Jane's Encyclopedia of Aviation
Armstrong Whitworth A.W.27 Ensign (UK)
The Ensign class of airliner was designed to an Imperial Airways specification for a new aircraft capable of carrying a large number of passengers and mail over the land sections of the Empire routes to
South Africa and Australia. In the event the aircraft was proposed in two forms: the 40-seat 'European' or ‘Western’ (with 12 passengers in the front cabin, 4 in the card room, 12 in the middle cabin and 12 in the rear cabin, plus 3 toilets) and the 27-seat ‘Empire’ or ‘Eastern’(with 3 cabins and 2 toilets) which could also be configured as a 20-passenger sleeper. Both versions were externally similar, being shoulderwing monoplanes with the four 596 kW (800 hp) Armstrong Siddeley Tiger IX radial engines mounted in the leading edges of the wings. The fuselage was long and slim and a retractable undercarriage was fitted, each main leg carrying a single large Dunlop wheel.
The first A.W.27 flew on 23 January 1938 and from October it flew the London-Paris service. Production was slow, mainly because of the company’s heavy commitment to the manufacture of bombers for the RAF, but nevertheless three others were completed in time for mail-carrying flights to Australia in late 1938. However, due to engine troubles, all broke down well short of their goal. The sixth production A.W .27 was fitted with 637 kW (855 hp) Tiger IXC engines driving new de Havilland three-blade constant-speed propellers, and had a modified tail unit. This arrangement subsequently became standard on all the AAV.27s.
With the outbreak of World War II the A.W.27s were used to ferry RAF personnel initially to France and then between RAF stations within the UK. During this period several were destroyed or damaged by German fighters. In 1941 the surviving aircraft were re-engined with 671 kW (900 hp) Wright R-1820-G Cyclone radials and were known as A.W.27A Ensign Mk IIs. With the end of the war the airliners were scrapped. Altogether 14 A.W.27s had been built.
Data: Engines as above Wing span 37.49 m (123 ft 0 in) Length 34.8 m (114 ft 0 in) Max T-O weight (Mk II) 23,813 kg (52,500 lb) Max level speed 338 km/h (210 mph) Normal range (in still air) 2,205 km (1,370 miles)
Flight, April 1937
SALUTE to the ENSIGN
A Complete Survey of the New Armstrong Whitworth Monoplane, of which Twelve have been Ordered by Imperial Airways
CHARACTERISTICALLY effusive, recent publicity releases from America announcing orders for fleets of large new transport aircraft herald what they are pleased to call the ''four-engine era.''
The authors, in their overwhelming enthusiasm for the highly promising designs concerned, seem conveniently to have forgotten the superb record of service compiled by the Hannibal, Atalanta, Scipio, Scylla and Diana classes of Imperial Airways on the European and Empire routes since 1930, so we hereby offer for their consideration the fact that by the time American air lines have four-engined landplanes in everyday service Imperial Airways will be quietly celebrating at least eight years of experience with aircraft of this calibre.
Familiar with the largest practical transport machines in the world, Imperials did not hesitate, as their pioneer four-engined types passed into the twilight of their days, to order from Sir W. G. Armstrong Whitworth Aircraft, Ltd., of Coventry (whose Argosies and Atalantas with their Siddeley Jaguar and Serval engines had given such exemplary service), a dozen monoplanes powered with four Tigers apiece.
Allotted the Armstrong Whitworth works designation "A.W.27" and bearing the contractor's class name Ensign, the new machines exhibit great originality, as might well have been expected in view of the surprises sprung upon the aeronautical world by Mr. Lloyd and his colleagues in the Atalanta.
The entire batch of Ensigns is to be assembled at Hamble (leaving the Coventry works free for the production of Whitley bombers, which, incidentally, bear a number of structural similarities to the "27"), where four fuselages are now on the stocks, the first awaiting its wing. No effort is being spared by Mr. A. E. Arch and his staff, and in a few weeks the world will be shown the first completed machine of the series.
An outline of the structural features of the A.W.27 may prove acceptable before setting out to describe the equipment, power plants, accommodation, etc.
Essentially the machine is an all-metal, high-wing monoplane with an undercarriage the halves of which retract into the inner pair of the four wing-mounted engine nacelles.
The wing structure was dealt with in some detail in Flight of January 7 this year. Tapering in plan form and thickness, the wing has comparatively square-cut tips. It is built round a single patented rectangular box-spar with top and bottom sides of corrugated light-alloy sheet, the box being stabilised by tubes arranged in diamond formations. Metal covering is used for the leading edge, but aft of the spar, where the structure is of rolled light-alloy sections, fabric is employed. Automatic servo flaps are inset into the trailing edge of each of the mass-balanced Frise ailerons, that on the port side being under the control of the pilot for lateral trimming purposes. Split trailing-edge flaps, actuated by four Lockheed hydraulic jacks, extend between the ailerons and fuselage.
