Aircraft Profile #182. Handley Page Heyford

Last of the R.A.F.'s biplane heavy bombers, the Heyford was built to the same 1927 specification (B.19/27) as the Fairey Hendon, the first of the big monoplane bombers, but unlike the latter (whose production was long delayed) it was destined to serve with no less than eleven first-line squadrons. Compared with its predecessors, the Handley Page Hinaidi and the Vickers Virginia, the Heyford was a much cleaner-lined machine and it introduced many original features including a rotating and retractable ventral "dustbin" turret.

The Heyford was termed "express bomber" by Handley Page because not only could it carry a considerable load of bombs at high speed, but its arrangements for ground servicing were such that refuelling, re-arming and running adjustments could all be undertaken simultaneously in the shortest possible time. The makers claimed that the machine could be turned round after a 1500km flight in the space of half-an-hour.

The arrangement of the fuselage abutting under the surface of the top wing gave the crew a field of vision hitherto unknown in a bomber and this, with the wide field of fire enjoyed by the gunners, combined in the Heyford some of the advantages of a monoplane with the manoeuvrability of

The H.P.38, J9130, as originally flown, seen at Radlett in June 1930

a biplane. However, it meant that the pilot's cockpit was a long way from the ground. The pilot, in fact, sat 5m up, which meant that much practice was required to make a good landing.

The prototype of the Heyford was the H.P.38 which was designed by Mr. G. R. Volkert (then H.P.'s Chief Designer) and his team to meet Air Ministry Specification B.19/27. Serialled J9130, it had a fabric-covered all-metal airframe and two 550hp Rolls-Royce Kestrel II engines; it first flew in June 1930 at Handley Page's then-new airfield at Radlett, piloted by S/Ldr. T. H. England, the company's chief test pilot. During the summer of 1932 J9130 appeared in the New Types Park at the R.A.F. Display, Hendon, and was also test flown together with the Fairey B.19/27 by pilots of several bomber squadrons, including Nos. 9 and 99. No. 99 considered the H.P. 38 “nice to fly and easy to handle but doubts were expressed concerning the strength of the undercarriage." The doubts were well-founded, for on 10th June, 1932, the H.P.'s undercarriage collapsed at Upper Heyford "for no apparent reason" following a flying demonstration before the Air Member for Supply and Research and the A.O.C.

The H.P.38 at Radlett in June 1930 in company with Hinaidi, its immediately lineal precursor

Western Bombing Area. The machine was repaired only to be crashed on 8th July by a No.10 Squadron pilot at the Armament Practice Camp at North Coates Fitties; it hit an embankment on the edge of the airfield, caught fire and was totally destroyed – fortunately without causing injuries to personnel.

By this time the H.P.38 had been accepted by the Air Ministry and an order placed for a production version known as the H.P.50 (to B.23/32), eventually named Heyford after the bomber station at Upper Heyford, Oxfordshire. The production Mk.I incorporated various improvements. For example, the undercarriage was not only strengthened but now featured deeper spats which covered the lower part of the wheels. Smoother cowlings covered the two 575hp Kestrel IIIS or IIIS-5 engines in the Mk.I, short "ram's horn" exhaust manifolds replaced the long exhausts of the H.P.38 and the underslung radiator beneath each engine was enclosed in a tunnel housing.

The fuselage of the Heyford was made in four main sections, joined together by bolts. The front, monocoque, portion was built up of duralumin formers and longerons covered with Alclad; the skin was reinforced by external stringers and the side of the rear half of the

Maj. Cordes revs up the prototype's Kestrels for take-off at the R.A.F. Display, Hendon, 25th June 1932. Note the machine's modified exhausts ("ram's horn" type) and wheel spats

monocoque was reinforced by an internal diagonal member. The after sections of the fuselage were built up from steel tubular longerons and struts with tie-rod cross-bracing and were fabric-covered. The extreme end of the fuselage was faired off by an aluminium monocoque streamlined box, hinged to the main structure so as to allow access to the complete interior of the tail. The fuselage was carried over the bottom wing centre section by two metal vee struts.

