Partial engine failure - lesson learned

[facthunter]

Lovely looking "little" radial made in the old iron curtain countries. Fitted to the sukhoi aerobatic planes and lot s of others that need a 250+ HP engine. Nev

 

 

[Oscar]

It's 'little' by most radial sizes, but it's a large lump in the front of a Pitts! I had a good look at DR's plane in Dave Dent's hangar (standing at a respectful distance, DR, believe me - no grubby finger-marks on that immaculate finish). Dave's hangar is usually a swarm of Pitts (Ok, Ok, it's 'THE Pitts' in the best possible way - someone has to stoop to make that joke..), but all the others I have seen there, are an aircraft with an engine in the front. Not that I could ever use one; I've tried patting several affectionately but they never follow me home.. Damn.

 

But the S12 gives the feeling of being an engine with sufficient aerodynamic surfaces behind it, to go do wonders. It is an aircraft that one mentally says: 'Sir' to, touching the forelock and backing away every so slightly....

 

I know that Dave Dent hankers to build a GeeBee racer replica. I don't know what engine he has in mind for it, but whatever that will be, a GeeBee has always struck me as an engine with just sufficient flying surfaces behind it to get you into vast amounts of trouble, so quickly that you wouldn't have time to say 'OH SH..'. With the engine in the S12, those surfaces would be two paddlepop sticks and three toothpicks. At least the S12 has FOUR paddlepop sticks...

 

 

[facthunter]

A Gee Bee is a flying engine and nacelle and not quite enough of anything else. I would be terrified of flying the original thing. There's a fair bit on line about these planes. Worth looking into. Nev

 

 

[Pearo]

Indeed; praise be to Him for your safety! Psalm 44...

Please take your religious crap to the off topic area pls.

 

 

[Oscar]

Of course, if you want to look at 'ludicrous'...Barry Manktelow ( who built the superb Pitts Samson that Pip Bormann killed himself in by fiddling where he should not have) recently built for a US nutter, the fuselage of a Laird 'Super Solution': http://supersolutionproject.blogspot.com.au/

 

 

[Oscar]

Please take your religious crap to the off topic area pls.

Jeez, be tolerant! Did not the Lord say unto Gilgamesh: 'It is better to have Stalled Oxen than the bread of the fruitful, lest the seeds of the fishes rain down upon the Halls of the Unmighty?'

 

You should consider that.

 

 

[BLA82]

Jeez, be tolerant! Did not the Lord say unto Gilgamesh: 'It is better to have Stalled Oxen than the bread of the fruitful, lest the seeds of the fishes rain down upon the Halls of the Unmighty?'You should consider that.

I think I just vomited in my mouth

 

 

[BLA82]

Glad your ok Dutch

 

 

[Gnarly Gnu]

Please take your religious crap to the off topic area pls.

You talking to Dutch? He brought this us. Or you feel only fundy atheists like him and you should be allowed to? Free speech for only those you choose.

 

 

[M61A1]

Please.....can we have a "face palm " emoticon?

 

 

[BLA82]

You talking to Dutch? He brought this us. Or you feel only fundy atheists like him and you should be allowed to? Free speech for only those you choose.

No this forum is about rec flying not rec happy clapping. Time and place and this isnt it. I am a firm believer that Dutchs skill and knowledge saved his arse not some imaginary carpenter.

 

 

[Gnarly Gnu]

Either comprehension isn't such a strong point or you didn't read his posts. Like a drink to go with your big serve of intolerance Mr blog owner?

 

 

[BLA82]

Either comprehension isn't such a strong point or you didn't read his posts. Like a drink to go with your big serve of intolerance Mr blog owner?

Just throw another 50 on the plate mate and all your problems will go away. Intolerant YES. Why do we need to hear your crap on a forum. If i want to be saved I will go to church. Outside of that keep it to yourself

 

 

[Teckair]

Why do we need to hear your crap on a forum

The same reason we hear your crap after all it is a forum.

 

 

[dutchroll]

Yes with both plugs sooted the rev drop test is not valid. I don't know how elastic your engine mounts are, but I'm surprised the engine didn't rock a bit with one pot out. Did you check your revs achieved on Take off? I know its C/S but it's on the fine pitch stop initially or your plane doesn't a have a usable prop safety speed. Nev

Takeoff power was fine. It sat right on the redline at full power, which is where it normally is.

 

 

[facthunter]

Because its C/S. It's only going to show early in the take off run. (Different RPM). I cylinder out of nine? It has to show. I had one out of six once and it went no place. Yours is only a bit better loss ratio. Nev

 

 

[old man emu]

Please take your religious crap to the off topic area pls.

It is an accepted literary practice to misuse a quote from a well-known source. Gnarly's problem was that he didn't give the quotation that had meaning in this topic.

 

Indeed; praise be to Him for your safety! Psalm 44...

