The Airspeed AS4 Ferry - Constructed in 1932
Aeroplane Monthly Magazine August 1987 Author John Stroud
Only 4 Airspeed Ferry Aircraft were built. Civil Register G-ABSI G-ABYX G-ACFB G-ACBT
Sir Alan Cobham, in his book “A time to fly” (Shepheard-Walwyn, 1978) stated that the National Aviation Day Campaign kept him busy from 1931 until 1935 and was perhaps his "greatest single contribution to the cause of civil aviation". Remembering Cobham's pioneering flights to and round Africa, to Burma and Australia, and his Municipal Aerodrome Campaign, his regard for the importance of the National Aviation Day displays is surprising; yet there is no question that these displays played a great part in creating air-mindedness and got many people into the air for the first time.
The idea for the National Aviation Day displays came to Cobham early in 1931 and he decided that for these displays he would need a small airliner, simple and robust, capable of carrying about ten passengers and taking off with full load with a run of 200yd or less. It should provide a good view for its pilot and passengers, be easy to land after a steep, slow approach, and be low-slung with doors each side to minimize embarkation and disembarkation times. It should also make flying seem ordinary.
By chance, Airspeed Ltd had been formed in York on March 13, 1931, and Sir Alan Cobham was one of the directors. Lord Grimthorpe was chairman and later was to be involved in the setting up of North Eastern Airways which included a number of Airspeed Envoys in its fleet. The two men, who originated the idea of Airspeed, although they could not finance it, were N. S. (Nevil Shute) Norway and A. Hessell Tiltman. Both had worked for the Airship Guarantee Company and been involved in the design and construction of the R100, but following the loss of the R101 all work on development of the R100 ceased and the company was closed down on December 2, 1930. Norway and Tiltman had earlier worked for de Havilland and Tiltman's experience went back as far as 1916 when he joined George Holt Thomas's Airco.
At the Airspeed board meeting on April 17, 1931, Sir Alan Cobham first put forward his proposals for his simple multi-engine airliner, and at the end of June ordered two examples for delivery in April 1932 at a cost of £5,195 each.
Hessell Tiltman was responsible for the design and was assisted by A. E. Ellison, who had worked with him on the R100. The new aeroplane bore the designation AS.4, was named Ferry, and was the first powered aircraft built by Airspeed; the AS.l was a sailplane (see One good Tern, January 1984 Aeroplane the AS.2 and AS.3 were unbuilt projects, the former also being a design for a glider.
The Ferry was a simple equal-span biplane with three engines, but both the wing layout and the engine arrangement were unusual—although not unique. The centre section of the upper wing had a span of about 14ft, without dihedral, and was carried high above the fuselage on four struts attached to the fuselage top longerons. The forward struts slanted inward towards their upper ends and supported the centre engine which was mounted immediately ahead of the wing. The rear struts met at the centreline and formed an inverted V. The outer wings were two-bay strut- and wire-braced structures with 4i° dihedral. These outer wings, like the upper centre section, were untapered in chord and thickness and rigged without stagger. The inner sections of the lower wing were attached to the upper fuselage longerons, sloped down sharply to meet the outer wings and tapered in chord and thickness—being thinnest at the fuselage attachments. At the root these inner wings had their greatest chord, and they were tapered on their trailing edges.
The wings were two-spar structures with spruce flanges and ply walls. Steel- tube compression members and tie-rods took the drag loads. There were nose ribs between each pair of main ribs and all wing surfaces were of fabric. The tips had inverse taper and all four wings had inset Frise-type ailerons which were wire- connected. The interplane struts were of circular-section steel tube with balsa fairings. Wing chord was 5ft 9in and gap about 6ft.
The fuselage was a rectangular-section box structure with spruce longerons and frames covered by birch three-ply. There was comparatively little taper of the rear fuselage in side elevation. The nose was quite blunt and had a bulged metal panel on the port side which covered the engine controls. The extreme nose was covered in beaten aluminium and could be removed for inspection and there were also triangular inspection panels in the floor.
The tail unit comprised a strut-braced adjustable tailplane and divided elevators of constant chord, a tapered fin and horn- balanced rudder. The tail structure was of wood with fabric covering and there was adequate directional control with either outer engine shut down, although initially the rudder was found to be slightly overbalanced. The aeroplane was also initially somewhat nose-heavy.
The 14ft 2in track divided undercarriage comprised half-axles and radius- rods hinged to the lower longerons and Dowty shock-absorbing legs with steel springs and oleo damping running vertically to the lower wings. The half-axles and radius-rods were enclosed in aerofoil- section fairings which were said to provide an extra 35ft" of lifting area. The wheels had Palmer hydraulic brakes and were enclosed in large detachable spats. There was a steerable tailskid. After some time in service the spats were removed and replaced by mudguards.
