The Fairey Hendon is unique amongst the family of Fairey aircraft, aside from their very
first– the F.2 prototype of 1917 – the Hendon would be Fairey’s only other twin-engine
aircraft and their sole foray into heavy bomber design.
In 1927 the Air Ministry issued specification B.19/27.
This called for a twin-engine night bomber that could carry a 1500lb bomb load over a
range of 920miles at 115 mph, it also specified that the bomber should be able to climb from
ground level to 10,000ft in half an hour.
Fairey submitted two designs in December that year; both of the designs were very similar
with the exception that one would be powered by Bristol Mercury radial engines, and the
other by Rolls Royce liquid cooled vee engines.
Along with Fairey, the Air Ministry also received submissions from Avro, Handley Page and Vickers,
but Fairey’s design was the most advanced.
All of the other submissions were traditional biplane designs, whereas Fairey was proposing
an all-new metal-framed monoplane.
The man who led the design team, P.A.
Ralli, had been responsible for the design, aerodynamics and testing of Fairey’s striking
Long Range Monoplane, and there is no doubt those aircraft influenced the decisions he
made when designing the Hendon.
The Air Ministry was interested in the proposal, and after discussions about the general layout,
equipment, weapons and crew positions, a contract was placed in October 1929 for the production
of a radial-engine prototype.
The design of Fairey’s new bomber had a number of new features, and it also had a
somewhat curious wing design.
The large cantilever wing had a very deep cross-section when compared to a lot of other
designs and the centre section of the wing was built integrally with the fuselage.
This centre section was built up around two main steel spars with each of the upper and
lower spar-boom consisting of square tubes.
The wing sections further out from this were braced by a system of tubes arranged into
pyramids, a Fairey design by the way, and these were supported by bracing wires.
The fuselage was also built from steel tubing, with the rear section built as a warren truss,
and the whole aircraft was supported by a large fixed undercarriage that was housed
in streamlined fairings.
Though the aircraft clung to tradition in some ways – the fabric coverings of the
wings and fuselage being the best example- it also featured several innovations.
Among these was the complete internal stowage of its bombload.
Most bombers at the time either had their armament suspended beneath the wing or had
a hybrid system with a small bomb bay, but the Hendon carried all of its bombs internally.
Now it didn’t have one large bomb bay as you would imagine, but rather a series of
bomb cells.
Ten large bomb cells spanned the wing and the fuselage between the engines, and behind
these were six smaller cells, three on each side.
The large cells were designed from the outset to be large enough to accommodate one of the
new 1000lb bombs, and the Hendon was to have a total carrying capacity of 2,548lbs.
Though innovative, this arrangement came with a compromise: It shared the available space
of the wings centre section with the fuel tanks.
The Hendon had two large 250 gallon fuel tanks, each located behind the engines in the thick
centre section of the wing -it also had a pair of smaller gravity-fed 20 gallon tanks
directly behind each engine- but the main point is this: if the aircraft carried a full
fuel load, it could not carry a full bombload.
If the full 2500lb bombload was taken it would only have a range of 680 miles, conversely
if the full fuel load was taken then the bombload was reduced from 2500lbs to 1600lbs but the
range went up to 950 miles – so it was a bit of a balancing act.
Another new feature was an aluminium catwalk that ran between the tail and nose bomb aimer
and gunner positions.
This meant that all crew members were free to move to different positions whilst still
in flight, which when it came to combat survivability was a huge bonus as it meant that crew members
could tend first aid to each other, or a gunner’s position could be replaced.
To facilitate this catwalk the pilot’s cockpit was offset to the port side, which also had
the added advantage of providing a good view of the ground during taxiing, take-off and
landing.
The cockpit also had its own new feature: a fully enclosed canopy, which considering
the historically depressing state of British weather would have come as a relief for the
pilot.
Speaking of pilots and crew, a couple of sources conflict on the nominal crew compliment of
the production model.
The prototype had a crew of four, but this was later changed, and the majority seem to
agree that it was designed to finally operate with a crew of five: two pilots, of whom the
second acted as navigator, a radio operator who also acted as dorsal gunner, a tail gunner,
and the bomb aimer who also operated the nose gunner.
This last crew member is where some sources seem to conflict, with a few suggesting that
the co-pilot would also act as bomb aimer – but for me that just doesn’t make sense
to have him running…well, crawling to and from the nose all the time, so I’m going
with the five-crew layout.
Construction of the prototype was somewhat delayed as Fairey was still making up its
mind on the final wing design.
Initially the Air Ministry had been sceptical of its practicality, and although Fairey had
convinced them with the help of the Royal Aircraft Establishment, they had to finance
several wind tunnel tests before reaching a final decision in January of 1930.