The high-wing arrangement offers not only aerodynamic advantages, but is a godsend to passengers, who might otherwise have to endeavour to crane their necks to view scenery past the trailing or leading edge of a low wing. Typically practical, Imperial Airways claim that the high wing also has the advantage of sheltering passengers entering or leaving the machine from sun or rain.
An oval monocoque structure a hundred and ten feet long, the fuselage is more or less conventional in conception, incorporating transverse frames, longitudinal stringers and sheet-metal covering. A section is suitably recessed to receive the wing and in this region embodies a massive structure to take the flying stresses. A substantial system of tubular girders is built into the lower portion of the fuselage beneath the floor.
The student of modern design will doubtless be struck by the fact that, as on the Empire flying boats, a single fin-and-rudder assembly is employed, whereas the general tendency abroad is to duplicate this structure. The length of the fuselage and ample fin and rudder area should result in good directional qualities.
Structurally the tail unit is of the monoplane type, the tailplane being built up in a similar manner to the wing. Fore-and-aft trim is maintained by tabs in the elevator, which, incidentally, is not aerodynamic ally balanced, but has a spring-loaded balancing device incorporated in the internal controls. A servo flap, which is also arranged to function as a trimmer, extends over the entire trailing edge of the rudder. Like the fin, this member is fabric-covered.
Since each of the two Ensign types has been designed to the order of a single operating company, it might be expected that the accommodation and interior equipment would bear some resemblance to those of the Short Empire flying boat. This resemblance is, however, superficial, for the machines have been developed for somewhat different purposes.
As in the case of the boat, the big Armstrong Whitworth has its passenger quarters arranged so that either chairs or bunks may be fitted, and it is interesting to learn that the change-over in the long-distance or Empire class can be made in a matter of a quarter of an hour. Twenty-seven seats are removed and are replaced by twenty bunks, with partitions, curtains, and all the necessary equipment for sleeper comfort.
On through services, when a machine is flying by day and night, the change-over would probably be made while the passengers were eating their dinner at the aerodrome hotel or rest-house. The bunks are arranged in tiers of two; those using the lower ones will have the normal cabin windows at their level, while those in the upper berths have small auxiliary windows which normally serve to increase the amount of light in the upper parts of the exceptionally deep cabins.
An interesting aspect of the method of making the day-to-night change-over is the fact that the seats and backs of the daytime chairs are transferred to the bunks and form part of the mattresses; this somewhat peculiar transfer is necessary because these parts of the chair are designed to act as the life-savers which are a legal necessity for any sea-crossing service. The chairs are entirely similar to those developed for the Empire beats, which are the result of some two years of test and experiment and are made at Imperial Airways' own furniture factory at Wandsworth.
There are three passenger compartments in the Ensign, and each of these has its own emergency exit in the form of a sliding panel in the roof. The drawing on the two previous pages clearly shows the general layout. The first compartment lies directly behind the control cabin while the other two are towards the rear of the fuselage. All of them, of course, are well away from the plane of the airscrews and from the vicinity of the main spar, which carries the power units. Furthermore, the corrugations in the bulkheads and so forth should prevent any sign of drumming. The cabins should, consequently, be very quiet even without the addition of the soundproofing equipment which one might expect to see.
Behind the forward passenger compartment is a large freight hold (which can be loaded from the outside through two wide doors), a pantry, a mail department and a lavatory. Beside these compartments, on the port side, is a feature which appears to be very popular with passengers on the Empire boats - the promenade deck. Both here and in the front compartment smoking will be permitted. In the upper part of the fuselage, above the promenade deck area, is a space for normal luggage. The main entrance for the passengers is on the promenade deck and there is another at the rear of the cabin - where, also, there is a lavatory and a second freight compartment with a sliding door. The interior of the tail may be reached, for purposes of inspection, through the rearmost bulkhead.
Apart from the normal fresh-air ventilators, which can be adjusted by each passenger, an exhaust-heated ventilation system is under the control of the steward. Tins system is described elsewhere.
In the European class of A.W.27 forty-two passengers are carried. Obviously it would not be possible to accommodate them all in the three main compartments, and in the case of this type the forward freight compartment becomes a "cardroom," where four passengers are comfortably ensconced. In addition, there are twelve seats in the forward cabin and twelve and fourteen, respectively, in the two rear compartments.
The cabin windows are of Perspex made up by the Triplex Company, the pilots' windows are of Splintex safety glass, and various inspection panels are covered with Rhodoid.
Generally speaking, the instrument layout is similar to that in the Short boats - not unnaturally, since this layout was the subject of a very great deal of thought and because the boat pilots may occasionally be expected to take over these landplanes at short notice.
In the centre of the dashboard is the Sperry automatic pilot panel, while above this are the engine switches and a master switch controlling the undercarriage and flap indicators; until this master switch is moved to the "on" position the engine switches themselves are inoperative and the captain, therefore, cannot possibly take off without first checking the positions of the flaps and undercarriage. Above the screen, in the centre, are the four engine starter and two windscreen wiper switches.
