AR-1 accident final report from NTSB N11TG

[Resasi]

A glowing endorsement for my choice of power plant.

 

[Tyger]

I came across this today, on aviation carburetors (although not the Rotax kind):

Carburetors: Surprisingly Reliable

A part of airplanes since there was dirt, your carb should last through engine TBO with regular inspections and occasional tweaks.

www.avweb.com

 

[Abid]

I came across this today, on aviation carburetors (although not the Rotax kind):

Carburetors: Surprisingly Reliable

A part of airplanes since there was dirt, your carb should last through engine TBO with regular inspections and occasional tweaks.

www.avweb.com

Rotax Carbs are Bing and Made in Germany. Like all German cars they break down. No one tell that to my wife who bought a VW ID4 but its made in Tennessee
They could not figure out how to make the floats for 5 years there and instead of floats had sinkers half the time. In the meantime there are good products like

Rotax®/Bing Blue Epoxy Float Set of Two - MS80-430 | Marvel-Schebler Aircraft Carburetors

Why Choose Rotax Epoxy Floats to Solve Your Carburetor Problem?

In the past, there always seemed to be an issue with floats. Now Rotax Epoxy Floats are here without the problems of past floats for airplane carburetors.

www.airpowerinc.com

available and finally when Rotax started using a UK company to make the floats instead of Bing, they solved the 5 year problem.
In my experience all fuel pumps on all iS engines as well as 914UL engines made in 2020 (starting with serial number 20. are also junk. They all stop working in the first 2 hours. Fortunately you find that out right during warm up and not in the air. Every single 915iS I put out that had 20.xx serial number fuel pumps all had to have the fuel pumps replaced. The ones starting with 21.xx are ok and ones before 20.xx (from 2018, 2019) are also good.

 

[Loren Jones]

In my experience all fuel pumps on all iS engines as well as 914UL engines made in 2020 (starting with serial number 20. are also junk. They all stop working in the first 2 hours. Fortunately you find that out right during warm up and not in the air. Every single 915iS I put out that had 20.xx serial number fuel pumps all had to have the fuel pumps replaced. The ones starting with 21.xx are ok and ones before 20.xx (from 2018, 2019) are also good.

Is that date stamped on the stainless steel housing the pumps are in, or do you have to get to the individual pumps to check the date?

 

[Greg Vos]

Is that date stamped on the stainless steel housing the pumps are in, or do you have to get to the individual pumps to check the date?

I recently replaced both pumps on my xenon not based on the 1000 hours usage. I did it based on the maintenance schedule saying 1000 hours or 5 years ….what an expensive exercise the pump numbers come on the casing on the box and on the documentation for recording in the airframe log book

pic of supplier invoice reflecting pump numbers
a point worth noting, the new pumps are smaller, the small gauss filter found in the entry of the older pumps does not fit in the new ones, the electrical connections ate different and do not use a brass nut on a brass thread with a star washer they use a water proof connector and one needs a tool for that to crimp the cables ( just a heads up to those who are thinking about replacing pumps)

 

[Andino]

There was no water found in the fuel tank or the left carb bowl, correct? Hmmm, quite a poser. My hunch is that both carbs had some water introduced to them, but the left side evaporated it more successfully (perhaps because of the turbo's close proximity, but its radiant heat has been accused of insufficiency for that).

Nevertheless, a gyro engine-out should rarely be a lethal emergency, and it's lamentable that the pilot was routinely flying low altitude over a forest.

 

[PJB]

Rotax Carbs are Bing and Made in Germany. Like all German cars they break down. No one tell that to my wife who bought a VW ID4 but its made in Tennessee
They could not figure out how to make the floats for 5 years there and instead of floats had sinkers half the time. In the meantime there are good products like

Rotax®/Bing Blue Epoxy Float Set of Two - MS80-430 | Marvel-Schebler Aircraft Carburetors

Why Choose Rotax Epoxy Floats to Solve Your Carburetor Problem?

In the past, there always seemed to be an issue with floats. Now Rotax Epoxy Floats are here without the problems of past floats for airplane carburetors.

www.airpowerinc.com

available and finally when Rotax started using a UK company to make the floats instead of Bing, they solved the 5 year problem.
In my experience all fuel pumps on all iS engines as well as 914UL engines made in 2020 (starting with serial number 20. are also junk. They all stop working in the first 2 hours. Fortunately you find that out right during warm up and not in the air. Every single 915iS I put out that had 20.xx serial number fuel pumps all had to have the fuel pumps replaced. The ones starting with 21.xx are ok and ones before 20.xx (from 2018, 2019) are also good.

That is good information. Is there no service bulletin from Rotax for the same??

