User Guide to the Aircraft Cumulative Probability Chart Template

To ensure aircraft structural integrity is maintained to an acceptable level, probabilistic approaches may be used to calculate the risk of cracking (or failure) over the life of the aircraft or fleet. One such risk analysis technique employs a lognormal probability distribution to model the likelihood of cracking (or failure) in the fleet with respect to hours. This technique was programmed into Microsoft Excel to create a simple and easy to use template. An outline of the theory behind the probabilistic approach is provided as well as a comprehensive user guide to the template. This template allows the quick and simple determination of probability distributions of cracking (or failure) which may be used to assess the life of aircraft structures.