Two 120 h.p. de Havilland Gipsy II upright four-cylinder inline air-cooled engines were mounted on the lower wing and V-struts ran from the engine mounting spar junction to the lower fuselage longerons. The centre engine, on the upper wing, was an inverted Gipsy III also of 120 h.p. The wooden two-bladed fixed- pitch propellers had a diameter of about 7ft. A 65gal fuel tank was mounted on the upper centre section.
The Ferry was also designed to be powered by three Gipsy III, Gipsy Major or Hermes IV engines.It comprised a pilot's seat in the nose and a cabin for ten passengers with five single metal-framed and very simple seats each side. At that time it was ruled that an aeroplane with ten or more passenger seats must be equipped with radio but, had radio been installed, seating would have been reduced to nine so radio would not have been required. However, agreement was reached and Cobham's Ferries could and did carry their full passenger loads of ten at a time. The cabin was 12ft 7in long, 3ft 9in wide and 5ft 9in high. The pilot's section was separated from the passengers by a transparent bulkhead, in the starboard side of which was a door which I think may have been removed at least on the first aeroplane. There was a main door in each side of the cabin beneath the inner wings and an emergency exit in the roof at the rear. The floor was only about 18in above the ground. The control runs were fully visible as they were led to the top of the fuselage between the pilot's seat and the transparent bulkhead. The pilot's and the passengers' cabins were well supplied with windows and there were sliding panels in the windscreen and forward side windows. The entire interior was austere but adequate, being in a similar category to the Armstrong Whitworth Argosy and de Havilland Hercules of a somewhat earlier period.
The Cobham Ferries were built in part of a leased and formerly empty bus garage at Piccadilly, York, and the first example, G-ABSI c/n 4, although ordered only in June 1931, was completed at the end of March 1932. The aeroplane, measuring about 16ft in width, was towed to Sherburn-in-Elmet for its first flight, meeting on the way the rudder of the liner Berengaria which was being carried in the opposite direction.
At Sherburn-in-Elmet on April 5 H. V. Worrall, who had shared the flying with Cobham on the round-Africa flight in the Short Singapore, took the Ferry on its first flight. It was generally satisfactory, apart from the small problems mentioned earlier, but its loaded take-off run of 570ft and its taking 45min to reach 10,000ft were not considered satisfactory. After fitting finer-pitch propellers, an improvement in performance was achieved. Empty weight, at 3,4361b, was 241b less than estimated. All-up weight was 5,4001b.
From Sherburn-in-Elmet G-ABSI went to Martlesham Heath for its certification trials. These were completed in four days, the C of A was issued on April 21, and on April 24, after 13hr flying, it was delivered to National Aviation Day and named Youth of Britain II.
Performance figures in the Martlesham report included: maximum speed at sea level 108 m.p.h., at 5,000ft 103 m.p.h.; cruising speed at 1,000ft 85-90 m.p.h.; stalling speed 49 m.p.h.; take-off run in still air 600ft; take-off distance to 80ft 1,500ft; initial rate of climb 520ft/min; time to 5,000ft 14min; time to 10,000ft 38min; absolute ceiling 13,000ft; range 320-340 miles.
Delivery of G-ABSI was too late for the start of the National Aviation Day 1932 season which began at Hanworth on April 12. It is believed to have made its first appearance in the display at Stag Lane on May 1. The delay in the Ferry joining the display team was partly due to two minor mishaps following its Certificate of Airworthiness tests—a broken bolt in the undercarriage and trouble with an exhaust pipe.
The second Ferry, G-ABSJ c/n 5 Youth of Britain III (later Youth of Africa), received its C of A on June 10 but was out of service for a time after an accident in July. By the end of the display season on October 16, the two Ferries had flown 640hr with Cobham, made 9,100 flights and carried 92,000 passengers (presumably there were some children in arms). In its first three months G-ABSI, alone, had flown 288hr, made 3,600 flights and carried about 36,000 passengers. H. A. (Tony) Taylor in his Airspeed Aircraft since 1931 (Putnam, 1970) reported that turnrounds were made in less than 30sec and refuelling was done in 90sec.
G-ABSI was silver overall with green struts, spats and lettering (as, I believe, was G-ABSJ) and retained this livery in 1933.It is reported to have been pink in 1934 I cannot confirm the colour but by that time it was no longer carrying its name and its spats had been removed.
