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Poll...TFE 731 inflight shutdown

LJ45

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How many people have had to shutdown or had a TFE 731 fail?
How many hours with the TFE 731 before this happen?

I had my first yesterday at 3200 hrs. of flying with these types of engines.

Thanks,
 

LJ45

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gear_guy said:
Has'nt happened yet.:eek:

Lets hear the details

Climbing thru 16,000 in our Learjet 45, we got a high oil pressure caution, chip detect, smell of something burning and a loud grinding noise. All of this in about 15 seconds. Shut down the engine came back to our home base where we await a loaner engine. The engine is hard to rotate by hand and the chip detector is full of metal. Sounds like we lost the carbon seal and then the bearing very quickly.

Anyway, all worked out and felt like we were in sim. training.

OK, I corrected the spelling...should have ran spell check first
 
Last edited:

h25b

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I've heard about the software problem in the N1 DEEC causing flameouts on idle power descents on the TFE731 but have only heard of a couple shut-downs for other reasons. NONE of the failures I have heard about were due to the core engine.

By the way, I just received an advisory wire announcing a software update for the N1 DEECS that solves the flameout problem.
 

thatpilotguy

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I had a "fuel computer" problem that resulted in an engine run away at F410 in a Lear 35. The temp went to 920 and the N1 was racing away before we got it shut down. Sneeky little bugger started a slow temp and N1 increase for no reason. The PF and Captain I was flying with pulled back the throttle a little and that was all she wrote. I was told that is could have been nuematic icing...In anycase it was the last flight for the company before they ceased flight operations the following day.
 

CapnVegetto

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h25b said:
I've heard about the software problem in the N1 DEEC causing flameouts on idle power descents on the TFE731 but have only heard of a couple shut-downs for other reasons. NONE of the failures I have heard about were due to the core engine.

By the way, I just received an advisory wire announcing a software update for the N1 DEECS that solves the flameout problem.


Used to fly a LR-35 with DEECS. Never had any kind of problem like you're talking about. Never had to shut one down either. I've only had one thing happen....and it was really f-ing weird!

Took off out of BTR one night, nasty weather everywhere. As we were climbing out through about 3000 feet or so, we felt the airplane yawing. Our freaking left engine would drop 40%, then come back up, drop 40%, come back up, drop, rise, drop, rise,......the entire drop/rise cycle lasted about 2 seconds each time it did it. CP and I were like, what the f-ck?? Hell, there's no checklist for that. Airplane was yawing, boss was wondering WTF we were doing.....:) Hell, we had no idea how to fix it, like I said, there's no checklist, and we didn't want to shut it down, because it was never anywhere out of limits on anything......it was just acting really f-ing weird. After scratching my head, I said 'Hey Ed, try turning off the fuel computer'. We did that, and it fixed the problem. So, we concluded it was a DEEC problem. We turned the DEEC back on at altitude and experienced no problems at all. When we got home, we had it looked at, and of course, they could find nothing at all wrong with anything. So we kept flying it, and it didn't do it again for about 8 flights. Then sure enough, there it was. Of course, once we turned off the FC switch it quit doing it, and once again, when we got back, they could find nothing wrong with the FC, engine, probes, wires, nothing. Right about then the engine was due for a hot section, so we charged Garrett in Augusta, GA with finding out what the hell was wrong, and after tearing down the entire engine, taking out the DEEC and running full diagnostics, changing out the temp probes, they STILL could find absolutely nothing wrong with anything. So we flew it home and sure enough about 4 or 5 flights later, it did it again. By then we just said f-ck it!!! We give up. Turn off the da-n FC when it does it. To this day, I have no idea what caused it, why it did it. It would never do it on takeoff, cruise, decent, landing, or anything. Only on initial climbout, through about 1000 to 4000 feet, good or bad weather, and it would quit doing it after we turned off the FC. And it would only do it once about every 8 or so flights. I don't think I'll ever know what the hell caused that!!! :) :) Weirdest thing I've ever seen.
 

TransMach

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Garrett's Grenade

4,500 flight hours in TFE-731 powered airplanes, 2 inflight failures ...

Lots of time in GE-CF-700, Pratt JTs, PT-6, and RR RB611 ... no other failures.

TransMach
 

PGH STEEL

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We had the same fuel computer thing happening to us in our LJ-35 Vegetto never did find out what it was.
 

GVFlyer

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When I was flying C-21's in the military, we had roll-backs on the TFE 731-2-2B's all the time. The engines would go to idle at all the most convenient times - during take-off roll, first turn in holding and so forth. After installation of the DEEC's the engines quit rolling back, they just quit instead.

GV
 

Captain4242

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Had a 731 roll back on me a few years ago while on a short base in VFR.
Maintenance said it was a fuel controller problem.
 

