Times and Temperatures
An Aeronautical Correspondent writes: One of the chief responsibilities of those international bodies which control speed records is to lay down a standard set of conditions. For the world absolute speed record the Federation Aeronautique Internationale's conditions are designed to pro- duce speed figures which are truly representative of the aircraft's abilities in straight and level flight in still air and which are truly comparable between one aircraft and another. But the Federation cannot standardise temperature, and this has become a critical factor. Temperature differences can take away or put on many miles an hour. Hence the desire of Squadron Leader Neville Duke, of Lieut.-Commander Lithgow and of thd American challengers to make their speed runs in places where temperatures are high. It has been suggested that the speed figures obtained by the aircraft should subsequently be adjusted to a standard temperature; but this has the serious defect that the record would then become more a calculation than an actuality. At present the beauty of the official world record is that the aircraft's passage over the three-kilometres base is measured by observers outside the .machine, using apparatus entirely independent of the aircraft's own instruments. It is a direct and independent observation. This is one reason why the official world record deserves so much more attention than the speed figures occasionally claimed for rocket aircraft flying at great heights. These rocket aircraft speeds are not achieved in standard conditions, nor are they independently measured. But there is likely to be a new development in the air speed record. When aircraft reach the point of being able to blast their way through Mach 1 to supersonic speed, straight and level, the relative importance of ambient temperature will be much reduced.
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