The wings were of duralumin construction with fabric covering. They were equal in span and chord and the top wings were fitted with Handley Page automatic slots. Both sets of wings were in three sections, two outer and one centre section. The lower centre section was deep to accommodate the bombs and was suitably reinforced. The interplane struts were streamlined metal tubes.

The tail unit was of the strut-braced monoplane type with twin-balanced rudders and strut-braced fins. It was metal-framed with fabric covering, and the angle of incidence of the tailplane was adjustable in flight.

The undercarriage comprised twin single units with wheels (Palmer, with pneumatically-operated brakes) faired into the lower wing. The telescopic oleo struts were hinged to the front interplane strut inside the

The first production H.P.50 Heyford, K3489, in original form 23rd June 1933 shortly before appearing at the Hendon Display.

engine mounting. Each wheel was carried on a fork, and the single telescopic strut allowed the wheel to rise and fall, together with its spat. The tailwheel was of the fully-castoring type and was fitted with a low-pressure tyre.

For normal operations the Heyford carried a crew of four comprising (1) pilot; (2) navigator, combining duties of bomb-aimer and front gunner; (3) wireless operator (who in a defensive action doubled as mid-upper gunner); and (4) rear gunner, normally located in the mid-upper gun position, but manning the ventral "dustbin" turret in a defensive action. The crew had quick and unimpeded access to one another, and were provided with intercommunication apparatus. Dual control could be fitted alongside the first pilot's seat, for instructional purposes; the extra set of controls was built up as a complete unit and could be installed within half-an-hour.

Entry into the Heyford was gained via a small trap door in the fuselage floor, above the trailing edge of the lower centre section. Steps, fitted on the vee struts which supported the fuselage from the lower wing, rendered access to the interior very easy. Aft of the trapdoor were the rear gunner's cockpit and the retractable "dustbin" turret,

A delightful study of two Heyford I's of No.99 Squadron at Mildenhall, being prepared for a night raid during the 1935 Air Excercises. Note that crews are wearing electrically-heated flying suits and Heyfords are carrying reconnaissance flares beneath lower wing.

while ahead stretched the front fuselage with, first, a large stowage compartment, then navigation and wireless compartment, pilot's cockpit, and finally, in the extreme nose, the front gunner's compartment.

In the rear gunner's compartment there was a tip-up seat on the starboard side, ammunition drums on pegs, points for the electric heating of flying clothing, etc., and so forth. The floor of this compartment was slightly raised, and to the rear was the retractable gun turret, which was entered from the gunner's compartment and lowered by him. When in the "down" position the turret could be rotated through a considerable range. In the front of the gunner's cockpit was a large compartment used for stowing all manner of gear, but with ample gangway space. The floor was corrugated aluminium with wooden strips, for walking on, let into the corrugations.

Immediately ahead of the plane of the front spars was the navigation and wireless compartment, with revolving seat and holding table on the port side. Forward of the table, and also on the port side, were shelves on tubular stanchions carrying the wireless equipment, the battery of which was placed on the floor under the set.

Separating the wireless compartment from the

The first production Heyford, K3489, 25th November 1933, after modifications had been made to wheel spats and exhausts. Heyford Mk.I's were originally fitted with two-bladed airscrews but in service they were retro-fitted with four-bladers

pilot's cockpit was a half bulkhead, on the port side. On the inner edge of this bulkhead was the very large tail-trimming wheel. On the starboard was a seat for the second pilot. This was designed in such a way that it folded flat against the wall, providing a free passageway to the nose. On the port side, just ahead of the bulkhead, was the seat for the first pilot. This was divided into two halves, the half nearest the outer wall being fixed, while the inner half hinged down to enable the pilot to get into his seat between the back rest, the rim of the tail-trimming wheel, and the engine-control pillar rising from the floor. Once in his place, the pilot raised the inner half of the seat which was provided with a catch.

A bulkhead with a two-fold door on the starboard side divided the pilot's cockpit from the front gunner's cockpit. This was provided with a "piano stool" type of seat which folded away when not in use. Firing steps were provided at the sides of this compartment so that the gunner could stand up on them and fire in a downward direction. In the

Big cloth bomber banking with ease. A splendid action study of the first production Heyford at rooftop height over Radlett airfield, 25th November 1933.

extreme nose of the fuselage was a large window, hinged along its upper edge and used for bomb-aiming. On the starboard side were the bomb selection switches, while on the rear wall of this compartment were stored ammunition drums and other equipment.

