The Convenience Store Syndrome
"Hi mate...ready for the ride of your life?"
Have you ever stopped at a convenience store and ran in quickly to get what you need, leaving your car engine idling? Sure you have - we all have. In our fast-paced society, with a million errands to do in 10 min, why bother shutting off the engine? Short of having a thief steal your car during the few seconds you’re away, the car will still be there and waiting. In fact, some will even argue it’s better for the engine.
Not surprisingly, some pilots have decided to try this with their aircraft; the results may differ wildly from leaving your 1978 Volaré in the parking lot of your nearest 7-11. A recent case in point: the pilot of a 1990 Robinson R22 Beta, with one passenger on board, landed his helicopter at an oil field to check a building. To avoid a lengthy shutdown, he applied the friction lock to the collective and cyclic and left the helicopter with the engine running. When he got to the building, he heard the engine RPM increase. The pilot turned around to see the helicopter lift off the ground and then nose over into the muskeg. Damage to the helicopter was substantial.
In another incident, the pilot of a 1986 Air Tractor AT-301 taxied to some fuel pumps, then stopped, leaving the aircraft unchocked and the engine at the "idle power setting," before leaving the cockpit to make a telephone call. A ramp attendant, who was neither a pilot nor an engineer, was refueling the aircraft when a sudden gust of wind got the aircraft moving. The ramp attendant jumped into the aircraft and, in an attempt to stop it, inadvertently opened the throttle and the aircraft started to move faster. The ramp attendant then jumped clear of the aircraft.
The pilot heard the power increase and ran out but was unsuccessful in his attempt to get on board and stop the aircraft. The aircraft headed towards a hangar, and the hangar doors started to open as the aircraft got closer. The aircraft was not properly aligned with the door opening and about six feet of the left wing struck the hangar door, which put the aircraft in a left turn; then its right wing struck and substantially damaged a Grumman American AA5-B. The aircraft completed its journey when the propeller struck and heavily damaged a parked automobile.
There were no injuries during these two nasty occurrences, except for torn metal, bruised egos and very embarrassing insurance claims. If you want to learn from the mistakes of others, never leave an aircraft unattended with the engine running, not even for a very short period. Simply shut it down. The benefit of avoiding a start cycle is long forgotten when the expense of a totally preventable accident sets in.