PT6 failures?
 

Has anyone ever experienced a PT6A engine failure?

If so, what section or component failed, what was the time/cycles on the engine, type of pt6, type aircraft, etc.?

A few minutes with google yielded:


The PC-12 is a state-of-the-art single engine turboprop aircraft. Since the first date of
manufacture, all single engine turboprop aircraft combined have compiled over
8,000,000 (eight million) flight hours with no (that’s zero) fatalities due to engine
failure.

http://www.westair.com/images/pdfs/P...%20Article.pdf

The PT6 has earned a reputation for excellent reliability. ATC position paper,2 entitled Commercial Passenger Service-Night/Instrument Meteorological Conditions in Single-Engined Aeroplanes, refers to an optimistic engine failure rate for the Pratt & Whitney PT6 engine of 1/200000hr. The source of this data is not cited.

Feature - Transport Canada


Blade failure:

African Bush Pilot: Caravan Engine failure... severe PT6 (turbo prop engine) malfunction revisited
African Bush Pilot: Bush Pilot highs and lows

Hot section failure:

http://www.atsb.gov.au/publications/...507077_002.pdf


When I last flew the Caravan in 2000, there had been no documented engine failures, but there had been a few times when the emergency power lever was used (pneumatic issues).

I know there have been a few Ng rollbacks in the Pilatus. None of which were recovered with the MOR. They make pretty good gliders with the prop feathered or so I have heard.

I have not been impressed with the -66. I don't know if it is because of the pusher design, but I know of many failures.

The one I had was a gearbox failure.

No failures, a few chip detect lights in the -65B.
That stat from Google says "no (that’s zero) fatalities due to engine failure," not zero engine failures. Wonder if any Platypus drivers out there have lost their big fan...

-44 power turbine failure (8k+ hours since new)
-20 #3 bearing failure (10k+ hours since new)
-34 FCU failure (15 hrs SOH)
-28 Compressor turbine failure (6k+ since new)
-20 gearbox failure. ( who knows how much)

All were on king airs

I knew of a caravan with a pratt who lost its oil pump, had to shut down. Pretty rare occurrence losing a pratt but anythings possible

That's quite a bit of experience right there.

Were those engines all overhauled at the factory?

I have had one inflight failure due to gearbox self-destruct, chiplight, shutdown and divert in Saudi Arabia. I have witnessed two other failures, one shed most of the turbine through the exhaust leaving some nice dents in those beautiful hand welded parts and another that made it back to base with half of the turbine melted away.

Overall they have proved incredibly reliable though, but like any machine they can and will fail. You can also be struck by lightning. The odds are that neither will happen, but the longer your timeline the more likely a failure.

Snakebit much?

Not an engine-issue per se, but the T-6A has a PT-6, and had a rash of prop-problems (called "Prop-sleeve touchdown"). Could cause the prop to go flat, coarse, or make it depart the engine shaft.

Don't think they had any fatalities, or even losses, but lots of landings that weren't planned. Supposedly fixed now (I think the third or fourth iteration of "the final fix").

I was chatting with a pilot in an FBO that was out of KBMI that had an engine failure in a TBM a couple years back. I can't remember what exactly happened, just remember it was a PT-6 issue. Apparently he glided the thing down from ~25k, and landed in the grass like 100 feet short of the runway he was aiming for because of a strong headwind. It messed up the landing gear pretty badly, but he and all of the pax walked away. He told a story of being grilled by a panel of people from the FSDO where it happened because "they don't see many people who have engine failures in single engine planes up in the flight levels that live to tell about it." Apparently after like some 8 hours or so of Friendly Aviation Administration scouring his logbooks and interrogating him they couldn't catch him on anything, and I remember him saying during the accident investigations it was found to be a freak problem with the PT6 that caused the engine failure.

I have over 2500 hours of incident free PT6 time. Most of the failures I hear about are components failing but usually nothing catastrophic. The biggest component is the High Pressure pump. If that fails, engine quits.

I flew a Beech 99 in for engine overhaul, and the mechanic showed me a couple of the turbine blades that had to be removed. I was amazed that the engine could still run with such badly eroded blades.

Joe

My friend Ameer was the CPT of the ACE Air Cargo flight that went down off of Sand Point, Alaska a few years ago. I am not sure if the NTSB has determined a cause yet.

Ray -

I thought I would try to help you out with your buddy's accident there and see what the NTSB/FAA had to say about it but I couldn't find anything using the NTSB database:
NTSB Aviation Database Query Page

or the FAA Accident/Incident database:
http://www.asias.faa.gov/portal/pls/...ssionid=111085

Let us know if you find anything.
Flying a PT-6 now I'm always interested in others experiences.

USMCFLYR

I have about 1800 problem free hours in PT-6's (not a lot) but a guy I fly with has over 5000 hours PT-6's with zero engine problems (most of his hours are in PC-12's fwiw). I try to treat it nice as often as I can and we do trend monitoring as well. Only time we've had to replace a motor (PC-12) was after lightening struck the prop, arced onto the spinner, through the main shaft welding one of the bearings together (as well as doing some other component damage), eventually making it's way out the left elevator burning a rather large hole. It was a 2 hour flight to a suitable airfield and the motor took it in stride.

I have very limited experience with the PT-6 (700 hours), but the MC-12's in Afghansitan are flying a ton. The number of hours each week is classified (don't know why), but they are flying more than any other manned squadron anywhere in DoD.
And with the tons of hours they are putting on the PT-6, there is virtually no problem.
We had one engine run away and over-torque, but it was due to improper maintenance: a nut that wasn't safety wired came off, etc...

