles in idle?

b) I am wondering if flight test pilots have to follow the same procedures (I mean abnormal procedures from QRH after problems or emergency conditions such stall, engine fire...etc) as other regular pilots OR flight test pilots have different abnormal procedures than the QRH?

Feedback appreciated.

Only if they were testing it for that weight on that particular flight, and nothing in the quote indicates that. Also, since they were testing an engine and not the airplane, I don't see a reason to be flying at a high weight.

No.

Fly the aircraft to a safe altitude then reduce thrust as normal. Take a breath and see whats happening.
Had an RB211 cough it's guts out during base training. It's more startling than catastrophic. Especially if the flames are shooting forward of the nose. But a surge is due to bad airflow and a change in thrust or airspeed could fix it.

So use it while you can and make it safe when you don't need it anymore.

RAT 5,
Small point here,but both checklists say to reduce thrust until either surge cured or overheat meassage goes away..then run at reduced thrust,..(or,as you see fit)
Apologies,Rat..I'm reading for 777..

:D. Fly the airplane and then as FE Hoppy's quote.

RAT 5 is right: close for overheat, retard (until...) for limit/surge/stall. This is for 737-700/800/900.

Aero Teck
 

I think tdracer are talking about an 767 and AirCanada did some testing with regards to this from FL410. They did a good 100 plus Nm glide and made Gimli airport famous. No climb. Some sideslip on final as they were high tough.

With regards to test pilots and what they do and dont , with critical testing , extra sensors and engineers involved they do a lot we would never consider.
Super planed.

I have seen some interesting non-standard stuff being pulled off by testpilots.
Checklist , CRM and SOP not a strong side . Great gang , but old boring standard stuff , Naahh.
Murphy has his ways!
But going from testpilot for Boeing to glider pilot in one day ,
As one testpilot once told me with a blush; We testpilots make mistakes too!
( Turned out the engine started much better with the firebutton in again, as we had just concluded it worked as intended when pushed and released!)