Today we’re taking a look at the Saunders Kittiwake, which was only the second aircraft
fully designed by the company, the first being a little-known biplane from the first world
war called the Saunders T.1.
This aircraft was a product of the tumultuous years that immediately followed the war.
This was a time when the aviation industry was trying to justify its existence in the
civil market as the new form of transport to compete with the long-established train
and shipping services.
In early 1920 the Air Ministry had announced a competition that would be held between August
and September to encourage the development of civil transports with this very goal in
mind.
This competition was open to both landplanes and amphibians, and Saunders organised a team
to prepare an entry for the latter, believing that amphibious aircraft would be more competitive.
It was designed by a man called FP Hyde Beadle, who had recently joined Saunders, and with
the assistance of two other Saunders designers roughly 6000 design drawings were completed
over a six week period during the summer of 1920.
The result was the Kittiwake, and it was a remarkably adventurous design for what was
meant to be the company’s first real attempt at a civil transport.
The most striking feature of the Kittiwake was its hull, which made it appear rather
ugly, and the three-deck arrangement of said hull, with a raised cockpit and cabin, also
made the aircraft appear top-heavy.
The middle and upper sections served as crew and passenger cabins, with the raised position
providing better visibility for the pilots when they were on the water.
The enclosed cockpit – a very novel feature for the time – had side-by-side seating
for two pilots, and an internal stairway connected it to the passenger cabin which could accommodate
up to 7 additional people.
Access for the passengers was provided by a companion ladder on the starboard side,
and the pilots could either enter in this way or use a small hatch on the roof of the
cockpit.
Having the cabins mounted above the hull was not only good for visibility, but it also
allowed them to be detachable from the hull, so that if damaged it could be easily replaced.
Additionally, it freed up space within the hull to accommodate the undercarriage without
compromising cabin space for either the passengers or the pilots.
The mainwheels were raised using a handcrank that was operated by the flight engineer,
who probably had the world’s strongest forearm, and because of their location they had a very
narrow track.
This was not considered much of an issue as the Kittiwake would spend most of its time
on the water, as opposed to land, but they did provide enough stability for taxiing about
on the ground if needed.
The wings of the Kittiwake were as unique as the hull.
They featured a camber-changing mechanism which caused almost the entire leading and
trailing edges of both wings to move.
These leading and trailing-edge flaps were operated simultaneously through a single control,
and the added lift provided by this arrangement was intended to offset the relatively high
take-off loads.
When fully laden, the Kittiwake was to weigh 6,200 lbs (or 2800 kilos), but it was only
powered by a pair of 200hp seven-cylinder wasps driving two-blade propellers.
This would normally be considered underpowered, but using the variable camber system, the
speed of the Kittiwake was designed to range from 40mph at the stall, to a cruising speed
of 90mph, and up to a maximum speed of 120mp.
Though not a blistering pace by today’s standard, this estimated top speed was impressive
for the time, especially as the Kittiwake was by no means small.
But for all its innovations, the design of this flying boat also forced some compromises.
Because the trailing-edge cambering mechanism ran almost the full length of the wing, the
ailerons had to be installed between the upper and lowed wings, being mounted behind the
two outermost of the interplane struts.
The latter of these was also used to support the two wing floats when on the water, and
this meant that in rough conditions the impact of the waves on the floats could transfer
through the struts and possibly interfere with the ailerons.
But this being 1920, there was no real way to simulate much of this in tests, and Saunders
had to simply design the floats to absorb as much of the impact as possible until the
aircraft could get onto the plane of the water, at which point the floats would be clear.
As with many pioneering aircraft, the Kittiwake’s story isn’t a particularly happy one.
The construction of the Kittiwake was hampered by the novelty of its design, as a number
problems had to be overcome, which caused delays.
As a result, it was completed too late to compete in the Air Ministry competition.
However, it was still felt that the design was as good, if not better, than the other
entrants of the competition, in no small way due to the camber changing devices on the
wings which gave it a greater speed range at heavy loads.
Thus expectations were still high for it as a commercial aircraft.
The Kittiwake began its water trials on the 11th of September 1920.
Test pilot Norman Macmillan had intended to also fly that day, but during the trials the
undercarriage would not fully retract – courtesy of a missing locking pin – and he had to
content himself with engine and hydrodynamic tests.
The Kittiwake finally flew on the 19th of September, again with Macmillan at the controls,
and the performance during take-off was good, with no signs of porpoising, however at a
height of 600 feet the inboard section of the starboard lower leading-edge flap was
torn away from its spar.
The Kittiwake then yawed violentely to Starboard, but -happily and unhappily -a few moments
later the instability was partially corrected by a failure of the portside leading-edge
flap.
Macmillan brought the aircraft down as fast as possible, but just a few feet from the
water it stalled out completely, and came down hard enough that it struck the submerged
reef of Egypt Point.
It promptly took on water and sank to the level of the lower wing roots.
The Kittiwake was quickly recovered and put in for repairs.
The damage to the hull turned out to be slight, and was no challenge, but almost the entire
leading-edge camber mechanism had failed which required more attention.
The aircraft was repaired, and the flaps were reinforced with a system of tabs and wires
that were designed to hold them more firmly in place.
It was then the engines turn to be the source of Saunder’s daily headahces.
When trials resumed on the 27th of September the aircraft now appeared to be down on power
and refused to take off.
When the engines were inspected more closely it was found that they had been produced by
two different facilities, the Starboard engine was a hand-made pre-production example, but
the port engine was a sub-contracted production unit and it barely managed 1500 rpm.
In addition to this it was found that the undercarriage failed after a prolonged period
of static load, not exactly helpful, and it was then found that the interplane ailerons
were ineffective at small angles of deflection.
Basically a lot of things had gone wrong all at once.
Further flight testing was delayed for over six months while all of this was addressed,
however the problem of low power continued and it failed to meet what would soon be the
standard requirement for civil aircraft: cruise at half-power to ensure economy and reliability,
but sufficient power reserves for take-off and emergencies.
Ultimately, the Kittiwake was too experimental to be assured of any real success.
After all, a three-decked flying boat, with adjustable leading and trailing edge flaps
in 1921?
In the immediate postwar years, reliability and economy was far more important than innovation,
and in fact this was the crucial period in which the aircraft industry as a whole had
to prove itself as a useful and vital tool rather than a novelty – which had been their
view before the war.
Because of the disappointing trials, there was almost no commercial interest for the
Kittiwake, and after it crashed at Cowes in 1921 the decision was made to scrap it.
Shortle after this, Hyde Beadle, the main designer, left Saunders, and it was not until
1923 that a new design team was established.
This team would have better luck, coming in as the underdog in a market that was being
dominated by Shorts, Supermarine, and Blackburn.
But that’s a story for another day.
As always, thank you all so much for watching, and a big thank you of course to the Patreons,
with whom I’ve been recently discussing some top secret plans for the channel, and
A special shoutout, of course, to the Wing Commander tier Patreons as well, the top tier
members of this illustrious club.
Now some of these plans will be made public in the semi-near future, so keep an eye out
for that; I’m incredibly excited for whats coming and hopefully I’ll have some stuff
ready to share within the next few weeks – time and my health permitting – this lingering
cough is a pain.
But thank you all so much, and I’ll catch you all next time.
Goodbye.