A great engine.

After 8000 hours operating the Dash 7, I had one that shutdown itself. I am not sure what happened to it.

PT6 failures?
 

I've heard they have ran for years on end pumping oil down the Alaskan pipeline , agreed great engines.

In 1995 I was flying a Pilatus Porter (PT-6-27 powered) in Algeria heading out to a drilling rig location, about 1.5 hour into a 3 hour flight she started to developed compressor stalls. With partial power I was able to land at an Italian production facility which had a suitable airstrip. MX was flown out to the location some hours later to have a look and found a bleed valve that was failing. Replaced the bleed valve and continued with no further issues. I have many hour both working on and behind PT-6's and consider them to be an almost bulletproof power plant when taken care of properly.

The air handling bleed valve on the -67b for the pc12 is the only thing that has given me issues, we had one that would stick or only partially open when fully closed...ie at FL280 going from Cruz power to close to idle would result in a compressor stall. Only one engine did this, we changed the part and serviced the spring and it fixed the issue. Only other issue u have had is with the pc12 when the airplane is cold soaked with a older battery it is hard to reach 12 percent NG....

Lost oil pressure and shut down a -66 in a P180, with a turn back to the airport.

I lost a -28 in a BE9L. It didn't make much difference as we were headed downhill at the time, anyway.

Lost power and experienced an ongoing incipient compressor stall in a different -66 in a P180, but it wasn't directly the engine's fault. The ice vane door failed and sucked into the intake stream, causing a hooting and a need to operate at reduced power.

I made a precautionary landing this year in a -67AG equipped AT802, due to a fuel filter light, but it was uneventful, with no power loss.

I've had more problems with TPE-331's, though.

Over how many hours did these incidents occur?

I have no idea.

Those specifically were in the space of a few years, all on different aircraft. Two were for the same operator (fractional).

During that time period I had a forced landing in a garrett powered single following a catastrauphic failure for a different operator, and prior to those, quite a few in radial engines. A few since then in large turbofans, too.

I thought there was a PC-12 that had an engine failure not that long ago. Maybe up in Montana or Oregon?

My airline has had multiple low oil pressure issues on our PT-6s resulting in precautionary engine shutdowns.

Okay just an FYI, I am one of very few that has had a catastrophic failure on a PT-6. I am currently writing a book about this experience. It is quite interesting to happen on a single engine in the mountains.

I have spent several thousand hours sitting behind PT-6's, bunch of Atlantic crossings in King Airs, 6 in the Twin Otter, and 2 in the Caravan...fortunately they have never let me down.

Mokulele Airlines had a catastrophic engine failure on a Caravan back on October 21st at night over water. The crew successfully landed on a highway on Maui with no injuries.

Martinaire had a failure Friday night near Edenton, NC in a Caravan. Guy put it down on an uncontrolled field with no damage.

Had a -28 go out on a king air once. Starting the decent out of fl220, as I reduced the power the left engine started compressor stalling. I put the power back up and everything ran fine until I brought back the power back before the final app fix where it really made some loud bangs. Again I increased the power and it went away until short final where all hell broke loose. The engine started surging, the torque and fuel flow fluctuated with every bang. At this point we were already commited to landing so we touched down and went into a little reverse as we slowed down. The thing didn't stop coughing until we came out of high idle. When taxing to park each time the engine accelerated out of idle the engine gave off a Garrett howl like on the MU-2.

Turns out what happened was the oil pump started to fail and the insides started eating into the housing. It caused enough drag in the 85-71% n1 range to cause a compressor stall. It never even have off a chip detect or decrease in oil pressure. Needless to say, I'm glad it happened that way, I couldn't imagine what a complete oil starved pt-6 sounds like as it welds itself together.

The engine was 3600 since new I believe.

It's not really that exciting, actually. You'll likely have shut it down by then, as complete oil loss (if occurring) is detected through the propeller. If the engine freezes and isn't shut down, it may run hot and you'll end up with a core lock and simply fuel chop it. Either way, it's done, and should ultimately run to feather.

lol well thanks

I'm thinking about working for them, been trying to find out what caused the failure- anyone know?

I had a Fuel Control Unit fail in a King Air 90 one night climbing through 5,000 feet. Naturally the weather was about a mile and a half visibility with 200 foot ceilings as I'd just departed UTA. It caused a torque runaway & I had it shut down in about 8 seconds. I was light with no pax. It flew just fine on one. I did a SE ILS into MEM - 18L as I recall. Hard to taxi on one....LOL!

Luckily, I'd trained at SimCom for just such an occurrence and the training was excellent. This engine had about 1,400 hrs SOH I believe.

I had one hard seize on takeoff from an outlying field near Yuma many Moons ago in a UC-12B. The torque from the seizure broke two of the three engine mounts. The good engine brought us back to the field with no problems.

Used to work for an operator that flew seasonally in the Caribbean. My last season down there, one of the Caravans lost a blade on a takeoff roll, fortunately at a point where the takeoff could be aborted. Despite regular compressor washes, it was attributed to corrosion, I believe.

When I was flying the BE-1900D for Air Midwest the left engine auto shutdown during cruise. They found the P3 line to fuel control unit had broke.

When I was flying a Dash 7 for Pan Am Express, the number four engine shut down during cruise, unknown reason.

We also had a Dash 7 number two engine experience an uncontained failure while landing in ALB. Turbine blades pierced the cabin and injured several passengers.

Over 8,000 hours behind various PT-6 engines in all types of weather, over all types of terrain. I love those engines more than my wife! Thanks Pratt &Whitney!