LJDRVR

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With over 2000 hours behind the TFE731, I've had the following issues:

Precautionary shutdown during approach for T/R unlock light on a Lear 35. Faulty lower DPI switch. (Banged on it with fist and light extinguished.) Crappy Aeroncas and poor maintainance. (At a 135 operator, imagine that!)

Lear 35, FL410, cabin fills with whitish smoke, no abnormal indications or annunciators. 7 minutes later we're rolling out at Philly with the fire trucks. Number two bearing failed and threw oil into the breather tube, oil coked off and filled cabin with smoke.

Lear 55, 10-15% up and down engine surge on number one during climb through mid-twenties, switched to manual on fuel computer. RTB. Faulty N2 pickup.

Somebody had mentioned icing in the pneumatics. Correct me if I'm remembering this wrong, I don't fly the Lear anymore. If the fuel computers is turned off, the FCU is evacuated of fuel. The resulting decrease in pressure and temperature can result in P-3 icing. Loss of P-3 air opens the fuel metering pin, and the engine will runaway. (Without full overspeed protection, as the the computer is off.) And yet you'll still find folks who think it's cool to save fuel on the descent by turning the fuel computers off.

The only "real" engine failure I ever had the Lear was a CJ610 that flamed out.
 

kingaira90

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CapnVegetto said:
By then we just said f-ck it!!! We give up. Turn off the da-n FC when it does it. .

I had that problem with windows 2000 too! Just had to reboot and it worked fine for a couple of days, Maybe the DEEC's are windows based ;) -kingaira90
 

Capt1124

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My first job on a Westwind was as an SIC on a II. It had the digital ITT readout that has the "H" light up when the temp reaches 885.

Because of this, the PICs I flew with believed as long as the "H" wasn't lit up, it was OK. (The climb limit of 870 and the cruise limit of 849 often ignored.)

One day the "Fuel Controller Manual Mode" light comes on the left engine and I get the checklist. The PIC saw that it was over temping and shut it down, but it was too late. We landed and there was a stream of metal particles coming out the tailpipe.

Another Westwind I flew had minor fuel controller malfunctions (going to manual mode) but nothing particularly disturbing.

I was told once by an old hand that the reason the MSP program came about was the high unreliability of these engines when they first came out. Duncan told me these engines tend to be very beat up when coming off Westwinds and Hawkers, which I suspect is from pilots running them hot to try to make the plane go faster.

In my opinion the one thing you must do with these engines is always carefully observe the temp limits. That's ture of all engines but my impression is these are more sensitive than most.
 

Lead Sled

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Two in-flight shutdowns and one catastrohphic failure on the ground. Of the in-flight shutdowns, both were caused by maintenance center screwups - one engine had an over torqued oil fitting which failed and all engine oil was lost. The other was a precautionary shutdown after a false "bleed air leak" annunciator light could not be extinguished. The ground failure was caused when a turbine wheel came apart on start up.

'Sled
 

gern_blanston

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Ahh, Garrett Grenades.
Lost a seal in a -3 back in my Westwind days. Allowed high-pressure air into the oil system. Oil pressure gauge moved just like the fuel flow gauge: More throttle, more oil pressure (LOTS more!). Less throttle, less oil pressure.
Shut 'er down and parked it.
Before I joined this company, the high-pressure compressor let go on the brand new Hawker 800 at 65 knots on the takeoff roll in Red Deer, Alberta. 60 hours on the plane.
Zero problems with the CFE's on the current plane, which are half Garrett.
 

Pilot_Ryan

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Speaking of which, at Simuflite I've heard a couple of times that there has never been a TFE731 involved in an inflight fire. Anyone know if this is true?
 

falcondriver

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I have had more problems with the computers than the engine. Our computer on the 731 AR spooled back the right engine to idle at 410 on our Falcon 20. The Hawker would surge the right engine 10 %. We would have to go to manual mode to stop it. They would fix it and as soon as you got comfortable it would do it again.
I was told the same thing about no true fires.

FD
 

Lead Sled

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Pilot_Ryan said:
Speaking of which, at Simuflite I've heard a couple of times that there has never been a TFE731 involved in an inflight fire. Anyone know if this is true?
There have been plenty of false indications, but until recently, no fires. I seem to remember something about a recent one in Westwind, but that may have been something else. It's pretty hard to stay awake in groundschool. :eek:

'Sled
 

some_dude

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3,000+ hours in 731s in Lears, Falcons, Westwinds, no failures. A couple of minor computer issues but that's it.

Now, of course, I've jinxed myself...
 

suen1843

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The 731 seems to have gotten a pretty good reputation for reliability lately, but when it was first introduced it was a POS. Early Lear 35 operators always had a CJ powered LR25 follow them around with a spare 731 in the back.

A lot of newly introduced engines have problems...the original PW305 and ALF 500 series come to mind. Also, ask some of the 2000EX guys what they think of the upgraded Pratts. Lots of replacements there already.
 
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