Sikorsky Telescoping Rotor Aircraft (TRAC) projects

[hesham]

Sikorsky TRAC variable-diameter rotor (c1970).

 

[Triton]

Artist's impression of Sikorsky TRAC (Telescoping Rotor Aircraft)

Rotor system in which the rotor diameter could be decreased up to 60%. TRAC system intended to be applied to any VTOL that uses rotors for lift (i.e. compound helicopter and tiltrotor). In this design, the rotors would tilt for horizontal flight and then fold into nacelles. Turbofans would take over for cruise.

Characteristics:

• Cruise Speed: 500 mph (740 km/h)
• Capacity: 90 seats
• Range: 550 miles
• Wing span: 78 ft
• Length: 101 ft
• Height: 34 ft
• Maximum Take-off weight: 122,750 lbs.
• Payload: 35,000 lbs.

Source:
http://www.aiaa.org/tc/vstol/unbuilt/
"Straight Up and Away" Flying Review International. May 1969: 52-53

 

[hesham]

The Sikorsky TRAC variants,


http://www.dtic.mil/dtic/tr/fulltext/u2/a023448.pdf

 

[hesham]

And;

 

[jsport]

Wow, awesome, thank you sir.

 

[Stingray]

Far out. Thanks, Hesham!

 

[hesham]

Hi,

http://archive.aviationweek.com/image/spread/19680624/44/2/zoom

 

[Bazinga]

I took some time to reassemble the pics from this http://www.dtic.mil/dtic/tr/fulltext/u2/a023448.pdf url and here it is more visible what the difs are.

 

[yasotay]

Thank you for taking the time to make the reassembled pictures.