MOSAIC and Repairman Work with Experimentals (from Kid wants to fly thread)

[knot4u]

Until an E-AB jet takes down a something bug, I think E-AB will thrive in the shadows. Thankfully, with few exceptions, E-AB’s crash for the same reasons GA aircraft crash.

My dad built a Dragonfly that I did my best to destroy and I built a Mini-500 (with a friend) and a Team HiMax.

A Mini-500? Was that endeavor successful? Is it still flying and what engine did your friend put in it? I like helicopters, believe it or not at one point rotary wing machines were my bread and butter long before I started working on jets. I don't think I would've ever gotten involved with a Mini-500, those things are dangerous.

 

[Pilot Fighter]

A Mini-500? Was that endeavor successful? Is it still flying and what engine did your friend put in it? I like helicopters, believe it or not at one point rotary wing machines were my bread and butter long before I started working on jets. I don't think I would've ever gotten involved with a Mini-500, those things are dangerous.

Deep breath.

I could type for hours on the subjects of Augusto Cicare, Revolution Helicopters, Dennis Fetters, Heli-Sport, CH-6, Mini-500, and CH-7.

My buddy had a Solar APU and acquired a partially-assembled Mini-500 kit. He planned on eventually mating the two.

He never installed the Solar but did finish and fly the 500 about 75 hours. It had a donkey-load of design and QA issues. My buddy was an A/P and thought he was the perfect guy for a Mini-500, a 150lb pilot and A/P with a couple hundred hours of rotary time.

The CH-6, Mini-500, and original CH-7 had 582’s. Surprisingly, the CH-6 and CH-7 had pretty good luck with the 582. Better quality control and 150lb pilots. Dennis Fetters (Revolution) stole the CH-6 design after his deal with Cicare fell apart. The same thing happened with Heli-Sport and Cicare. Heli-Sport had success with the 582 CH-7 but eventually gave it a larger engine.

So, I think it’s fair to say the Mini-500 was dangerous because it was unless you were a 150lb experienced pilot that was also a mechanic with experience with high-performance two-stroke engines.

More than half the fatalities followed engine failures and the inability of low-time pilots to effectively execute an auto-rotation with a very low-inertia rotor system .

 

[knot4u]

Deep breath.

I could type for hours on the subjects of Augusto Cicare, Revolution Helicopters, Dennis Fetters, Heli-Sport, CH-6, Mini-500, and CH-7.

My buddy had a Solar APU and acquired a partially-assembled Mini-500 kit. He planned on eventually mating the two.

He never installed the Solar but did finish and fly the 500 about 75 hours. It had a donkey-load of design and QA issues. My buddy was an A/P and thought he was the perfect guy for a Mini-500, a 150lb pilot and A/P with a couple hundred hours of rotary time.

The CH-6, Mini-500, and original CH-7 had 582’s. Surprisingly, the CH-6 and CH-7 had pretty good luck with the 582. Better quality control and 150lb pilots. Dennis Fetters (Revolution) stole the CH-6 design after his deal with Cicare fell apart. The same thing happened with Heli-Sport and Cicare. Heli-Sport had success with the 582 CH-7 but eventually gave it a larger engine.

So, I think it’s fair to say the Mini-500 was dangerous because it was unless you were a 150lb experienced pilot that was also a mechanic with experience with high-performance two-stroke engines.

More than half the fatalities followed engine failures and the inability of low-time pilots to effectively execute an auto-rotation with a very low-inertia rotor system .

Thanks for the reply. Maybe there's a bunch of Mini-500s flying in heaven. I'd wager many of the builders wanted to paint their project like the Magnum P.I. helicopter but modesty and finances precluded it. Oddly enough my first helicopter ride was in a MD-500 on floats, painted like the Magnum helicopter, out of Long Beach in 1983. My dad knew I loved helicopters and it was my 6th grade graduation gift. Still remember it like yesterday.

 

[Pilot Fighter]

Until an E-AB jet takes down a something bug …

I meant to type “something big”, “a something bug” communicated the same thing with a humorous twist.

 

[GolfChuck]

If you park an RV next to a certified aircraft like a mooney or cessna of similar construction, you realize it is completely over-built and thus forgiving of mistakes, both in build and flight. Some of these fringe experimentals, not so much. And usually when an experimental crashes it is due to the same things that kill other light piston pilots. When it's not, it's usually at least partially caused by a deviation from the plans (John Denver comes to mind). Popular kits and plans built airplanes are popular for a reason.

 

[killbilly]

If you park an RV next to a certified aircraft like a mooney or cessna of similar construction, you realize it is completely over-built and thus forgiving of mistakes, both in build and flight. Some of these fringe experimentals, not so much. And usually when an experimental crashes it is due to the same things that kill other light piston pilots. When it's not, it's usually at least partially caused by a deviation from the plans (John Denver comes to mind). Popular kits and plans built airplanes are popular for a reason.

I gotta admit that this thread (and several others) have gotten my interest in flying an EAB and/or building one really, really piqued. I miss spending my afternoons in the hangar tinkering with my airplane, learning stuff, and solving vexing problems with tribal knowledge from the internet and Aircraft Spruce and a very well-worn credit card.

