How do I restart engine in flight?

[chaps]

The Oil Temp seems to be very sensitive also. Just to see what happens if the oil cooler flaps were shut , I shut them when at cruising alt. and watched the temp very carefully. within <1min the temp started rising very slowly, I immediately reached to the switch to open it and the LEFT engine , again, failed. I had to limp to my destination on one engine. I never closed the cooler flaps before and from what happened I will only use open or auto , unless I want to experience another engine failure.

[cruster]

That's really strange, chaps. On my last flight I flew almost two hours at FL140 with the cooler flaps closed and had zero problems. And I was about 680 kg over max weight (it was a v$24,000 job in FSE and I just couldn't resist pushing the envelope. HA!). Here's a shot of my gauges about, oh, one-quarter into the flight (LTBI-LB40):

 

 

Side note: had winds of just over 50 kts coming out of 225-230 the whole way.

 

[arb65912]

I think the mystery is solved.

I also did not read about new limitation of 100% RPM for more than 5 minutes.

 

Today at 16,000' flight I have kept the RPM at the border line of 100% what translated to torque only  around 60% and resulted KIAS around 210 KT.

 

I am SO happy, what caused the problem, it was not the oil cooler flaps, outside temperature or fuel boost, but just RPM over 100% for more than 5 minutes.

 

Of course, with that limitation, climbing to FL250  would take very long time if it was possible at all.

 

I think, I am going to make a test now.

 

Thank you all for great responses and thank you Javier for excellent plane, love it even more... but I have to admit that I was pissed pretty bad after 3 in a row engines failures ..lol,lol and the cause was a dummy me, nothing else.

 

Cheers, AJ 

[arb65912]

Made the test. Successful. 

See screen shots , one just before reaching FL250 and the other one stabilized flight at FL250.

 

Notice KIAS, torque and outside temperature.

 

KTAS was 230  Ground speed with 87 KT tail wind was  318 and  with the 87 KT head wind 143 accordingly.

 

Amazing plane and lots of fun ( after one figures out all the tricks)

 

 

Edited January 20, 2013 by arb65912

[chaps]

That's really strange, chaps. On my last flight I flew almost two hours at FL140 with the cooler flaps closed and had zero problems. And I was about 680 kg over max weight (it was a v$24,000 job in FSE and I just couldn't resist pushing the envelope. HA!). Here's a shot of my gauges about, oh, one-quarter into the flight (LTBI-LB40):

 

 

Side note: had winds of just over 50 kts coming out of 225-230 the whole way.

Strange, I see your oil temps are around 7. Mine were just below 5 when I closed the flaps and were just above 5 when the left, as always, failed. Looks like I'll have to do some more experimenting.

I also just noticed that your RPMs are at the top of the range. If I leave mine there , engine failure in a few minutes for sure. hmmm?? Thanks

Edited January 21, 2013 by chaps

[Intrance]

Try reducing RPM to 97% percent at about 1000' AGL. Keeping them at 100% creates a lot of drag you don't need. And you won't have to worry about running RPM too high.

[Keith Smith]

I was on page 1 of this thread, reading through all the posts and immediately figured it was an over-rpm issue. As I pointed out a few weeks ago, once you're in cruise up at altitude, you have to work hard to stop the RPM from creeping up (I still haven't gained an understanding of why this is). The prop governor appears to get the blades to a certain angle (based on data output to the screen) and no further than that.

 

Once the governor can't move the blades beyond that point, it's essentially a fixed-pitched prop, and as the speed increase, so too do the RPMs.

 

Ultimately, you have to pull power to stop keep the speed down, which, in turn, keeps the rpm managable.

[cruster]

I was on page 1 of this thread, reading through all the posts and immediately figured it was an over-rpm issue. As I pointed out a few weeks ago, once you're in cruise up at altitude, you have to work hard to stop the RPM from creeping up (I still haven't gained an understanding of why this is). The prop governor appears to get the blades to a certain angle (based on data output to the screen) and no further than that.

 

Once the governor can't move the blades beyond that point, it's essentially a fixed-pitched prop, and as the speed increase, so too do the RPMs.

 

Ultimately, you have to pull power to stop keep the speed down, which, in turn, keeps the rpm managable.

