“… the most exhaustively tested airplane in history.”
-Expert opinion on the DeHavilland Comet
Today, commercial jet air travel is standard fare. Estimates for the amount of air traffic over the United States in a given day have been in the range of 87,000 flights. With clever planning, clear skies and smooth service, a citizen almost anywhere in the world can get anywhere else by plane in less than 24 hours. But looking back at the history of aviation show us how far safety has come. Consider the DeHavilland Comet, the first commercial jet to reach production. British aviation specialists finalized the Comet’s design with much excitement in 1945 in hopes it would position their industry to establish a revolutionary service in commercial jet flight. Unfortunately, the Comet crashed on January 10th and April 8th in 1954.
What happened? We can identify some of the causes in a Cause Map, or visual root cause analysis.
CAUSE #1: POOR TESTING When you test an extremely heavy object carrying hundreds of people at high speeds thousands of feet above the ground, you would think planning for the worst case scenario would make the most sense. Unfortunately, the Comet tests were performed in tainted conditions on the strongest part of the plane.
Add in the fact that there was no prototype for the plane and you’ve got a test not worth having… and a plane not worth flying.
CAUSE #2: UNEXPECTED PRESSURE Altitude leads to pressure, and pressure puts stress on planes. But this stress wasn’t evenly distributed, and certain parts of the planes’ bodies were unevenly affected. So rather than the expected amount of pressure on the planes, the Comets faced an unforeseen squeeze.
CAUSE #3: FLYING ABOVE AND BEYOND The Comet flew at twice the speed, height and cabin pressure of any previous aircraft, displaying a rather dangerous amount of ambition.
Combine all of this, Cause Map it, and you’ve got a plane flying under incredible conditions it couldn’t withstand, facing high pressure where it was most vulnerable.
In other words, an airborne recipe for disaster.
FALLOUT #1) SAFETY As expected, the pressure cycle in the planes’ cabins cracked the bodies of the planes. When the planes broke up, the lives of 56 passengers and crew members were lost.
#2) CUSTOMER SERVICE Some British industry institutions have a highly prestigious reputation (the Royal Navy’s impact on British sea travel comes to mind). The loss of the aircraft, though, was a black eye on British Aviation. Aviation historian George Bibel called the Comet an “adventurous step forward and a supreme tragedy.”
#3) MATERIALS/LABOR Effective airplanes have never been cheap, and this was no different. Not only would it cost money to investigate the cause of the accidents, but to replace the airplanes.
FUTURE SOLUTION The Comet’s tragic crash had one silver lining: the post-crash analysis performed by its designers (including Sir Geoffrey de Havilland) set the precedent for future air accident investigations. In fact, the Comet was redesigned to solve the issues that caused the crashes and would later fly successfully. But by then, Boeing had already taken over most of the commercial jet market.
In the end, the Comet was first in flight but last in the market.
See more aviation cause maps:
Want us to cause map a specific plane crash for you? Tell us in the comments and we’ll pilot our way through it.