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Technam Crash in Mason, Mi.


Runtoeat

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I was talking to the local Rotax repair guy today and he said that a Tecnam crashed this September at the Mason, MI airport (KTEW). The plane apparently lost power during takeoff and made an emergency landing in a soybean field. The Rotax guy was asked by the FAA to travel to the crash scene and assist the FAA in determing why the engine quit. The engine was a Rotax 912 ULS. He said that the carbs had fuel in them, there didn't appear to be any restrictions in any of the fuel filters and the engine could be turned freely by hand. The fuel valves - I believe he said there is one on each side of the cockpit in the Tecnam, were open. There was nothing he or two other experienced Rotax engine mechanics could find that would have caused the engine to quit. He took the ignition system off the crashed Tecnam and installed this on a Remos that was at his airport (Ann Arbor KARB) per FAA's request. The Remos ran fine with the Tecnam ignition.

 

The impact of the forced landing resulted in the landing gear pushing thru the floor of the plane and then striking the pilot', breaking his back and puncturing his lungs. Unfortunately, the pilot passed away as a result of mulitple injuries while in intensive care. He never came out of a coma and therefore couldn't provide any information about the crash. I met this pilot last year at his request to look at my CTSW. He had an older aircraft and he wanted to sell this and buy a LSA. He was interested in the CTSW or CTLS but apparently ended up buying the Tecnam. Perhaps more information will be found after the complete investigation is made by the FAA.

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Farmer Steve, thanks for the report. There only appears to be short newspaper articles such as this but no official FAA accident report. It concerns me this Rotax engine stopped running so suddently and there is no indication why. I'm really hoping that a reason can be found so we all might learn from this unfortunate accident.

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It concerns me this Rotax engine stopped running so suddently and there is no indication why.

 

Tell me about it!

 

Flying out of my home base in the GA mountains, a power failure any time between rotation and about 600' would be serious indeed, with very few options available.

 

Engines rarely fail without some prior indication of something amiss. But it can and does happen.

 

I would caution all about cold weather operation. On a cold engine start, I will see initially high oil pressure indications, only to have it drop very low a short time later, accompanied by the oil pressure light. I've posted about that before, and even found a reference to it in the ROTAX 912 Owner's manual.

 

Here's what it can do while taxiing out, after prior normal indications:

 

5138863363_963dd01d90_z.jpg

 

The pressure comes back up in a minute or two, but I've heard of one emergency after taking off with a cold engine and losing oil pressure.

 

Just be careful out there!

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Ed, I do see your oil temp and oil pressure gages show the needles being being on the left peg and the red light is definitely getting your attention! Our CT's are supposed to have 120F before engine runnup and full power operation. It takes me about 10 minutes at 2400 rpm to get the temp up to 120F on cold weather start ups. Here's where having the Tanis pre-heater would be nice. Do you think that the low oil temp could be causing your low pressure warning? I don't recall ever seeing my oil pressure drop after startup. During flight, I have seen oil pressure drop to low 30's on occasion and then raise back to mid 40's. I have not installed the new Rotax oil pressure relief parts yet. Those red lights are scary!

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Dick,

 

Again, this was taxiing out at a low power setting.

 

I try to have the oil temp at least coming "off the peg" before doing the runup, and at least bisecting the "0" in the "50" (ºC) on the oil temp gauge before takeoff.

 

This is what the ROTAX Owner's Manual says (p. 10-16):

 

"At an engine start with low temperature, continue to observe the oil pressure as it could drop again due to the increased flow resistance in the suction line. The number of revolutions may be only so far increased that the oil pressure remains steady."

 

Other than the odd grammar, that sounds like what I'm experiencing is not unheard of.

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Ed, some more thoughts on your occasional oil pressure drop. I do see that the Rotax manual says that this can occur and it's not unusual to see. But just to compare things, how about type of oil and engine pre-heat? I'm not sure what temps you are presently seeing where live but I'm wondering what type of oil viscosity you're using and if you're pre-heating your oil/engine before startup? Temps here have been low 30F and I am currently seeing 75F oil temp prior to starting using my 100w light bulb hung near the oil reservoir. I also pre-heat my engine with a hair dryer for about 15 minutes while getting things ready to go in the hangar. I am using Mobile 1 full synthetic racing 4T oil (10W-40). I have steam gages but don't ever recall seeing any pressure drops after starting and during warm up and taxi. At start up my pressure is about 50psi and by time of take off I'm at 45psi. During flight I am at 35 to 45psi with occasional drop down to 31psi noted during some flights. Just some data from me - FYI.

 

 

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Hi Guys,

 

There are a few things that could cause this oil pressure fluctuation. 1. a bad sender, 2. a bad connection, 3. a partial ground, 4. a bad gauge and if you haven't done so replace the old style oil pressure regulator cone with the new Rotax parts even if you don't qualify for the 2000 hr. extended TBO. The new parts do make a difference in many engines, but not all will see a change. The only way to help diagnose this issue is to put a mechanical gauge in line and do your taxi or run ups and see if the electrical and mechanical gauges are the same. Usually the oil pressure isn't doing the things the owner thinks. The oil pressure is usually good and it is one of the other problems, but until you try the mechanical gauge in line then you will never know for sure and it is only a guessing game. You need to rule out electrical or mechanical issue.

My bet is a wire connection, bad ground (it can be intermittent) then a bad sender, then regulator ball bearing.

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Roger,

 

Based on my observation, I think my oil pressure really does drop, as warned about in the manual.

 

1) My oil pressure is rock steady at all other times, other than very cold startups

 

2) After the initial drop into the yellow a couple minutes after startup, the pressure reliable begins a slow climb back to normal in step with the increasing water and oil temps. Not the kind of behavior a loose connection or bad sender would normally exhibit.

 

I have not yet replaced the oil pressure regulator cone - maybe its something I'll consider at my annual in December.

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Dick,

 

At the time of the photo the startup had been at below 30ºf and the oil was Pennzoil 20w50 motorcycle oil (dino).

 

I'm now running Aeroshell Sport4 10w40 semi-synthetic.

 

In flight my oil pressure settles down at just over 4 bars and never varies much.

 

I actually have a Red Dragon per-heater that I bought used for my Cirrus but never used. I probably will try it one cold morning, but it doesn't help much if you overnight somewhere without services.

 

5140595943_069132ca8d.jpg

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Ed,

 

Do you use a cowl cover (blanket) when you preheat? Cowl covers make a big difference in the effectiveness of your preheat.

 

I guess I wasn't clear - I haven't actually used the preheater yet. I plan to try it this winter.

 

Thanks for the tip on the cowl covers.

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