On the left of the Sperry panel are all the essential navigational instruments, including the usual Sperry horizon and gyro, a sensitive altimeter, a rate-of-climb indicator, and so forth. Beside the captain, on his left, are levers controlling the oil relief valve (permitting a heavy circulation of oil during the warming-up process) and the slow-running cut-outs for the four Tiger engines. Farther aft on the same side are the fuel tap controls.
The central throttle bank column carries, in addition to and alongside the four throttle levers, the v.p. airscrew control on the left, and the mixture control on the right. Ahead of the gates, on either side of the column, there are two other levers; that on the left controls the valves for the undercarriage retraction pumps, and that on the right controls the flap-operation valves. The pilot has merely to move one or other of the levers into its new position and the engine-driven pumps do the rest.
On the face of this central column is a small lever which can be moved up, down, or sideways. This little affair controls the entire Dunlop pneumatic braking system. Movement in the fore-and-aft plane applies or releases the brakes, while sideways movement brings the differential operation into play for manoeuvring on the ground. On the left of the column and at the level of the brake control lever is the usual Sperry pilot cut-out lever.
A useful feature which is not often to be seen on British transport machines is a direct-reading drift-sight, which is arranged on the floor of the cabin between the two pilots. Each pilot, of course, has his own compass.
The Ensign type can not only be trimmed in the fore and aft and directional planes, but has tabs on each of the ailerons, so that any slight lateral trim differences may be corrected while in flight. This aileron trimming wheel is mounted on the roof above the chief pilot's seat, while the elevator and rudder trimming wheels lie, one behind the other, on the right-hand side of his seat, so that they may be reached by either pilot. An interesting comfort detail concerns the first officer's chair, which not only slides backwards and forwards, but also swivels in order to simplify movements in and about the cabin. Entrance is normally effected through a trap-door in the floor behind the "bridge," though there is, of course, a door leading to the front compartment. An emergency exit is provided.
Behind the pilot's "platform” is the radio operator, who sits facing starboard, on which side are his Marconi transmitters and receivers. In the case of the European type these will have the normal medium-wave tuning range, while the Empire class will, in addition, have short-wave equipment.
Additionally, D/F. equipment is installed; this may be used either for obtaining direct bearings or, with the loop in a fixed position, for "homing." An indicator lies in front of the captain, immediately below his more important navigational instruments. The loop is not of the retractable type.
On the port side of the operator's compartment is a small petrol motor, similar to that used in the Empire boat equipment, which is permanently coupled to a generator. Thus, in case of a long wait on the ground with, perhaps, the radio and lighting in action, the main battery system may be replenished without the necessity of running one or other of the engines, which, through their generators, normally keep the battery up to scratch. A Rotax switchboard, covering the domestic electrical equipment of the machine, is in charge of the steward. The following Rotax equipment is specified: Two 24-volt, 1,000-watt engine-driven generators with two voltage control boxes; cabin lamps; roof lamps; navigation lights; switches and fuse boxes.
Power is supplied by four Siddeley Tiger IX geared and moderately supercharged radials, which are carried on welded tubular structures forward of the leading edge, these being provided with Armstrong Siddeley patented flexible rubber mountings.
The Siddeley Tiger IX is a recently introduced engine developed from the Tiger VI, as used in large quantities by the Royal Air Force. The engines for the Ensigns will be standard units except for certain drives introduced specially for service with Imperial Airways.
Rated at 790 h.p. at 2,375 r.p.m. at 6,500 feet, the Tiger will deliver 810 h.p. maximum at 2,450 r.p.m. at 6,400 feet. With the three-bladed De Havilland two-position variable pitch airscrews set a t fine pitch, 880 h.p. is available for take-off at 2,375 r.p.m., the automatic boost control then being "over-ridden."
The engine has fourteen cylinders, arranged in two staggered rows, the capacity being 1,996 cubic inches, and measures 50.8 inches in diameter.
The engines are enclosed in standard Siddeley long-chord cowling rings, which have inner and outer sections for the purposes, respectively, of directing the air flow round the cylinders and giving an aerodynamically efficient exterior.
Petrol and oil tanks with respective total capacities of 670 gall, and 40 gall, are mounted in the leading edge.
A boiler on the exhaust pipe of one of the inboard engines supplies steam to a heater box. Cold air is blown through this box, warmed, and delivered to the cabin, the supply being regulated by the steward. A system of branch pipes supplies cold air.
The A.W.27 has the largest retractable undercarriage developed to date, the entire mechanism for raising and lowering being of Lockheed production. Each of the two independent units is located under each of the engine nacelles, which are of considerably larger dimensions than their outboard neighbours. The Dunlop wheels stand over 6ft. 3m. high and are about 27 inches wide. The retracting movement is rearward and upward into the fairings behind the main spar, a portion of each wheel being left protruding below each nacelle when the gear is completely raised. Doors are provided to preserve a smooth contour when the undercarriage is up, these being interconnected with the retracting mechanism. A special valve allows the fluid controlling these doors to be jettisoned in an emergency without the loss of fluid in the other systems.
