Summary
On October 06, 2016, a Piper PA 17 (N4584H) was involved in an incident near Keene Valley, NY. All 2 people aboard were uninjured. The aircraft sustained substantial damage.
The National Transportation Safety Board determined the probable cause of this incident to be: The pilot's failure to use the proper hand propping procedures, resulting in a runaway airplane and an impact with trees.
The pilot reported that he attempted to hand prop the unoccupied and unchocked airplane, but was unsuccessful. He returned to the cockpit to prime the engine, but then decided to instruct his passenger on how to enter and exit the cockpit, which she then practiced multiple times before exiting the airplane to watch the start procedures again. The pilot further reported that he attempted to hand prop the airplane a second time and the engine started and accelerated to a high revolution per minute (RPM) setting. The pilot was unable to restrain the airplane by holding the right wing lift strut and the airplane made a right circle, entered a wooded area, and impacted trees.
The airplane sustained substantial damage to the wings and fuselage.
This incident is documented in NTSB report GAA17CA017. AviatorDB cross-references NTSB investigation data with FAA registry records to provide comprehensive safety information for aircraft N4584H.
Accident Details
Probable Cause and Findings
The pilot's failure to use the proper hand propping procedures, resulting in a runaway airplane and an impact with trees.
Aircraft Information
Registered Owner (Current)
Analysis
The pilot reported that he attempted to hand prop the unoccupied and unchocked airplane, but was unsuccessful. He returned to the cockpit to prime the engine, but then decided to instruct his passenger on how to enter and exit the cockpit, which she then practiced multiple times before exiting the airplane to watch the start procedures again. The pilot further reported that he attempted to hand prop the airplane a second time and the engine started and accelerated to a high revolution per minute (RPM) setting. The pilot was unable to restrain the airplane by holding the right wing lift strut and the airplane made a right circle, entered a wooded area, and impacted trees.
The airplane sustained substantial damage to the wings and fuselage.
The pilot later reported that the airplane was not equipped with a parking brake.
The pilot reported that there were no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation.
Federal Aviation Administration's Airplane Flying Handbook, FAA-H-8083-3A, contains a section titled "Hand Propping" which states:
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 person pulling the propeller blades through directs all activity and is in charge of the procedure. The other person, thoroughly familiar with the controls, must be seated in the airplane with the brakes set. As an additional precaution, chocks may be placed in front of the main wheels. If this is not feasible, the airplane's tail may be securely tied. Never allow a person unfamiliar with the controls to occupy the pilot's seat when hand propping. The procedure should never be attempted alone.
Data Source
Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# GAA17CA017