Armstrong Whitworth AW 27 Ensign
In 1934 the British government
decided that all first-class mail for the Empire
would in future be sent by air, and Imperial
Airways therefore needed larger aircraft on its
South African and Australian routes. Although most
of the requirements were to be met by Short flying
boats, a new four-engine landplane was needed for
European and Eastern routes.
A specification was issued in May 1934 by the airline
to Armstrong Whitworth and the result was the A.W.27 Ensign, the first of
which was ordered in September 1934 at a price of £70,000; delivery was to
take place within two years and in May 1935 a further 11 were ordered at
£37,000 each. The price differential was accounted for by design and
initial manufacture changes for the first aircraft. A final two were
ordered in January 1937, raising overall Ensign production to 14 aircraft.
As Armstrong Whitworth was busy with Whitley bomber production at its
Coventry factory, the airliners were assembled in the Air Service Training
workshops at Hamble. Constant detail changes in the design and
construction periods were required by Imperial Airways (a pattern
subsequently repeated post-war by BOAC with certain airliners), with a
result that the first Ensign was almost two years late, making its first
flight from Hamble on 24th January 1938.
Subsequent tests at Martlesham Heath in June 1938 showed that the aircraft
was underpowered and a number of minor problems also occurred, but a
certificate of airworthiness was issued. The following month the first
aircraft flew a Croydon to Paris trip, but proper services did not begin
on the route until October. Just prior to Christmas 1938, three more
aircraft had joined the first and left the UK as relief aircraft, carrying
Christmas mail to Australia. All three became unserviceable, one at
Athens, one at Karachi and another in India. The type was subsequently
withdrawn and returned to the manufacturers for performance and
reliability up grading.
A modest increase in performance was achieved by
fitting the more powerful Armstrong Siddeley Tiger IXC engines to the
sixth aircraft, and in spite of problems the Ensign fleet served the
airline's European routes; 11 had been delivered by the outbreak of war.
Two configurations were in use: four aircraft (named 'Eddystone',
'Ettrick', 'Empyrean' and 'Elysian') were the European type with seats for
40 passengers, while the other seven ('Ensign', 'Egeria', 'Elsinore',
Euterpe', 'Explorer', 'Euryalus' and 'Echo'), intended for the Empire
routes, carried 27 passengers in three cabins or, alternatively, sleeping
berths for 20. The twelfth A.W.27 ('Endymion') received its certificate of
airworthiness in October 1939, and the fleet was evacuated to Bristol's
Whitchurch airport along with a number of other airliners. Camouflage was
hastily applied, and the A.W.27s operated a twice-daily service between
Heston and Paris (Le Bourget).
When BOAC was formed in November 1939 by the merger of British Airways and
Imperial Airways, ownership of the A.W.27s passed to the new company.
Wartime service soon began to take its toll, and 'Elysian' was destroyed
on the ground at Merville on 23rd May 1940. Others followed, 'Ettrick'
being abandoned at Le Bourget (it was subsequently repaired and used by
the Germans with Daimler-Benz engines) and 'Endymion' destroyed at
Whitchurch in an air raid in November 1940.
A final two A.W.27s, on which construction had been halted, were
subsequently completed in 1941. Named 'Everest' and 'Enterprise', they
were fitted with Wright Cyclone GR-1820 engines of 950 hp (708 kW) each,
providing an extra 400 hp (298 kW) in all compared with the earlier
Tigers, and in this form the type was designated A.W.27 Ensign 2. The
remaining eight Mk 1s were also re-engined, and with the extra power were
considered suitable for hot climates. Used between West and East Africa
and Egypt, the A.W.27s were hard pushed, and since their American engines
were out of production, they were difficult to maintain.
In the face of mounting problems it was decided to bring the survivors
home, and seven ('Egeria', 'Elsinore', 'Explorer', 'Eddystone',
'Empyrean', 'Echo' and 'Everest') were scrapped at Hamble in 1947.
'Enterprise' had been abandoned in West Africa during 1942, was salvaged
by the Vichy French and, like 'Ettrick', was eventually re-engined and
flown by the Germans. The original 'Ensign' had been damaged at Lagos in
1943 and was scrapped in 1945, while 'Euterpe' and 'Euryalus', damaged at
Almaza and Lympne respectively, were cannibalized for spares.
'Eddystone' was the last flying A.W.27, returning from Cairo to Hurn in
Ensign II G-ADSV 'Explorer' on wartime service with BOAC at Takoradi, West
A.W.27 Ensign Mk 1: Retrospective designation of the initial 12 aircraft
fitted with Armstrong Siddeley Tiger radials.
A.W.27 Ensign Mk 2: Designation of the last two aircraft, built with four
950 hp (708 kW) Wright Cyclone GR-1820-G102A radial piston engines; eight
Mk 1 aircraft were subsequently upgraded to Mk 2 standard; maximum speed
210 mph (338 km/h), cruising speed 180 mph (290 km/h), service ceiling
24,000 ft (7315 m), range 1,370 miles (2205 km), empty weight 36,586 lb
(16,595 kg) and maximum take-off weight 55,500 lb (25,174 kg).
Power Plant: Four 850 h.p. Tiger IXC (Mk.I)
Four 950 h.p. Wright Cyclone (Mk.II)
Span: 123 ft 0 in
Length: 111 ft 0 in
Height: 23 ft 0 in
Weight (All-Up): 48,500 lb (Mk.I) 55,500 lb (Mk.II)
Max Speed: 200 m.p.h. (Mk.I) 208 m.p.h. (Mk.II)
Cruise: 170 m.p.h. (Mk.I) 180 m.p.h. (Mk.II)
Stall Speed: 68 m.p.h.
Range: 860 miles (Mk.I) 1,370 miles (Mk.II)
Passengers: 40 (Western) 27 (Eastern)