As mentioned earlier, particular attention was given by the Heyford's designers to rapid turn-round between sorties. A bomb loading arrangement was devised which enabled adjustment of the bombs on to the racks, fuse-setting and so forth to be done away from the aircraft, thus reducing the time taken to re-arm. A novel feature of the Heyford was that the bombs, together with racks, and correctly adjusted, were hoisted into the machine as an integral unit, by a special winch in such a manner that when the bomb carrier reached the locating point, the rack was instantly locked; no further adjustments were necessary other than plugging in the electrical leads for the fusing and release of the bombs.

Fuelling (oil and petrol) points were provided in a convenient position on either side of the main undercarriage "spats", thus rendering it unnecessary for men to climb over the machine with long hosepipes. Supports for the crank handles of the engine

K3503, the interim Heyford I/IA which served as the prototype Mk.II pictured at Radlett on 21st June 1934, shortly before appearing in that year's R.A.F. Display at Hendon. This aircraft was later converted to Mk.III standart and at some time served with No.166 Squadron

hand--starting gear were located on a covered platform above each wheel spat; the crank handles were not, of course, permanently fitted but could be shipped and unshipped in a few moments and carried from one engine to the other.

The high mounting rendered the engines somewhat inaccessible (although this did enable the armourers to reload the bomb bay in perfect safety while the engines were running) but light hook-on ladders helped the mechanics to overcome this difficulty. The ladders (which were stowed inside the fuselage when not in use) could be placed in position in a few seconds, and the side panels of the engine nacelles swung down to form working platforms.

The first production Heyford, K3489, made its maiden flight on 21st June, 1933, at Radlett, piloted by Major J. L. Cordes who had now succeeded S/Ldr. England as Handley Page's chief test pilot. This machine was rushed through the shops in order that it might be demonstrated, a few days later, at the S.B.A.C. Display at Hendon, and it did in fact fly at Hendon as programmed. After Service equipment had been installed, the machine underwent official performance tests at Martlesham Heath and was judged by the

Mk.I, K3492 'N', of No.99 Squadron

Air Ministry to be the most efficient large biplane ever tested up to that time.

Chosen as the first squadron to receive the Heyford was No. 99, appropriately at Upper Heyford; this unit had also been the first to get the Heyford's two immediate lineal predecessors, the Hyderabad and the Hinaidi. Delivery of Heyford Mk.Is to No. 99 began on 14th November, 1933, and re-equipment continued until the following March, by which time 10 (I.E.) and 3 (L.R.) were on strength.

A sub-variant of the Heyford Mk.I was the Mk.IA which could only be distinguished from the original version by the absence of the wind-driven generator on the IA. This latter mark had modified engine bearers and a motor-driven generator. As these alterations affected loading weights -important when arranging the bomb load - a suffix to cover them was given to the mark number. Following the Mk.IA came the Mk.II and Mk.III each powered by 640hp Kestrel VIs (de-rated in the case of the Mk.II but operating at full power in the Mk.III) and built to Specifications 28/34 and 27/35 respectively. Both types differed from its predecessor not only in the mark of Kestrel installed but also in having the

K4029, the intermediate Mk.IA/II seen at Radlett on 29th May 1935

engines in mountings raised 45cm and of smaller cross-sectional area. These modifications reduced the aircraft's weight, drag and fuel consumption and thereby improved its performance all round. A further change — but only in the Mk.III - was the installation of steam condensers in the leading edges of the top outer main-planes. The prototype Mk.II, K3503 from the initial batch of Mk.Is, had an enclosed cockpit canopy with part of the front coaming cut away to improve view. An interim Mk.I/IA, K4029, also had a canopy fitted, while the mid-upper gunner was sheltered by a streamlined fairing which eliminated the adjustable windscreen normally fitted to the Heyford and reduced drag. However, neither the canopy nor the fairing were adopted for subsequent production aircraft.

