Accident and defect

[Thruster88]

I just renewed my rego for the Corby and while I was on the RAAus site I thought I would look at the accident statistics reported.

8 reported this month with absolutely no details.

An interesting one this month made me wonder.

An Evector Sportstar had a partial engine failure. Managed to land safely off field and checked engine. Nothing found, so pilot overnighted and continued on way next morning.

What I wonder is what caused the partial engine failure? Has RAAus looked into it? Was it a good decision to continue, with an engine which had partially failed without a known reason? Did the pilot have an idea of what the reason was and if so why wasn't it in the report.

I have an idea of what the reason could be, but was it correctly handled and reported?

 

Yes that one had me thinking if I was involved in any management position in RAAus I would not be letting this type of garbage report appear on the web site.

[Old Koreelah]

I think that was the incident that led to the demand for a chronometer, which sparked a fight between John Harrison and one of my ancestors.

Can you tell us that story, Turbs?

[facthunter]

He will have to find the time first. Nev

[facthunter]

If a thruster is flying too slow it doesn't do much except MUSH. Some of those descriptions of flight conditions are really" er-WOT?" moments. Just an aggregation of somewhat unconnected facts. What matters is how much weight was in the plane? How good was the engine and prop combo and the skins (fabric tension).? Was the plane capable of flight under the conditions? Nev

[walrus]

Sir Cloudesly Shovell was the Admiral that had the amateur navigator hanged. He drowned when the fleet hit the Scillys - poetic justice in 1707.

[Downunder]

An Evector Sportstar had a partial engine failure. Managed to land safely off field and checked engine. Nothing found, so pilot overnighted and continued on way next morning.

What I wonder is what caused the partial engine failure? Has RAAus looked into it? Was it a good decision to continue, with an engine which had partially failed without a known reason? Did the pilot have an idea of what the reason was and if so why wasn't it in the report.

I have an idea of what the reason could be, but was it correctly handled and reported?

The engine lost power to idle soon after take off from a strip it had landed and stopped at, a short time previously.

An experienced Rotax L2 looked at the aircraft before it was flown home. The engine ran fine and did not exibit any problems.

The flight home and subsequent engine runs were all ok.

The loss of power was put down to vapour lock. It is assumed heat soak from a freshly shut down engine heated the fuel and components.

[Yenn]

That info ought to be on the RAAus website. It would provide something of value instead of the rubbish that they did post.

[Bruce Tuncks]

That Roco ( Rotax engine ) plane which had to have a coolant leak fixed at William Creek has another $20,000 problem. There is damage around the nose-leg attachment which indicates probably a heavy landing. Nobody has come forward to claim it ( the landing ) as their own however.

So far it is not doing as well as the Jabirus. A light air-cooled engine and a glass airframe are hard to beat cost-wise.

[Flightrite]

That Roco ( Rotax engine ) plane which had to have a coolant leak fixed at William Creek has another $20,000 problem. There is damage around the nose-leg attachment which indicates probably a heavy landing. Nobody has come forward to claim it ( the landing ) as their own however.

So far it is not doing as well as the Jabirus. A light air-cooled engine and a glass airframe are hard to beat cost-wise.

 

I remember seeing that busted plane at Willy Creek late last year under some trees. Rotax engine have a good name but the risks of something going wrong are greater especially out in the boon docks! As a side note there was an RV7 there with RA rego, hmmmmmmm?

[KRviator]

As a side note there was an RV7 there with RA rego, hmmmmmmm?

You can get -7's and -9's onto the RAAus register, but then they are very niche machines, essentially, single-seat high-speed cross-country or medium-range 1+1 aircraft. I've just transferred my RV-9A from RAAus toVH to make full use of its' payload and take the KRviatrix, not just Mini-Me flying...

[Flightrite]

A typical 7 would be around 470-500 kg?, 600 MTOW in RA ya wanna be stick thin with every 2nd molecule removed from the fuel!??

[KRviator]

A typical 7 would be around 470-500 kg?, 600 MTOW in RA ya wanna be stick thin with every 2nd molecule removed from the fuel!

981.5Lbs / 445Kg BEW for my RV-9A, but that was before autopilot servos and wheelpants. 450Kg after. Still, a 150Kg payload, less 80Kg of pilot gave enough fuel for a Sydney-Brisbane flight or a 2 hour local junket with Mini-Me. I could have got a bunch more if I hadn't stuck an O-340 in it! At least on VH- now I can take 2 adults, AND fuel!