 

[WaspAir]

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

 

[MikeBoyette]

I don’t understand why Rotax uses the far superior designed Mikuni carburetors. They use them on their two stroke sled engines. I wonder if it’s the same reason they use the lesser quality Bosch ignition. I heard Denso will not allow them to use their ignition on any aircraft engines for fear of being shark/lawyer bait.

 

[georgio744]

That is good information. Is there no service bulletin from Rotax for the same??

ROTAX Carburetor Floats Identification

A MANDATORY Bulletin has been issued for a range of 912, 914, and 2-stroke engines , or engines equipped with ROTAX 861185 and/or 861188 floats during repair

www.rotax-owner.com

 

[DavePA11]

I recently replaced both pumps on my xenon not based on the 1000 hours usage. I did it based on the maintenance schedule saying 1000 hours or 5 years ….what an expensive exercise the pump numbers come on the casing on the box and on the documentation for recording in the airframe log book

pic of supplier invoice reflecting pump numbers
a point worth noting, the new pumps are smaller, the small gauss filter found in the entry of the older pumps does not fit in the new ones, the electrical connections ate different and do not use a brass nut on a brass thread with a star washer they use a water proof connector and one needs a tool for that to crimp the cables ( just a heads up to those who are thinking about replacing pumps)

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

 

[Vance]

I don’t understand why Rotax uses the far superior designed Mikuni carburetors. They use them on their two stroke sled engines. I wonder if it’s the same reason they use the lesser quality Bosch ignition. I heard Denso will not allow them to use their ignition on any aircraft engines for fear of being shark/lawyer bait.

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.

 

[500e]

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.

 

[Mci]

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 instru

 

[PJB]

ROTAX Carburetor Floats Identification

A MANDATORY Bulletin has been issued for a range of 912, 914, and 2-stroke engines , or engines equipped with ROTAX 861185 and/or 861188 floats during repair

www.rotax-owner.com

Thanks - so question (and it is a question because I don’t know) how / why if this is from the engine manufacturer can this be a factor??

 

[Abid]

There was no water found in the fuel tank or the left carb bowl, correct? Hmmm, quite a poser. My hunch is that both carbs had some water introduced to them, but the left side evaporated it more successfully (perhaps because of the turbo's close proximity, but its radiant heat has been accused of insufficiency for that).

Nevertheless, a gyro engine-out should rarely be a lethal emergency, and it's lamentable that the pilot was routinely flying low altitude over a forest.

I think he would have flown high if he could. The problem was he was caught in low ceilings MVFR and had to fly low. Unfortunately, that combined with contaminated fuel at the exact wrong time got him. A lot of gyroplane pilots fly very low. I mean like 500 feet AGL. I find that that is not quite safe for going anywhere besides staying right around your airport.

 

[Vance]

When I was a Harley Davidson Dealer in Santa Maria I would call about a particular challenge like the gas eating the Sportster inlet manifolds and they would tell me I was the only dealer who ever had this problem.

I would make them aware of another nearby dealer who had this problem and they would tell me it was only in California.

I had dealer friends all over the country so that didn’t fly either.

Eventually they would get around to fixing the problem.

It is traditional for the manufacturer to blame the dealer and then the customer for unanticipated problems.

I don’t think Rotax is any worse than other manufactures.

 

[Andino]

I think he would have flown high if he could. The problem was he was caught in low ceilings MVFR and had to fly low. Unfortunately, that combined with contaminated fuel at the exact wrong time got him

If low ceilings would prevent me from a sufficient altitude to glide past unlandable terrain...then I just stay in the pattern.

MVFR has a habit of turning into SVFR and then IFR. I once foolishly chanced a 50 mile gyro x/c leg in SVFR which by the time I arrived at the controlled airport was approaching IFR minimums. I landed and stopped right on the numbers, and a few minutes later the airport was below IFR mins. Even in a gyro, don't mess about with low ceilings!

 

[PJB]

When I was a Harley Davidson Dealer in Santa Maria I would call about a particular challenge like the gas eating the Sportster inlet manifolds and they would tell me I was the only dealer who ever had this problem.

I would make them aware of another nearby dealer who had this problem and they would tell me it was only in California.

I had dealer friends all over the country so that didn’t fly either.

Eventually they would get around to fixing the problem.

It is traditional for the manufacturer to blame the dealer and then the customer for unanticipated problems.

I don’t think Rotax is any worse than other manufactures.

I hear you, although with flying you kind of expect some element of understanding given with a Harley (or any other road going kit that goes INOP) it’s likely nothing more than inconvenient and an early Coca Cola. Slightly different when you’re airborne.

AutoGyro UK were exactly the same “oh no we have never seen that before… you’re the first one with xyz issue…”

Yet here was that Rotax bulletin before or after this crash??

 

[Abid]

Thanks - so question (and it is a question because I don’t know) how / why if this is from the engine manufacturer can this be a factor??

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.