Because of this the prototype, known as K1695, was not completed until November, several
months after the prototypes by Vickers and Handley Page had already flown.
Although initially designed to be powered by Mercury engines, the aircraft was completed
with two 525hp Bristol Jupiter engines instead.
It finally took to the skies on the 25th of November, flown by Norman Macmillan, and in
fact this was to be the last aircraft flown by the famous test pilot before he moved on
from the company.
All went reasonably well, though the aileron and rudder controls felt heavy, there was
some longitudinal instability, and quite a bit of care was needed to land such a sleek
aircraft, especially as it didn’t have any flaps.
It was not long after this that Fairey ran into a stroke of luck.
Their competitor’s prototypes were encountering various problems, and the Air Ministry decided
to delay the competitive evaluations by nine months.
Fairey’s good luck meant that when their aircraft decided to overrun the aerodrome
runway on landing and crash, they now had sufficient time to repair and improve it.
There had been some airflow disturbances, buffeting, and premature stalling behind the
cowled engines, and as a result of this the Jupiter engines were replaced by Rolls Royce
Kestrel V12 engines.
Around this time the control cables were replaced by rods and the slight dihedral in the tailplane
was removed.
The canopy was removed from the cockpit and a second cockpit was installed in tandem,
though this whole arrangement would later on get its own larger canopy.
During this period of time the prototype was modified several times, and it looks slightly
different in almost every photo.
The rebuilt prototype flew again in November 1931 and the following May it arrived at Martlesham
for contract trials.
After these were completed, it went on for performance and armament trials with No.10
bomber squadron of the RAF.
The report on the Hendon was not unfavourable, but the Handley Page Heyford was preferred
because of its more conventional handling characteristics, and so orders were placed
for the Heyford – not the Hendon – to go into production.
Fairey was undeterred, and the aircraft went back for further modifications.
In the meantime the RAE at Farnborough had – at Fairey’s expense – completed small-scale
wind tunnel tests with different ailerons and hinge gaps, the hope being to reduce control
loads without affecting its rate of roll.
In consequence of this the prototype was fitted with revised ailerons and servo tabs for the
elevators and rudders before being flown back to Martlesham for more tests.
This time the report was more favourable, though it still tended to land heavily at
slow speeds.
With the Vickers Wellington and Armstrong Whitworth Whitley bombers still pretty far
off, and with the Heyford already showing its obsolescence, the Air Ministry’s interest
in Fairey’s bomber began to grow and an initial order for 14 aircraft was placed in
the spring of 1934 – these would be known as the Hendon II.
This would be followed by further orders later that year, and in 1935, though they would
eventually be cancelled.
A new specification was drawn up to cover the change to the Kestrel engines and a list
of other modifications which included the reintroduction of an enclosed cockpit (to
the rejoice of all), a rotating front turret, and slipstream deflectors for the other two
gunner positions.
Production Hendons were built at Fairey’s new factory at Heaton Chapel, in Stockport.
They entered RAF service with No.38 Squadron at the end of 1936, amongst them was the original
prototype which had been upgraded and modernised to comply with the new specification.
No.38 Squadron was based at Mildenhall, which had one of the largest RAF airfields at the
time.
Due to the tendency of the Hendon to float down the runway due to its lack of flaps,
this was certainly not a coincidence, and the pilots were advised to land with plenty
of room to spare.
Despite its proclivity for hurtling off the airstrip, only two Hendons were written off
in accidents.
One of these was an interesting case.
In November 1938, a dual control Hendon (serial K5094) was crashed by a pair of leading aircraftmen
who decided it would be a great idea to take it out for a joyride at night.
Shortly after the unauthorised takeoff one of the pilots accidentally pulled the throttle
all the way shut, the aircraft promptly stalled and crashed.
Thankfully it was only about 150ft in the air, the two men weren’t seriously injured,
and they had plenty of time to contemplate their actions during their 12-month detention
after the subsequent court-martial.
Aside from rebellious crewmen, the Hendon saw little excitement during its brief service
life.
No.38 Squadron began to take delivery of the new Wellington bombers in November of 1938,
and they ceased flying the Hendon at the beginning of 1939.
Most were struck off from the list and scrapped, but four examples were delivered as ground
instruction machines to a radio school at RAF Cranwell.
If the prototype had been developed faster, and if Fairey had been taken more seriously
from the outset, the Hendon could have distinguished itself during the early-to-mid 1930s.
However, fate was mostly unkind to what was -for its time in 1930- a pretty modern aircraft,
and its poor history is perhaps the main reason why Fairey never pursued building bombers.
As always, thank you all very much for watching, and I’ll catch you all next time.