At the end of 1933, a new and very strange looking bomber entered service with the Royal
Air Force. This was the Handley Page Heyford, and although it looked a bit like the result
of giving an airfix kit over to a group of toddlers, it was in fact a solid attempt at
building a fast, reliable, modern heavy bomber. With a biplane wing layout, a top speed of
142 mph, and a bomb carrying capacity of just 2,500 lbs, it would appear that the Heyford
had failed to meet two of these requirements: it was neither fast, nor did it appear modern
in any way. But the Heyford, like many other aircraft of its time, was a victim to the
rapid pace of aircraft development, and while it was a mix-mash of various design choices,
in a way the aircraft equivalent of the Platypus, these choices were all made for sensible reasons.
The development of the Heyford began six years earlier, with Air Ministry specification B.19/27.
This arose out of a dire need for a dedicated long-range night-time bomber. Since the end
of the first world war (almost a decade earlier), this class of aircraft had remained virtually
unchanged in the Royal Air Force, and this was for a number of reasons. 1) The air ministry
was constantly trying to save costs. 2) Unless relationships with France suddenly worsened
there was no real need for a long range bomber. And 3) There were efforts being made by members
of the League of Nations to limit the development of heavy bombers, if not ban them altogether.
Because of this, the most modern heavy bombers in the RAF inventory in 1927 were things like
the Handley Page Hyderabad…with a top speed of just 109 mph, wood and fabric construction,
and a range of no better than 500 miles. Obviously this would not do for the long term, lest
the RAF fall far behind its European counterparts, and although experiments had been made on
using metal structures with some bombers, such as the Handley Page Hinaidi, it was accepted
that the template for RAF night time bombers had to be modernised.
The specification that led to the Heyford called for a twin-engine bomber that had a
range of 920 miles; a military load of 3,165 lb (including crew and defensive guns); a
cruising speed of no less than 115mph at 10,000 feet; and service ceiling of no less than
17,000 feet. Additionally, the aircraft was to provide excellent visibility for level
bombing at night; positive stability for hands-off cruising when trimmed; adequate self defence;
and the ability to maintain level flight on one engine. Though reasonably modest, these
requirements represented a significant upgrade for the RAF night time bomber force in 1927.
In response to this specification the design team at Handley Page, led by George Volkert,
proposed the Handley Page HP.38. Though slightly different from the Heyford Bomber that would
eventually enter service, this initial design featured all of the technical innovations
that made the bomber so interesting – both visually and technologically.
It was the first Handley Page bomber to be built with an all-metal structure from the
outset, and it featured semi-monocoque construction in its fuselage. This was used at the extreme
front and rear of the fuselage, and the rest was built up from a framework of tubular steel
longerons and struts that were covered in fabric.
This fuselage held a crew of four: a pilot, a navigator who also kept busy filling the
roles of bomb aimer and front gunner, then there was the wireless operator who also doubled
as the dorsal gunner, and then there was the rear gunner who often spent their time in
this: the dustbin turret. Though it had the aerodynamic properties of, well, a dustbin,
it did provide excellent all-round defence for the Heyford’s underbelly, an area that
was often considered the weakest spot for many bombers of this period.
Another weakness of many bombers of that time was speed, or rather a lack thereof. The interesting
placement of the Heyford’s fuselage was part of an attempt to address this. Brute
engine power could only do so much, and to improve aerodynamic performance it was realised
that the upper surfaces of the Heyford’s wings had to be kept clear. This resulted
in two things: the wingspan was limited to 75 feet, to prevent the need for wing-folding
mechanisms, and the fuselage was suspended below the upper wing, rather than sitting
atop the lower wing. Now while this did place the pilot and aircrew
at a dizzying height above the ground, it did provide benefits for the ground crew.
With the fuselage out of the way, the central part of the lower wing was thickened to facilitate
a series of bomb cells. This, combined with the fact the engines were mounted so high
off the ground, would allow ground crews to re-arm the Heyford on the ground with the
engines running, which while probably very loud and blustery was mostly safe – unless
the ground crew happened to be about 10 foot tall.