In 1933 the National Aviation Day programme was split into No 1 and No 2 Tours, with No 1 Tour beginning at Dagenham on April 15 and No 2 Tour starting at Southend on the previous day. For part of the season at least, G-ABSI flew with No 1 Tour and G-ABSJ flew with No 2 Tour. On April 20 No 2 Tour visited Hertford. It was a warm, wet day and I remember seeing the display formation flight over the town—my first view of the Airspeed Ferry. According to Cobham's list of towns visited in 1933, No 1 Tour was at Welwyn on April 26, but it was not. Cobham had invited me to that day's display and I went from Hatfield to Welwyn by bus. It was a hot day and I walked for miles following the "To the Air Display" signs and arrived at a field near Welwyn Garden City which I had passed a long while before. During the display I heard Cobham tell his publicity people exactly what he thought of their inaccurate signposting, for he had forgotten that his voice would come over the public address speakers!
April 26, 1933, is a date I shall never forget because Cobham gave me a free ticket for my first flight. I climbed aboard G-ABSI, took the front starboard seat and as soon as all seats were filled the pilot (J. King) opened the throttles and began a rolling take-off, making about a 100° turn into wind. I remember looking down at the big green starboard spat and up at the starboard Gipsy II. I also remember reading 85 m.p.h. on the ASI and being astounded because we appeared to be travelling so slowly. On getting out I noticed an advertisement on the rear bulkhead which read "No smoking not even Abdullahs".
G-ABSJ was disposed of in 1934, but G-ABSI remained with Cobham until the end of the National Aviation Day displays on September 29, 1935. From July 1 that year the displays were split into two as the "Astra" Show (with the Handley Page Clive G-ABYX) and the "Ferry" Show (with G-ABSI). The last Ferry Show was at Tonbridge.
Only two other Ferries were built, G-ACBT and G-ACFB (c/ns 6 and 9), and both went to Midland & Scottish Air Ferries, the first being delivered from York in February 1933 and the second from Airspeed's new Portsmouth factory that June. G-ACBT received its C of A on February 7 and G-ACFB on June 2. The latter had radio and a lavatory, without undue loss of payload because the permissible all-up weight had been increased and both had modified fuel systems, with the tank removed from above the centre engine.
Midland & Scottish Air Ferries was founded by John Sword, a director of SMT (Scottish Motor Traction Co), on March 10, 1933, and the airline began Glasgow—Campbeltown—Islay and Glasgow—Campbeltown—Belfast services on June 1 that year with de Havilland Dragons. On September 1 a Hooton—Speke—Dublin service was begun and operated with an Avro Ten. Whether the Ferries ever operated on these routes I do not know, but they did work Hooton—Castle Bromwich (Birmingham) and Heston—Castle Bromwich services during the period February 19—March 2, 1934, in connection with the British Industries Fair. They did play some part in working the Romford (later Abridge)— Birmingham—Liverpool—Glasgow and Liverpool—Isle of Man—Belfast services which began on April 9, 1934, there being photographic evidence of G-ACBT at Ronaldsway, Isle of Man. However, Midland & Scottish ceased operations on September 30, 1934. G-ACBT was never used again and I saw it at Renfrew on the second day of the war—it was covered with tree branches to prevent the Germans seeing it!
What happened to G-ACFB after the closure of Midland & Scottish is not recorded, but in April 1936 it went to C. W. A. Scott Air Displays which had acquired G-ABSI the previous month. That November both were acquired by Air Publicity at Heston and during the winter of 1936-37 the Ferries were re-engined, each getting three 130 h.p. D. H. Gipsy on September 29, 1935. From July 1 that year the displays were split into two as the "Astra" Show (with the Handley Page Clive G-ABYX) and the "Ferry" Show (with G-ABSI). The last Ferry Show was at Tonbridge.
Only two other Ferries were built, G-ACBT and G-ACFB (c/ns 6 and 9), and both went to Midland & Scottish Air Ferries, the first being delivered from York in February 1933 and the second from Airspeed's new Portsmouth factory that June. G-ACBT received its C of A on February 7 and G-ACFB on June 2. The latter had radio and a lavatory, without undue loss of payload because the permissible all-up weight had been increased.
Both had modified fuel systems, with the tank removed from above the centre engine. Midland & Scottish Air Ferries was founded by John Sword, a director of SMT (Scottish Motor Traction Co), on March 10, 1933, and the airline began Glasgow—Campbeltown—Islay and Glasgow—Campbeltown—Belfast services on June 1 that year with de Havilland Dragons. On September 1 a Hooton—Speke—Dublin service was begun and operated with an Avro Ten. Whether the Ferries ever operated on these routes I do not know, but they did work Hooton—Castle Bromwich (Birmingham) and Heston—Castle Bromwich services during the period February 19—March 2, 1934, in connection with the British Industries Fair. They did play some part in working the Romford (later Abridge)— Birmingham—Liverpool—Glasgow and Liverpool—Isle of Man—Belfast services which began on April 9, 1934, there being photographic evidence of G-ACBT at Ronaldsway, Isle of Man. However, Midland & Scottish ceased operations on September 30, 1934. G-ACBT was never used again and I saw it at Renfrew on the second day of the war—it was covered with tree branches to prevent the Germans seeing it!
