# NTSB ANC06CA138: Cessna 172, N7939B, Palmer, AK, September 24, 2006 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: September 24, 2006, 13:00 local (17:00 UTC) - Place: Palmer, AK - Coordinates: 61.521667, -148.925003 - Nearby events: https://openairdocs.org/map.md?lat=61.5217&lon=-148.9250&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report January 31, 2007 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 64593 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC06CA138 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/64593/pdf - Page: https://openairdocs.org/ntsb/ANC06CA138 ## Probable cause The pilot's failure to follow the checklist to ensure the proper positioning of the magneto switch during the takeoff roll, which resulted in a partial loss of engine power, and a subsequent collision with high vegetation during the takeoff run. A factor contributing to the accident was the pilot's improper positioning of the magneto switch on the left magneto position. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(partial) - nonmechanical, takeoff - roll/run - ignition system,magneto - improper (contributing factor) - checklist - not followed, pilot in command (cause) - On ground/water encounter with terrain/water, takeoff - roll/run - terrain condition - high vegetation ## Analysis The private certificated pilot was departing from a remote area that was about 900 feet long on a Title 14, CFR Part 91, local area personal flight. The pilot reported that he previously had trouble with the airplane's charging system. When he attempted to start the airplane for takeoff, the battery was dead. He placed the magneto switch on the left magneto to facilitate starting, and hand-propped the engine. He then began the takeoff roll, which was longer than he expected. In order to miss trees at the end of the departure area, the pilot applied left rudder to maneuver past the trees, but the right horizontal stabilizer and right elevator collided with high brush. The airplane became airborne, and the pilot continued to his destination, about 8 miles away. Upon landing, the pilot discovered substantial damage to the stabilizer and elevator. The pilot reported that he also discovered that the magneto switch was still on the left magneto position, and that he did not select the "both" magneto position prior to the takeoff, thereby reducing available engine power. ## Factual narrative The private certificated pilot was departing from a remote area that was about 900 feet long on a Title 14, CFR Part 91, local area personal flight. The pilot reported that he previously had trouble with the airplane's charging system. When he attempted to start the airplane for takeoff, the battery was dead. He placed the magneto switch on the left magneto to facilitate starting, and hand-propped the engine. He then began the takeoff roll, which was longer than he expected. In order to miss trees at the end of the departure area, the pilot applied left rudder to maneuver past the trees, but the right horizontal stabilizer and right elevator collided with high brush. The airplane became airborne, and the pilot continued to his destination, about 8 miles away. Upon landing, the pilot discovered substantial damage to the stabilizer and elevator. The pilot reported that he also discovered that the magneto switch was still on the left magneto position, and that he did not select the "both" magneto position prior to the takeoff, thereby reducing available engine power. ## Aircraft - Registration: [N7939B](https://openairdocs.org/aircraft/N7939B), registered now, S/N 29739, built 1956 (OpenAirDocs) - Reported make and model: Cessna 172 - Registry model: [Cessna 172](https://openairdocs.org/model/cessna-172) (registry code 2072402) (OpenAirDocs) - Registry engine: [Continental 0-300 series](https://openairdocs.org/engine/continental-0-300-series) (registry code 17022, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 29739 - Engines: Continental O-300 145 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Joel L. Hard - Airworthiness certificate: Standard, Normal - Departed: Palmer, AK - Destination: PAAQ, Palmer, AK ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 46; private; airplane ratings: single-engine land; medical: class 3; flight hours: 732 total, 55 in this make and model, 27 in the last 90 days, 9 in the last 30 days ## Weather - Conditions: Visual (VMC), Day ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20060924023369A](https://openairdocs.org/incident/20060924023369A), Sep 24, 2006: Cessna 172, Palmer, AK, Minor damage. (-23) Aircraft battery dead. Left magneto selected for starting. Takeoff was made on left mag only. Engine will not develop full power unless switched to both.… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.