Saro A.27 London
In
1928 a Supermarine Southampton was flown with an experimental weight
saving hull. This designated A.14 and had been designed and built by
Saunders-Roe. Successful testing of this aircraft encouraged design in
1930 of the Saro A.7 Severn, a military flying boat of sesquiplane
configuration that incorporated an almost identical hull and had a
powerplant of three 485 hp (362 kW) Bristol Jupiter IX radial engines.
Its performance was better the twin engine Southamptons and comparable
with the three engined Southampton X but, presumably because the
Supermarine aircraft were already in production for the Royal Air
Force, no orders were received for the Saro A.7 Severn. With the issue
of Air Ministry Specification R.24/31 for a coastal patrol flying boat
Saunders-Roe designated the A.27 London which, of similar
configuration and only slightly smaller in size than the A.7 Severn
from which it was developed. The prototype London flew for the first
time in 1934 and the type was ordered into production in the following
March. Deliveries began in 1936 and the first 10 aircraft were
designated London Mk Is. Construction Nos 11 to 48 (the final
production London) were all London Mk IIs, which differed in having
915 hp (682 kW) Bristol Pegasus X engines driving four-bladed
propellers, in place of the London Mk I's 820 hp (611 kW) Pegasus III
engines with two-bladed propellers.
First service
deliveries, between April and September 1936, were to No. 201
Squadron, replacing Supermarine Southamptons at Calshot with further
batches delivered in October 1936 to No. 204 Squadron at Mount Batten,
Plymouth, also replacing Southamptons. More were delivered to the same
squadron at Mount Batten the following year to replace Blackbum Perths,
and in 1938 the London Mk IIs supplanted Supermarine Scapas of No. 202
Squadron in Malta.
No.204 Squadron used
five Londons on a long-distance training flight to New South Wales,
Australia and back between December 1937 and May 1938. They were
fitted with exteral overload tanks to increase thier range to 2,600
miles (4184 km).
Between the two World
Wars the flying-boat reigned supreme for coastal patrol work with the
RAF, and the Saro London, together with its contemporary, the
Supermarine Stranraer, were the last of the biplane flying-boats to
see service before replacement by the Short Sunderland. Twenty-nine
Londons were still in service at the outbreak of World War II.
Nos. 201, 202, and 240
squadrons were still operating Londons in first-line service at the
outbreak of World War II, flying patrols over the Straits of Gibraltar
and the North Sea. They were eventually retired early in 1941 when
they were replaced by the Consolidated Catalina . At this time a
number of the Londons were transferred to the Royal Canadian Air
Force.
Variants
Saro A.27 London Mk I
- Two 820 hp (611 kW) Pegasus III radial engines driving a two blade
propeller. 10 aircraft were built, and all were later converted to the
Mk II standard.
Saro A.27 London Mk II
- Two 915 hp (682 kW) Bristol Pegasus X radial piston engines driving
a four blade propeller. 20 aircraft were built.
Specifications (Saro
A.27 London Mk II)
Type: Six Seat
General Reconnaissance Flying Boat
Design:
Saunders-Roe Design Team
Manufacturer:
Saunders-Roe Aircraft Company
Powerplant: (Mk
II) Two 915 hp (682 kW) Bristol Pegasus X radial piston engines
driving a four blade propeller. (Mk I) Two 820 hp (611 kW) Pegasus III
radial engines driving a two blade propeller.
Performance:
Maximum speed 155 mph (249 km/h) at 6,250 ft (1905 m); cruising speed
129 mph (208 km/h); service ceiling 19,900 ft (6066 m).
Range: 1,100
miles (1770 km) with internal fuel. Range increased to 2,600 miles
(4184 km) with external overload fuel tanks installed.
Weight: Empty
11,000 lbs (5035 kg) with a maximum take-off weight of 18,400 lbs
(8346 kg).
Dimensions:
Span 80 ft 0 in (24.38 m); length 56 ft 9 1/2 in (17.32 m); height 18
ft 9 in (5.72 m); wing area 1,425 sq ft (132.38 sq m).
Armament: Three
7.7 mm (0.303 in) Lewis machine-guns with one in the nose, dorsal and
tail positions plus up to 2,000 lbs (907 kg) of bombs.
Variants:
London Mk I, London Mk II.
Avionics: None.
History: First
flight (prototype) 1934; first delivery (Mk I) 1936; retired from
service in early 1941.
Operators:
United Kingdom (RAF Coastal Command), Canada (RCAF).
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