engine relight

[gootybalajiniranjan]

did any body carried out successful relight in a single engine failure or if you know of some incidents please post thanq

[BOBAKAT]

Sorry, after nearly 6000 hours on rotary, i never experiment a engine relight in flight...
Each time i touch down before shutdown the engine.

Remenber, you need minimum 5000 ft under your seat to try the relightduring the descent : that'is is theorical...IRL, i think you need 6000 or 7000 ft...

Most of single engine helicopters flying under the limit to relight...

[oleary]

Depends what you are talking about.

The Bell 206, Hughes 500, S76 and many others have "auto relight". Some operate on Q others on N1.

If the donk quits with these systems the relight is almost immediate (assuming you have fuel and the engine is mechanically OK). Gauge needle jump and tail wag are about all you will see.

If you are describing an engine at zero N1, then yeah, it's gonna take a while to get her goin'. I have relit a a C250 in 1000 feet.

Try this, time how long it takes to get your engine to flight RPM - say one minute. Then calculate your auto descent rate - say 1500 fpm - and there's your answer.

Some old guys (not me) when flying a 205 would pull the starter trigger as soon as the engine quit - not to engage the starter so much but to turn on the igniters.

[GipsyMagpie]

The Merlin helicopter has the facility to shutdown one of its engines in flight to save fuel (you are not running the gas generator of the shutdown engine and the other two run at higher power and so higher efficiency). It would not be sufficient to just put the engine at idle to save fuel incidentally. The aircraft is maintained above 90kts to help with restart (the compressor freewheels in the airflow).

I have heard of an A109E having both its engines turned off in flight and successfully relighting. I know of an exercise on test pilots course (see excellent old BBC series on YouTube) where single engined helicopter intentionally does full shut down and restart to practice assessing this. I think 3700 ft was used as a minimum.

So if in a single engined helicopter make sure you can land on what is under you!

[whoknows idont]

Double engine failure on German Chancellor's helicopter (http://www.pprune.org/rotorheads/446214-double-engine-failure-german-chancellors-helicopter.html)

For some reason they shut off intake anti-ice at 5000 ASL and both engines quit 5 seconds later. They managed to relight no 1 engine during A/R and levelled off at 300ft AGL. :eek:

[Devil 49]

Had an auto-relight event in flight in a Twinstar. Hard yaw to the right, relight, back to trim, cruise continued- 2 minutes back to base for maintenance precautionary landing. Compressor stall due to C20 stator vane detaching.

Legend was that a colleague had both engines quit sequentially in 300-2 due to inlet icing, manually restarted each. So, we got auto relight...

[gootybalajiniranjan]

thanks all for valuble inputs

[Lama Bear]

206B-lll with particle separator and de-ice on, no deflectors. Engine failed for ice ingestion. Speed 80 knots and altitude 200 AGL. Hit the starter while N-1 was above 90%. Engine re-lit with no noticeable torque or tot spike, throttle was in the flight position and the collective was full down.

[RyRy]

A couple buddies of mine had an engine quit in an S76-A. They were coming off a hospital helipad and it died shortly after rotation at about 100'. Flew away on the remaining engine and later elected to try relighting the failed engine, and got it going again without any further issues. Returned to base safe and sound.

The engine flamed out due to a fault in the fuel line. I guess at the time, the fuel lines in the C30 engines were not limited to a certain amount of hours before they need to be replaced. It's a typical steel-braided flex hose wrapped in insulation. Of course with it being a steel braided line, it should have immense rigidity. Well.... these had been in place so long that all that rigidity was gone. With just two fingers we could pinch it closed!!

When they started the fly-away and lowered collective to set normal climb power, that reduction in pressure in the fuel line caused a momentary vacuum effect and it pinched closed.

Not sure if Allison or Sikorsky issued a SB after that or not, but the lines in our whole fleet got changed out as a result.

[Maff]

I was looking up some data in my EC130 T2 POH today and noticed it says relight can be done as long as you have at least 1000 agl at vy. Fadec engine switch to off, then on and it sorts the rest. Don't think I'd want to try it at only 1000' !!

[SilsoeSid]

Engine failure in a single; last thing I would be thinking about is restarting a failed engine.

[BOBAKAT]

:ok: for sure !
:= looking for autorotation landing place....