Back Kellett XR-10

Kellett XR-10

When it made its first nights in April 1947 this helicopter was the largest and most powerful designed for the United States Air Force at that time. Like the XR-8, it was of the "synchropter" type with contra-rotating and intermeshing rotors.

The rotors were driven by two engines mounted on nacelles on either side of the fuselage so as to leave the cargo space unobstructed, and cooling was by the flow of air induced through the nacelles. Rotor head linkage allowed the blades to pivot in the horizontal and vertical planes. In the horizontal plane, blade movements were damped by vibration dampers; the position of the blades was a function of the centrifugal force and the loading conditions, but there were, of course, stops to limit these movements. The rotors were synchronized through a cross drive between the upper transmissions.

One special feature of this XH-10 was its ability to fly on one engine with normal gross weight at altitudes of up to 1400 metres.

P.Lambermont "Helicopters and Autogyros of the World", 1958

Kellett XR-10

Technical data for Kellett XR-10

Crew + passengers: 10, engine: 2 x Continental R-975-15 rated at 390kW, main rotor diameter: 19.8m, max take-off weight: 6990kg, empty weight: 4341kg, max speed: 160km/h, cruising speed: 135km/h, range: 240km, endurance: 2h

Kellett XR-10

tpxtozfdmn, e-mail, 12.11.2020reply

Muchas gracias. ?Como puedo iniciar sesion?

Sajesh, e-mail, 11.05.2013reply

Is there any project related to this active now?

silas dittmer, e-mail, 29.08.2010reply

I aggre with jozef about the diagram i just dont get it

Don, e-mail, 19.09.2010reply

Think of the rotors as a set of gears with only 3 teeth each,each tooth going between the other as it turns,,,,,simple,use card board and draw a 3 bladed rotor X2 and cut them out ,hold them in each hand (thumb & index fingers) and hold then close and at an angle as seen in the picture,now turn them like gears,The blades will miss the others and turn on its own axis......

Tony Morris, e-mail, 20.01.2012reply

My father E.B. Morris was a Vice-President for Kellett in 1949 I was taken to the Kellett facility in North Wales Pennsylvania to observe the XH-10 under construction and testing. In addition my father worked with a Czech engineer he was able to bring to Philadelphia after he was liberated by U.S. troops at the end of WW II . His last name was Kadenecy - he was forced to work on V-2 rocket engines by the Germans.

Gordon, e-mail, 29.03.2013reply

Perhaps an USAA mechanic manual of years gone by would go a long eat in understanding the flight concept.....?

mike upton, e-mail, 21.12.2014reply

It looks like a nervous breakdown for a mechanic. And you'd neeneed a very trusting flight crew. Wonder if there is any vidvideo of this thing in flight

H. Wessels, e-mail, 03.08.2009reply

The rotors were synchronized via a cross-drive between the upper transmissions. If one engine failed, the remaining engine drove its own transmission as well as the opposite one, via the cross-drive.

jozsef morrissey, e-mail, 13.03.2009reply

ok im confused in the pictures it appears that the blades intersect. i know on your page it says that the motors were synchronized but i would think that if they were to the extent that the blades were interwoven that would be a characteristic more emphasized but you also state that it could run on one motor witch would not work if the blades did cross for obvious reasons. so i guess i would like an explanation or maybe a diagram witch better depicts the structural design of this machine.

thank you for your time,

Do you have any comments ?

Name   E-mail

Virtual Aircraft Museum

All the World's Rotorcraft