# NTSB SEA96LA172: Grumman-Schweizer G-164A, N5390, Dubois, ID, July 27, 1996 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 27, 1996, 07:00 local (13:00 UTC) - Place: Dubois, ID - Coordinates: 44.219654, -112.369712 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.2197&lon=-112.3697&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 August 21, 1997 - Report: Approved by Office Director - NTSB case key (mKey): 42431 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA96LA172 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/42431/pdf - Page: https://openairdocs.org/ntsb/SEA96LA172 ## Probable cause failure of the pilot to remain clear of an irrigation spray device, which resulted in inadvertent water ingestion and flameout of the aircraft's turboprop engine. Factors relating to the accident were: the proximity of the irrigation spray device (close to the airstrip), insufficient time available to attempt an engine restart after the flameout, and high vegetation (wheat crop) in the forced landing area. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - nonmechanical, takeoff - initial climb - object - other (contributing factor) - clearance - not maintained, pilot in command (contributing factor) - fluid,water - ingested (cause) - remedial action - not possible (contributing factor) - Forced landing, emergency descent/landing - Nose over, emergency landing after takeoff - terrain condition - crop (contributing factor) ## Analysis Immediately after takeoff, the pilot began a turn which took him within 75 feet of an operating agricultural irrigation spray device. This device was located 500 feet from the takeoff runway. The pilot reported that as he passed the device, the water stream from the device pivoted and shot a two-to-three-inch stream of water directly in front of the engine air intake of the turboprop-engine-equipped aircraft, resulting in engine flameout. This occurred at an altitude of about 75 feet above ground level. A forced landing was then made in a wheat field, where the airplane nosed over. ## Factual narrative On July 27, 1996, approximately 0700 mountain daylight time, a Grumman-Schweizer G-164A, N5390, registered to Buzz Ruchert Flying Service of Pomeroy, Washington, was substantially damaged in a forced landing in a wheat field following a loss of engine power immediately after takeoff from a private airstrip approximately 7 miles south of Dubois, Idaho. The commercial pilot of the single-seat agricultural aircraft was not injured. The 14 CFR 137 local agricultural aerial application flight was not on a flight plan. Visual meteorological conditions prevailed, according to the pilot. The airplane had a Garrett TPE331-1 turboprop engine conversion installed. The pilot stated that immediately after takeoff to the south, he began a right turn back to the north. After completing about 90 degrees of turn, while at an altitude of about 75 feet above ground level, he passed about 75 feet from a pivoting irrigation device which was spraying. This device was located approximately 500 feet southwest of the takeoff runway. The pilot stated that as he passed the device, the water stream from the device pivoted around and "shot a [two to three inch] stream of water directly in front of the engine air intake resulting in flame out." The ensuing forced landing was made into a "waist high, thick mature wheat field in sandy soil...." The airplane nosed over during the forced landing into the wheat. On his accident report, the pilot recommended an auto-relight system triggered by negative torque sensing, and avoidance of flight near high-output sprinkler systems with turboprop aircraft, as possible ways that the accident could have been prevented. A representative of the AlliedSignal Engines air safety investigation department, in a telephone conversation with the NTSB investigator-in-charge (IIC), stated that a water ingestion tolerance test had been accomplished on a TPE331-16 engine on a previous occasion, in conjunction with another accident investigation. He stated that the test consisted of spraying a water stream from a fire hose into the intake of an operating engine. The AlliedSignal representative stated that the engine continued to run under those conditions, but that the TPE331-16 has a larger compressor than the TPE331-1. On his accident report, the pilot (who was also a co-owner of the aircraft) reported that the engine had 457 hours in service since inspection of the hot section and gearbox, and 3,510 hours since overhaul. The AlliedSignal Engines representative stated to the NTSB IIC that the TPE331 engine has a recommended time between overhauls of 3,000 hours, which may be extended to 3,600 hours if certain service bulletins are accomplished. It was not determined whether the applicable service bulletins had been accomplished on the accident engine. Per 14 CFR 33.77, the following airworthiness standards are applicable to the design and construction of turbine aircraft engines with respect to tolerance to water ingestion: "Ingestion of water...under the conditions prescribed in...this section, may not cause a sustained power or thrust loss or require the engine to be shut down. It must be demonstrated that the engine can accelerate and decelerate safely while inducting a mixture of at least 4 percent water by weight of engine airflow following stabilized operation at both flight idle and takeoff power settings with at least a 4 percent water-to-air ratio." The regulation specifies that the engine must be capable of ingesting at least 4 percent water by weight of engine airflow, sucked into the engine, for 3 minutes each at flight idle and takeoff, and "during acceleration and deceleration in spray to simulate rain." ## Aircraft - Registration: [N5390](https://openairdocs.org/deregistered/N5390-2013-04-09), registration cancelled 2013-04-09, S/N 1147, built 1973 (OpenAirDocs) - Reported make and model: Grumman-Schweizer G-164A - Registry model: [Grumman Acft ENG Cor-Schweizer G-164A](https://openairdocs.org/model/grumman-acft-eng-cor-schweizer-g-164a) (registry code 3952801) (OpenAirDocs) - Registry engine: [Pratt & Whitney R1340 series](https://openairdocs.org/engine/pratt-whitney-r1340-series) (registry code 52016, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 1147 - Airframe hours: 4776 - Engines: Garrett TPE-331-1 665 horsepower turbo prop - Damage: Substantial damage - Flight: Aerial application, Part 137 - Registered owner: Dennis Ruchert - Airworthiness certificate: Special, Restricted (Special) - Last inspection: 100 hour, July 19, 1996, 24 hours before - Departed: ID ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 33; commercial; airplane ratings: single-engine land, single-engine sea; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; flight hours: 5,134 total, 3,496 in this make and model, 4,976 as pilot in command, 350 in the last 90 days, 98 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 30 statute miles - Lowest ceiling: none - Temperature: 68 °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 19960727020159A](https://openairdocs.org/incident/19960727020159A), Jul 27, 1996: Grumav STCG164, Dubois, ID, Substantial damage. Lost power on climbout. Engine flamed out after being sprayed by irrigation rig. Nosed over. Engine over tbo. 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.