Applications Finder

Airframe Fatigue Testing is a rigorous process of testing that is performed on an airframe as part of the flight certification process.

The test is used to validate the design calculations that will determine the "fatigue life" of the airframe, in terms of the number of flight hours permissible and the number of take-off and landing cycles that it will be allowed to perform during its service life.

The Airframe Fatigue Test involves the application of simulated cyclical loading on all parts of the airframe, including the flight control system.

Loads may comprise an element of static load with the addition of cyclical loading where this is more representative of service conditions.

Througout the test, the stress levels of the various airframe sections will be recorded via hundreds of channels of strain gauge measurements, being taken in synchronisation with the recording of the actual loads being applied, via load cells mounted in line with each of the cyclic load actuators.

The results from the tests will be compared to the theoretical stress levels that were calculated during design, and any deviations have to be accounted for.

Airframe Fatigue Testing is a very costly process and it demands the ultimate in reliability from the various items of test equipment that are involved. A fault in a piece of test equipment could render part of the test invalid and this could result in the need for a partial re-test. Ultimately, the delay in the aircraft certification timetable could cost far more than the cost of the re-test itself, due to the need to compensate customers for the service launch date delay.