Lockheeds were faced with some pretty problems in developing gear to operate the flaps, undercarriage and wheel doors. In all, there are sixteen jacks - four for retracting and lowering the undercarriage, four for the flaps, four for the wheel doors and four to lock the undercarriage in the raised position. The fluid system has three engine-driven pumps. The pilot is provided with the new Lockheed selector valves which return the operating levers to neutral when an operation is completed.
The undercarriage jacks are 3 1/2 inches in diameter, and should raise the wheels in 1 1/3 minutes and lower them in 50 seconds.
Over 200 m.p.h.
Complete estimated performance figures for the A.W.27s are not available, but the top speed should exceed 200 m.p.h., and the economical cruising speed is expected to be about 160 m.p.h., although, undoubtedly, the machines could be continuously operated quite safely at a higher speed. Fully laden they will weigh rather more than 20 tons and should be able to maintain height at 12,500ft., using only three of their four Tigers and at 4,000ft. on two engines.
The normal range will be 500 miles against a 40 m p.h. head wind, but with extra tankage and reduced payload this can be increased to 1,000 miles under the same conditions.
Among the firms which are stated by the makers to have supplied components and accessories for the Ensigns are the following :-
Accles and Pollock, Ltd., Aircraft Materials, Ltd., Albion Drop Forgings, Ltd., Aluminium Corporation, Ltd., Arens Controls, Ltd., Automotive Products, Ltd.
Benton and Stone, Ltd., J. Biresford, Ltd., T. M. Birkett, Ltd., Birmabright, Ltd., Birmingham Aluminium Castings, Ltd., P. H. Bonnella, Ltd., James Booth and Co., Ltd., Bowden Engineering Co., Ltd., British Aluminium Co., Ltd., British Celanese, Ltd. (Celastoid), British Marine Aircraft, Ltd., Brooke Tool Mfg. Co., Ltd., E. G. Brown and Co., Ltd., Brown Bros. (Aircraft), Ltd.
Cork Mfg. Co., Ltd., De Bergue Patents, Ltd., De Havilland Aircraft Co., Ltd., Dunlop Rubber Co., Ltd., Fairey Aviation Co., Ltd., Firth-Vickers, Ltd., General Aircraft, Ltd., High-Duty Alloys, Ltd., Hoffman Mfg. Co., Ltd., Lightalloys, Ltd., Magnesium Castings and Products, Ltd., Manganese Bronze and Brass Co., Ltd., Masson, Seeley and Co., Ltd., May and Baker, Ltd. (Rhodoid).
Northern Aluminium Co., Ltd., Parnall Aircraft, Ltd., Ransome and Maries, Ltd., Reynolds Tube Co., Ltd., Rotax, Ltd., Rotherhams, Ltd., Rubery Owen and Co., Ltd.
Geo. Salter and Co., Ltd., Short Bros., Ltd., Simmonds Aerocessories, Ltd., Skefko Ball Bearing Co., Ltd., Smith's Aircraft Instruments, Ltd., Sperry Gyroscope Co., Ltd., Splintex Safety Glass Co., Ltd., Stirling Metals. Ltd.. Superflexit, Ltd., Tecalernit, Ltd., Geo. Tucker Eyelet Co., Ltd , Viekers Aviation, Ltd., Vokes, Ltd.
Flight, October 1938
British Commercial Aircraft
LAST week the first example of the Imperial Airways’ fourteen Armstrong Whitworth Ensign class transports went into preliminary service on the Paris run. Actually this first machine is one of those intended for the overland service to India, and when experience has been gained and others of the class have been delivered it will go on to this route.
The A.W.27, as this machine is officially designated, is the largest commercial landplane to be put into regular service. It is, moreover, one of the very few high-wing monoplanes among transport types, imperial Airways having decided on this layout in order to give the passengers a range of view which is not obtainable in low-wing machines. The Ensigns, which are each powered with four 880 h.p. Siddeley Tiger IX engines, are being laid out in two versions. One, for European operations, will carry forty passengers, and the other, for the Empire routes, will carry twenty-seven by day or twenty by night. In the empire version there are three main passenger compartments, one immediately aft of the control cabin, and two others aft of the monumental centre section. As in the case of the Empire boats, a promenade deck has been arranged below the wing between the forward and the centre cabins.
The wing of the Ensign is built round a single rectangular box spar in which the top and bottom sides are of corrugated sheet, and the entire structure is stabilised by means of tubes arranged in diamond formation. Metal covering is used for the leading edge, but aft of the spar, where the wing is built up of light alloy sections, fabric covering is used. Split trailing-edge flaps, actuated by four hydraulic jacks, extend between the ailerons and the fuselage. The latter is a monocoque structure, the length of which - 110ft. - enters the realm of marine engineering. It is more or less conventional, involving the use of transverse frames, longitudinal stringers, and a metal covering. The top of the fuselage is recessed to take the wing spar, and the area concerned is, of course, substantially strengthened to take the flying stresses.
