Skip to content

Atlas / NTSB / GAA17CA017

NTSB CAROL · Event

Event GAA17CA017

2016-10-06 Keene Valley, New York, United States Airport · 1I1 None 1 aircraft Status: Completed

Registry · N4584H

FAA Aircraft Registry record.

Make / Model

PIPER PA-17

Year of manufacture

1948 · 68 years old at event

Engine

CONT MOTOR A&C65 SERIES (65 hp)

Seats / Engines

2 seats · 1 engine

Last airworthiness date

19580421

ADS-B equipped

Yes — Mode-S A592C0

Registrant of record

SCOOTAIR LLC

Source: FAA Aircraft Registry (releasable master file).

Aircraft involved

Probable cause & findings

The pilot's failure to use the proper hand propping procedures, resulting in a runaway airplane and an impact with trees.

Factual narrative

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. 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. Source: NTSB Aviation Accident Database Retrieved: 2026-02-12

NTSB Findings

Hierarchical cause / factor breakdown from the FAA bulk avdata database. Each finding tagged C (Cause) or F (Factor).

  • C Personnel issues-Task performance-Use of equip/info-Use of policy/procedure-Pilot - C
  • C Personnel issues-Action/decision-Info processing/decision-Decision making/judgment-Pilot - C
  • Aircraft-Aircraft systems-Landing gear system-Brake-Not installed/available
  • Environmental issues-Physical environment-Object/animal/substance-Tree(s)-Effect on equipment

Verbatim from NTSB's published report. Source file NTSB_2016_GAA17CA017.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.