The Avro Avian was a light aircraft developed during the 1920s, and despite only achieving
moderate commercial success it still left its mark on the fields of competitive flying
and aviation record setting.
Following the first world war, the market for civil aircraft began to grow at a rapid
pace.
In Britain this was spurred on by the shrinking of the class-gap and the general consensus
that enjoying aircraft shouldn’t be restricted to people with wealth or mechanical obsessions.
As a result of this the Lympne light aircraft trials were held to encourage the development
of light aircraft for private ownership.
This event was held three times in 1923, 1924, and 1926 – and it was in this final event
that the avian would make its appearance.
The first prototype avian was developed from a modified autogiro fuselage.
In 1926 the Air Ministry had placed a new contract for autogiros with Avro – which
were to be designated the Avro 576.
Not long after construction began, one of these new aircraft were set aside to be modified
for the two-seat light aeroplane trials at Lympne, and it was re-designated as the Avro
581 Avian.
The prototype was completed and given the registration G-EBOV.
It had a remarkably low structural weight which gave a tare weight to all-up weight
ration of less than 0.5.
The aircraft trials had strict weight allowances, with a maximum engine weight of only 170lbs,
and as a result of this the 70hp Genet engine from the Avro 576 was retained as it was the
most powerful engine in this weight class.
For competitive purposes the Avian had a large wing area for its size and the wing structure
itself was built as simple as possible in order to save weight.
The outer sections were mounted on two pairs of wing structs, and the centre section was
mounted on four smaller struts attached to the fuselage.
Ailerons were only fitted to the lower wing, and fuel was stored in the front of the fuselage
to leave the upper mainplane clear.
To comply with the rules of the light aircraft competition, the wings folded around the rear
spar, and this was accomplished with quick release bolts.
The Avian was flown in the Lympne trials by Australian pilot Herbert J Hinkler, and overall,
it did pretty well.
Hinkler flew 1074 miles over three days and despite a leaking fuel tank he gained second
place in three of the six tests.
He averaged just under 69 mph for the 312 mile, three lap cross-country to Shoreham
on September 12th.
On the 14th he averaged 69mph for three laps of the 366 mile Hastings circuit, and on the
14th he averaged 78mph over a 396 mile, six-lap course.
The Avian was proving to have excellent endurance for such a light airframe, however its luck
ran out when the drive of its magneto sheared, and the aircraft was eliminated from the remainder
of the competition.
The blow was somewhat lessened when Hinkler won a separate race on the 18th of September
which covered 6 laps of the Lympne course, and he averaged 90mph.
After this the Avian was taken back to Avro’s works in Hamble for modifications.
The wingspan was reduced to 28ft and the nose was lengthened to accommodate an 85hp ADC
Cirrus II inline engine.
This engine was gravity-fed from a large centre section tank, whose weight necessitated the
addition of two more sloping struts between the upper wing and the fuselage.
A new triangular fin and an enlarged rudder were fitted to compensate the increased side
area of the lengthened nose, and it was in this guise that the Avian was re-designated
as the Avro 581A.
After these modifications were complete Hinkler – who liked the Avian – bought the prototype
and competed in several races over the course of 1927, winning the Kill Joy stakes at the
Bournemouth Easter Meeting.
At the same time Avro began work on the production version of the Avian, but Hinkler continued
to score impressive achievements with their first prototype.
He had his sights set on long distance flights, and over the summer of 1927 Hinkler made various
modifications to the aircraft.
These included a new undercarriage of his own design, lowering the engine to make it
more accessible for maintenance, and adding a long-range fuel tank.
As long-distance flights carried the risk of possible emergency landings in fields,
bogs, and other places not well suited to aircraft, Hinkler widened the undercarriage
when he re-designed it; he also designed it to be able to be moved further back which
allowed the tail to be lifted more easily when the wings were folded.
Hinkler made his first record setting flight on the 27th of August 1927, flying 1200 miles
from England to Latvia in approximately 10 hours 45 minutes.
This was the longest non-stop flight by a light aircraft at the time, and when it was
inspected the Avian impressed the Latvian Air Force who then placed orders for the Avian
as a training aircraft.
After this flight, Hinkler embarked on a far more ambitious endeavour.
The Avia’s fuel consumption during the England-Latvia flight convinced him that it was capable of
flying him all the way from England to his homeland of Australia.
As this was a considerably longer distance than anything so far attempted with the Avian,
he decided to further modify it.
A more rugged, non-folding divided undercarriage was added, the wings from another Avian – one
that had set altitude records – were fitted to the aircraft, and the wooden propeller
was replaced by a metal one built by Fairey.
In this new configuration, Hinkler’s avian was re-designated again to the Avro 581E.
It took off from Croydon on the 7th of February 1928 with Darwin as his intended destination.
At the beginning of his flight there was little media attention, perhaps because many thought
that such a light aircraft lacked the endurance for such an attempt, but by the time he was
half way to his destinate his attempt had caught the attention of the aviation world.
