Welcome to The online forum and website of the Helio Aircraft Association, Inc.

Main Menu

Mistral is still hanging in there.

Started by Gerald Jordan, April 16, 2010, 08:39:54 AM

Previous topic - Next topic

Gerald Jordan

I just came across this on the Mistral site.

16 June 2011
Since march 2011 Mistral Engines has restarted the FAA certification program of the G-300 rotary aircraft engine.
Economical constraints are now behind us thanks to the arrival of a new main shareholder.
A press release will be issued in a few days.

Doug Johnson

I believe the rotary has the best chance of succeeding. Especially if they  direct injection, turbo compounding and a fadec single lever engine prop control system in the works.

Whats the Latest? Maybe I'm asking to soon its only been a week since you posted this.


Gerald Jordan

It looks like they did what they said they would.  They have found a new investor and have started the certification process again.
I hope for the moment they keep on track and finish the certification before they start working to hard on the Kerosene version. Although the kerosene multi fuel version would be welcome, I would like to see something that could replace the GO-435s and GO-480 engines. The G-300 and G-360-TS turbo version is closest at the moment.
I feel that the low price of the Helio's at the moment is the fear people have of the geared engines. We all don't feel the same as new would be Helio owners. As far as myself I like the quirkiness of running these old engines well and believe they could make it past TBO every time.
I believe one of the problems with the geared engines in the Helios is the CSTOL label on the plane. Everybody wants to go from slow idle to full throttle too quickly. This is fine if you don't mind the TBO not being achieved. Most pilots wouldn't come up on the power so fast on a non geared engine but in the Helio people like the do the short takeoff even when it isn't necessary.
These are my own feelings only and I don't mind being corrected.


March 1, 2011, Mistral resumed his activities, albeit in a modest, but sufficient way to consolidate gains and prepare the ground for a full resumption of operations. A first group of key engineers, all former Mistral employees, are back to work. The FAA certification of Mistral’s G300 engine has resumed and shall be completed by next year.
The company would like to thank all those who expressed their support and encouragement during this “chapter 11” period. The market appreciation we received and the global interest for Mistral’s technology greatly helped cheering up the Board’s morale. Mr Claude Geles, President of Mistral, said “We don’t give up easily and we don’t take no for an answer. There would be a way to get Mistral back in business, it just took us some time to find it”.
Mistral’s rescue has been made possible thanks to Mr Robert Herrmann, a business man and a private pilot, who read once an article about the company and decided something had to be done. “Everyone in the industry understands the benefits of Mistral’s technology. I found the risk/reward ratio quite favorable and decided to bring this financial spark that would start the venture again.”, said Mr Herrmann.
As soon as adequate financing will be secured, Mistral will also resume the development of the Kerosene version which is strongly expected by the market.

Doug Johnson

I believe from what I've been reading that all individually owned general aviation aircraft sales are depressed because of fuel concerns, both cost and availability, noise restrictions, airport restrictions, the new and friendlier FAA restrictions, the lack of interest by young people, and the list goes on.

I think we need the new engine more for fuel concerns than anything and the fact that Lycoming no longer supports the GO-435/480/540 engines and we are running out of parts, and there are certain things against the turbo prop, acquisition cost and  fuel burn at low altitude are only a couple.

My biggest concern with the rotary is the noise, if you've ever heard an unmuffled rotary engine you'll know what I'm talking about. I think noise pollution is going to become a legitimate concern sooner than we like.

I suspect the G-360-TS turbo version will be quieter, but I believe a turbo compounded version would be quieter yet and more fuel efficient. 

Another reason to hope for a new engine is the fact that David Maytag tried the radial and the turboprop and couldn't seem to come up with something that would sell. But Maytag was trying to start a new Piper or Cessna  which will never happen the Helio is too much of a specialty aircraft and needs a little Mom Pop factory selling at best 10 or 12 airplanes a year and making parts.

I believe Stephen has already said this last part but it needs to be repeated  until a certain someone hears and comprehends.

Just my opinion. What is  yours? Anyone?


Gerald Jordan

The noise problem was being addressed with a muffler. One of the original test beds (I think a Cherokee) was flying and the muffler had a melt down, collapsed and blocked the exhaust gasses.
It was investigated and found there was no problem with the engine other than pushing a lot of heat out the exhaust.

