Whenever we are going to work around a propeller, we need to exercise extreme caution.
An apprentice AME was performing a 100 hour inspection on a C-150 aircraft. As part of the engine compression test, he moved the propeller. The engine fired and the propeller came around and clipped the young man on the forehead causing a gash that required a dozen stitches.
The key had been left in the ignition and the ignition was in the magnetos – both position.
A 2,000 hour pilot was conducting a pre-purchase inspection on a Piper PA 12 and was turning the propeller as part of an engine compression test. The engine suddenly started due to faulty ground wire connection on the left magneto and the pilot was struck on the head by the propeller.
A pilot attempted to start his ERCO 415C at the fuel pumps by hand propping it. When the engine started, the aircraft swung 180 degrees and struck the fuel cabinet, damaging it and the aircraft. The pilot was able to get out of the way and was uninjured. He said he thought that he had set the brake.
The ski equipped Aeronca Champ was being started by the owner by hand. The engine started and the aircraft moved forward striking the owner on the forehead. The injured owner could not get inside the aircraft to stop it. The aircraft struck the owner’s truck and then continued across the lake. The owner gave chase on his snowmobile and collided with the tail of the aircraft. He then gave up the chase and the aircraft came to a stop in the trees on the far shore line of the lake.
A pilot planning a pleasure flight found he was blocked in the hangar by a Bellanca 7ECA. He was unsuccessful in his attempts to start the Bellanca with the starter, so he attempted to hand prop it. The aircraft started to move as soon as the engine started. The pilot ducked under the wing and tried to enter the aircraft but was dragged a few feet before losing his grip on the door and falling to the ground. The aircraft continued between two hangars, hit some trees and nosed over.
A pilot of a notoriously hard to start C-206G was in the habit of setting the propeller by hand prior to each start attempt. He accidentally left the right magneto switch in the "on" position before his third setting of the propeller. The aircraft started as he moved the propeller and rolled forward into some bush. The pilot was uninjured.
Before approaching a propeller for any reason, it is necessary to ensure magneto switches are not left in the "on" position. If the aircraft is started with an ignition key, it is a good idea to leave the key on the dash of the aircraft in plain sight, whenever it is removed from the ignition. For other aircraft, a check of all switches must be made.
If maintenance is being performed it also a good idea to make sure the throttle is fully closed and the mixture is in idle cut off. Another safety precaution is to disconnect the spark plug leads to prevent the plugs from firing.
The apprentice AME did not perform a cockpit check. The 2,000 hour pilot would not have been hurt if he had disconnected the spark plug leads.
Body position is also important so that if a cylinder does fire, you are not in the way of the moving propeller.
For aircraft with relatively low compression, it is a good idea to stand behind the propeller, moving it with one hand while balancing yourself with the other on the fuselage. Both of the above mentioned gentlemen stood in front of the propeller.
The CARs state that an aircraft is not to be started or left running if a pilot’s seat is not occupied by someone competent to control the aircraft on the ground, or unless the aircraft is prevented from moving forward. Brakes and chocks are not adequate methods of prevention. A tie down is.
Dale Nielsen is an ex-Armed Forces pilot and aerial photography pilot. He lives in Abbotsford, B.C., and currently flies air charters. He still freelances as a flying instructor and seminar facilitator. Nielsen is also the author of seven flight training manuals published by Canuck West Holdings.
Got an aviation safety story to tell? Dale Nielsen would like to hear from pilots who have educational aviation experiences to relate. Excerpts from these stories will be used in upcoming safety articles. Dale can be contacted via e-mail: firstname.lastname@example.org.