The Ensign is somewhat unusual, according to modern practice, since the fin and rudder assembly is not duplicated. Apparently the length of the fuselage and the ample area of this assembly give good directional stability. Most interesting of all, perhaps, is the engineering feat involved in designing and manufacturing an undercarriage retracting gear to suit a high-wing machine of such dimensions; the hydraulic jacks in the undercarriage are 7ft. long in their extended position, yet the raising operation takes only 1 1/4 minutes.
Ensign Data.- Span, 123ft.; length, 110ft.; height, 23ft.; wing area, 2.443 sq. ft.; all-up weight, 48,500 lb.; weight empty, 33,000 lb.; payload, 9,500 lb.; wing loading, 20 Ib./sq. ft.; power loading, 13.8 lb./h.p.; span loading, 3.2 Ib./sq. ft.; maximum speed (sea-level), 182 m.p.h.; maximum speed (7,000ft.), 205 m.p.h.; cruising speed (7,000ft.) on two-thirds power, 170 m.p.h.; stalling speed, 66 m.p.h.; initial rate of climb, 700 ft./min.; rate of climb at 10,000ft., 500 ft./min.; service ceiling, 16.500ft.; range at cruising speed, 850 miles; price, 752,000.
Makers:- Sir W. G. Armstrong Whitworth Aircraft. Ltd.. Coventry (Coventry 60071).
Flight, November 1939
Britain's Civil Aircraft
RE-RATED Armstrong Siddeley Tiger IX engines give the big Armstrong Whitworth Ensign a performance which, considering the date of the design, must be considered very creditable, the top speed being 205 m.p.h. and the cruising speed 170 m.p.h. The machine is an all-metal four-engined high-wing monoplane originally designed to carry forty passengers for European operations or twenty-seven passengers by day and twenty by night on the over-land Empire services.
The wing is of the single-spar type and the fuselage is a monocoque structure. The undercarriage, which retracts into the inboard engine nacelles, is probably the biggest of its kind in the world.
Sir W. G. Armstrong Whitworth Aircraft, Ltd., Whitley, Coventry.
24 октября 1938г.: "Imperial Airways" начала эксплуатацию пассажирского авиалайнера Armstrong Whitworth AW.27 (27-40). Самолет RMA Ensign (G-ADSR) появился на авиалинии Лондон - Париж.
Armstrong Whitworth Ensign.
Ensign at Croydon during its operations on the Paris route.
ENSIGN, the first of the imposing new class for Imperial Airways, arrived at Croydon last week. That worthy veteran Scylla can be glimpsed in the background.
G-ADSR, the first A.W.27, at Hamble before its first flight.
Sister company Armstrong Siddeley not only made fine aero engines at the Parkside plant in Coventry but excellent cars and the appearance of G-ADSR ‘Ensign’ was used to great effect in marketing the latter.
Imperial Airways introduces the first of its fleet of fourteen new Ensign air liners - the biggest in Europe and the most comfortable in the world. Observation corridor, smoking cabin and kitchen aboard. Four engines for security, and London-Paris 80 minutes’ flying
Ensign at Croydon in November 1938 after entry into service on the London-Paris route.
OUT AND UP. This unusual picture by a Flight photographer shows the Armstrong Whitworth Ensign tucking-up ner wheels as she takes off from her makers’ aerodrome. She was due to go to Martlesham yesterday.
The first flight of the first Ensign. G-ADSR rises from Hamble on January 24, 1938, piloted by C.K.Turner-Hughes.
An interesting picture of the Ensign flagship G-ADSR over Southampton water, with the fabric covering of the wing behind the box spar clearly visible.
G-ADSR: Last Monday morning the huge Armstrong Whitworth Ensign, first of the new 42-seaters for Imperial Airways, made her first flight, Flt. Lt. C. K. Turner-Hughes and F/O. Eric Greenwood taking her off from the A.S.T. Aerodrome, at Hamble, for an uneventful and satisfactory 15-minute flight. The machine, which is of 123ft. span, has four Armstrong Siddeley 800 h.p. 14-cylinder Tiger IXs.
The Armstrong Whitworth "Ensign" Imperial Air-liner (four Armstrong Siddeley "Tiger" engines) seen from below.
A low-wing configuration was originally preferred, but the high wing was finally chosen for passenger appeal. The Ensign was Britain's largest pre-war airliner.
HOFFMANN. The 4 Armstrong Siddeley Tiger engines of the new "ENSIGN" planes by Messrs. Armstrong Whitworth Aircraft Co. Ltd. are fitted with these bearings
The Armstrong Whitworth Ensign is one of the largest transport land planes now flying, having a span of 123 ft. and a loaded weight of 46,500 lb.
The first AW 27, G-ADSR Ensign, did not enter airline service until October 24, owing to repeated modifications for Imperial Airways.
