Subject: Combined flight hours
From: "rotaryeng@earthlink.net" <rotaryeng@earthlink.net>
Date: 3/12/2015, 9:21 AM
To: AA-1-Me


Hey group,

Do we have a handle on the combined flight hours in the rotary fleet?

Chris Cosman


You mean since 1973 when the first one flew?


Paul Lamar


Or some point in time that makes sense, like when Everett Hatch or Tracy first flew...

Chris Cosman


Lew Ross flew a Mooney and Dave Garber flew his huff and Puff in the early 70's. Then there was Duncan in Oklahoma selling Mazda conversions.  Everett and Tracy where not the first to fly.

Paul Lamar

I had someone recently question my wisdom for choosing the rotary for my design and told me there weren't very many flying and those that are don't accumulate many hours due to the need to constantly fiddle with them. This gentleman was a proponent of certificated engines. Not having any hard numbers I said nothing at the time.

I would like to give him an answer. So here are my questions:

1.  How many aircraft have flown with a rotary? 2.  Of those how many still have the rotary installed?  Meaning some people swap out the rotary for a certificated engine after becoming frustrated. 3.
About what percentage of installs get past their teething problems in say the first 100 hrs of flight time, not ground run time? 4. How many rotaries are currently flying annual to annual without major issues? I know the experimental crowd likes to fiddle and some will make major changes just cause they feel like it. 5.  What is the highest time install you know of?

These are just some questions I could think of off the top of my head. If you have other data you think is more pertinent I'd like to hear it.

Will Aldridge


1.  How many aircraft have flown with a rotary?

My guess is well over a hundread.

2.  Of those how many still have the rotary installed?  Meaning some people swap out the rotary for a certificated engine after becoming frustrated.

No idea.


3.  About what percentage of installs get past their teething problems in say the first 100 hrs of flight time, not ground run time?

More lately since I wrote the book How to Cool Your Wankel. The major cause of failure in the past was cooling difficulties.

4.  How many rotaries are currently flying annual to annual without major issues?  I know the experimental crowd likes to fiddle and some will make major changes just cause they feel like it.

My guess is dozens.

5.  What is the highest time install you know of?

2500 hours in a gyro copter used for training. Most PP's put about only 50 hours a year or less than 100 hours per year.

A lot of people don't start until retirement age. Projects are some times sold several times before they fly. My over all goal is to cut the time necessary to install a rotary.

We now have a universal  motor mount kit and people to make gear boxes and P-ports.

EFI systems can be bought from multiple sources. IMHO MoTec is the best but expensive http://www.motec.com/

I hope to have an open source simple system soon that anybody can program. One can also use a carb. The 500 CFM 2 barrel Holley is the best IMHO.

Paul Lamar

That was the motivation for my question as well, a very vocal naysayer.  Don't worry, we're still good friends.

If the list is interested, and with Paul's permission, I volunteer to compile rotary flight hour statistics and make them available. This will require some participation by the group of course...

Chris Cosman

Sure but not all flyers are on here. Some have quit flying.

Paul Lamar

Anyone on the list flying a rotary and willing to participate in this contact me at cmcosman@icloud.com <mailto:cmcosman@icloud.com> <mailto:cmcosman@icloud.com <mailto:cmcosman@icloud.com>> <mailto:cmcosman@icloud.com <mailto:cmcosman@icloud.com> <mailto:cmcosman@icloud.com <mailto:cmcosman@icloud.com>> <mailto:cmcosman@icloud.com <mailto:cmcosman@icloud.com> <mailto:cmcosman@icloud.com <mailto:cmcosman@icloud.com>> . Include pertinent things like make, model, FI or carb, redrive ratio, electronic ignition or stock, firewall forward weight if known, flight hours of course, year of your Mazda motor, 1 or 2 rotors.  Other fun facts might be the volume of your radiator, fuel burn @ ___ airspeed, a picture of the plane and another of the install...  or anything else you feel; I'm just the compiler.

Chris Cosman

Chris can your Icloud host a web site?

Paul Lamar

I'm sure they can.  We already have youshouldfly.com <http://youshouldfly.com <http://youshouldfly.com/><http://youshouldfly.com/>. What are you thinking?

Chris Cosman


They sell clouds in Fry's for not much money. That would give me total control my being a control freq :) Save money in the long run.

I assume there are permissions involved.


Paul Lamar

Has the newsletter been shut down temporarily?  I haven't received any mail since Feb 21.

Chris Cosman


No. I am still in Germany.  I demonstrated the new High RPM multi spark ignition to Wankel Ag, AIXRO and PVL.
Then I will be in Washington DC for a few days.
Good email is hard to find in Germany. Best is McDonald's.

Back soon.

Paul Lamar

I've got a bit over 100 hours on my plane, it's bee flying for 5 years now, initially some problems with the CAS being wired backwards, but other than that, it's been pretty much trouble free. I keep the plane in Everett, Wa, and have been to Medford Ore twice, Walla Walla once, Roslyn, Wa, the San Juan Islands many times, the Olympic Peninsula, and tons of sightseeing. The plane has cooled well since day one. My oil and coolant run between 170- 200 degrees f.


My only real concern is the exhaust temps, I used  .125 thick 308 SS for the first 12 inches of the exhaust, then inconel for the next 40 inches or so , and then the rest is 321 ss. I have  V-band clamps about 20 inches downstream of my exhaust ports and the bands are always a bit loose due to the extreme heat and so there is a bit of exhaust leakage inside my engine cowl. I use a few scoops to ram air through my cowl to keep  dilute the exhaust gases there and temps down, but my next maintenance item is to see if I can remove the V-band and just weld the joints so that there are no joints to leak exhaust gases. I'll have to evaluate whether or not this is possible, or if this would make it impossible to then install the exhaust system, it then being one unit. I also have incorporated a bellows flex joint just downstream of where the two headers join.

Brian Trubee

I have put together a collage of pictures Brian has sent me over the years and some I took.
The cowl is all aluminium and Brian is a real artist with an English wheel.

Brian, is the Coax muffler still working?
http://www.rotaryeng.net/coax.html

Paul Lamar    in VA. Soon to be back in CA.



My biggest concern at this point is that I have 2 2" v band clamps holding the headers to the rest of the exhaust system about 18 inches downstream from the exhaust ports. Due to heating expansion from the exhaust, the clamps are always just a little loose, not enough for the pipes to come apart, but loose enough for there to be exhaust inside the engine cowl. I've provided enough ventilation inside the engine compartment and heat shielded everything from the exhaust pipes, but I don't like the idea of exhaust gases inside my engine compartment at all. I don't think it would be possible to weld up the exhaust system so that it would be in one piece- it would be impossible to install at that point.  Still looking to improve upon this.....


Brian Trubee

Since it is 18 inches down (cooler)  there is some braided flex exhaust pipe that could be used.  Get a friend to use a hand held infra red temp gun and measure the temp at that point when your are running up at static RPM.

Here is one from harbour freight.

Paul Lamar



You might take a look at Larry Vettermans site, he uses this type fastener (photo attached).
http://vettermanexhaust.com/

Harold Lunt


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