The Blackburn Perth was a British flying boat which was in service during the interwar period.
It was essentially an upgraded Iris, and hence the largest flying-boat to serve with the Royal Air Force at the time and was the largest biplane flying boat ever to serve with the RAF.
The Blackburn R.B.3A Perth was designed as a replacement for the earlier Iris to Air Ministry Specification 20/32.
Developed from the Iris Mk. V, the Perth first flew in 1933.
It differed from the Iris by replacing the Rolls-Royce Condor engines of the Iris by more powerful Rolls-Royce Buzzards and having an enclosed cockpit for the pilots.
Unusually, in addition to its normal armament, the Perth was fitted with a Coventry Ordnance Works C.O.W 37 mm (1.46 in) auto cannon in its bows.
Four Perth’s were ordered for service for the RAF.
The Perth entered service with the RAF in January 1934, when the second aircraft was delivered to No. 209 Squadron RAF at RAF Mount Batten Plymouth.
Perth’s remained in service until 1937, being replaced by the Short Singapore and the Saro London.
One aircraft was retained by the Marine Aircraft Experimental Establishment until 1938.
Specifications
Crew
5
Length
70 ft 0 in (21.34 m)
Wingspan
97 ft 0 in (29.57 m)
Height
26 ft 5.5 in (8.065 m)
Wing area
2,461 sq ft (228.6 m2)
Empty weight
20,927 lb (9,492 kg)
Gross weight
32,500 lb (14,742 kg)
Max take-off weight
38,000 lb (17,237 kg)
Powerplant
3 × Rolls-Royce Buzzard II MS V-12 water-cooled piston engines,
825 hp (615 kW) each
Propellers
2-bladed fixed-pitch propellers
Performance
Maximum speed
132 mph (212 km/h, 115 kn)
Cruise speed
109 mph (175 km/h, 95 kn)
Range
1,300 mi (2,100 km, 1,100 nmi)
Service ceiling
11,500 ft (3,500 m)
Rate of climb
800 ft/min (4.1 m/s)
Wing loading
13.2 lb/sq ft (64 kg/m2)
Power/mass
0.076 hp/lb (0.125 kW/kg)
Armament
Guns
1 × C.O.W 37 mm (1.46 in) automatic cannon in bow
3 × .303 in (7.7 mm) Lewis guns in bow, amidships and tail positions
