The
de Havilland Express was a four-engined
passenger aircraft from the 1930s manufactured by the
de Havilland Aircraft
Company.
Development
During
1933, talks between the governments of United Kingdom
, India
, Malaya, the Straits Settlements
and Australia resulted in
an agreement to establish an Empire Air Mail Service.
The
Australian Government called for tenders on 22 September 1933 for
the Singapore
-Australia legs of the route, continuing as far
south as Tasmania
.
On the
following day Qantas, anticipating success in
contracting for the Singapore-Brisbane
leg, placed
an order with de Havilland for an as-yet non-existent aircraft to
be designated the de Havilland 86, the prototype
to fly by the end of January 1934. This order was soon
followed by one from Holymans Airways of Launceston,
Tasmania
to operate the Bass Strait
leg of the service. The D.H.86 was initially
styled the
Express or
Express Air
Liner although the name was soon discontinued.
The D.H.86 was conceptually a four-engined enlargement of the
successful
de Havilland Dragon,
but of more streamlined appearance with tapered wings and extensive
use of metal farings around struts and undercarriage. The most
powerful engine made by de Havilland, the new 200
hp (149 kW)
Gipsy Six, was selected. For
long-range work the aircraft was to carry a single pilot in the
streamlined nose, with a wireless operator behind. Maximum seating
for ten passengers was provided in the long-range type, however the
short-range Holyman aircraft were fitted with twelve seats.
The prototype D.H.86 first flew on 14 January 1934, but the
Qantas representative
Lester Brain immediately rejected the single
pilot layout because he anticipated pilot
fatigue over long stretches, and the
fuselage was promptly redesigned with a dual-pilot nose. Only four
examples of the single-pilot D.H.86 were built, and of these the
prototype was rebuilt as the dual-pilot prototype. When she entered
service in October 1934 the first production aircraft, Holymans'
single-pilot D.H.86
Miss Hobart, was the fastest
British-built passenger aircraft operating anywhere in the world.
Despite de Havilland's predictions to the contrary, the dual pilot
type with its lengthened nose proved to be even faster.
Investigations in 1936 following a series of fatal crashes resulted
in late production aircraft being built with additional
fin area in the shape of vertical "
Zulu Shield" extensions to the tail planes to improve
lateral stability - these aircraft were designated
D.H.86Bs.
Operational History
DH.86B G-ADVJ of charter airline Bond
Air Services at Liverpool (Speke) Airport in March 1950
Dual pilot D.H.86s were built for
Imperial Airways and given the class name
Diana.
They were used on European and Empire air
routes including the run from Khartoum
to Lagos
.
Railway Air Services (RAS)
operated a fleet of seven Expresses between 1934 and 1946. RAS used
the aircraft on their UK scheduled flight network including their
trunk route from London (Croydon) via Birmingham,
Manchester/Liverpool to Glasgow.
D.H.86s
were also built for New
Zealand
's Union Airways,
flying between Auckland
, Palmerston
North
and Wellington
. During World War II, the New Zealand
aircraft were fitted with bomb racks and used by the
Royal New Zealand Air Force to
hunt German raiders and Japanese shipping. The survivors served
with
NAC post
war.
A total of
15 D.H.86s, D.H.86As and D.H.86Bs operated commercially within
Australia and New
Guinea
up to the outbreak of World
War II. Eight D.H.86A and D.H.86B aircraft were
impressed into the
Royal
Australian Air Force and served as A31-1 to A31-8 during the
War. Some served as air ambulances in the
Middle East, while others did sterling work as
transport aircraft and air ambulances in Australia and New
Guinea.
A total of 62 D.H.86s of all types were built. Most of those still
flying in Europe at start of World War II, except for the Railway
Air Services aircraft, were taken into military service, mostly for
communications and radio navigational training. A few Expresses
survived the war and were used by UK air charter operators until
the last example was burnt out in 1958.
Technical Deficiencies
This section is largely sourced from the book Air Crash,
Volume One
by Macarthur Job.
Seriously lacking in directional stability, the D.H.86s were
frequently in trouble.
On 19 October 1934 Holyman's VH-URN Miss
Hobart was lost in Bass Strait with no survivors. Flotsam that may have been wreckage from the
aircraft was seen from the air three days later but surface ships
failed to locate it in rough seas; the aircraft had effectively
vanished. At the time
Miss Hobart disappeared the design
of the aircraft was not suspect, and it was thought that an
accident may had occurred when Captain Jenkins and the wireless
operator/assistant pilot
Victor
Holyman (one of the proprietors of Holymans Airways) were
swapping seats in mid flight.
