Much has been written about Australia's Two-Airline Policy
enacted in 1952, which the federal Liberal government
of the day under Robert Menzies, rightly or wrongly, forced
upon the Australian travelling public.
The major result of that now defunct policy was that both
domestic airlines in the late 1950's - TAA and Ansett-ANA,
were compelled to fly parallel schedules and to operate
common aircraft equipment. Two aircraft types had to be
shared by each - the DC-6B and the Viscount, and this
included cross-leasing, where Ansett-ANA exchanged two
DC-6B's for three TAA Viscounts. Whilst both airlines
would schedule identical types for the same routes, often
as not, a Skychief and a Viscount could be pitted against
each other.
This treatise endeavours to point out the more obvious
operational aspects of these two aircraft types, but the
actual rationale for their being selected for Australian
service is not the focus here.
The Douglas product came in two main versions with little
difference in cockpit setup or procedures. The Viscount
on the other hand, had variants within variants, all requiring
slight differences in operation due to different marks
of engine, variations in gross weight and even differences
in certain cockpit controls. Each type was powered by
four engines, the Douglas using tried and proven supercharged
Pratt & Whitney Double Wasp piston engines, whilst
the smaller Vickers used the then quite novel, Rolls Royce
Dart turbine propeller engines.
Skychief
The DC-6 prototype first flew as the USAF's XC-112 on
15th February 1946, and was later civilianised as a DC-6.
It was essentially a pressurised, stretched and higher
power version of the famous DC-4 employing the same wing
but now built from stronger alloys, with a gross weight
of 100,000 lbs. Further developed into the C-118, a militarised
version of the slightly longer (by 60 inches) and higher
gross weight (107,000 lbs) DC-6A freighter, the type was
ordered in quantity by both the US Air Force and US Navy.
The joint airline launch customers for the DC-6 were American
AL & United AL, both commencing operations on 27th
April 1947. First Australian operator of the type was
British Commonwealth Pacific Airlines from 19th November
1948 with four in service by December of that year. On
1st December 1953, two more were delivered to Australian
National Airways, albeit second-hand and Trans Australia
Airlines leased one for a period of four months from KLM
on 4th December of that year, ostensibly to cover a forecast
Christmas rush.
Employing the stretched fuselage of the DC-6A without
the large cargo door, but with more windows and seating,
the prototype DC-6B first flew on 10th February 1951.
This was to become the definitive, most popular and most
widely built version of the series and was loved by aircrew
and maintenance personnel alike. Airline managements everywhere
also considered that on a seat/mile basis, it was the
most economical airliner ever built to that time. The
DC-6B gross weight was now a hefty 107,000 lbs and the
engines fitted were the excellent Pratt & Whitney
R2800-CB17's rated at 2,500 hp with water methanol injection.
The only Australian operator of new DC-6B's was ANA, with
the first of four being delivered on 11th February 1955,
and all were in service by October 1956.
TAA and Ansett-ANA each obtained a second-hand DC-6B in
November 1963, bringing their Skychief fleet up to three
each, in accordance with the then-current Two-Airline
Policy. The Douglas name applied to the DC-6 series was
"Skychief" which followed on from previous Douglas
aircraft "Sky" names such as the DC-3 Skyliner
and the DC-4 Skymaster.
Viscount
The Viscount prototype first flew as the Vickers Type
630 on 16th July 1948, and the enlarged and definitive
V700 series completed its maiden flight on 28th August
1950. Airline launch customer British European Airways
commenced Viscount operations in January 1953, followed
by Air France in March of the same year. Large orders
followed on from North America, followed by smaller orders
worldwide.
Ironically, the Dutch Fokker F27-100 Friendship, which
first entered airline service with Aer Lingus in December
1958, carried 40 passengers using only two RR Dart prop-jet
engines as opposed to the V700's four RR Darts lifting
an initial load of 48 passengers.
The V700 design maximum weight was 56,000 lbs, and was
progressively increased to 60,000 lbs. The V800 series
maximum weight started out at 69,000 lbs but was later
increased to 72,500 lbs. In both models increasingly powerful
versions of the Rolls Royce Dart turbo-prop engine were
fitted, permitting these increases in gross weight.
The first Australian Viscount 700 delivery was to TAA
on 5th October 1954, with their sixth aircraft being accepted
on 2nd April 1955, this being the first to have removable
slipper tanks for added range. TAA was unique among local
V700 operators in using wing-mounted slipper tanks. Four
more V700's were delivered in 1956, two in 1957 and the
last three in 1958, for a TAA fleet total of fifteen.
Only one other Australian operator received new V700's
- two for Butler Air Transport, the first being accepted
on 27th September 1955 and the second on 14th September
1956. The fact that B.A.T. had prop-jets before Ansett,
was a major factor in the hostile takeover of Butlers
by Ansett in 1959. A total of seventeen V700's were used
in Australian airline service.
