Today we’re taking a look at something of an anomaly, an early interwar aircraft built
by Blackburn that was actually fairly successful.
Now I know Blackburn is a bit of a running joke in many aviation circles, but to their
credit they often built weird and wonderful aeroplanes because they were thinking outside
the box, rather than sniffing fumes.
But the Kangaroo was more of a conventional design, and that more than anything else is
probably why it fared a bit better.
Now recently, we looked at the short-lived Blackburn G.P, which was a twin-engine floatplane
that was intended for long range bombing and naval patrol.
The Kangaroo was an offshoot from this aircraft but its design and eventual use was different
enough from the Blackburn G.P to, in my mind at least, warrant its own video.
Unfortunately, not a huge number of photos or drawings are available of this aircraft,
so if this video feels a bit like a glorified PowerPoint presentation, I apologise in advance.
The Kangaroo was known internally at Blackburn as the R.T.1, which stood for Reconnaissance-Torpedo
type 1.
Its development was prompted by the decision of the Air Board to prioritise the use of
landplanes in its maritime patrols.
This decision was in part due to the growing power and efficiency of aero-engines, which
allowed aircraft to fly both faster and further.
Up until this point most maritime patrol aircraft were float planes, as deploying the aircraft
from the water -rather than an airfield inland- represented the saving of time and fuel.
But this also meant that a patrol mission could be scrubbed by poor weather, as unsurprisingly
wood and fabric biplanes didn’t exactly have much in the way of seakeeping.
This would be somewhat rectified later on by the construction of metal-hulled flying
boats and all-metal floatplanes, but for moment the Air Board were resigned to launching most
of their naval patrols from the safety of dry land.
In converting the sea-based Blackburn G.P to the land-based Blackburn Kangaroo, various
changes were made to the design of the aircraft.
The floats were replaced by a four-wheeled undercarriage arranged in two pairs with fixed
axles; these were connected to the structure supporting the engine nacelles to better distribute
the impact forces of landing.
For reasons never fully explained the decision was made to not install any kind of shock
absorbers, and the only cushioning provided would come from the tyres.
As the original Blackburn GP was designed to absorb the harsh impacts of water landing,
it was probably assumed that landing on an airfield was a less strenuous affair and that
the shock absorbers were a needless addition of weight.
Though the general construction of the wood and fabric airframe was retained, subtle differences
could be found that set the Kangaroo apart.
The engine nacelles were raised to sit in the gap of the wings, rather than upon the
lower one; the side-mounted radiators were replaced by frontal honeycomb-style units;
the top decking of the fuselage was deleted, further slimming its lines; most of the metal
fittings were now machined, rather than being built up from sheet metal; the rudder was
increased in size, now boasting a rounded trailing edge; and the pylons that braced
the overhang of the upper wings were changed from triangular to square in shape.
Like the Blackburn GP, the Kangaroo was ideally suited to carrying a large torpedo thanks
to its divided undercarriage, but it was never used in this capacity.
Instead, it would carry four 230lb bombs, or a single 520lb bomb suspended beneath the
fuselage, and four smaller bombs could also be attached to racks mounted on the lower
longerons.
These would be aimed by the front gunner, who made use of a RNAS MkIIa bombsight.
The defensive armament used by both front and rear gunners remained the same, a single
Lewis gun for each, but additional radio equipment was given to the rear gunner -who served as
radio operator- to facilitate night-time operations.
Most of the modifications made to the Kangaroo had the benefit of reducing its empty weight
by about 500lbs (or 230kg); additionally, it was to come with far more powerful engines,
with the Rolls Royce Falcon IIs producing 250hp each, compared to the 190hp Rolls Royce
engines of the Blackburn GP.
It was with high hopes therefore that Blackburn flight tested its new aircraft towards the
end of 1917, and on the 3rd of January 1918 it went to the experimental station at Martlesham
Heath for its official trials.
Here it competed against the Avro 529, which was a perplexing decision as the Avro had
less powerful engines, was smaller, and sat in a completely different weight class.
