# NTSB CHI95LA250: Grumman G-164, N949X, Park River, ND, July 27, 1995 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 27, 1995, 12:30 local (17:30 UTC) - Place: Park River, ND - Coordinates: 48.390872, -97.739074 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=48.3909&lon=-97.7391&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report February 27, 1996 - Report: Approved by Office Director - NTSB case key (mKey): 9969 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI95LA250 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/9969/pdf - Page: https://openairdocs.org/ntsb/CHI95LA250 ## Probable cause the loss of power due to the primary lead in the left magneto being grounded against the case, and the improper clearance of the breaker point gaps. A factor was the lack of suitable terrain on which to perform the forced landing. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, takeoff - initial climb - ignition system,magneto grounding lead (p-lead) - shorted (cause) - ignition system,ignition points - clearance (cause) - Ditching, emergency landing after takeoff - terrain condition - none suitable (contributing factor) ## Analysis The pilot reported that the engine run-up, magneto check, and takeoff were normal. He reported that the engine started to pop and shake when he reduced engine power to 2050 RPM's. He applied full throttle but the engine failed to produce additional power. The airplane began to lose altitude and airspeed. An emergency landing was performed into a reservoir. The first post accident engine run was unsuccessful. The left and right magneto breaker point gaps were found set at .003 of an inch instead of .009 of an inch as required. Also the primary lead in the left magneto was grounded against the case and distributor cover. After the two discrepancies were corrected, the engine started and ran to 2050 RPM. ## Factual narrative On July 31, 1995, at 1230 central daylight time, a Grumman 164, N949X, registered to Valley Sprayers, Inc., sustained substantial damage following loss of engine power and subsequent ditching in a man made reservoir. The commercial pilot reported no injuries. The 14 CFR Part 137 flight departed from Park River, North Dakota, on a local flight. Visual meteorological conditions prevailed and no flight plan was filed. The pilot reported that when he performed the engine run-up he checked his magnetos several times and cycled the prop about seven times. The takeoff was normal. He reported that just as he was reducing the RPM's back to 2050 RPM's, the engine started to pop and shake. He applied full throttle but the engine failed to produce any additional power. He reported that he began to lose altitude and airspeed. He looked for a place to perform an emergency landing and chose to land in the reservoir. After impact with the water the airplane remained "right side up," and he was able to get free of the aircraft and swim to shore. After the airplane was recovered from the reservoir, an Airworthiness Inspector from the Federal Aviation Administration examined the airplane. He reported that a visual inspection of the engine did not reveal any unusual conditions. The compression ckecked normal, and the engine and supercharger had continuity. (See attachments) The engine was sent to a repair facility for further examination. After the engine had been cleaned and minor repairs performed, which were required as a result of the airplane being submerged for 24 hours, the engine was run on a test stand. The first engine run was unsucessful. It was determined that the left and right magneto breaker point gaps were set at .003 of an inch instead of .009 of an inch specified in the maintenance manuals. Also the primary lead in the left magneto was grounded against the case and distributor cover. After those two discrepancies were corrected, the engine was started and run up to 2050 RPM. The engine ran well but full power was not applied due to the bent crankshaft. The maintenance manager concluded in his report that he felt, "the magnetos were the key problem." He also reported that, "Carburetor adjustments were made to assure a good run because of the cold weather. Keep in mind, because of the submersion, we had little to no cylinder compression and spark plugs tested weak." (See attachments) ## Aircraft - Registration: [N949X](https://openairdocs.org/aircraft/N949X), registered now, S/N 463, built 1967 (OpenAirDocs) - Reported make and model: GRUMMAN G-164 - Registry model: [Grumman G-164A](https://openairdocs.org/model/grumman-g-164a) (registry code 3952704) (OpenAirDocs) - Registry engine: [Pratt & Whitney R-985 series](https://openairdocs.org/engine/pratt-whitney-r-985-series) (registry code 52008, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 463 - Airframe hours: 8347 - Engines: P&W R-985-AN1 450 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Registered owner: Valley Sprayers Inc - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, April 20, 1995, 157 hours before - Departed: Y37 - Destination: Y37 ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 21; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: front; flight hours: 370 total, 73 in this make and model, 291 as pilot in command, 176 in the last 90 days, 63 in the last 30 days, 9 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 310° at 8 knots - Visibility: 15 statute miles - Lowest ceiling: 2,000 ft broken - Temperature: 84 °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 19950727019769A](https://openairdocs.org/incident/19950727019769A), Jul 27, 1995: Scwzer G164, Park River, ND, Substantial damage. Engine popping shaking power losson climb. Ditched in reservoir. Mag points off. P lead ground . Plugs were weak. (-23) pilot departed Park River to conduct… 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.