2. Small aircraft fatigue
Like any aircraft, the LSA are subjected to a wide spectrum of
operational loads. The level of allowed acceleration for the LSA is
higher than for the planes of transport category: the maximum positive
load factor prescribed, for example for the Viper SD-4 [3] is equal
to +4.0g, the minimum is – 2.0g.
As a proof of the necessity of the special attention to the metal
fatigue for small aircraft the fatigue damage case study of the Piper
aeroplane primary structure may be considered. During a routine
inspection of a Piper Model PA-46-350P aeroplane, 1.53-inch () fatigue
crack was discovered in the main spar lower cap (Fig.1). The crack
discovery was at 5,273-hour time-in-service (TIS) versus the type
certificated life limit of 15,580 hours TIS [4].
The list of fatigue issues could be extended, but even these examples
prove the requirements for the special attention for the aircraft
primary structure fatigue.