The pilot of the Cessna 172RG planned to fly from Abbeville, Louisiana, but when he went to start the airplane he found the engine battery was dead. He decided to hand-prop the airplane to start the engine.
He tied the tail of the airplane down via a brass snap-hook that attached to a metal fastener underneath the tail section. The snap-hook was attached to a rope that was secured to the ground.
The pilot set the parking brake and checked the throttle position, but did not secure the wheels with chocks.
The engine started on the third attempt. As the pilot walked back toward the cockpit, the RPM increased and the brass snap-hook broke and the airplane began to roll forward.
The pilot was unable to get to the cockpit and the airplane taxied away with out him. The airplane hit a parked airplane, resulting in substantial damage.
The NTSB determined the probable cause as the pilot’s failure to properly secure the airplane before hand starting the engine and the failure of the brass tie down hook.
NTSB Identification: CEN13CA282
This May 2013 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
http://www.attwoodmarine.com/store/product/Fixed-Eye-Snap-Hook
According to this website, the breaking strength of a brass hook like the one on the C172RG is a whopping 200 lbs. (see the NTSB docket for this accident which includes a photo image of the broken hook). The failure was a foregone conclusion. FWIW, the company immediately!!! prohibited hand propping starts after this accident. Duh.
Is this Murphy’s law at work or a case of a lying pilot? The RPM increased as he was walking back to climb in? I suspect the throttle was set at too high an RPM before the engine was propped especially given the pull was sufficient to break the brass hook tail tiedown which despite it being a poor choice should have been sufficient to hold the airplane in place especially with the brakes set. I seriously doubt the veracity of this pilot’s story.
You nailed it !
Hand propping an aircraft with a dead battery is ALWAYS a bad idea.
The 1st question is – why is the battery dead ? Was the master switch left on ?
Is the battery defective ? Is the alternator/ voltage regulator not working ?
The other bad idea is to have the FBO bring a start-cart and jump start the engine…
Why ? The alternator, if it’s working, will provide a very high charge rate to the battery, on the order of 60 amps, for a 12 volt system. The battery capacity is about 20 AH and should be recharged on a bench at 2 amps max. The very high charge rate will overheat the battery and will severely shorten the life of the battery.
The 3rd reason this is a bad idea is that on this RG, when the pilot does get the aircraft in the air, and selects the gear-up, the alternator will immediately go off-line, since it cannot supply the 100+ amps load that the power pack draws. Since the battery is still being recharged, it has little to no capacity.
The result is a total loss of electrical power, with the gear in ‘who knows what position’, no radios, no flaps. Good luck getting back on the ground safely.!!
Be safe. Think first,
JimH.
Well said, Joe ! We’ve all been there.
“What can go wrong, will go wrong”
Tell me (To those that give a monkeys uncle). How often is it, your happily driving along paying close attention to what your doing, when you suddenly take your eyes off the ball for a second (pretty girl, car, house, whatever), and lo and behold the moron in front of you, that your been following forever, decides to jam on his brakes….If you drive enough, then once, twice, three times a day?
Or your plodding along VFR/IFR, holding your height and heading, then for a few seconds your distracted for whatever. Look back and..’goddamn it’ your plus/minus how many hundred feet and degrees out of sync.
Be thankful for little mercies, it could have been much worse, and probably has been for some poor soul we haven’t heard from (yet).