Wars, especially modern ones that involve huge masses of people, one of the many consequences - often tragic - have the ability to uproot brilliant minds from the most disparate sectors and confront them with issues that probably would never have attracted their attention. This is what happened in 1943 to Conrad Hal Waddington. Evolutionary biologist, paleontologist, geneticist, embryologist, philosopher, poet and painter, Waddington was not particularly interested in aviation but with the outbreak of the Second World War he found himself enlisted in the Royal Air Force (RAF).
Aged forty, when he became scientific advisor to the Commander-in-Chief of the Coastal Command, Waddington was already an established scientist but fighting the German submarine threat more effectively seemed to have little relevance to his studies on epigenetics. Waddington and his colleagues developed a series of surprising recommendations that challenged the conventional military wisdom of the time in terms of attack tactics but what we remember him for here was his observation concerning the fact that of the 40 B-24 "Liberators" of the Coastal Command only half were flying in search of German U-boats while the other 50% was systematically grounded largely undergoing maintenance or waiting for it, whether planned or unplanned.
Adopting the methods that had already challenged his established beliefs, Waddington applied statistics and observed that scheduled preventive maintenance at very intense cycles was harmful, increasing the frequency of failures after the interventions. As with surgery, maintenance had to be performed no more than necessary otherwise risking reducing safety and reliability. The proposed solution was to increase the time interval between scheduled maintenance cycles and to eliminate all preventive maintenance activities that could not be proven effective.