# NTSB ANC93LA101: Grumman American AA5A, N9765U, Comet Mine, AK, June 24, 1993 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: June 23, 1993, 16:05 local (Jun 24, 1993, 00:05 UTC) - Place: Comet Mine, AK - Coordinates: 58.579921, -134.769104 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=58.5799&lon=-134.7691&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report October 20, 1994 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 2368 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC93LA101 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/2368/pdf - Page: https://openairdocs.org/ntsb/ANC93LA101 ## Probable cause LOSS OF ENGINE POWER FOR UNDETERMINED REASONS. A FACTOR IN THE ACCIDENT WAS THE UNSUITABLE TERRAIN ON WHICH AN EMERGENCY LANDING COULD BE MADE SUCCESSFULLY. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, cruise - normal - reason for occurrence undetermined (cause) - Forced landing, descent - emergency - Ditching, descent - emergency - terrain condition - none suitable (contributing factor) ## Analysis A POWERPLANT FAILURE FOR UNDETERMINED REASONS OCCURED OVER TERRAIN UNSUITABLE FOR AN EMERGENCY LANDING. THE PILOT DITCHED THE AIRPLANE AND IT SANK. ## Factual narrative On June 23, 1993, at approximately 1605 Alaska daylight time, a wheel equipped Grumman American AASA airplane, N9765U, ditched in the Lynn Canal near Comet Mine, approximately 50 miles north of Juneau, Alaska. The flight was reportedly conducted under 14 CFR Part 91 for personal reasons, and had departed Juneau earlier on June 23 at an unknown time without a flight plan filed. Visual meteorological conditions existed. The Commercial pilot and the two passengers were not injured. The aircraft sank in shallow water and was substantially damaged. Information received from aircraft flying in the vicinity of the ditching indicated the pilot reported a loss of engine power at 2,500 feet while on a local sightseeing flight and elected to "land in the water" because of the unsuitability of the rocky shoreline. The sectional chart of the Lynn Canal, north of Juneau to Skagway and Haines, indicates no airports along the "fiord" type waterway for a distance of approximately 50 miles. The shoreline rises in most places from sea level to over 6000 feet in a distance of less than a mile. The pilot in command had selected a route of flight and an altitude within this fiord route. The airplane sank in shallow water and was recovered at low tide and on June 24, 1993, the airplane wreckage was transported by external-load helicopter to the road system connecting to Juneau. FAA inspectors from the FAA FSDO-S Juneau office told the NTSB that their efforts to see the airplane when it was recovered by external load helicopter were unsuccessful. The aircraft was reported lifted from the water ditching site to the road system north of Juneau. The operator told the NTSB that he "took the airplane apart and brought it to my garage." When asked if the NTSB could review his log books and maintenance records, the operator said that "I lost all of my log books." The pilot reported that the aircraft had 38 gallons of automobile gasoline in the airplane at takeoff from Juneau. The circumstances and events relating to the amount of fuel actually in the aircraft on departure and at the time of the power loss remain undetermined. Recent maintenance and annual inspection data could likewise not be verified, nor could the Supplementary Type Certificate (STC) for the use of automobile fuel. All records were reportedly lost at the time of the ditching, as the operator told investigators that they were aboard the aircraft in flight but not after the aircraft was salvaged. The pilot reported that airplane's carburetor, model MA-4 SPA (Marvel Schebler) malfunctioned, caused by "capscrews holding float chamber to throttle body were working loose." He also stated that "Safety lock tabs did not hold float body to throttle plate securely." Investigators could not verify the pilot's statement due to the removal of the airplane after the accident. ## Aircraft - Registration: [N9765U](https://openairdocs.org/deregistered/N9765U-2013-08-27), registration cancelled 2013-08-27, S/N AA5A-0165, built 1976 (OpenAirDocs) - Reported make and model: GRUMMAN AMERICAN AA5A - Registry model: [Grumman American Avn. AA-5A](https://openairdocs.org/model/grumman-american-avn-aa-5a) (registry code 3960106) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: AA5A-0165 - Airframe hours: 2700 - Engines: LYCOMING O-320-E2G 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Dawson, John B. - Registered owner: John B. Dawson - Airworthiness certificate: Standard, Normal - Last inspection: Annual, July 1, 1992, 90 hours before - Departed: JNU, JUNEAU, AK ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 71; commercial; airplane ratings: multi-engine land, single-engine sea, single-engine land, multi-engine sea; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 11,500 total, 1,500 in this make and model, 11,500 as pilot in command, 10 in the last 90 days, 10 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 210° at 8 knots - Visibility: 50 statute miles - Lowest ceiling: none - Temperature: 57 °F, dew point -0 °F ## 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 19930623019959A](https://openairdocs.org/incident/19930623019959A), Jun 23, 1993: Gulstm AA5A, Juneau, AK, Substantial damage. Lost power ditched in canal off shore. Pilot beleives carburetor came loose. Not verified. 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.