In the end the results of the initial trials were inconclusive, not because of the disparity
between the two aircraft, but because the Kangaroo’s rigid undercarriage decided to
imitate the German economy of 1918 and completely collapse.
This resulted in significant damage and brought the trials to a temporary halt whilst urgent
repair work was carried out.
Despite the continued bad luck of Blackburn, who’s chief had clearly offended some sort
of aviation deity, the Kangaroo was accepted into service.
Of the original planned order for fifty floatplane Blackburn GPs, approximately 20 had been under
construction, and it was these that were converted over to the Blackburn Kangaroo.
Following the Martlesham reports a few changes were made before their completion; the front
gunner station was raised to allow easier operation; the landing gear received shock
absorbers to prevent the whole thing deflating like a souflee upon landing; and the fuselage
structure was reinforced to counter a highly disconcerting tendency for the whole thing
to twist and bow during steep turns.
Along with this, the last fifteen Kangaroos completed would also benefit from the upgraded
270hp Rolls-Royce Falcon III.
Unfortunately, Blackburn was still a relatively small company at the time, and this production
order presented a significant challenge.
A lack of manpower, combined with a general shortage of suitable spruce wood, meant that
the Kangaroo’s, initially destined for the Admiralty and then given over to the Royal
Flying Corps, were not in fact ready until the RFC had turned into the RAF.
Still, contrary to some opinions at the time that Blackburn’s were good on paper but
not in practice, some of the Kangaroo’s did indeed do themselves credit during their
brief service in the last year of the war.
10 were operated by 240 Squadron of RAF Seaton Carew, with their primary mission being maritime
reconnaissance and patrol.
Between the 1st of May 1918 and the Armistice, they flew more than 600 hours over the North
Sea.
Some of these sorties involved convoy protection, and the Kangaroos sighted twelve U-Boats,
attacked eleven, sank one (U.C.70 off Runswick Bay), and damaged another four which wasn’t
bad at all considering how difficult it was to keep these old planes steady.
Following the Armistice, the Disposals Board put all Blackburn Kangaroos up for sale.
The Blackburn company had planned to buy back all of their Kangaroos, but they had competition.
The Grahame-White Aviation Company purchased three aircraft and flew them back to their
facility at Hendon, here they were stripped of their military equipment and converted
into eight-seat passenger aircraft for joyriding.
Unfortunately, two of the three would be wrecked within a few months (a combination of poor
luck, inexperienced pilots, and in once case a recalcitrant engine), but these occurred
with no loss of life, and the third aircraft carried on for the next eighteen months – dropping
parachutists, giving demonstration flights to foreign delegations, and of course entertaining
the general public.
In another part of the country, Blackburn had purchased eight Kangaroos and had also
modified them into civil transports.
The central part of the fuselage was extended vertically to facilitation the installation
of a large glazed cabin, this accommodated seven passengers, and an eighth passenger
(ideally one with a strong constitution) could be housed in the forward gunner’s station,
which had been modified with glass sides so that said passenger had both protection and
unobstructed views of the outside world.
This modification was not universal, but it does appear to represent the majority of the
aircraft that Blackburn had purchased back.
In April 1919 Blackburn formed a subsidiary known as the North Sea Aerial Navigation Company
to run full commercial services.
The first of these was inaugurated on the 10th of May, flying freight from Gosport to
Leeds, and others quickly followed.
These early services were very sporadic, and often unprofitable, but like many others at
the time they paved the way for more successful commercial enterprises in the mid-1920s.
The most ambitious commercial service undertaken by the Kangaroo was that between Britain and
the Netherlands.
In 1919 the Dutch had been impressed by the Blackburn Kangaroo when three visited the
country for the first Air Traffic Exhibition, held at Amsterdam.
The first official flight between the two countries was in-fact a charter flight to
counter the effects of a dockyard strike in the Netherlands.
On the 6th of March 1920, Blackburn’s chief test pilot, R.W.
Kenworthy, took off from England with a 1,000lb cargo load of fashionable ladies clothing.
