Saunders-Roe Princess

infobox Aircraft
name = SR.45 Princess
type = flying boat airliner
manufacturer = Saunders-Roe



caption = Saunders-Roe Princess "G-ALUN"
designer =
first flight = 22 August 1952
introduced =
retired =
status =
primary user =
more users =
produced =
number built = 3
unit cost =
developed from =
variants with their own articles =

The Saunders-Roe Princess was a British flying boat aircraft built by Saunders-Roe, based in Cowes on the Isle of Wight. The "Princess" was one of the largest aircraft in existence.

By the 1950s, large, commercial flying boats were being overshadowed by land-based aircraft. Factors such as runway and airport improvements added to the viability of land-based aircraft, which did not have the weight and drag of the boat hulls on seaplanes nor the issues with seawater corrosion.

Design and development

The "Princess" was powered by ten Bristol Proteus turboprop engines, powering six propellers. The four inner propellers were double, contra-rotating propellers driven by a twin version of the Proteus, the "Bristol Coupled Proteus"; each engine drove one of the propellers. The two outer propellers were single and powered by single engines.

The rounded, bulbous, 'double-bubble' fuselage contained two passenger decks, with room for 105 passengers in great comfort.

The prototype, "G-ALUN", first flew on 22 August 1952 and was flown by test pilot Geoffrey Tyson. It was the only one to fly - making 46 test flights in total, about 100 hours flying time. It appeared at the Farnborough Airshow [Flying Boats of the Solent. Norman Hull.ISBN 1-85794-161-6] . Two others ("G-ALUO" and "G-ALUP") were built, but they never flew. After spending a number of years in mothballs , two at Calshot Spit, awaiting further use, NASA considered using the fleet as heavy-duty freight aircraft for transporting Saturn V rocket components. The nascent Airbus consortium thought of using two for transporting A300 fusealage sections, but opted to use Super Guppies instead. All three Princesses were broken up in 1967.

They were the last fixed-wing commercial aircraft produced by Saunders-Roe. The company built one more fixed-wing design, the Saunders-Roe SR.53 mixed powered (rocket and turbojet) fighter design; aside from that, the company concentrated on helicopters and hovercraft after this point.

Saunders-Roe developed the world's first practical fly-by-wire system for the Princess. Whilst the prototype aircraft had advanced (but conventional) hydraulic controls, S-R intended for production aircraft to use an analogue system based around electrical servos with hydraulic final control actuators. Such a system was built and ground-tested, but the Princess project was cancelled before any aircraft was fitted with the system. The knowledge gained from work on this system was fed into the development of the Avro Vulcan bomber, which became the first aircraft to be fitted with fly-by-wire.

pecifications

aircraft specifications
plane or copter?=plane
jet or prop?=prop
ref=British Aircraft Directory [ [http://www.britishaircraft.co.uk/aircraftpage.php?ID=134 British Aircraft Directory] ]
crew=2 pilots, 2 flight engineers, radio operator and navigator
capacity=105 passengers in tourist and first class cabins
payload main=
payload alt=
length main= 148 ft
length alt=42.1 m
span main=219 ft 6 in [With wingtip floats retracted ] http://www.aviastar.org/air/england/saunders_princess.php] ]
span alt=66.9 m
height main=55 ft 9 in
height alt=17 m
area main= 5,019 sq ft
area alt= 466 m²
airfoil=
empty weight main= 190,000 lb
empty weight alt= 86,184 kg
loaded weight main=
loaded weight alt=
useful load main=
useful load alt=
max takeoff weight main= 345,025 lb
max takeoff weight alt= 156,500 kg
more general=
engine (prop)=Bristol Proteus
type of prop=turboprop
number of props=10
power main= 3,200 hp
power alt=2,386 kW
power original=
propeller or rotor?=propeller
propellers=4 bladed
propeller diameter main=16 ft 6 in
number of propellers per engine=1
max speed main= 380 mph
max speed alt= 579 km/h
cruise speed main= 360 mph
cruise speed alt=
cruise speed more=at 37,000 ft
stall speed main=
stall speed alt=
never exceed speed main=
never exceed speed alt=
range main= 5,720 miles
range alt= 9,205 km
ceiling main= 39,000 ft
ceiling alt= 11,887 m
climb rate main= 1,900 ft/min
climb rate alt= 579 m/min
climb rate more =at sea level
loading main=
loading alt=
thrust/weight=
power/mass main=
power/mass alt=
more performance=
armament=
avionics=

ee also

aircontent
see also=
related=
similar aircraft=
sequence=
lists=
*List of seaplanes and flying boats

References

External links

* [http://www.britishaircraft.co.uk/aircraftpage.php?ID=134 British Aircraft Directory entry]
* [http://www.seawings.co.uk/ sea wings flying boat site includes a walkround gallery of images]
* [http://www.seawings.co.uk/saroprinwalk.htm]