So, if not Super Sonic, might it have been moving "Ahead.....Warp Speed"?

On the Canadian Harvard Aircraft Association website it says "The 9 foot propeller is powered by a massive radial engine causing the propeller tips to go supersonic causing an unforgettable roar."

CHAA

The third entry in the second section states how propellers go supersonic - Aerospaceweb.org

I believe those fellas on the Harvard site are stretching it a little bit, that 'massive' engine is a 600 hp 9 cylinder radial engine used in trainers, a 'massive' engine would be something like an 18 cylinder radial engine producing 2,500 hp or even the 28 cylinder R4360 used in bombers and transports. I have a lot of time with the same engine they are calling 'massive' and 'massive' is far from what most in our industry would call an R1340.

The current turbine engines I fly now and have thousands of hours behind are turning 39,000 rpm and have a gear reduction transmission that turns the propller a maximum of 2,200 rpm so that it won't go faster than transonic for the reasons I stated above.

I have NO idea, Rick. I just enjoy searching and learning .

Cam see if you can find some FAA sites and the mechanics of aircraft propulsion, it can get complicated due to the fine window of keeping propeller driven aircraft within the limits of transonic speeds. The only reason we have never seen a propeller driven plane go supersonic is because of the limitations of the propeller, not the plane or engine!

Mark is right, we all need a Warp-Speed button!

Hi Rick,

I did a little digging and the fixed wing version I was thinking of was called the NA-64. Would like to figure out how to get a chance to fly a P47 though.

Man wouldn't we all love to get some P47 time! You know if you ever make it down our way I can get you hooked up in a two seat side by side turbine ag plane flight in an Air Tractor 504 (http://www.airtractor.com/aircraft/504), I think you'll really enjoy it!

When will we be expecting you?

I couldn't find anything published by the FAA, but I found this interesting article from the American Institute of Aeronautics and Astronautics. It mentions the P-47 among others - link.

I've never pretended to understand the aerodynamic properties of rotor craft - it's all magic to me. Our training program included old movies of helo blades taken from the rotor hub out along the length of the blade. After watching the gyrations of a blade while it rotates in flight makes me wonder why I ever continued flying them! There must be some of those types of videos on YouTube & are worth a view.

Rotor blades are subject to enough torture as it is, without subjecting them to supersonic speeds at the blade tips, although they do come close. In those days, blades were made of metal & subject to fatigue due to constant flexing, corrosion & eventual failure if not changed out after so many hours. In fact our unit lost a CH113A Voyageur & crew during a night training trip on base due to a metal blade failure causing catastrophic disintegration of the helo at 500 feet. I had flown that particular machine in the morning & afternoon flights & it came apart that evening - not my time I guess. Today, blades are all composite materials & are much stronger & safer.

The Huey's characteristic sound was from 2 quite wide (chordwise) blades that really compressed the air when coming head on. I heard a 3-ship approaching one day on a cold prairie winter morning at about -35C - the sound was absolutely surreal - reminding me of the 'Apocalypse Now' soundtrack but at extreme levels. It was really quite amazing & I don't think that most HTs could adequately reproduce that awesome sound in all its glory (unless there were a couple of EP800s involved, ha!)...

TAM