Most of us in the aviation maintenance world are well aware of Murphy’s Law. Its boiled down reality simply states that “anything that can possibly go wrong, usually does, often with catastrophic results”. As aircraft maintainers we must be aware that Murphy’s Law lies dormant in every task we undertake.

For those not acquainted with the history of this principle, it is generally believed that Murphy’s Law was named after Major Edward A. Murphy Jr., an American aerospace engineer, while he worked for the US Air Force Institute of Technology. In 1949 he was working as an R&D officer at Wright-Patterson Air Force Base, where he was deeply involved with testing G-force effects on pilots using ground-based rocket sleds (USAF project MX981). Major Murphy had designed transducers for the sledge to accurately measure the g-forces, but after Dr. John Paul Stapp was subjected to a very high-g test, it was discovered that a technician had wired the transducers backwards and therefore no readings were recorded. After this intense ride, Dr. Stapp was not impressed, and it is this faux pas that caused Major Murphy to coin the famous phrase, “If there are two or more ways to do something and one of those results in a catastrophe, then someone will do it that way.” The rest, along with all the variations and misquotes, is history.

A good example of this phenomenon occurred to me in the winter of 1977. I had returned to Toronto and landed a job at DeHavilland in Downsview. Despite the many trials and tribulations inherent in working for an aircraft manufacturer, this tale involved a Murphy’s Law winter nightmare with a 1974 MGB sports car.

I had rented a room in a large house at the base of Dufferin Street in Toronto and consequently my previously pampered MG was relegated to the horrors of common street parking. Early one Monday morning after a heavy snowfall, it refused to start. After clearing and popping open the “bonnet” I discovered that someone who had parked in front of me had inadvertently filled the engine bay with snow, likely while clearing their own car. After much digging and fooling around without satisfaction, I caught the bus for the long ride up Dufferin Street, vowing to re-attack the situation after work that evening. When I returned, the weather had worsened, but undaunted in darkness with an extension cord running across the street, I continued my quest for internal combustion by the glow of a trouble light. Now the cars battery was getting low from the incessant cranking and cold temps, so I took it inside and charged it for the night. Next morning, it was another Public Transit extravaganza the length of Dufferin Street.

Tuesday night saw me out in the street once again, now with a freshly charged battery, but still no joy. I decided to remove and inspect the distributor cap. Murphy’s Law seized the opportunity and my cold numb fingers allowed one of the distributor clips to ricochet into the snow-covered road below, never to be seen again despite hours of searching. Another bus ride on Wednesday with a detour on the way home to a British Leyland dealer to purchase a new clip resulted in an order being placed for pick-up the next day. A few more bus rides and the weekend arrived, the sun shone and the MG was running once again. I quietly cursed Murphy and smiled every time I passed a bus.

The second Murphy’s tale resulted in an outcome that was much more serious than numb fingers and a bruised ego. A young but experienced pilot was looking to buy a float plane and had made arrangements to do a visual pre-purchase inspection on a very cold winter night. The aircraft in question was in a cold storage hangar for the winter. As part of his discovery, he decided to pull the prop through to get a sense of how good the compression was. He diligently checked that the magnetos were switched off and placed a plank across the floats for secure footing. Unfortunately, when he pulled on the prop, the engine kicked over and struck him with a fatal blow.

When the investigation began, the TC Inspector was baffled. The mag switches were off and the p-leads were properly connected. Both magnetos were grounded and harmless. How could this have happened? Digging a little deeper, he checked the facts of the date the catastrophe took place. It had been an exceptionally cold night. Being ever vigilant he took both magnetos and cooled them both to the same temperature they were exposed to on that fateful night. The results revealed a poorly soldered connection to the p-lead inside one of the magnetos creating an open circuit. That particular magneto was now live, but only in super-cold temperatures.

The two lessons to be learned here are obvious. On the lighter side of things, never expect a British sports car to get you to work on a regular basis, but if you must, always carry tools and transit fare.

On the serious side, never, ever trust a propeller. Always treat it as if it were live and poised to kill – for your own safety and preservation. Remember, in the aviation business, the mayhem created by Murphy’s Law has no conscience or prejudice. Be cognisant that the results of your actions could just as easily end as a funny story or a fatal one. Vigilance and professionalism is our only known defence!