Hell Is Spending Two Months In A Cessna That Never Lands

[nittany03]

There's a company that's been working to get a Corvette engine certified in a C-172. They've been flying it for several years and it's apparently been bulletproof. It burns auto fuel, gets better fuel burn, and has more power. Unfortunately the FAA has been dragging their feet and won't return phone calls now.

I’m told there are several RVs flying around with rotary conversions out of RX-7s and RX-8s.

 

[nittany03]

It’s just not a priority for them, and it’s not a simple “approved” stamp for something like this. The FAA is frequently overtasked with other work and “whistle blower” calls, and there isn’t enough money in the piston market for manufacturers to push for certification of a new engine (which is major $$$ and time).

Honestly, auto engines are heavy, complex, and not designed to be operated at a significant fraction of their available horsepower continuously for most of their life. I’m skeptical that- as designed- they could be anything but a novelty for GA.

Liquid-cooled and/or diesel engines designed for aviation on the other hand…I think there’s decent potential there, it just needs (a lot) of R&D and certification cash, and the new piston sales market remains pretty small.

It would be interesting to do an overall empirical analysis of the regulatory burden on the GA market to find out what oversight ensures safety of flight and what is just waste.

 

[sevenhelmet]

It would be interesting to do an overall empirical analysis of the regulatory burden on the GA market to find out what oversight ensures safety of flight and what is just waste.

Ask any five OEM test pilots and you’ll get 10 opinions. ?‍♂️

 

[Griz882]

Yep. I agree. Jet A is a cleaner solution- there just aren’t many certified diesels out there yet. I think piston aviation is in for a rough time, unfortunately.

Sad, but true.

 

[taxi1]

Hell Is Spending Two Months In A Cessna That Never Lands​

Reminds me of the time we were riding the chairlift up after my friend had ditched his girlfriend to ski the extra hard/fun stuff with me, and there she was at the top of the chairlift, arms crossed, look of death on her face, waiting for him.

He’d still be riding that chairlift now if he could have.

 

[Gatordev]

Honestly, auto engines are heavy, complex, and not designed to be operated at a significant fraction of their available horsepower continuously for most of their life. I’m skeptical that- as designed- they could be anything but a novelty for GA.

Historically that's been a problem. The particular example I mentioned has gone much farther than the experimental one-offs apparently. They've been using it for flight instruction and long-hauls to wring it out. You're right, it is heavier, but it's also making more power. I finally found the link with the latest update here.

It looks like they have dealt with the long-standing issue of operating continuously by down-rating the engine, I'm assuming to make it run at a lower power rating (and thereby RPM). They've also worked hard at making the electronic engine controls easy to diagnose remotely, as well as deal with issues of Mogas at altitude.

I understand your point about it being a novelty now, but if something like this were to get approved now, as people rebuild their engines, these certified options could start to come into the market.

LL avgas is doomed. Diesel/Jet A recips Is the only way forward. Anything else is too risky and/or too costly.

It will be interesting to see how quickly GAMA and Swift can get their products to the market as a whole. Swift is starting to show up. It would be nice if the FAA could spare a little time to certify the engine mentioned above as well as continue to focus on the 94/100 UL options.

But I don’t think all the big bangers have an STC available.

Not just STC availability, but capabilities of the engine. The O-300 can accept Mogas, but the O-320s and above have too high a compression for it to make power. (My very un-mechanical description of the problem).

I think piston aviation is in for a rough time, unfortunately.

I agree, and not just because of fuel.