# NTSB NYC01LA164: Stinson 108-3, N6647M, Friendly, MD, July 5, 2001 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: July 5, 2001, 11:00 local (15:00 UTC) - Place: Friendly, MD - Coordinates: 38.729728, -77.000595 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=38.7297&lon=-77.0006&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 1 serious, 1 minor - Status: Completed, report February 20, 2002 - Report: Approved by Office Director - NTSB case key (mKey): 52621 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC01LA164 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/52621/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=52621 - Page: https://openairdocs.org/ntsb/NYC01LA164 ## Probable cause A baffling failure within the exhaust system. Factors were an inadequate annual inspection and the pilot's operation of the airplane with known deficiencies in equipment. ## 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, takeoff - initial climb - maintenance,annual inspection - inadequate, other maintenance personnel (contributing factor) - exhaust system,baffle - failure (cause) - operation with known deficiencies in equipment - performed, pilot in command (contributing factor) - In flight collision with terrain/water, descent - emergency ## Analysis The pilot started the engine, taxied to runway 24, and performed a magneto check. No anomalies were observed, and he initiated a takeoff roll. However, the engine began to run rough, and the pilot aborted the takeoff. He then ran the engine at different RPM, and performed a second satisfactory magneto check. During the second takeoff roll, the engine ran rough again, and the pilot aborted the takeoff. The pilot then let the engine run for 5 minutes at different RPM, and it passed a third magneto check. On the third takeoff attempt, the engine "had good power," but as the airplane climbed above the trees, the engine lost all power and the pilot performed a forced landing into trees. Examination of the wreckage revealed that the right-side muffler baffling was mostly disintegrated, consistent with a baffling failure and subsequent blockage of the engine exhaust. The muffler baffling was required to be inspected for cracks and wear during the annual inspection of the airplane. The last annual inspection of the airplane was performed about 3 months and 2 weeks prior to the accident, and the airplane had accumulated approximately 28 hours of operation since that inspection. ## Factual narrative On July 5, 2001, about 1100 eastern daylight time, a Stinson 108-3, N6647M, was substantially damaged during a forced landing, after takeoff from Potomac Airfield (VKX), Friendly, Maryland. The certificated private pilot sustained minor injuries, and the passenger was seriously injured. Visual meteorological conditions prevailed, and no flight plan was filed for the personal conducted under 14 CFR Part 91. The pilot reported that he purchased fuel at VKX, and intended to return to his home airport, Washington Executive Airport (W32), Clinton, Maryland, located about 2 miles to the east. The pilot added that he started the engine, taxied to runway 24, and performed a magneto check. No anomalies were observed, and the pilot initiated a takeoff roll. However, the engine began to run rough, and the pilot aborted the takeoff. He then ran the engine at different RPM, and performed a second satisfactory magneto check. During the second takeoff roll, the engine ran rough again, and the pilot aborted the takeoff. The pilot then let the engine run for 5 minutes at different RPM, and it passed a third magneto check. On the third takeoff attempt, the engine "had good power," but as the airplane climbed above the trees, the engine lost all power. The pilot performed a forced landing into trees, and the airplane settled to the ground in a wooded area. A Safety Board investigator and Federal Aviation Administration (FAA) inspector examined the engine after the wreckage was recovered. They observed that the right-side muffler baffling was mostly disintegrated, consistent with a baffling failure and subsequent blockage of the engine exhaust. The FAA inspector stated that the muffler was manufactured by Hanlon Wilson Muffler Systems, and the baffling was required to be inspected for cracks and wear during the annual inspection of the airplane. The last annual inspection of the airplane was performed on March 22, 2001, and the airplane had accumulated approximately 28 hours of operation since that inspection. ## Aircraft - Registration: [N6647M](https://openairdocs.org/deregistered/N6647M-2010-02-03), registration cancelled 2010-02-03, S/N 108-4647, built 1948 (OpenAirDocs) - Reported make and model: Stinson 108-3 - Registry model: [Stinson 108-3](https://openairdocs.org/model/stinson-108-3) (registry code 9230408) (OpenAirDocs) - Registry engine: [Franklin 6A4165 series](https://openairdocs.org/engine/franklin-6a4165-series) (registry code 27025, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 108-4647 - Airframe hours: 1409 - Engines: Franklin 6A4165 165 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Alan L. Williams - Airworthiness certificate: Standard, Normal - Last inspection: Annual, March 22, 2001, 28 hours before - Departed: VKX, Friendly, MD - Destination: W32, Clinton, MD - Airport: VKX, Potomac Airfield, runway 24, 2,665 × 40 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 45; injuries: minor; private; airplane ratings: single-engine land; medical: class 1, valid medical--no waivers/lim.; last flight review March 13, 2001; seat: left; flight hours: 192 total, 67 in this make and model, 86 as pilot in command, 13 in the last 90 days, 5 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 250° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 66 °F - Altimeter: 29.89 inHg - Observed at: DCA, 8 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 20010705022339A](https://openairdocs.org/incident/20010705022339A), Jul 5, 2001: Univar 1083, Friendly, MD, No damage. (-23) On July 5th 2001, inspector dunlop was requested to go with Mr. Rolandos lazaris and Mr. Bruce mcgray to investigage an airplane accident in the vicinity… ## Docket (2 files) The files NTSB released with the investigation on January 23, 2002, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=52621. 398 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 366 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424989&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Interview Summary (item 2, .PDF, 32 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424990&FileExtension=.PDF&FileName=Interview%20Summary-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.