 

Pulling the power off is exactly what I do to keep the prop RPM under 100% (I let them run up to the bottom edge of the red line, but no farther). It does require fiddling/adjustment during flight, as wind changes and pressure changes seem to effect the engines/props. I've done multi-hour flights at normal flight levels, though, with no problems at all.

[Keith Smith]

Cruster, agreed...but I'd argue that it shouldn't be necessary. I spoke with an MU-2 pilot and he looked at me like I was an idiot. He says the rpm will be rock solid during cruise and that you won't hit the prop governor's limit at cruise speed.

 

Wind and pressure changes should have nothing to do with RPM. There....I said it

 

As I said, it appears to be a blade angle limit that was set in plane maker. The governor already has them as coarse as they'll go (something that is transparent to the pilot), so as the airspeed picks up, you essentially have a fixed pitch prop because it can't make them any more coarse, and the RPM creeps up. This should not be happening afaik and should be corrected by giving the prop governor more room to work.

[cessna729]

A very good set of Pilots Notes on the TPE331 (Engines on the JS-32)is available here.

http://eastaire.us/files/TPE331pilotnotes.pdf

Quotes from same are taken out-of-context: by me

The TPE331 is a pilot’s engine; it is simple to operate and easy to manage.

Unlike other engine makes, which require the manipulation of three and even four power management controls (levers), the TPE331 engine has only two: a Power Lever and a Speed Lever.

The Power Lever of the TPE-331 engine is “primarily used to control output power. Whether it be fuel or torque depends upon the MODE of operation.”14 That is, when advanced forward from the flight idle gate, the Power Lever controls fuel flow, similar to a reciprocating engine throttle. During this mode, the propeller governor automatically maintains set engine speed by varying propeller blade angles in response to changing flight conditions and/or power.

Speed Lever (SL), sometimes called the Condition Lever19 (CL) or RPMLever, basically serves one function; to select the engine operating speed. Normal Speed Lever positions are: High, Cruise, and Low. The RPM selected is according to the flight or ground condition, and once set, requires resetting only when the flight condition changes. High (100%) RPM is used for takeoff and landing, Cruise (96-97%) RPM for normal climb/cruise/

descent operations, and Low (65-73%) RPM for engine starting and ground or taxi operations.

MAXIMUM ENGINE OPERATING RPM LIMITATIONS

Condition Operating Limits (Engine RPM in %)

100.0 – 101.0 Normal Continuous

101.0 – 101.5 5 minutes

101.5 – 105.5 30 seconds

105.5 – 106.0 5 seconds

106.0 NEVER EXCEED

See Section 6 for RECOMMENDED TPE331 OPS PROCEDURES.

This next quote (from the ENGINE RIGGING/GROUND CHECKS) is very interesting if taken out-of-context as it may appear to indicate that the "Real JS-32" may have been prone to the occasional "overspeeding RPM" at times if given a tough life. The use of capitals is taken straight from the doc, and is NOT me shouting!!

ENGINE RIGGING/GROUND CHECKS SHOULD BE ACCOMPLISHED AT LEAST EVERY 100 HOURS,

FOLLOWING ENGINE MAINTENANCE AND WHENEVER A HEAVY GROSS WEIGHT AT HIGH ALTITUDE OR HOT DAY TAKE OFF IS REQUIRED (OR AS SPECIFIED IN THE APPROPRIATE AFM/POH).

NOTE: ENGINE RPM IN EXCESS OF 94.5% (during the checks or as in footnote 86) INDICATES THE PROP GOVERNOR LOW SETTING IS MALADJUSTED OR A POSSIBLE NTS SYSTEM MALFUNCTION.

And also this quote from same ENGINE RIGGING/GROUND CHECKS:

NOTE: COLD ENGINE OIL MAY RESULT IN SLIGHTLY HIGHER PROPELLER GOVERNING RPM.WHEREAS, HOT ENGINE OIL MAY RESULT IN SLIGHTLY LOWER PROPELLER GOVERNING RPM.

So it appears that Javier may have managed to design/build his JS-32 to have some of the same idiosyncrasies as the "Real Aircraft"

cessna729.

Edited January 25, 2013 by cessna729