The Royal Air Force’s only airworthy Second World War-era Lancaster bomber flying over eastern England. Powered by four of the Rolls Royce Merlin engines that powered such fighter aircraft as the Supermarine Spitfire, the Hawker Hurricane, and the North American Aviation Mustang, the Avro Lancaster was the subject of an off-target statistical analysis intended to improve the survivability of the aircraft in combat.

Walking home from a meeting recently I heard a strangely familiar growl growing over my left shoulder. I finally looked back to see a Boeing B-17 Flying Fortress — the mainstay of the strategic bombing campaign of the American Eight Air Force During the Second World War — flying toward me at a surprisingly low altitude.

The plane sounded pretty much as they do in the movies except, since this plane presumably wasn’t carrying several tons of high explosives, the engines weren’t working as hard as the sound effects in the movies so they sounded less stressed. I watched until the plane disappeared in the haze to the north.

Seeing this septuagenarian aircraft (the last one was built in 1945) reminded me of the use of statistics during the war to try to assess the effectiveness of various war-making efforts. It was, of course, during the war that Edwards Deming put into practice in American industry the sort of statistical controls he later introduced in Japan.

I once read a story about a statistical survey done by the RAF on the survivability of the Avro Lancaster bomber, the main British four-engine heavy bomber during the war. The survey illustrated the importance of knowing exactly what we are trying to measure with statistics, and why. Continue reading →