FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1953
1953 - 1133.PDF
Bristol 171 EQUIPPED to carry a pilot and four passengers, the Bristol 171 Mk 3A has recently earned the distinction of being the first British heli copter to enter airline service. Two are being used by B.E.A. on regular cargo flights, and passenger services are imminent—including, possibly, a shuttle service between London Airport and the Waterloo Air Terminal. Military versions, differing in detail fittings but having in common the name Sycamore, are serving with the Army, R.A.F. and Royal Australian Navy. Civil and military models alike are powered by the reliable Alvis Leonides (550 h.p.), which gives a cruising speed of 106 m.p.h. and initial rate of climb of l,000ft/min. A slightly lower cruising speed of 91 m.p.h. gives the best range performance—270 miles at sea level on 65 gallons of fuel with a payload of over 700 lb. High rotor-speed is an important feature of the Bristol 1»71: the kinetic energy thus stored in the blades is a safeguard against the effects of engine failure, whatever the height or aircraft-speed. Flight instruments are driven off the main rotor, and would continue to function in the event of engine failure. Bristol 173 THE success of preliminary tests with the prototype 173 is starting to reward Bristol's ambitious attempt to produce a helicopter possessing real "airliner" characteristics. These include comfortable seating for 13 passengers and the reassuring knowledge that sustained flight is possible in the event of complete failure of one engine. A synchro nizing shaft between the two 550 h.p. Alvis Leonides ensures that both turn at the same speed and enables one engine to drive both rotors if the other fails. Like the 171, the bigger helicopter has a high rotor speed; it is capable of full autorotation with both engines out. Apart from possible military applications, the Type 173 is likely to be used extensively by B.E.A. as part of the airline's long-term development programme. After tests with the second prototype Mk 2, B.E.A. hope to introduce a small number of Mk 3s powered by 870 h.p. Leonides Majors and fitted with stub wings to relieve rotor-load (and thus increase cruising speed from 113 m.p.h. to nearly 140 m.p.h.). Carrying 14 passengers and baggage, this version would be capable of operating a 190 mile stage-length.
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