The appropriate verse from Psalm 44 is verse 15.

 

" My confusion is continually before me, and the shame of my face hath covered me,", which describes what Dutchroll did pretty well.

 

OME

 

 

[dutchroll]

Because its C/S. It's only going to show early in the take off run. (Different RPM). I cylinder out of nine? It has to show. I had one out of six once and it went no place. Yours is only a bit better loss ratio. Nev

As far as vibration etc goes, this plane rocks and rolls a lot on the ground with its 2.6m diameter propeller and sprung aluminium gear legs. I have once or twice noticed quite a significant difference with a couple of fouled plugs on different cylinders which cleared by the time the runup was completed, however it's entirely possible that I'm still not accustomed to detecting subtle differences in that area as I haven't flown anywhere near the number of hours on it that I've wanted to.

Downloaded engine data from the flight shows takeoff RPM at 3000, and manifold pressure at 37.4 inches. Exactly as per a normal takeoff, which is a relief to me personally, because although my takeoff roll is very short (about 5 seconds) I do quickly glance at the RPM and MAP when the throttle is fully forward. There are no distinct peaks or troughs in the RPM and MAP data showing the afterfiring events. Possibly this might be to do with the sample rate of the engine data recording. It just shows when I reduced the power.

 

The M14P is an amazing engine. The Russians built it like the proverbial brick s***house, as many M14P pilots will attest to. Personally I reckon they designed it to run on vodka and be lubricated by whale fat. Avgas and Aeroshell are Dom Perignon and caviar to it. But the downloaded data is very clear: full power was achieved throughout the very brief takeoff roll.

 

 

[Marty_d]

End of the day, Dutch, you're safe and your aircraft is unbent. All else is irrelevant, except for what you (and now, the rest of us) have learned from the experience.

 

Thanks for sharing it!

 

 

[facthunter]

I'm only searching for a way to detect a partial failure. No criticism implied .On a fixed pitch prop as a talking point, with one cylinder out you would not achieve normal T/O revs. Your manifold pressure should be HIGHER on idle for the same revs (which you set) I f it's on the idle stop, then the revs would be slower. Your exhaust (beat) would be different. Nev

 

 

[dutchroll]

I'm only searching for a way to detect a partial failure. No criticism implied .On a fixed pitch prop as a talking point, with one cylinder out you would not achieve normal T/O revs. Your manifold pressure should be HIGHER on idle for the same revs (which you set) I f it's on the idle stop, then the revs would be slower. Your exhaust (beat) would be different. Nev

Sorry, writing on forums often doesn't convey "tone" very well, but honestly there was no criticism taken Nev. You made a valid point and I immediately thought: "Ok I thought I checked takeoff power, but did I misread it?" The answer is no I didn't misread it. That's one less thing I need to self-assess.

My main self-assessment is going down this path:

 

1) Be much more tuned into the deeper meaning of EGT and CHT indications, especially the EGT.

 

2) With a modern engine monitor I am spoiled for information. They're not just for cruise leaning like the marketing blurbs tend to suggest. It can give me excellent engine health information during engine runup which I must pay more attention to.

 

3) If it sounds right, but doesn't look right, assume it isn't right, even if everything else is within normal limits!

 

4) Catching the train home isn't so bad.

 

 

 

[facthunter]

I think we are different generations. Most of the "failures' I had were detected with it not behaving right and at a time when engineers ran along behind the exhaust of a plane taxying in to listen if a pot was out. They are all oily motors and I think they spend too much time idling. You are unlucky to have both plugs sooted at the same time, but these things will happen. Most motors go "off song' a bit before they fail, and I'm someone who notices if things aren't sounding right. I'm an engine nut, I guess but it's saved my neck at times. Nev

 

 

[dutchroll]

Update today:

 

On both plugs, #5 cylinder. Not a lot of sparking going on there. Cleaning away the liquid oil revealed a burnt "bridge" of oil.

 

 

 

[fly_tornado]

how many hours on the plugs?

 

 

[dutchroll]

There's 86 hours on the Hobbs and I'm 99% sure they're the original plugs (I don't recall any advice that they were ever changed during servicing). So that includes quite a few engine runs going all the way back to manufacture and ground testing. We were going to change them at the annual a few weeks ago because they're cheap as chips but the new batch we bought had some suspect markings on the ceramic parts and the originals were actually in pretty good condition, so we left them in.

 

Interestingly going back through engine download data I found that the cylinder actually dropped off line when it was previously run - which was a startup and short taxi from the hangar to the refuelling station. It dropped off 6 minutes after engine start, as I was waiting a few minutes with the engine running at just over 1000 RPM queued behind another aircraft which was refuelling. I didn't even notice it. Immediately after the refuel I went straight to the runup bay for my departure. Lots of good stuff to think about.