The plan was to deliver the goods and return to England with an inbound cargo of dyes.
But upon seeing their strike being circumvented by the Blackburn Kangaroo, the Dockyard workers
became understandably hostile and Kenworthy had to hastily fly off to Soesterberg Aerodrome
and seek military protection.
When the Kangroo wasn’t incurring the ire of underpaid, overworked dockmen (armed with
a frightening array of blunt instruments), it was bouncing between its home aerodrome
in Brough, the custom’s aerodrome in Lympne, and its destination aerodrome in Amsterdam.
The service only lasted for a month or so, as the requirement to fly to a customs stop
and then depart the country added so much cost to the endeavour that it never turned
a profit.
Still, during this short time the service flew 20,000 miles and carried some 18,000lbs
of freight and around 1,200 passengers.
Not bad at all for 1920.
Not all of the Kangaroos were used for commercial operations during this time.
One of the Kangaroos owned by Blackburn, retained as a training aircraft with tandem cockpits,
was sold to the Peruvian Army Air Service.
Along with an Avro 504K, it was intended to be used to train Peruvian pilots as part of
a military co-operation mission between Britain and Peru in 1922; but after this endeavour
was terminated later that year there was nobody left who was qualified to fly it, and the
aircraft was scrapped later on in Peru in 1923.
Though the Kangaroo certainly contributed to the pioneering attempts at early commercial
air travel, one of the more memorable parts of its history was the ill-fated attempt at
a long-distance record.
Appropriately, the Blackburn Kangaroo had been selected by Lt Valdemar Rendle to fly
from England to Australia.
It was one of four aircraft competing for the 10,000 pound prize, which was to be awarded
to whoever was the first to fly a British aircraft with an Australian crew from the
former country to the latter.
As we already know from my video covering the Vickers Vimy, the Blackburn Kangaroo was
not successful in this endeavour.
The aircraft came to grief in the Mediterranean, not due to any apparent defect, but supposedly
due to sabotage.
The Australian crew twice complained that the magnetos had twice been tampered with,
and on the 8th of December a pipe feeding oil to the port engine fractured.
The Kangaroo was 80 miles out from Crete at the time, and the crew just made it back on
one engine, but -landing downwind and low on power- the aircraft ran over a small ditch,
punctured a tyre, slewed round and ran up an embankment.
Upon assessing the damage, it appeared that the broken pipe had been bent back and forth
several dozen times, leading to a weakening of the metal that led to the failure.
Though the aircraft was generally undamaged, failed attempts to telegraph home for a replacement
engine led to it being abandoned in Crete.
It was housed in a local museum for some time, but after the German invasion of Crete in
WW2 it was supposedly hidden away in a cave for preservation, but after the war nobody
had ever managed to find it again, and it is a mystery that has never been fully solved.
The final years of the Blackburn Kangaroos would see them back in service with the RAF.
When the RAF reserve school was established, the Surviving Kangaroos were fitted with dual
controls in tandem cockpits and used for training flights at their home airfield at Brough.
This they did between 1924 and March 1929, when they were finally laid up in a hangar
and gradually scrapped over the following 12 months.
Discounting the possibility of a Kangaroo airframe rotting away in a cave in Crete,
only one part of its history survives today, which is a four-blade propeller that sits
on display at Leeds Bradford airport.
Unfortunately, I can’t find any photos of said display, but apparently its there.
And it represents the first Blackburn aircraft -other than the Pioneering Mercury- that could
probably be considered an overall success.
As always, thank you all so much for watching, and a big thank you of course to the supporters
over on Patreon.
Unfortunately a behind the scenes cockup has prevented the release of the Q&A video for
this month, but hopefully it should be out in the first week or so of February.
I’ve also been having some internet issues this week, so if a video is a day or two late,
that’s why.
A big thank you as well to our wing commander tier patreons, our highest tier supporters,
and a special shoutout to M.V who is the newest member of this special group.
Thank you all so so much for your continued support, and I’ll catch you all next time.
Goodbye.