07 June 2008
On Tuesday morning, 3rd of June, our test pilot, Mr Stephen Roth, took off for a first one-hour flight that went flawlessly. He landed at Palatka’s Kay Larkin Field Airport, Florida, to refuel. Pre-take-off checks were normal and so was take-off. On initial climb, however, the engine started to lose power while still running perfectly smoothly. The pilot performed a 180° turn to return to the airport. The loss of power increased, and the pilot was unable to maintain altitude.
He landed the plane under control and at minimal airspeed in a wooded area to avoid buildings and houses. The wings were sheared off, one of them staying in a tree, and the fuselage fell sideways onto the ground. Coming to his rescue, two courageous citizens helped him out of the cockpit conscious and unharmed. There was no post-crash fire, only smoke from engine coolant leaking onto the heat exhaust.
MISTRAL Engines is extremely happy and most relieved to announce that Stephen Roth suffers only from minor cuts and bruises. After a thorough check in the hospital, which proved to be short, he was released and able to go back to the site to contribute to the beginning FAA enquiry.
MISTRAL Engines immediately dispatched to the site Mr Gordon Anderson, its Chief Operating Officer. On Thursday 5th of June, Mr Anderson, Mr Roth and the FAA investigator inspected the plane’s wreckage as well as the whole engine data log which was retrieved entirely uncompromised from MISTRAL’s proprietary Digital Engine Management (DEM) system.
It was quickly evident that all engine parameters were normal from the moment of take-off to the moment of the accident, with the exception of abnormally low propeller RPM. The cause of the power loss was subsequently found in the failure of the internals of the exhaust system’s muffler, obstructing the free flow of exhaust gases from the engine.
This particular muffler was a temporary and experimental solution developed and manufactured by a third party, which was planned to be replaced this coming summer by a certifiable unit, developed in-house. The FAA, acting on behalf of the NTSB1, retained the muffler in order to conduct flow tests.
A preliminary report, downloadble in PDF version here below, was produced by MISTRAL Engines. A final company report will be issued after further analysis of the engine is conducted at MISTRAL’s facility in Geneva.
After its pilot emerging unscarred from this mishap, MISTRAL is extremely relieved that its technology is proven uninvolved in the cause of the accident and that, through the innovative data logging capability of its DEM system, it was able to significantly contribute to a prompt and thorough determination of the causes.
MISTRAL Engines is in the process of acquiring a new airframe to resume its flight testing programme as soon as possible, and the type certification programme of its G-300 engine model continues unhindered.
1 NTSB : National Transportation Safety Board

Full report here.


Doug Johnson

Seems to me that unless they come up with a bullet proof muffler system they'll need to come up with a bypass. like the alternate air for a blocked air inlet on an injected engine.

I'd still like to see them put that heat noise and pressure to work by turbo compounding. Maybe that will come later.




Another interesting engine that was in developement but must have flopped is the Nagel 444 twelve cylinder opposed. It has relatively small pistons-3"bore and 3"stroke. I can't find any recent info on it but was at Oshkosh in 2003. It had liquid cooled heads similar to a Rotax.  Should have low vibration since it has 12 small cylinders. Rated at 450hp@4400 rpm with the prop running at 2200 on the camshaft similar to a Continental Tiara- although I think it should be an odd number on the gearing because of harmful resonance.  One of the good points about it is that its using long tie bolts through the crankcase to secure each set of opposing cylinders taking a lot of stress off the crankcase. Not sure if the opposing cylinders fire simultaneously. Its weight was close to 540 Lycoming giving it a very good power to weight ratio. Anybody know where to find out more about it?   Paul



Can anyone tell me the current status of the Mistral company and how far it is to FAA certification? Does anyone have any info on the mysterious Mr Robert Herrmann?
I may have an interest in investing.

Dr Chris Ohms PhD


To the guy inquiring about complete chiropractic, dr chiro, duigan chiropractic, back alignment near me, spieles chiropractic, good chiropractor, foot chiropractor, complete chiro, whole health chiropractic, precisely chiropractic, frontier chiropractic, a chiropractor, namaste chiropractic, sport and spine chiropractic, clear chiropractic, hip adjustment, spine care chiropractic, female chiropractor, richmond chiropractic, chiro adjustment,  I can vouch for this top Poundbury chiropractor url for upper cervical, chiro clinic, total chiropractic, mckinney chiropractor, back to back chiro, westman chiropractic, 614 chiropractic, went to chiropractor now pain is worse, duigan chiropractic, advanced chiro, quiropractico near me, essential chiropractic, accident chiropractic, spinal adjustment, best chiropractor, vivo chiropractic, first chiropractic adjustment, o neill chiropractic, subluxation chiropractic, lux chiropractic, also. See More Top Ideas For Choosing Software Download 289f5b2