Work well and glow pretty nice at night.

Because they're not diesels. A single-stage centrifugal compressor can already give you sea-level MP up to ~20,000 feet and cruise power into the mid-20s. A compound turbo could maybe double that but what would be the point? You could use it to increase sea-level MP, but to prevent detonation in a gas engine you'd have to reduce compression ratio, which hurts efficiency. A diesel can effectively use much higher MP so a compound turbo can make sense.

This actually has been done, for some extreme high-altitude planes, mostly UAVs. The manned piston aircraft altitude record of over 60,000 feet is held by the Grob Strato 2C using a two-stage compound turbo on TCM 550s. The unmanned piston record is held by the Boeing Condor, with a two-stage compound turbo on TCM 300s. But the prize for complexity must go to the NASA Perseus B with a three-stage(!) compound turbo, a total of four turbos feeding a Rotax 912. It maintained sea-level horsepower to over 60,000 feet.

The safety of escrow has come up a few times here. From the Raptor fan FB page today:Another posted that he did get a refund but it took more than 6 weeks AND calls to executives at escrow.com threatening them with his personal contacts at FBI's Internet Fraud division.

There was recently an interesting Reddit thread on that; including an interview with the pilot. The pilot speaks about how complicated the supercharging was.

https://www.reddit.com/r/WeirdWings/com ... older_for/

Listening to the interview is definitely worth 30 minutes of your time.

Cool story about the Grob!

Not surprising to hear that- engine handling (acceleration and deceleration) with jet engines with two spool compressors is complicated enough (which is why a lot of GE engines have variable stator vanes in their compressors, which is a different solution that it also complicated), three spools even more so. There's a lot more to it than just putting more gas in and the shafts spin faster- the spool up and spool down at different speeds from each other, so each one is either trying to draw more air than it should or less than it should, compared to the others.

I haven't watched any of the videos until recently. She's a porkly girl at almost 3200 lbs. Also, 800 lbs static thrust. Isn't that kind of low? I thought I saw tests with a C172 that put out that much static thrust.

https://medium.com/@RaptorAircraft/succ ... bbf40792ff

Way low. We get a little over #1000 in a super cub with an IO-390. My 150hp Super cub and Catto pulled #658. #800 isn’t gonna move that pig.

If I get time I’ll do a pull test on my TSIO-550. 350hp.

Seems like with doors open and cowl removed that would effect thrust?

I am sure there are still lots of details that need to be worked out on that engine and prop set up. I have never seen a project like this not have issues that are unknown at first.

Mike

I want to see cruise thrust figures before I dismiss the static thrust number. A small diameter prop generally makes a good cruiser but a poor takeoff prop.

Michael, good point about the conditions of the static thrust test.

800lbs static thrust for a 3,200lb airplane is low though.

We should do a drawing on guessing what TAS he gets out of her. I don't think the engine has been dynoed to see what the real horsepower number with the current setup.

We should do a drawing on guessing what TAS he gets out of her. I don't think the engine has been dynoed to see what the real horsepower number with the current setup.

Price is Right rules...... you can’t go over.

If the horsepower is up there where it should be, I could see 220 knot cruise.

I think we should do a drawing to see if it is even going to fly...
Reminds me of a Rutan wanna be... But can he deliver?
Lots of very high and not realistic numbers... Just to get some sucker to invest.
He has some really impossible claims to back up.
Who knows... Maybe he is that big of a genius.
Gravity is not the same for flat earth believers.