The prototype HP.38 took some time to complete, not being ready until mid-1930. This was not
only due to its all metal structure, which included the first duralumin monocoque to
be fitted to Handley Page bombers, but also due to problems in wind tunnel testing. Numerous
modifications had to be made to both the fixed undercarriage and the various gunner’s stations;
the dustbin turret in particular proved to be a bit of a headache. Its mechanisms were
initially prone to jamming, and there was only so much you could do to negate the effects
of a giant, protruding cylinder on the aerodynamics of the aircraft.
When the prototype was complete it was powered by a pair of Rolls-Royce Kestrel II engines.
These produced 525hp and drove two-blade fixed pitch propellers – though four-blade units
would be fitted later. Variable pitch propellers were considered, but problems in adequately
synchronising them during early tests led to them being set aside as too complex for
the time being, particularly as Handley Page was now under considerable time pressure to
get the aircraft airborne and evaluated. Its first flight took place on the 12th of
June 1930, with pilot Jim Cordes at the controls. His report, and that of subsequent pilots,
was mostly favourable. The aircraft had effective controls, good handling across the entire
speed range, and, despite the cockpit being 17 feet above the ground, it was quite easy
to take-off and land. There were two points of concern. Firstly, low amplitude fin vibrations
caused the throttle lever to slowly move down to the closed position (not ideal), and secondly
it was felt that the undercarriage was both too stiff and not strong enough to handle
the repeated forces of landing. These latter doubts were quick proven correct when the
undercarriage collapsed later that day during taxiing.
The next few months were a bit of a scramble to update the prototype in preparation for
a competition against models submitted by Fairey and Vickers. Larger radiators were
to be fitted to address overheating issues during sustained climbs; various reinforcements
were made to the undercarriage so that the aircraft could actually taxi, and not try
to imitate a field plough; the layout of the cockpit was revised; and numerous small changes
were made to the airframe. Things were then further complicated in September, when Squadron
Leader Mansell inspected the prototype and passed serious remarks that there was not
nearly enough space to adequately accommodate the four-man crew.
The changes he recommended, which included widening the forward fuselage by five inches,
and expanding the gunner stations, could not have been achieved before the competition
at Martlesham Heath was to begin. However, fate intervened, and the competing aircraft
built by Vickers crashed due to a double engine failure; the competition was postponed, and
modifications were made to the Handley Page prototype to bring it up to scratch.
These changes would eventually bear fruit, for numerous other delays meant that the prototypes
evaluation report would not be complete until early 1932 – the aircraft competition now
being well over a year behind schedule. Handley Page received an anonymous, but well informed
letter, telling him that his bomber was the most popular of the competition, boasting
superior crew comfort than its rivals. The letter also went on to comment that with the
Vickers project delayed yet again, and with the Fairey monoplane suffering from all kinds
of stability problems, Handley Page should feel moderately confident of a production
order. With this in mind, a final redesign was carried
out to improve the bomber as much as possible for RAF service. This redesign not only involved
changes to the monocoque, but also the tailplane, rudders, undercarriage fairings, and the engine
nacelles – which had revised radiators and fuel tanks. These revisions resulted in the
aircraft being redesignated as the HP.50 It was at this point that the project almost
came to a complete end. The League of Nations had raised the question of completely abolishing
bombing, and the Air Ministry had to hold off on any new production contracts until
a decision had been made. This nearly resulted in a mass layoff at Handley Page, a company
who’s bread a butter was the production of bomber aircraft. But just a few months
later the situation was completely reversed by the Japanese invasion of Manchuria, and
a production order for fifteen Handley Page Heyford was placed in March 1933.
The prototype should have been the first to join the RAF, but after years of dutiful testing
it was destroyed during armament trials with no.10 Squadron. In truth, it was somewhat
of a miracle that the prototype had lasted this long. Previously a pilot had landed it
with only one break applied, resulting in 2 ½ ground loops; another incident involved
the collapse of the starboard undercarriage, and another resulted in a shattered propeller
due to spent gun casings striking the blade. Because of this loss, the first production
Heyford was assembled by hand and used as a stand-in prototype, though it was structurally
identical to all other production models. It made its first flight on the 21st of June
1933, and following a brief visit to Hendon where it was displayed at the SBAC trade show,
it was then sent to Martlesham for its service trials.