On the 22nd of February he safely arrived at Darwin, completing the first solo flight
from England to Australia.
For his exploits he would eventually be made an honorary RAAF Squadron Leader.
The production models of the Avian were known as the Avro 594.
They had limited success in competitive events and only moderate commercial success when
compared to the De Havilland Moth, however like the prototype, some of these Avians would
go on to set some records.
An Avian MkII flown by Dudley Watt won an altitude race in 1927, reaching 12750 ft in
90 minutes.
The prototype model of the Avian MkIII – nicknamed the Red Rose - was flown by Captain Bill Lancaster
from England to Australia.
He actually began his flight before Hinkler, taking off on the 14th of October 1927, however
he was plagued by various mechanical problems and did not arrive in Darwin until March the
following year.
His Avian performed better after this, and set a new record for crossing the Bass strait
from Melbourne in just six and a half hours.
A production Avian MkIII was purchased by Lady Heath, who flew solo from the South African
cape to England between March and May of 1928.
She then later sold her aircraft to another female pilot who was beginning to make a name
for herself: Amelia Earhart.
She would fly the Avian on her first long-distance solo flight, becoming the first woman to fly
across the North American continent and back in August 1928.
Another Avian, a 616 Sports model dubbed the Southern Cross Junior, was flown by Guy Menzies
on the first solo flight from Australia to New Zealand in 1931.
This same aircraft would later be used by Bill Lancaster on his ill-fated attempt to
beat the England-to-South Africa speed record.
Its wreckage was eventually discovered in 1962 and is now on display at the Queensland
Museum.
Along with being a record-setter, the Avian also had a moment of heroism.
On the 1st of January 1929, Canadians Wilfrid May and Vic Horner flew an Avian from Edmonton
to Fort Vermillion to deliver much needed Diphtheria medicine.
Including the return journey, the total distance covered was over 700 miles which was a truly
impressive feat considering the appalling temperature and flying conditions.
The flight became known as the Race Against Death, a title shared by the exploits of a
dog sled team, who in 1925 also had to deliver diphtheria medication to a remote region,
in appalling conditions, during the middle of the Canadian winter.
Only two pre-production models, dubbed the Avian Mk I, were built.
They closely resembled the original prototype, with the exception of having slightly rounded
wingtip and a triangular rudder.
Things quickly moved on to the Avian Mk II, which had a 85hp Cirrus engine, and subsequent
models after that would eventually move onto the 95hp Cirrus III.
The production run of the Avian was somewhat chaotic as internal arguments that would put
parliament to shame resulted in multiple design changes.
Some Mk IIs were fitted with the Armstrong Siddeley Genet Radial engine, as was a single
Avian Mk III, and these would be known as the Avro 594B.
Two Avian Mk IIIs were also converted to floatplanes, and these would be known as the Avro 605.
The Avian Mk IV came in a variety of shapes, sizes and flavours for aviation enthusiasts
to chose from, along with several improvements – these included a more robust undercarriage
support structure and new horn balanced ailerons.
This aircraft was also powered by the Cirrus III engine and it had a production run of
90 units.
Of these, only a handful were sold in the British market, with the bulk being sold overseas
to Argentina, Australia, Brazil, Mexico, Norway, South Africa, and Spain.
The Avian Mk IV M, known as the Avro 616, could really be considered its own aircraft.
Its fuselage had welded steel tube framing in place of wood, and the Cirrus engine was
replaced either Hermes or Genet Major engines depending on the specific airframe.
A large quantity of these were exported to Canada who also built 18 specifically for
the Royal Canadian Air force as training aircraft, and an equally large amount of the Hermes
models were also sold to China.
Many were used in flying schools, but some were also used as light mail carriers in the
early 1930s, however by this point the Avian’s age was starting to show, and it became apparent
that it was nearing the end of its development life.
An attempt was made to improve its chances on the competitive scene by building two Avian
Mk IVs as low-wing monoplanes.
These were known as the Avro 625.
Neither of these saw much success in races, and the first model was eventually rebuilt
as a standard biplane.
The last Avians were built in 1933, and only a handful saw military service in World War
2.
Ten wooden and four metal frame Avians were impressed by the RAF at the start of the war
and were used solely as training aircraft.
Several surviving Avians can be found today.
Despite having logged over 35000 flying miles, the first prototype avian flown by Hinkler
was in remarkably good condition, however it was never registered in Australia.
Instead, it was placed in the Brisbane Museum – which became the Queensland Museum, with
its original markings.
Its still there today, and I snapped this photo during a recent visit.
Two airworthy Avians can also be found in Australia, and several other models are on
display in the US, Canada, Britain, and Sweden.
Though it was only a moderately successful light Aircraft, the Avian certainly had an
interesting life, and one that is often overshadowed by the more popular De Havilland Moth – so
I hoped you enjoyed today’s video on this little plane, and I’ll catch you all next
time.