Alas, my circumstances in life right now do not permit this. At all. But it doesn't stop me from looking. And while my father's shop down in SRQ is absolutely perfect for this sort of project, living down there doesn't work for me right now, nor do I have the financial wherewithal.

Yet I keep looking.

And now that my time-building/XC needs are long since met, I've had my eye on a Kitfox.

The prices have gone up on them, like everything else. A nicely-optioned kit with a mid-size Rotax is probably going to run you the near side of what an RV-8 would have cost pre-COVID, which is a bit disheartening, but I do love the idea of flying something light and low with the doors off. Folding wings are just gravy on the potatoes, and it's a well-proven design.

 

[knot4u]

Deep breath.

I could type for hours on the subjects of Augusto Cicare, Revolution Helicopters, Dennis Fetters, Heli-Sport, CH-6, Mini-500, and CH-7.

My buddy had a Solar APU and acquired a partially-assembled Mini-500 kit. He planned on eventually mating the two.

He never installed the Solar but did finish and fly the 500 about 75 hours. It had a donkey-load of design and QA issues. My buddy was an A/P and thought he was the perfect guy for a Mini-500, a 150lb pilot and A/P with a couple hundred hours of rotary time.

The CH-6, Mini-500, and original CH-7 had 582’s. Surprisingly, the CH-6 and CH-7 had pretty good luck with the 582. Better quality control and 150lb pilots. Dennis Fetters (Revolution) stole the CH-6 design after his deal with Cicare fell apart. The same thing happened with Heli-Sport and Cicare. Heli-Sport had success with the 582 CH-7 but eventually gave it a larger engine.

So, I think it’s fair to say the Mini-500 was dangerous because it was unless you were a 150lb experienced pilot that was also a mechanic with experience with high-performance two-stroke engines.

More than half the fatalities followed engine failures and the inability of low-time pilots to effectively execute an auto-rotation with a very low-inertia rotor system .

I was thinking about this post and it got me contemplating about using an APU as the engine in a home built helicopter. Has anyone done this successfully? I have no intention of building a helicopter, I'm just curious.

 

[Pilot Fighter]

I was thinking about this post and it got me contemplating about using an APU as the engine in a home built helicopter. Has anyone done this successfully? I have no intention of building a helicopter, I'm just curious.

Yes! The Solar turbine has been been a popular powerplant in a number of experimental helicopters. There was one guy that was installing them in Mini-500’s until he was sued by the Revolution owner.

 

[knot4u]

Yes! The Solar turbine has been been a popular powerplant in a number of experimental helicopters. There was one guy that was installing them in Mini-500’s until he was sued by the Revolution owner.

Did they have to modify them? IMHE APUs are built to run at 100% RPM all of the time with a fairly steady load (mainly a torque load from an alternator) and are designed to accept changes in bleed air loads (obviously more of a temp rather than torque load). Because they're built to basically run independently they monitor themselves and will shut down if any parameter is exceeded, this is not ideal in a helicopter. So the question(s) is how to modify an APU to operate it without the nanny and put that responsibility on the pilot, does the gearbox get modified? If it works is it a bad idea? Like I said your post got me pondering, I want no part in any of this nonsense, I'm just curious. You can get an Allison 250 fairly cheap, why reinvent the wheel?

 

[Pilot Fighter]

Did they have to modify them? IMHE APUs are built to run at 100% RPM all of the time with a fairly steady load (mainly a torque load from an alternator) and are designed to accept changes in bleed air loads (obviously more of a temp rather than torque load). Because they're built to basically run independently they monitor themselves and will shut down if any parameter is exceeded, this is not ideal in a helicopter. So the question(s) is how to modify an APU to operate it without the nanny and put that responsibility on the pilot, does the gearbox get modified? If it works is it a bad idea? Like I said your post got me pondering, I want no part in any of this nonsense, I'm just curious. You can get an Allison 250 fairly cheap, why reinvent the wheel?

Google “Solar T62 experimental helicopters”,
It’s a well-sorted solution but I don’t know many technical details.

With the 582 experimentals, they pretty much run at a constant rpm, I think this might be the case for certified piston helicopters.

The Mini-500 was under-powered and one big issue with owners was the factory sanctioning running the 582 at 104% continuously. Revolution designed a PEP kit (tuned exhaust) that helped but if you were over 170lbs it struggled to hover.

In defense of Revolution, many owners threw their kits together quickly and didn’t properly balance the rotors or address other vibration issues. Half the units experienced frame cracking.

 

[knot4u]

Google “Solar T62 experimental helicopters”,
It’s a well-sorted solution but I don’t know many technical details.

With the 582 experimentals, they pretty much run at a constant rpm, I think this might be the case for certified piston helicopters.

The Mini-500 was under-powered and one big issue with owners was the factory sanctioning running the 582 at 104% continuously. Revolution designed a PEP kit (tuned exhaust) that helped but if you were over 170lbs it struggled to hover.

In defense of Revolution, many owners threw their kits together quickly and didn’t properly balance the rotors or address other vibration issues. Half the units experienced frame cracking.

I appreciate your response but I'm not going to search for anything that involves experimental helicopters, I don't need that in my algorithm.