What happened to G-ACFB after the closure of Midland & Scottish is not recorded, but in April 1936 it went to C. W. A. Scott Air Displays which had acquired G-ABSI the previous month. That November both were acquired by Air Publicity at Heston and during the winter of 1936-37 the Ferries were re-engined, each getting three 130 h.p. D. H. Gipsy Major four-cylinder inverted inline units. G-ABSI went to Portsmouth Southsea and Isle of Wight Aviation in June 1939 although it is thought to have seen little use on the company's ferry services. It was impressed as AV968, served the Halton Station Flight, and finally went to No 474 ATC Sqn at Long Eaton in Derbyshire, becoming instructional airframe 2758M. It was struck off charge in June 1945. G-ACFB had remained at Heston since expiry of its C of A in November 1938 and was impressed in February 1941 as DJ715. It was then dismantled and taken by road to Meir, Stoke-on-Trent, for No 1037 ATC Sqn.
G-ABSJ, which had been disposed of by Cobham in 1934, went to Himalaya Air Transport and Survey Co as VT-AFO Dragoman and spent six months carrying pilgrims from Hardwar to Gaucher. Long reported as having been eaten by white ants, it appears that its ultimate fate was to be burned by vandals when in a hangar at Delhi on October 5, 1936. During its service in India the Ferry was flown by K. R. (Keki) Gazder who later became a senior Air-India commander
Airspeed had hopes of securing worthwhile orders for the Ferry and even envisaged a cargo version, but the appearance at the end of 1932 of the de Havilland Dragon seems to have sealed the Ferry's fate. The Dragon sold for £2,800 compared with £3,975 then quoted for the Ferry, it was a simpler aircraft with folding wings, and had the advantage of using only two engines. The Dragon was also faster and did not have to meet the Ferry's stringent take-off and landing requirements. Even the financing of the few Ferries built was none too satisfactory for Airspeed. Cobham's two examples were paid for at the rate of £400 a month from the revenue they earned, and the first payment on Midland & Scottish's second Ferry was John Sword's Bentley, Airspeed selling it for only £700 instead of the estimated £900.
Although so few in number, the Airspeed Ferries played a vital role in getting people into the air and many who had their first flight in one of the Ferries went on to make their careers in aviation.
From "Airspeed - The Company and its Aeroplanes" by D H Middleton
A popular charter operation for the Airspeed Ferry was a series of flights from Stanley Park, Blackpool, to see the Illuminations. Aerodrome lighting was provided by a searchlight on a lorry.
An intriguing aeronautical theory was propounded when a Ferry was forced to land on Southport sands after a failure of one of the outer engines.
Having survived a serious row with the A.I.D (Aircraft Inspection Directorate). Capt. Orrell went to Southport to fly it home on two engines. When he arrived at site he was surprised to find that the recalcitrant engine had disappeared from the wing, the ground engineer explaining that, to save weight and drag he had carefully stowed it in the cabin. (Note : Not too sure how this saved weight perhaps the oil was drained off ?)
There it remained for the flight to Renfrew. The A.I.D. were even more incensed.
Through the summer of 1933 and 1934 the two Midland & Scottish Air Ferries (M.S.A.F). aircraft, attractively painted in white with red trim, flew from Renfrew to Campbeltown, Belfast and Speke.
At the end of 1934 Midland and Scottish was wound up and the Ferries offered for sale. Not until April 1936, was G-ACFB sold to Charles W. A. Scott's Air Display which already operated G-ABSI, the prototype, bought when the Cobham Circus closed in 1935. Scott operated them for one season and they were then flown by Air Publicity Limited.
During the following winter they were re-engined with three inverted Gipsy Major engines and carried joy riders in sprightly fashion for another season. In 1939 the prototype was bought by Portsmouth, Southsea and Isle of Wight Aviation Ltd. It saw very little service on this route. At this time G-ACBT was still awaiting a buyer at Renfrew. G-ABSI had a C. of A. overhaul in December, 1939, and was impressed into the R.A.F. G-ACFB was left picketed out at Heston when its C. of A. expired in November 1938 and ended its days with an Air Training Corps Squadron at Stoke-on-Trent.
So ended the careers of four interesting aeroplanes that were to be the precursors of the Envoy, Oxford, Horsa and Ambassador. Good reliable work-horses, built, as Hessell Tiltman said many times, with no data and no money, but none the worse for that