AR-1 accident final report from NTSB N11TG

[Aerofoam]

I never heard such stories about BMW motorcycles with Bing carbs.

I had a mid 80's BMW R65 LS ya know, the kinda, sort of, sport bike that was the red headed step child of the B-mer family.....
The left Bing carb (Low side parked, USA) would always drip when parked, even a little with the petcock closed.
I rebuilt it chasing this issue 2 times in a year and finally just did what the former owner did, which was put a piece of cardboard under it
when parked.....

 

[Aerofoam]

Had a water condensation problem on a Schweizer 300 first flight, did walk around then sump test all OK no water did internal checks 1/2 tanks of fuel, only 15 min flight ran up no problem mag checks OK, lifted off 3/400Ft silence managed to put it down no damage.
Would not start, anyhow did sump test again WATER!! wtf. looked in tank condensation still on sides above fuel.
Long shot I wonder if there was condensation above float level.
Always look inside tanks now as well as sump.

I have seen a fuel tank in a boat that had condensed water drops clinging to the underside of the flat top surface
of the tank. This could explain the sumps being fine until the engine vibration and movement shook them loose and they
formed a larger pool in the bottom of the tank. But it doesn't explain only one carb. being effected...

 

[Greg Vos]

Interesting. They have three people check and sign the order… Must have sent the wrong parts to someone in the past…

Aircraft parts are well regulated in SA and our local suppliers are very diligent in the supply process, one may not even under NTCA fit parts or make modification without it being approved by an AP, if it’s a mod, supporting document to our CAA along with there prescribed fee needs to be paid and submitted with records updated in the airframe log book. In this case Comet the supplier also handles TCA replacement parts and I’m assuming the same checks and balances apply to any order for dispatch.

 

[Abid]

I have seen a fuel tank in a boat that had condensed water drops clinging to the underside of the flat top surface
of the tank. This could explain the sumps being fine until the engine vibration and movement shook them loose and they
formed a larger pool in the bottom of the tank. But it doesn't explain only one carb. being effected...

That’s an interesting thought. We do haveAluminum fuel tanks bit so do thousands of airplanes in the US.
It is possible that water went to both carbs but somehow one carb ate it up and the other got a bit more water and it didn’t. The fuel pickup is 1 inch above the bottom where fuel is sumped. I would have expected a little water remaining at the very bottom of the header tank.

 

[MikeBoyette]

It is my understanding from a friend in the motorcycle business; Mikuni Corporation does not want their carburetors on man carrying aircraft because of potential law suits.

I figured.

 

[500e]

Have seen condensation in top of float chambers on Weber carbs.

 

[Resasi]

There is no way the fuel economy on iS is 30% more. Also not even 20 %. I have 100+ hours in the same aircraft with both. It’s closer to 15% for airplanes when flying cross country at 6000 feet or above. It’s less when lower than that.

Thanks Abid, nothing like an actual report from a user.

 

[Resasi]

Even in a gyro, don't mess about with low ceilings!

Can echo that. Am IFR rated and done enough hairy low viz approaches when down to absolute minimums.

I have never had the privilege to fly in any machine that has been equipped with zero zero Autoland, but do know through experience that with fog, how quickly it comes in, how dense it can be, and the minimal chance one would have even in a fully instrumented gyro of maintaining control.

 

[PJB]

Do you mean if this mandatory service bulletin is a factor in this fatal accident? The engine was supplied by Rotax past the time of release of this bulletin and usually newer engines would have previous bulletins either complied with or not applicable as the factory changed the parts or process right at the time of assembly. As I remember this engine already had the new floats.

So whilst the conversation around the same, as interesting as it is, will be unrelated - or if related a new service bulletin might be inbound?

 

[Abid]

So whilst the conversation around the same, as interesting as it is, will be unrelated - or if related a new service bulletin might be inbound?

I do not believe a new bulletin from Rotax is coming regarding carb floats at this point. The newest floats made in the UK seem to be performing well.

 

[Henry_GyroLife]

Ben...You nailed it! I have watched gyro videos over solid wooded areas
..over stretches of water, over miles of urban areas with wires like spider webs...and that engine better keep running. My gyro instructor drilled into my head not to fly over anything I could not glide out of if my engine ever quit. I had 1 forced landing in an ultralight, 17 in a gyro...and 2 in a helicopter. I thanked myself in the mirror each time for that instruction.

17 in gyro ? That sounds a lot. What kind engine and assume they happened in stretched years.

 

[MikeBoyette]

17 in gyro ? That sounds a lot. What kind engine and assume they happened in stretched years.

I don’t know for a fact but I would be willing to bet most were in a Mac powered Bensen. I didn’t ever have the pleasure of flying one but they only had one guarantee that was it will quit. This is one reason my Dad who was also one of my instructors pounded deadstick landings in my head. He did this with every student he had. This was due to his own experience learning to fly his Mac powered Bensen. He had 35 engine outs in his first 50 hours of flying. He said the first time he landed with the engine running he couldn’t figure out what that noise was. Then he realized it was the Mac and it was still alive. This way of training is probably looked at as old and outdated because of the reliability of Rotax 2 and 4 stroke engines. I have had two complete engine failures and my gear box becoming detached from the crank shaft. Each time I made a perfect landing. I always landed with my engine at an idle. This was accompanied with never flying over anything I can’t land or or glide past. I also use the rule of thumb if you’re low you better be fast however, altitude is a better friend than just airspeed. I’m afraid that with the proliferation of the Eurotubs and their treatment of their machines as if they were fixed wing machines with blades that some of the important lessons we all learned are being lost.

 

[500e]

Sounds the same as the way autos in helicopters are taught now, powered recovery above ground.
Auto to the ground is different and auto in reality with no power at all is different again.
Flying over forest and big towns at lowish level not good
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[loftus]

If I remember right he had told me that he used gas from a local gas station in Deland. Maybe a seven eleven gas station or something. He also owned a Tecnam and used the same gas in it.

I think I have experienced what you did in the Cavalon in another 914. I suspect that is vapor lock not carb ice. Cavalon engine cowling did not facilitate cooling specially if you went to low power setting for a while.

The fact that you had a hot carb and a cooler one is interesting though.

Tony had just moved into the hangar across from me shortly before the accident. Super nice guy. I expect he was using Ethanol free 91 Octane gas available at a fuel depot right next to the airport. The next closest Ethanol free is 87 at a Wawa. I think we also already had Swift Fuel at the Deland Airport at that time. Swift is pricey unfortunately, but runs much cleaner than either 100LL or available Ethanol free Mogas. 100 hour oil changes are normal on Swiftfuel.

 

[Abid]

Tony had just moved into the hangar across from me shortly before the accident. Super nice guy. I expect he was using Ethanol free 91 Octane gas available at a fuel depot right next to the airport. The next closest Ethanol free is 87 at a Wawa. I think we also already had Swift Fuel at the Deland Airport at that time. Swift is pricey unfortunately, but runs much cleaner than either 100LL or available Ethanol free Mogas. 100 hour oil changes are normal on Swiftfuel.

I think I remember Tony having gerry cans in his hanger. I used his hanger at Deland during one of the Deland Expos and saw those cans there. He must have been using that gas station gas instead of Swift fuel at Deland.