The second and subsequent Heyfords would first enter service with No.99 Squadron in Upper
Heyford, for which the aircraft was named after. Delivery of the bombers began on the
14th of November 1933, and the last of the first batch entered operational service the
following March. Operationally, the Heyford was a big improvement
on its predecessors. A novel feature was that the bombs, together with the racks, were hoisted
into position as an integral unit. This was done by a special winch in such a way that
when the bomb carrier reached the mounting point it was instantly locked, with no further
adjustments needed other than plugging in the electric wires for the fusing and release
of the bombs. This, along with the fuelling points being
mounted in convenient positions on each side of the undercarriage spats, allowed rapid
turnaround between sorties. In fact, it was claimed by Handley Page that turnaround between
two 900-mile missions could be done in as little as half an hour, which by any standard
is a considerable achievement. Despite its ungainly appearance, the Heyford
was easy to manage and quickly became well-liked by its crews. RAF pilots almost unanimously
declared it to be viceless, and the Heyford was manoeuvrable enough that it could even
be put through an aerobatic loop. This it did several times, one of which was during
an air show, which would have been interesting sight for onlookers who might reasonably have
assumed it had the handling abilities of a post-box.
It wasn’t long before sub-variants of the Heyford took over from the initial Mk.I model.
When a second order for 23 aircraft was placed, they incorporated several changes and were
known as the Mk.1A. These The changes included various weight and drag savings, and the aircraft
now had Kestrel III engines which boasted engine-driven electric generators. Many of
the first fifteen Heyford Mk.Is were later converted to this spec, and several aircraft
also had four-blade propellers of a reduced diameter replace the old two-blade units.
Following the Mk.IA came the MK.II and Mk.III. The only major difference with these was the
installation of the Rolls-Royce Kestrel IV. In the Mk.II the engine was slightly downrated
to 640hp, due to problems with cooling, but in the Mk.III they produced approximately
700hp thanks to the installation of newer condenser units. This last model was the most
produced, with two orders totalling 70 being placed as part of the RAF’s expansion plans
in 1936. Considering the time period in which they
operated, it will come as no surprise that the Heyford’s lived a fairly quiet life,
and that they weren’t in service for particularly long. When they weren’t doing cross-country
formation flights or bombing exercises, they were often seen at various air shows. In 1934
and 1936 the Heyfords of 99 Squadron would take part in the annual RAF Display at Hendon,
in the latter event they were also joined by Heyfords from 102 Squadron, who took part
in dummy bombing runs and various other demonstrations. 102 Squadron would also suffer the only major
loss of Heyfords during their operational service. Seven Heyfords were en route from
Northern Ireland to their base in Yorkshire when they encountered severe fog and icing
conditions over England. Only one aircraft ended up making it to its destination, three
made forced landings, and three more crashed – either due to poor visibility or due to
a loss of control as a result of ice. Total casualties amounting to three killed and three
wounded, and the loss or damage of several airframes, amounted to a major weather-related
incident, at least for peace time anyway. By the time that peacetime became decidedly
not peacetime, it was 1939, and by this point most Heyfords had been relegated to the training
role. They had began to be replaced as early as 1937, with the Vickers Wellington and Armstrong
Whitworth Whitleys joining the ranks of Bomber Command, but a few would actually find use
during the second world war. One Heyford was loaned for experiments in
aerial refuelling. Another was used to test the installation and use of various airborne
radar systems. And another was used by the Royal Aircraft Establishment for testing new
de-icing systems. The last Heyford’s weren’t struck off charge until the end of 1941, which
meant that for a time they served as amusing examples of just how quickly things had developed
in the world of aviation. Supposedly young RAF pilots more than once remarked that the
so-called “upside-down” bomber looked like it came from another age, except that
age was a mere 7 years ago. But that’s how things went during the 1930s,
aircraft were modern one day, obsolete the next, and sometimes they were even obsolete
before they left the factory – which is a category that the Handley Page Heyford almost
falls into. As always, thank you all so much for watching,
and a big thank you of course to the patreons, who’s names you’ll see here. Thank you
as well to Mark who made that brilliant model of the Heyford you saw just before, he has
produced an insane number of 3D models, and I’ve had the priveledge of being able to
commission some special ones. So there’s plenty more to look forward to. A big thank
you of course to our wing commander tier patreons, our highest tier members, and a warm welcome
to B Hijmering, who is the newest member of this special group. Providing nothing goes
wrong, the next video will be for the topic you all voted on last month, so stay tuned
for that. But as always, thank you all so much and I’ll catch you all next time. Goodbye.