With the wing set at a positive angle of incidence on the fuselage, the Ensign adopted a distinct nose-down attitude in cruising flight, as shown clearly in this early photograph of the first aircraft.
Ensign on a test flight: G-ADSR made its 15min maiden flight on January 24, 1938, from Hamble.
HANDED OVER: The Armstrong-Whitworth Ensign has now been delivered to Imperial Airways. Flight’s chief photographer, who secured the picture here, remarks that coming up alongside the vast length of Ensign is suggestive of overtaking an express train. Nose to tail, she measures 114 ft.
Almost twice the size of its Atalanta predecessor, the Armstrong Whitworth AW.27 Ensign made ts first flight on January 24, 1938. Capable of accommodating up to 27 passengers, the type incorporated a retractable undercarriage and was certainly a step in the right direction for Imperial in terms of modernising its equipment.
The first Armstrong Whitworth A.W.27, G-ADSR Ensign, flying over Coventry in April 1938.
A fine study of G-ADSR in its early days
Problematical though the AW.27 may have been, it was undoubtedly an attractive-looking machine when the undercarriage did eventually retract and it got to height!
READY: Imperial Airways should very shortly be taking delivery of the first of the fourteen A.W. Ensigns, which appear to be well up on contracted performance and payload. This is a photograph of the first of the series taken on an early test flight.
Now returning in series to service with Imperial Airways, the A.W. Ensign is the largest civil aeroplane at present in use. The Tiger engines have an increased power for take-off which, with constant speed airscrews, gives an initial rate of climb, with full load, of 800 ft./min.
FOUR-ENGINED FASHIONS: the Armstrong-Whitworth Ensign.
The Armstrong Whitworth Ensign Commercial Transport in its original form with four Armstrong Siddeley Tiger engines.
HOISTED: The photograph shows another stage in the flight-testing of the A.W. Ensign (four 880 h.p. Siddeley Tiger IX): she is seen with her wheels retracted. Each Lockheed undercarriage is retracted by two hydraulic jacks which have an extended length of seven feet; they are believed to be the largest yet built.
Great Britain’s reply to the highly developed four-engined transports nearing completion in America: The Armstrong Whitworth Ensign 42-seater with four 800 h.p. Siddeley Tiger IXs.
The first A.W.27 photographed during the summer of 1938.
G-ADSR passes over Purley Way on approach to Croydon Airport,
Britain's biggest air liner is equipped with Siddeley engines cowled with fairing rings by Northern Aircraft & Engineering Products, Ltd. In the background of the photograph is the “Whitley” bomber, also fitted with our cowlings.
‘Ensign ’, the prototype AW.27, is lent scale by the large crowd gathered, presumably at the roll out, January 1938. It carries neither its name nor Imperial Airways lettering.
Proportion: The first A.W. Ensign, now at Coventry, with a few attendants from the A.S.T. school fleet at Hamble.
A Miles Magister lends scale to five Ensigns awaiting modification in 1939. Front to rear, Ensign, Elsinore, Euterpe, Egeria and Empyrean.
Problems with the original Tiger engines dogged the early operations of the Ensign fleet; all five in this picture were at Hamble with work going on to rectify the engine problems.
As with the remainder of the fleet, with wartime came camouflage and the 'underlining' of the registration letters in red, white and blue. ‘Ensign’ joined BOAC in April 1940 and was converted to Mk II status. After only 2,099 hours flying time, it was withdrawn at Almaza, Cairo, in September 1944 and eventually scrapped there.
The second Ensign was G-ADSS Egeria, which made its first flight on May 26, 1938. It was scrapped at Hamble in April 1947.
EGERIA, second of the A.W Ensigns, crosses the road at Hamble on the way to her taxying tests.
Elsinore, the third AW 27, was accepted by Imperial Airways on November 7, 1938, and survived until March 1947.
Elsinore at Croydon, with Ensign in the background.
AW27 G-ADSU Euterpe takes on mail at Croydon.
G-ADSU Euterpe was originally allocated the Indian registration VT-AJF and the name Everest, but neither was used.
Former Imperial Airways Armstrong Whitworth Ensign G-ADSV in BOAC wartime markings at Takoradi, West Africa
Explorer being refuelled at Takoradi while operating trans-Africa services.
AW Ensign II G-ADSV Explorer of BOAC at Takoradi, circa 1943. Wellingtons in the background and a most impressive refuelling truck in the foreground.
Before and after the passage of a warm front. In the better weather conditions of the late afternoon, the A. W. Eddystone prepares to return to Croydon.
Another view of G-EBIA during the skeletal existence with Armstrong Whitworth. Ensign I G-ADSW ‘Eddystone’ provides scale,
Three Redhill V.R. Fairey Battles with the Sabena Douglas D.C.3 and the good Imperial “E” class ship Eddystone making the foreground.
Croydon scene just before the war. In this view are the A.W.27s Ettrick, Elysian, Elsinore, Eddystone and Explorer, the D.H.91s Frobisher and Falcon, the H.P.45 Horatius and the Short L.17 Syrinx. Just visible in the background is a Junkers-Ju 90.
