Select a Flight Magazine report
17 October 1946 - BEA future plans
31 October 1946 - Airscrew turbine progress
14 November 1946 - Todays British transports
21 November 1946 - Brabazon IIA/IIB contenders
28 November 1946 - VC2 first known as Viceroy
7 August 1947 - Viceroy becomes Viscount
20 November 1947 - Introducing the Viscount
22 July 1948 - The Viscounts first flight
1 February 1952 - Tropical trials
1 October 1954 - Britains Big Three
31 December 1954 - Delivery flight of VH-TVA
1 July 1955 - Transair buy Viscounts, + more
9 May 1958 - BEA Viscount 802 loss
Magazine Report
Discover the history of the Viscount with these contemporary reports from the pages of Flight Magazine
Airscrew turbine progress
Armstrong Siddeley Python about to begin flight tests:
The initial development of airscrew-turbines is proving a much longer and more exacting task than that of the less complicated turbo-jet units, and although the airscrew-turbine is generally
regarded for most duties as the intermediate stage between piston and pure jet engines, in this instance progress is in effect in reverse, the pure jet having reached the more advanced stage.
Very few flying hours have been completed with airscrew-turbines in this country or America, and only a small number of running hours with airscrews. Considerable experience has, however, been
gained on the test beds against the dynamometer.
Plans for the flight-testing of at least four different British airscrew-turbines are in an advanced stage, and several aircraft prototypes have been announced which are to be powered by these
units. The most favoured aircraft for use as flying test beds are the Avro Lancaster or its development, the Lincoln. On these airframes, power units to be tested may be installed in place of
the outboard Merlins, or one could be installed deep in the nose in place of the gun turret and in addition to the four Merlins. This last-named arrangement would provide an installation
accessible in flight but would have limitations in view of the forward position and the weight of the larger turbines.
Installing a Python in the wing test rig at Ansty, Coventry. The figures lend scale to this large power unit.
Airscrew-turbines are now earmarked for long, medium and short-range transports, and in the military sphere for naval aviation designs in particular. Two of the most interesting and promising
British examples are the Armstrong Siddeley Python and Mamba. These two, respectively the highest-powered and smallest airscrew turbine so far announced, are now well advanced, and are the
designated power units for many civil and military aircraft of the near future.
Fitted with its airscrews and spinners, the running Python has a particularly clean appearance.
Its maximum power output is 3,670 shp plus 1,150 lb thrust.
The Python has recently successfully completed a 25 hours' run with Rotol airscrews at the company's test establishment at Ansty, Coventry, and photographs of the installation and the unit
under test appear on these pages. Preparations and drawings are now complete for the installation of two Pythons in the outboard engine positions of a Lincoln. The associated company, Armstrong
Whitworth, await delivery during the next week or so of the two power units.
Because the test rig is stationary, special large oil coolers are required.
These and the air intakes will be in the wing leading edge.
Development of the newer Mamba is not quite so-far advanced, although the progress since design of this smaller unit has been exceptionally rapid, and remarkably few teething troubles have been
experienced. In September, six months after running for the first time, it was giving its designed full power.
Lowering a Mamba into its cradle. The weight is only 750 lb.
The gas flow is ‘straightened’ by clustering the combustion chambers between the axial-flow compressor and the turbine instead of packing them round the compressor casing, as on the Python. The
air, therefore, enters through an annular intake either around the spinner or just behind it, and passes direct through the compressor into the combustion chambers.
A Mamba is prepared for test against the brake. It delivers 1,010 shp and 320 lb thrust at 14,500 rpm.
A single 10ft hydromatic airscrew absorbs the 1,000 shaft hp. The total weight with airscrew will be just about 1,000 lb, and the diameter over the cowling only 27 in. Particular characteristics
of the Mamba are its high installed power-to-weight ratio and low fuel consumption.
First picture of a Mamba on test with airscrew fitted.
First of the Armstrong Siddeley gas turbines, and predecessor of the Python, the obsolete ASX turbo-jet, is still doing useful work at Ansty for the development of a starter for the Python. The
company have designed an efficient gas starter to work on compressed air or a slow-burning cartridge. The intention is to use it in conjunction with a small mobile ground compressor, but to
carry cartridges on the aircraft for ‘un-scheduled’ starting.
The starter turns the ASX up to 1,500 rpm in about 30 seconds, using an air pressure of 100-140 lb/sq in. The unit lights up and accelerates without difficulty from this speed. A separate
starting jet is now fitted to each combustion chamber.
