# NTSB SEA97LA172: Grumman G-164A, N6550, Pingree, ID, July 20, 1997 - Type: NTSB accident investigation - Classification: Accident · Fatal · Limited investigation · Final report - Date: July 20, 1997, 09:00 local (15:00 UTC) - Place: Pingree, ID - Coordinates: 43.119125, -112.600715 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=43.1191&lon=-112.6007&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Fatal - Injuries: 1 fatal - Status: Completed, report January 28, 2000 - Report: Approved by Office Director - NTSB case key (mKey): 42661 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA97LA172 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/42661/pdf - Page: https://openairdocs.org/ntsb/SEA97LA172 ## Probable cause The pilot-in-command's failure to maintain adequate clearance with the power lines. A contributing factor was the unmarked power lines. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with object, maneuvering - aerial application - object - wire,transmission (contributing factor) - clearance - not maintained, pilot in command (cause) - Loss of control - in flight, maneuvering - aerial application - In flight collision with terrain/water, descent - uncontrolled - terrain condition - ground ## Analysis The pilot-in-command impacted power lines during a pull-up maneuver, severing two of the three 161,000 volt unmarked power lines. The aircraft then descended out of control, impacting terrain in a nose low, upright attitude, and came to rest on the east side of the power lines. ## Factual narrative On July 20, 1997, approximately 0900 mountain daylight time, a Grumman G-164A "AgCat," N6550, registered to and being flown by a commercial pilot, was destroyed during a collision with high tension power lines and subsequent ground impact while executing a pull-up maneuver near Pingree, Idaho. The pilot was fatally injured. A post mortem and toxicological evaluation was not completed as the body of the pilot was released to the family shortly after the accident. Visual meteorological conditions existed and no flight plan had been filed. The flight, which was engaged in aerial application, was to have been operated under 14CFR137, and originated from a private airstrip belonging to the pilot/owner near Pingree. On site examination by an FAA inspector as well as Blackfoot County Sheriff personnel revealed that the aircraft impacted gently rolling terrain slightly east of a set of 161,000 volt unmarked power lines oriented along an approximate 320/140 degree true bearing line. The impact was with two of the three lower (mid tower) braided cables which measured about two inches in diameter. The two top ground wires were undamaged (refer to CHART I). According to FAA personnel there were no eyewitnesses to the accident. Additionally, they reported that the aircraft was engaged in a pull-up at the conclusion of a swath run at the time of the wire strike. The aircraft was observed at the accident site in an upright attitude. The engine was observed to have been pushed upward. Slightly short of the aircraft's engine, a large dirt impact area was noted. The engine was observed to have a substantial amount of dirt impacted around its lower cylinders. Two smaller ground impact craters were noted slightly short of the main crater, and were separated laterally by approximately the same distance as the aircraft's wheels. Also, the aircraft's lower right wing outboard leading edge displayed a number or sharp cuts characteristic of wire impacts (refer to photograph 1). Further inspection revealed gradual aft bending deformation at the outboard lower right wing leading edge (refer to photograph 2). Buckling and bending deformation of the aircraft's outboard left elevator were noted (refer to photograph 3). A substantial length of power cable was found entangled around the front right side of the aircraft where it came to rest (refer to photograph 4). ## Aircraft - Registration: [N6550](https://openairdocs.org/deregistered/N6550-1998-12-09), registration cancelled 1998-12-09, S/N 693 (OpenAirDocs) - Reported make and model: Grumman G-164A - Registry model: [Grumman G-164A](https://openairdocs.org/model/grumman-g-164a) (registry code 3952704) (OpenAirDocs) - Category: Airplane - Serial number: 693 - Engines: P&W R-1340 600 horsepower reciprocating - Damage: Destroyed - Flight: Aerial application, Part 137 - Registered owner: Jensen, Gaelard, K. - Airworthiness certificate: Special, Restricted (Special) ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 63; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: front; flight hours: 4,420 total ## Weather - Conditions: Visual (VMC), Day - Wind: 240° at 8 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 66 °F, dew point 48 °F - Altimeter: 30.00 inHg - Observed at: PIH, 11 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 19970720018839A](https://openairdocs.org/incident/19970720018839A), Jul 20, 1997: Scwzer G164A, Pingree, ID, Destroyed, 1 fatal. Aircraft struck a powerline during aerial application. 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.