Imperial Airways airliners grounded at Croydon during the last month of peace had to stand in the open. Behind G-ADSX Ettrick can be seen G-ADSZ Elysian and G-ADST Elsinore.
G-ADSY Empyrean after modification to Mark 2 standard.
Ensign G-ADSZ Elysian was first flown in June 1939 and is seen here during its early days of service.
Although it bore the Indian registration VT-AJG early in its life, G-ADTA Euryalus soon reverted to all-British markings.
G-ADTB Echo first flew on August 30, 1939, and survived until March 1947.
Photographed at Hurn in 1946, G-ADTB displays the final form of finish and markings carried by Ensigns during the last few months of service in Africa and for their return to the UK for scrapping.
Echo with Cyclones, wartime national colours and Speedbird on the nose.
Frobisher and a pair of Ensigns at Croydon.
IN SERVICE: The first Junkers Ju.90 to be seen in this country arrived on the normal Berlin-London run on August 1. The impressive size of this forty-seater is shown by the relative smallness of the Marcel Bloch on the right. The “accident” on the left is merely a group of Imperial machines, including two Frobisher-class and one Ensign-class liner. The Ju.90’s tail unit is interestingly complicated.
Perhaps because its designer was an Egyptian national, Helmy Aerogypt G-AFFG continued its development through the war. Illustrated is its Mk.III incarnation, last flown in September 1940. Work started again in 1943 when it became the Mk.IV with tricycle undercarriage. There is an AW Ensign in the background
After being re-engined with Wright Cyclone engines - identified by the shorter chord of the cowlings - the Ensigns were painted in a uniform type before being transferred to the Middle East for service with BOAC. These pictures show the camouflaged upper surfaces and the civil registrations, which were retained together with the BOAC "Speedbird" emblem and aircraft name on the nose.
Armstrong Whitworth A.W.27 Ensign G-AFZU Everest at Heliopolis, Egypt, in 1943. Everest survived being shot up by a Heinkel He 111 over Biscay during a ferry flight on November 9, 1941, and had logged 2,406 flying hours when il was finally scrapped at Hamble in April 1947. It was used on a shuttle service linking East and West African ports.
Everest in camouflage at Bramcote in 1941.
A W Ensign G-AFZV 'Enterprise' in camouflage. The type provided essential airlift capacity as the war started.
Ensign (nearest) and Everest, both camouflaged and with Wright Cyclones. On the outbreak of war the Ensigns began work with National Air Communications.
After its forced landing in French West Africa in 1942, G-AFZV, the final Ensign II, was taken to Dakar for repair by Vichy French personnel. There, the registration was changed to F-AFZV as a temporary expedient, but it later became F-BAHO after transfer to France.
Back on its undercarriage again, the Ensign has had its interim French civil registration applied with the simple substitution of the British "G" prefix letter with a French “F”. One of the chief problems facing the groundcrew tasked with maintaining the big British airliner was the availability of spare tyres for the mainwheels, which were an impressive 6ft 3in (1-9m) in diameter. Happily for the crews, a cache of spares was located in Paris.
A hive of activity, the Ensign is seen here at Agadir in 1942. Back in the UK, the inquiry into the Ensign’s loss concluded that, lacking any accurate measuring equipment, the crew had pumped too much oil into the engines from the auxiliary oil tanks fitted for the flight, resulting in the extensive oil leaks off the African coast.
Stripped of its British camouflage down to a bare-metal finish, the Ensign is seen here having its engines run up at Ouakam in French West Africa (now Senegal) in 1942. The aircraft’s official registration, F-BAHD, has been applied and tricolour stripes added to the rudder, wings and aft fuselage, along with a large “F” on the fin.
G-AFZV served with Air France as F-AFZV and, as seen here, F-BAHO.
Bearing Air France’s distinctive winged seahorse logo on the forward fuselage ahead of the company’s legend, as well as its name in French service, Nouakchott, on the nose, Ensign Mk II F-BAHD (not F-BAHO as stated in some sources) is prepared for another flight at Agadir, Morocco, in 1942, before its withdrawal to France.
Showing its shapely fuselage to good advantage, the Ensign sits on the ramp beside the hangar at Marignane, near Marseille, in 1942. That November the Ensign was moved for the final time to Montaudran, near Toulouse.
The Ensign beside the modest terminal building at Agadir. Although the type was remarkably aerodynamically clean for its day, it was heavy on the controls, with a poor rate of climb, and pilots found it extremely tiring to fly for long periods. Indeed, wartime BOAC Ensign pilots frequently lobbied their superiors to have the type replaced in service as soon as possible.
The largest retractable undercarriage unit in the world, as fitted to the Armstrong Whitworth Ensign transport used by Imperial Airways.
This view of the first A.W.27 fuselage outside the Hamble works gives a vivid idea of the immense size of the machine. The overall length is 110ft. The higher level windows were those on the promenade deck.