The slightly longer and heavier Viscount 800 first flew
on 27th July 1956, and was delivered to launch customer
British European Airways in February 1957. The initial
Australian V800 operator was Ansett-ANA, accepting the
first of four new aircraft on 12th March 1959, the remainder
being delivered by May of the same year. Two second-hand
V800's were delivered to Ansett-ANA in 1960 and 1962 respectively.
TAA bought two new V800's in May and June 1959 respectively,
but also obtained a second-hand example in 1962. The RAAF
introduced two second-hand V800's in September 1964 permanently
fitted with larger-capacity later model slipper tanks
and they were the only Australian V800 operator to carry
these devices. A total of eleven V800's flew in Australian
markings.
Operational comparisons
Author's note: All figures quoted are approximate only
but within the ballpark, as actual conditions of weather
and gross weight could vary on the day.
The DC-6B Skychief was universally feted as a true pilot's
aircraft based on excellent handling, performance and
airframe strength combined with a roomy, well laid out
cockpit and large cabin. Unfortunately, the Viscount did
not enjoy this same reputation.
In the collective opinion of pilots who had flown both
types, the Viscount was critically under-engineered in
many areas, requiring crucial limitations in operational
service. The Viscount cockpit was poorly designed and
ergonomically difficult, making it quite taxing on flight
crews. These combined drawbacks suffered by the Viscount
undoubtedly pointed to the type's poor safety record in
Australia - four fatal crashes from a national fleet total
of only 28 aircraft. The Viscount had a similar record
overseas.
The single major incident involving an Australian DC-6B
was the shedding of a propeller blade soon after take-off
from Essendon. With the #3 engine hanging below the level
of the undercarriage, a landing in that configuration
was out of the question. With considerable skill the pilot
managed to shake the engine off the wing and into Port
Phillip Bay, graphically illustrating the aircraft's considerable
ruggedness, followed by a safe landing back at Essendon.
A cost advantage held by the Viscount over the Skychief
was that it could operate with only two technical crew,
as opposed to three on the DC-6B, which required a Flight
Engineer. TAA's marketing department also widely touted
the smoothness of flying in the turbine-powered aircraft
and the Viscount's large oval windows with attendant passenger
appeal.
Climbing speed for the Douglas was 160 knots whilst the
Vickers climbed at 180 knots, meaning that a Viscount
on a parallel departure could be disadvantaged if the
Douglas got off first. Once on the way friendly competition
between aircraft to get there first was often the case.
Cruising speed for the DC-6B was usually around 240 knots
at 16 - 20,000 feet compared to the Viscount's 250 knots
at somewhat higher levels. The Viscount had higher specific
fuel consumption than the Skychief, but turbine fuel (Avtur)
being cheaper than gasoline (Avgas) helped to offset this.
The Skychief's passenger capacity was about one-third
greater than the Viscount's, with almost double the freight
capacity of the smaller propjet in the DC-6B cargo hold.
Where the DC-6B really shone by comparison was in the
descent phase, as it was able to maintain 250 knots all
the way down whilst the Viscount needed to reduce speed
to at least 200 knots or less dependant on flight conditions
for a safe descent, because of airframe structural considerations.
Due to close scheduling under the Two Airline Policy,
this sometimes caused consternation between the two aircraft
and air traffic control.
Another disadvantage of the Viscount was its relatively
short range when carrying a commercial payload and this
was drastically in evidence on the Perth route, flying
into the usual headwinds. A Viscount having to land at
Kalgoorlie for fuel was not uncommon. TAA solved the problem
by fitting removable slipper tanks at Adelaide, but then
had to accept a penalty in payload or passenger numbers.
The DC-6B did not have these quirks and could comfortably
accommodate the headwinds.
Comparing the two types in Australian domestic airline
service, and regardless of what some experts may have
espoused, the Skychief was the more economical, reliable
and proven aircraft when considering its sound maintenance
and flight operational record, excellent seat/mile economics
and its comfortable environment for both passengers and
working crew.
Conversely, the Viscount was widely considered as being
under-engineered, relatively cramped and suffering from
questionable airframe strength. Due to poorly designed
cockpit ergonomics, occasional crew confusion when changing
directly from one variant to another model in the same
duty tour, caused unnecessary difficulties and sometimes
quite close calls.
In hindsight, the Viscount could perhaps have been a better
performer in the critical areas of operations and maintenance
economics, had the manufacturer devoted time and finance
to a more thorough research and development program. However
the Viscount did outlast the Skychief on the Australian
domestic airline scene by some three years.
End of the line
Ansett-ANA retired their last "Straight Six"
(DC-6) in March 1960, whilst the last DC-6B ceased airline
duty in July 1968. The last Viscount 700 was scrapped
in May 1970, followed by retirement of the final V800
in April 1971. Thus ended the era of two dissimilar airliner
types compelled to operate under the demon of government
enforced parallel scheduling on common routes.
Footnote: Other than the odd privately flown Viscount,
none are believed to be in commercial service anywhere.
However the Skychief soldiers on both as a commercial
freighter and as a firebomber in parts of the Americas,
whilst a number are flown privately.
