# NTSB ATL96LA100: Cessna 172N, N75814, Hillsborough, NC, July 5, 1996 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: July 5, 1996, 11:30 local (15:30 UTC) - Place: Hillsborough, NC - Coordinates: 36.069221, -79.100463 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=36.0692&lon=-79.1005&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 2 minor - Status: Completed, report February 18, 1997 - Report: Approved by Office Director - NTSB case key (mKey): 3738 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL96LA100 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/3738/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=3738 - Page: https://openairdocs.org/ntsb/ATL96LA100 ## Probable cause The failure of the magneto impulse coupling spring. A factor was the power line at the approach end of the forced landing site. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - mech failure/malf, cruise - ignition system,magneto - failure,total (cause) - Forced landing, emergency descent/landing - terrain condition - high obstruction(s) (contributing factor) - In flight collision with object, emergency descent/landing - object - tree(s) (contributing factor) ## Analysis During cruise flight, the engine quit. A force landing was attempted in an open pasture that the pilot reported was the only available site. He circled the pasture to position the airplane for the forced landing. On final approach, the pilot extended the flaps, stopping them at ten degrees to ensure that the airplane would clear power lines at the approach end of the pasture. Consequently, the airplane overran the end of the downhill sloped pasture, then collided with trees at the end with the airspeed about 55 knots, according to the pilot. During the postaccident examination of the engine, the magneto impulse coupling spring of the single-drive dual magneto was found broken, resulting in a loss of engine to magneto timing and engine stoppage. ## Factual narrative On July 5, 1996, about 1130 eastern daylight time, a Cessna 172N, N75814, collided with trees and was substantially damaged during a forced landing attempt near Hillsborough, North Carolina. The private pilot and his passenger received minor injuries. The airplane was being operated by the pilot under the provisions of Title 14 CFR Part 91, and visual flight rules. Visual meteorological conditions existed at the time, and no flight plan had been filed for the local personal flight. The flight departed Burlington-Alamance Regional airport about 1115. The pilot stated that after a loss of engine power and an unsuccessful engine restart, he attempted a forced landing in a pasture. The airplane impacted trees, separating the wings, the horizontal stabilizers, and the vertical stabilizer. The engine was examined following the accident. The single-drive dual magneto timing was found to be incorrectly timed by 90 degrees. After disassembly of the magneto, the impulse coupling spring was found broken. Records for the overhaul of the magneto indicated that the spring had been reused during the overhaul in March 1989. According to a Bendix magneto representative, the overhaul manual allowed reuse of the spring in March 1989. The overhaul manual was subsequently changed, in July 1989, to require replacement of the spring at each disassembly with new parts. According to the quality assurance representative for the overhaul facility, the facility has revised its procedures to comply with the Bendix overhaul manual for replacement of the spring at each disassembly of the magneto. ## Aircraft - Registration: [N75814](https://openairdocs.org/deregistered/N75814-1998-04-21), registration cancelled 1998-04-21, S/N 17267971 (OpenAirDocs) - Reported make and model: Cessna 172N - Registry model: [Cessna 172N](https://openairdocs.org/model/cessna-172n) (registry code 2072434) (OpenAirDocs) - Category: Airplane - Serial number: 17267971 - Airframe hours: 3587 - Engines: Lycoming O-320-H2AD 160 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: James C. Edwards - Registered owner: N75814 Corp - Airworthiness certificate: Standard, Normal - Last inspection: Annual, August 29, 1995, 35 hours before - Departed: BUY, BURLINGTON, NC ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 67; private; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 764 total, 435 in this make and model, 700 as pilot in command, 9 in the last 90 days, 6 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: variable at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 79 °F, dew point 54 °F - Altimeter: 30.00 inHg - Observed at: RDU, 25 nm away ## 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 19960705020019A](https://openairdocs.org/incident/19960705020019A), Jul 5, 1996: Cessna 172N, Hillsborough, NC, Substantial damage. Lost power. Hit trees landing in pasture. Magneto off timing. Impulse coupling spring broken. ## Docket (4 files) The files NTSB released with the investigation on December 9, 1996, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=3738. 1.1 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 428 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40438948&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Supplement S (item 2, .PDF, 68 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40059112&FileExtension=.PDF&FileName=Supplement%20S-Master.PDF - Records of Interview (item 3, .PDF, 81 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40438949&FileExtension=.PDF&FileName=Records%20of%20Interview-Redacted.PDF - FAA Inspector's Report w/Attachments (item 4, .PDF, 483 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40438950&FileExtension=.PDF&FileName=FAA%20Inspector%27s%20Report%20w%2FAttachments-Redacted.PDF 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.