Manoeuvring the fuselage of what is believed to be No.1 from its jigs and into the main assembly hall - with the river that gave the aerodrome its name in the background. Note the jury-rigged wheels to move the stressed skin monocoque fuselage around, with the ‘main wheels’ attached to where the spar would sit.
The Armstrong Whitworth Ensign - the first of a large order for Imperial Airways - comes out for an engine run.
SNIFFING THE BREEZE: The first of the eagerly awaited Armstrong Whitworths of the Ensign class appeared outside the Hamble works last week-end in an almost finished condition. Twelve of these huge 42-seaters, of 123ft. span, were ordered by Imperial Airways. Four 800 h.p. fourteen-cylinder Tiger IX radials supply the power to lift more than 20 to <...> weight.
FULL-SIZED: Some idea of the size of the A.W. Ensign and, in particular, of the retractable undercarriage legs and wheels, may be gathered from this Flight photograph.
FINDING ITS LEGS: The main spar and undercarriage are now in place on the first of the Armstrong Whitworth Ensigns for Imperial Airways. The undercarriage is the largest retractable type in the world and is of Armstrong Whitworth design and production, except for the Lockheed hydraulic rams.
The first Ensign taking shape at Hamble, showing the all-metal wing torsion box and the main undercarriage attachment.
Literally "man's size," the Lockheed hydraulic undercarriage jacks, of which there are four, measure 54 in. in their closed position and 84 in. extended.
The Ensilage: Another view, taken in the shops, which gives an excellent idea of the massive proportions of the stressed skin body.
The after end: the fin skeleton.
Work in progress on the tail section, August 18, 1937. The A W.27 was 23ft (7.01m) high when sitting on its tailwheel.
July 7, 1937 and work on the first Ensign (c/n 1156, the flagship G-ADSR) is well under way. At this point the 123ft (37.49m) monster was 202 days from first flight. Note the access platforms, an ad hoc collection of scaffolding poles and wooden beams. The port out Armstrong Siddeley Tiger IXC has been ‘hung’.
A view of No.1 also on July 7, 1937, this time from behind the trailing edge of the port wing.- the film speed in the camera not coping with the movements of the workforce even though it appears most of them have been ‘tipped off’ and told to ‘hold it’! From the aft face of the huge box spar the wing was to be fabric covered.
A view from the front of No.1, taken on August 18, 1937 showing the workbenches for detail assembly and rectification in the foreground. All four Tigers are now in place, with the outer two cowled. Fuel tanks occupied the leading edges between the engines, between the inner engines and the wing root and outboard of the outer Tigers.
A view of the assembly shop, July 7, 1937. The huge, bridge-like inner portion of the main spar has been settled into place on the fuselage of No.2 (c/n 1157 G-ADSS at that point destined for Indian Trans-Continental Airways as VT-AJE ‘Ellora’) while the starboard out section of spar is readied for mating up. To the right is the nose section of what is believed to be No.3.
Work in hand on the port wing of No.5, February 2, 1938. Two engine bearers in the foreground on the plank work platform, while the outer leading edge tank has been installed.
The spar of No.5 (c/n 1160 G-ADSV ‘Explorer’) under assembly. Such a construction would not have looked out of place in a shipyard! In the foreground are jig tables for the oval-section fuselage frames and for the moving flying surfaces. The wooden balcony in the background was where the ‘looking down’ shot of the spars was taken from.
Wing spars lying in their forming up jigs. The spar was built in three parts (centre and two outers) and was made from light alloy with internal bracing. Behind to the right is a fuselage under way and in the background to the left the oval section frames that made up the fuselage are on their wooden pattern jigs.
The assembly line for front fuselages, with four aircraft in various stages of completion.
Work under way on the wing spar of No.6 (c/n 1161 G-ADSW ‘Eddystone’), August 18, 1937. The box spar format and internally-braced structure is evident - as is the depth of the spar, witness the man standing in it!
One of the wings of tie Ensign, in which corrugated metal sheeting forms the upper and lower sides of the single box spar. The covering is partly of metal and partly of fabric. Only the leading-edge formers are in place in this view.
The port wing of No.1, taken September 24, 1937. In the foreground can be seen was the largest pre-1939 aircraft tyre - all 6ft 3in (1.9m) diameter of the mainwheel. The huge main undercarriage construction retracted rearwards into the wing and was designed to do so it what must have been an agonising 90 seconds during the climb out. Try as Armstrong Whitworth and Automotive Products (who made the hydraulic jacks for the undercarriage and other functions in the Ensign) might, this time was seldom achieved and the legs were determined to retract asymmetrically.
Inside the fuselage. The longitudinal stringers are continuous and are joggled into the frames. The floor beam supports take the form of girders of tubular construction.
(Left) The "Office": Note the two control columns, ready for their wheels, and the hanging rudder pedals. The tail-trimming wheel is seen in the centre, at floor level. (Right) A view inside the forward cabin, looking towards the pilots' cockpit.