Armstrong Whitworth AW.681

Infobox Aircraft
name=AW.681 / HS.681


caption=Manufacturer's model of the AW.681
type=Projected VTOL Military transport
manufacturer= Hawker Siddeley
designer=
first flight=
introduced=
retired=
status=Project cancelled January avyear|1965
primary user=
more users=
produced=
number built=
variants with their own articles=The Armstrong Whitworth AW.681, also known as the Whitworth Gloster 681 or Hawker Siddeley HS.681, was a projected British long-range STOL military transport aircraft design by Armstrong Whitworth Aircraft and was to be capable of development to VTOL performance. The AW.681 was designed to meet the NATO specification BMR-4.

Design and development

To meet Royal Air Force Operation Requirement 351 to specification C.241, Armstrong Whitworths design was selected. [cite journal
title=Whitworth Gloster 681
date=1963-03-14
journal=Flight International
pages=p.361
url=http://www.flightglobal.com/pdfarchive/view/1963/1963%20-%200379.html
accessdate=2008-10-08]

The aircraft featured a swept shoulder mounted wing and a high T-tail. The rear fuselage was upswept with loading doors and a ramp. Four Rolls-Royce RB.142 Medway engines with vectored thrust nozzles were to be mounted on pylons under the wings which were to feature boundary layer control with blown flaps, leading edges, and ailerons. The Medway engines would have given STOL performance only. The use of an additional 18 RB.162-64 lift engines (6,000 lb, 26.7 kN each) or replacement of the Medways with four Bristol Siddeley Pegasus ducted flow turbofans was proposed to obtain VTOL capability. The Pegasus 5-6 would have been rated at around 18,000 lb. [ [http://www.harrier.org.uk/history/pegasus.htm Pegasus engine variants] ]

The project was under development for the Royal Air Force when it was cancelled in January 1965. [cite book
last=Taylor
first=John W.R.
title=The Lore of Flight
publisher=Universal Books
location=London
year=1990
isbn=0-9509620-15
pages=p.348]

pecifications (proposed STOL)

aircraft specifications
plane or copter?=plane
jet or prop?=jet
ref=Fact|date=May 2008
crew=
capacity=
payload main=
payload alt=
length main= 31.75
length alt=102 ft 2 in
span main=40.84
span alt=134 ft
height main=11.53 m
height alt=37 ft 10 in
area main=
area alt=
airfoil=
empty weight main=
empty weight alt=
loaded weight main=
loaded weight alt=
useful load main=
useful load alt=
max takeoff weight main=
max takeoff weight alt=
more general=
engine (jet)=Rolls-Royce Medway
type of jet=turbofan with thrust deflection
number of jets=4
thrust main= 61.3 kN
thrust alt= 13,790 lb
thrust original=
afterburning thrust main=
afterburning thrust alt=
thrust more=
max speed main=Mach 0.71
max speed alt=
max speed more=above 7,620 m
cruise speed main=
cruise speed alt=
cruise speed more
stall speed main=
stall speed alt=
never exceed speed main=
never exceed speed alt=
range main= 7,725 km
range alt=
ferry range main=
ferry range alt=
ferry range more=
ceiling main= 7,620 m
ceiling alt=
climb rate main=
climb rate alt=
loading main=
loading alt=
thrust/weight=
power/mass main=
power/mass alt=
more performance=
armament=
avionics=

ee also

aircontent
see also=
related=
similar aircraft=
* Boeing YC-14
* Dornier Do 31
* McDonnell Douglas YC-15
lists=

References

External links