In addition to serving with No.99 Squadron, Heyfords also equipped Nos. 7, 9, 10, 38, 78, 97, 102, 148, 149 and 166 (Bomber) Squadrons. Despite its rather ungainly appearance, the Heyford was well liked by its crews and was very easy to maintain. It had no tricks or vices and such was its manoeuvrability that it was looped on several occasions, including at least one air display when the spectators could hardly believe their eyes! In

A Heyford III (K5188) photographed in November 1935. This particular machine later served with No.102 Squadron and No.4 Air Observers School, in turn, and was struck off charge 19th July 1940

1934, and again in 1936, Heyfords of No.99 Squadron took part in the R.A.F. Display at Hendon. In 1936 four of No.102 Squadron's Heyfords did the "skittle bombing" event at Hendon and five No.102 squadron machines joined five more from No.99 Squadron in the finale "set piece" - a bombing attack on a dummy power station. At the Royal Review of the R.A.F. in July, Nos.10 and 99 Squadrons' Heyfords led the mass flypast of aircraft at Duxford where H.M. King George V took the salute after having previously inspected his squadrons on the ground at Mildenhall. To return to No. 102 Squadron: on 12th December, this unit suffered what amounted in peace time to a major disaster when seven Heyfords en route from Aldergrove, Northern Ireland (where they had attended armament practice camp) to Finningley, Yorkshire, encountered dense fog and icing conditions over England. Only one aircraft managed to reach its destination, three crashed (one having first been abandoned by its crew when it became uncontrollable), and three made forced landings, albeit successful. Total casualties were three airmen killed, one seriously injured and two slightly injured.

By today's standards the Heyford had a comparatively short Service life, being superseded within

A pleasing study of Heyford IA K4023 'K' of No.10 Squadron, flying near North Coates Fitties, 1935. The clearance between propeller tips and fuselage was about four inches — note pilot's guard rail.

the compass of six years by the monoplane bombers of the Expansion era — notably Whitleys and Wellingtons. It was completely obsolete by 1937 but it nevertheless soldiered on until the summer of 1940 as a bombing and gunnery trainer. The R.A.F.'s last two Heyfords were struck off charge in April and May, 1941.

One Heyford (K5184, a Mk.III) was loaned to Flight Refuelling Ltd., at Ford, Sussex, for experimental use in June 1939, while two-and-a-half years previously another Heyford (serial unknown) played an important part in some early radar experiments. At that time British scientists were striving to produce, on a scale to fit inside an aircraft, radar equipment to provide results comparable with those of the existing ground installations - which weighed tons and used aerials up to 70m high. By December, 1936, a small receiver was completed and fitted in a Heyford, and when used in conjunction with a ground transmitter, this set gave the first proof that echoes from one aircraft could be received in another. During early 1937 a transmitter was also installed in the Heyford. The emphasis at this time was still on producing equipment to detect other aircraft, but during test flights

Heyford I's of No.99 Squadron seen in flight, March 1934: K3493 'U'. Note raised windshield to protect mid-upper gunner from slipstream.

around Harwich it was noticed that echoes were received from the coastline and harbour installations. Later in 1937 a more advanced set was installed in an Anson and with this ships were successfully intercepted at sea; thus was born air-to-surface vessel (A.S.V.) radar equipment which was to play a major role in Coastal Command's war against the U-boats tn World War 2. A further experimental Heyford was the machine employed by the Royal Aircraft Establishment, Farnborough, for testing de-icing apparatus, and described by Air Commodore A. E. Clouston in his book “The Dangerous Skies”. A set of pipes, perforated with minute holes, was fitted along the leading edge and covered with a fine wire mesh, contoured to the shape of the wing. An anti-freeze mixture of glycol and alcohol was fed from a tank inside the aircraft to the pipes, from which the mixture escaped to ooze through the wire mesh and spread over the leading edge in flight. The mixture worked, although Clouston says he preferred an alternative system - "the clean, simple system" - of inflatable rubber de-icing shoes, which he had previously tested on a single-engined Northrop 2E bomber.

(C) Philip J. R. Moyes, 1967