View Full Version : Gyro speed record
01-31-2004, 03:16 PM
I have been trying to find the absolute speed record for a gyro.
If you have the info on type, no of seats, engine, ect..... that would be great.
Thanx in advance
01-31-2004, 04:19 PM
The record for a gyro still flying under control .... or one flippling through the air after a PPO? cause I think the PPO one will be faster. The fastest one I know of can get up to about 120
02-02-2004, 02:32 PM
I believe Wing Commander Ken Wallis still holds a closed-course record in the low 130-MPH range, which would suggest peak speed might have beel slightly higher. I don't recall whether that quoted speed was ground speed or airspeed.
02-02-2004, 08:09 PM
Aren't all rotorcraft's limited to the stall speed of the retreating blade?
02-03-2004, 03:33 AM
Yes John that is correct.
That is why Wallis used down to as low as 16' diameter blades for his speed trials. This kept the tip speed of the rotors high enough to stay away from retreating blade stalling longer.
02-03-2004, 08:17 PM
According to Bruce Charnov's book the Navy PA-34 [XOP-2] achieved 144 mph (p. 133).
02-04-2004, 02:31 PM
The Fairy Rotordyne achieved 190.9 mph in 1959 on 90ft diam rotorblades. It was a true gyroplane (only using rotor power to take off and land) although some of the weight at high speed was supported by small wings.
02-05-2004, 08:39 AM
Doesn't a true gyroplane or autogyro have to develope 100% of lift from the rotors? It appears that the Rotordyne, at speed, generate a good bit of lift from the wings, not the rotors.
02-05-2004, 09:38 AM
It was a Russian machine in the late 1930's, probably Kamov, and it clocked around 170 mph.
I will look it up tonight and repost if this is inaccurate.
It looked like a GeeBee racer.
02-05-2004, 10:25 AM
I believe you are correct. If I remember correctly that is basically the plan for the carter copter. The rotors will slow as the machine picks up speed and gains lift from the small stubby "wings". As the machine slows, the rotor will once again speed up and begin to create lift. I am just pulling this from my faulty memory so please correct me if I'm wrong.
02-05-2004, 07:56 PM
So here is my enterance into the gyro speed record. 8)
First, lets take a fiberglass pod and extend it into a sleak, long fuselage. Single seat place a little behind the rotors and the fuel tank on the CG between the pilot and engines.
Two rotors mounted like the Focke Wolf, only lower with small diameter rotors to decrease tip speed. No wings or "Stubbs." This has to be a true autogyro. Fixed pitch rotors or better said, no elevator control, only left and right cyclic control. However, each rotor can pitch fore and aft as needed for yaw control.
A pair of 100hp ducted fan engines mounted close to the nose like the Helio twin courier (except mounted on the fuselage rather than wings). This arrangement will allow for a taildragger configuation to reduce pitching and occillation. Why not, fully retractable taildragger.
Mounted on the keel at the rear of the fuselage, a horizontal stabilizer with 15 degrees dihedral and a speed sensitive elevator (this is your pitch control). At the tips of the horizontal stabilizer, vertical fins 90 degrees with the horizontal. No rudders placed directly behind each fan.
Ron Awad will be the test pilot ;D Although we know that the speed of sound cannot be broken using any kind of rotors of props, Ron will try to come d*mn close.
02-06-2004, 09:10 AM
Can anyone open the doc file I posted above?
02-06-2004, 09:35 AM
It loads fine! I want one!
02-06-2004, 10:36 AM
Older recprecating design that was never built :-[
02-06-2004, 12:31 PM
yeah, but with two ducted fan engines at the nose.
02-10-2004, 05:25 PM
Thanx guys, those were the ones I had scavenged, but could find a table with it on there.
While on the topic of speed, what is the general limiting factor for top speed on a gyro, retreating blade stall? Or is it the power required exceeding power available?
02-10-2004, 07:47 PM
IMHO Since the F-4 Phantom proved that with enough power a brick could fly, I believe you are limited to the stall speed of the retreating blade as with any other rotorcraft.
02-10-2004, 07:59 PM
I'm no expert but I would like to state what I think. If incorrect please be gentle, I'm learning:
I also think, that if you had an arrangement like the picture on page one, the stall speed of the retreating blade is not as critical. With two rotors, they do not have to be as large as a single to lift the same load. With both rotors being smaller in diameter the tip speeds are faster than a rotor of larger diameter. The faster the tips are traveling, the stall speed of the retreating blades are increased. With both of the advancing blades on the outside combined with faster forward velocity decreasing the disc size needed to sustain the load, I belive it is a safer environment to get close to stall speed of the retreating blades. "Full power Mr. Scott."
I may be wrong. Had work out the math on toilet paper.
02-11-2004, 01:29 PM
Yeh, your right there John.
I was unsure if the same rules applied for gyros, it seems they do.
One of the fastest helo ever built was the Sikorsky S-69.
It was known as the ABC (Advancing Blade Concept).
THe layout was a coaxial rotor layout with ridgid blades. Because there is an advancing blade on each side of the helo, RBS can go to hell.
Cant remeber the top speed now, but it was quick.
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