[Flightrite]

981.5Lbs / 445Kg BEW for my RV-9A, but that was before autopilot servos and wheelpants. 450Kg after. Still, a 150Kg payload, less 80Kg of pilot gave enough fuel for a Sydney-Brisbane flight or a 2 hour local junket with Mini-Me. I could have got a bunch more if I hadn't stuck an O-340 in it! At least on VH- now I can take 2 adults, AND fuel!

I was more ref to a 7. A lot of Aussies are fat! Typical for an Aussie more like 90-110kg? The Vans machines are very capable, could never understand why anyone would limit their ability like that? The best Vans (in my opinion) is the 8, proper conventional u/c of course.???

[M61A1]

The best Vans (in my opinion) is the 8, proper conventional u/c of course.

Shame they don't have a "Hard on" emoticon...... I've seen some damn nice RV8s, a bit out of my budget at this time though.

[Flightrite]

Shame they don't have a "Hard on" emoticon...... I've seen some damn nice RV8s, a bit out of my budget at this time though.

A real mans 8, fighter like interior/controls?

[Blueadventures]

The engine lost power to idle soon after take off from a strip it had landed and stopped at, a short time previously.

An experienced Rotax L2 looked at the aircraft before it was flown home. The engine ran fine and did not exibit any problems.

The flight home and subsequent engine runs were all ok.

The loss of power was put down to vapour lock. It is assumed heat soak from a freshly shut down engine heated the fuel and components.

Is it known if it was fitted with the fuel restriction / return line back to the fuel tank as that aides in eliminating vapour lock situations?

[Downunder]

Is it known if it was fitted with the fuel restriction / return line back to the fuel tank as that aides in eliminating vapour lock situations?

I believe it did have the return but the engine may not have been ground run long enough to clear vapour.....before take off.

And/or perhaps the the return system (1mm orifice?) was unable to handle WOT/full fuel flow.

[KRviator]

And/or perhaps the the return system (1mm orifice?) was unable to handle WOT/full fuel flow.

The maximum flow through the return line would be at ground idle, wouldn't it? At full power, most would be consumed by the engine??

[Flightrite]

There's zillions of these Rotax engines around the world, can't be too much of a problem vapour lock surely?

[Thruster88]

I believe it did have the return but the engine may not have been ground run long enough to clear vapour.....before take off.

And/or perhaps the the return system (1mm orifice?) was unable to handle WOT/full fuel flow.

The maximum flow through the return line would be at ground idle, wouldn't it? At full power, most would be consumed by the engine??

 

Fuel flow through the return orifice will be constant regardless of engine speed or power, only fuel pressure will effect flow rate. Fuel pressure is produced by the spring in the fuel pump and should not change with engine speed or power. The engine fuel pump is designed to deliver flow in excess of the 28.5 lph required at full power on a 912 100hp while maintaining required (5.8psi) pressure. Any drop in pressure at high power needs investigating.

 

Fuel quality especially vapour pressure of ULP is something to consider. In cars this is never a problem now with fuel injection. In tank fuel pumps pushing around 60, sixty psi through the system combined with return flow eliminates the problem of vapour lock.

[M61A1]

There's zillions of these Rotax engines around the world, can't be too much of a problem vapour lock surely?

It depends on the installation. some of the European designs do not have the Rotax recommended return line which isn't such a big deal in cooler climates. Some that do have them only return back to the gascolator so that their fuel flow meter will work.

There are many possibilities with this sort of event. Possibly took off with out the boost pump on, or had the fuel selector off, which will give you just enough to get airbourne if you a starting from hot and have a very short taxi to the strip, or just serious heat soak. The Sportstar is tightly cowled. An acquaintance has a different aircraft with close cowling and he can't run mogas even with return lines because of poor exhaust design which heats the float bowls on the carbs excessively at high power settings.

There are many possibilities here, usually to do with the installation and not so much the engine itself.

[Keith Page]

Rules

 

Are

 

Accasional

 

?

Would you say.

"Rafferty's" ?

[JEM]

I recall an Alpha years ago with persistant power loss after takeoff AFAIK Turned out to be a blocked muffler.

[Downunder]

There's zillions of these Rotax engines around the world, can't be too much of a problem vapour lock surely?

I believe low wings are more of a problem as fuel needs to be "sucked" up from the wing tanks. An electric pump at the tank or below the tank level in the fuse is one solution, producing positive pressure from the electric to the engine pump.

Vapour lock being created by not only heat but also pressure (negative pressure, suction, primarily ). High heat + low pressure = bad.

A high wing with a free flowing hose may already give 1 to 2 psi static head pressure so it is ahead of the game in this respect.

Edited July 30, 2020 by Downunder