It is said that a wise man learns from his mistakes, but a wiser man learns from the mistakes of others. This just in from April's Callback, published by NASA's Aviation Safety Reporting System (online subscriptions free). I know we've heard it all before, yet I'll bet these pilots have, too:
"Lesson One: What "Should Have" Been Done
Resorting to hand-propping due to a faulty battery could lead to the aircraft taxiing on its own for about 100 feet before being stopped by a collision.
The aircraft was pulled from the tie-down spot and turned 90-degrees for starting and taxi to the hangar. Due to a weak battery the aircraft did not start. The wheels were chocked for hand-propping and the throttle was cracked open. When the engine started, it revved up to approximately 1,800 RPM and then the aircraft rolled over the chocks and proceeded ahead about 100 feet where it contacted a parked aircraft. There was minor damage to both aircraft, but no injuries beyond a scraped knee when scrambled from the rotating prop and fell under the wing. The chocks were insufficient to hold the airplane past a certain engine RPM.
The brakes should have been set. The tail should have been secured as well. The throttle setting should have been lower. A second pilot in the cockpit holding the brakes and controlling the throttle would have been best.
Lesson Two: Know Your Crew
This pilot was familiar with the proper procedures for hand-propping, but despite a conscientious effort, one critical assumption led to a nose-to-nose encounter.
I was going to fly a 65 HP taildragger with no electrical system and no starting system. It requires the pilot to hand-prop the engine and either requires the aircraft to be tied down or a person to hold the brakes . instructed the passenger how to hold the brakes and how to pull the throttle to idle after engine start. Both holding the brakes and pulling the throttle to idle had been practiced. The passenger was in the rear seat, with the seatbelt fastened. After hand propping the engine, I noticed what sounded like an increase in engine rpm and the aircraft started to move forward rapidly. I got out of the way of the moving aircraft and around to the door. I was halfway inside the aircraft getting the engine to idle while telling the passenger to push the brakes when the aircraft struck a parked Cessna. The aircraft hit nose-to-nose . The aircraft had traveled approximately 25 yards across the tarmac. [There was] prop and cowling damage and both passenger and pilot were unhurt.
I had incorrectly assumed that the passenger would be able to hold the brakes after engine start and I placed too much confidence in the abilities of a non-pilot . The very act of hand-propping an aircraft is dangerous and I will never again pull the prop through without the aircraft being tied down . Even 65 HP is enough to overpower the person starting the engine.
Lesson Three: Double Jeopardy
An engine that was idling too fast was just the beginning of a bad start for this Cessna 140 pilot. Things quickly went from bad to worse.
I intended to start the engine and warm the oil prior to an oil change. The battery was low so I chocked both wheels and hand-propped the engine. Upon starting, the engine was idling too fast so I walked around the wing to the pilots door to retard the throttle. I had my left hand on the door and as I reached for the throttle, I fell and the door separated from the airplane. The engine was making enough power that it jumped the right chock and began circling to the left. I attempted to re-enter the cockpit, but was knocked down again by the wing strut. The airplane continued to circle to the left and struck my truck which stopped the engine .
Reflecting upon this incident, it is clear that my plane was not adequately restrained. One clear solution would have been to utilize another person at the controls during hand-propping .
While it is possible to find any number of published recommendations and checklists for solo hand-propping, it remains an extremely dangerous practice. The best procedure is to follow the Federal Aviation Administrations advice found in the Airplane Flying Handbook (FAA-H-8083-3) which states in part: An engine should not be hand-propped unless two people, both familiar with the airplane and hand-propping techniques, are available to perform the procedure . The procedure should never be attempted alone. "
Kind of amazing, don't you think?
"Lesson One: What "Should Have" Been Done
Resorting to hand-propping due to a faulty battery could lead to the aircraft taxiing on its own for about 100 feet before being stopped by a collision.
The aircraft was pulled from the tie-down spot and turned 90-degrees for starting and taxi to the hangar. Due to a weak battery the aircraft did not start. The wheels were chocked for hand-propping and the throttle was cracked open. When the engine started, it revved up to approximately 1,800 RPM and then the aircraft rolled over the chocks and proceeded ahead about 100 feet where it contacted a parked aircraft. There was minor damage to both aircraft, but no injuries beyond a scraped knee when scrambled from the rotating prop and fell under the wing. The chocks were insufficient to hold the airplane past a certain engine RPM.
The brakes should have been set. The tail should have been secured as well. The throttle setting should have been lower. A second pilot in the cockpit holding the brakes and controlling the throttle would have been best.
Lesson Two: Know Your Crew
This pilot was familiar with the proper procedures for hand-propping, but despite a conscientious effort, one critical assumption led to a nose-to-nose encounter.
I was going to fly a 65 HP taildragger with no electrical system and no starting system. It requires the pilot to hand-prop the engine and either requires the aircraft to be tied down or a person to hold the brakes . instructed the passenger how to hold the brakes and how to pull the throttle to idle after engine start. Both holding the brakes and pulling the throttle to idle had been practiced. The passenger was in the rear seat, with the seatbelt fastened. After hand propping the engine, I noticed what sounded like an increase in engine rpm and the aircraft started to move forward rapidly. I got out of the way of the moving aircraft and around to the door. I was halfway inside the aircraft getting the engine to idle while telling the passenger to push the brakes when the aircraft struck a parked Cessna. The aircraft hit nose-to-nose . The aircraft had traveled approximately 25 yards across the tarmac. [There was] prop and cowling damage and both passenger and pilot were unhurt.
I had incorrectly assumed that the passenger would be able to hold the brakes after engine start and I placed too much confidence in the abilities of a non-pilot . The very act of hand-propping an aircraft is dangerous and I will never again pull the prop through without the aircraft being tied down . Even 65 HP is enough to overpower the person starting the engine.
Lesson Three: Double Jeopardy
An engine that was idling too fast was just the beginning of a bad start for this Cessna 140 pilot. Things quickly went from bad to worse.
I intended to start the engine and warm the oil prior to an oil change. The battery was low so I chocked both wheels and hand-propped the engine. Upon starting, the engine was idling too fast so I walked around the wing to the pilots door to retard the throttle. I had my left hand on the door and as I reached for the throttle, I fell and the door separated from the airplane. The engine was making enough power that it jumped the right chock and began circling to the left. I attempted to re-enter the cockpit, but was knocked down again by the wing strut. The airplane continued to circle to the left and struck my truck which stopped the engine .
Reflecting upon this incident, it is clear that my plane was not adequately restrained. One clear solution would have been to utilize another person at the controls during hand-propping .
While it is possible to find any number of published recommendations and checklists for solo hand-propping, it remains an extremely dangerous practice. The best procedure is to follow the Federal Aviation Administrations advice found in the Airplane Flying Handbook (FAA-H-8083-3) which states in part: An engine should not be hand-propped unless two people, both familiar with the airplane and hand-propping techniques, are available to perform the procedure . The procedure should never be attempted alone. "
Kind of amazing, don't you think?