However following the loss of Qantas' VH-USG
near Longreach
four weeks later while on its delivery flight, it
was found that the fin bias mechanisms of the crashed aircraft and
at least one other were faulty, although it is doubtful that this
had any direct bearing on the accidents other than perhaps adding
to the aircraft’s lack of inherent stability. Further
investigation revealed that VH-USG had been loaded with a spare
engine in the rear of the cabin, and that one of the crew members
was in the lavatory in the extreme aft of the cabin when control
was lost. It was theorised that the aft
centre of gravity condition that thus
existed resulted in a loss-of-control at an altitude insufficient
for recovery (the aircraft was at an estimated height of prior to
the crash).
On 2 October 1935 Holyman's VH-URT
Loina was also lost in
Bass Strait, again with no survivors.
This time a
significant amount of wreckage was recovered from the sea and from
beaches on Flinders
Island
. Investigation of the wreckage revealed a
section of charred carpet on a piece of cabin flooring from just
ahead of the lavatory door. It was thought possible that a small
fire from a dropped cigarette had led to someone running aft
suddenly to stamp it out – the sort of sudden change in weight
distribution that could set up a fatal loss of directional control
while the aircraft was on a low-speed landing approach.
The
Royal Air Force's
Aeroplane and
Armament Experimental Establishment tested the D.H.86 design in
1936 following three fatal crashes in Europe. It would be forty
years before the report was published – one of the most damning
indictments ever written on the design of a commercial airliner put
into series production. The D.H.86 had been rushed from design
concept to test flight in a record four months to meet the
deadlines set by the Australian airmail contracts, and a lot of
attention to detail had been ignored. It was a big aircraft for its
power, and as a result very lightly built. There was poor response
to control movements in certain speed ranges, the wings were
inclined to twist badly if the ailerons were used coarsely and,
most seriously, the vertical tail surface was of inadequate area.
The result was an aircraft that, although quite safe under normal
conditions, could rapidly get out of control under certain flight
regimes.
Although the control problems were overcome on later-manufactured
D.H.86Bs, the results of the tests do not appear to have been
communicated to Australia and the D.H.86s already in use were never
modified to improve their safety. This lack of communication may
have caused a number of later accidents including at least one of
two further fatal disasters in commercial service.
The mid-air break-up
of Qantas' VH-USE Sydney in a thunderstorm near Brisbane in 1942 with the loss of nine lives was possibly
unavoidable, however the fin was found almost a mile away from the
main wreckage, which was burnt without an investigation being
carried out. The accident involving MacRobertson Miller Airlines’
ex-Qantas aircraft VH-USF at Geraldton
on 24 June 1945 most likely was entirely avoidable
had the AaAEE report been communicated to Australia. On its
first commercial flight for its new owners after military service,
the pilot and a passenger were killed in a classic loss-of-control
accident while taking off with a heavy load in gusty
conditions.
Another D.H.86, VH-USW (the former Holyman Airways
Lepena), was bought by MacRobertson Miller Airlines at
much the same time as VH-USF and was the last of the type to fly in
Australia.
MMA sold the eleven-year-old aircraft to an
English company late in 1946; it was abandoned in India in an
"unsafe state" while on her delivery flight. Edgar Johnston,
the Assistant Director General of the Australian Department of
Civil Aviation, then had it scrapped at Australian Government
expense to make sure that it never flew again.
The Political and Commercial Consequences
Following the first three fatal Australian D.H.86 accidents and a
forced landing to VH-USW
Lepena on 13 December 1935 (a
Friday) when the pilot believed his aircraft was about to break up
in mid-air, the Australian Government temporarily suspended the
type's
Certificate of
Airworthiness. This caused outrage in Britain as it reflected
on the whole British aircraft industry. In fact, the D.H.86 had
approached the limits to which traditional "plywood and canvas"
aircraft construction could be taken, and was obsolete compared to
all-aluminium stressed-skin aircraft like the
Boeing 247 and the
Douglas DC-1 that were already flying before it
was even designed (and the immortal
Douglas
DC-3 had its first flight just four days after the
forced-landing of VH-USW). Under pressure from Holymans and other
companies, the Australian Government rescinded its ban on the
import of American aircraft during 1936, and for the next 25 years
most large commercial aircraft imported into Australia were of
American manufacture.
Variant
- D.H.86 : Four engined medium transport
biplane. First production version with single-pilot cockpit.
- D.H.86A : Improved version with wider cockpit
for two pilots.
- D.H.86B : Fitted with auxiliary endplate fins
to the tailplane.
Operators
Civil Operators
Military Operators
Specifications (D.H.86A)
See also
References
- Cookson, Bert. The Historic Civil Aircraft Register of
Australia (Pre War) G-AUAA to VH-UZZ. 1996, Toombul,
Queensland: AustairData (privately published).
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