The Measurement of Accelerations: A Twenty‐Year‐Old Instrument for Road and Rail Vehicles Modified to Provide a Maximum Reading Accelerometer for Aircraft Available to Purchase

IN order to study the relationship of load factors to the stresses which arise in the normal manoeuvring of aircraft, it is customary to employ recording accelerometers. These instruments have been found quite satisfactory for this purpose, and almost as many models have been devised as the countries that use them. The instruments built in this country have been the very best of the type: the record is usually, though not invariably, made on a moving photographic film. For certain purposes, however, a simpler form suffices; one in which an easily‐visible pointer moving in front of an easily‐visible scale gives the maximum acceleration during any sustained manoeuvre, such as turning, rolling, looping, pulling out of a steep dive, etc. The inertia of the mechanical parts, though, of course, exceeding that of the mirror and spring of the usual recording type, can be made low enough to keep pace with the ordinary motions of an ordinary aircraft. Such a device needs to be light in weight, slight in bulk, and simple to use and maintain.