# NTSB DFW05CA186: Grumman-Schweizer G-164A, N8891H, Tallulah, LA, July 21, 2005 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Data collection · Final report - Date: July 21, 2005, 11:30 local (16:30 UTC) - Place: Tallulah, LA - Coordinates: 32.283332, -91.123336 - Nearby events: https://openairdocs.org/map.md?lat=32.2833&lon=-91.1233&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report October 27, 2005 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 62030 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DFW05CA186 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/62030/pdf - Page: https://openairdocs.org/ntsb/DFW05CA186 ## Probable cause The partial loss of engine power as result of the fracture of the number five-cylinder exhaust valve rocker arm mounting boss. A contributing factor was the lack of suitable terrain for the forced landing. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(partial) - mech failure/malf, maneuvering - aerial application - engine assembly,cylinder - fractured (cause) - Forced landing, emergency descent/landing - On ground/water encounter with terrain/water, emergency landing - terrain condition - none suitable (contributing factor) - Nose over, landing - roll ## Analysis At the completion of an east to west spray pass over a field, the bi-wing agricultural airplane's engine experienced a loss of power and exhibited an unusual vibration. The 2,697-hour private pilot turned the airplane in a southerly direction in an attempt to fly back to the originating airport. Realizing that the engine was not developing sufficient power to return to the airport, the pilot turned the airplane approximately 180-degrees towards a road that he thought would make a suitable landing area. Before the pilot could reach the road, the engine started making "popping" noises, trailing smoke, and experienced a further reduction of power. The pilot then elected to land in a cotton field. During the landing roll the left main landing gear collapsed and the airplane nosed over coming to rest in an inverted position. An examination of the engine revealed the number five-cylinder exhaust valve rocker arm mounting boss was fractured approximately 180 degrees around its circumference. This fracture allowed the exhaust valve to remain closed. ## Factual narrative On July 21, 2005, about 1130 central daylight time, a single-engine Grumman-Schweizer G-164A, agricultural bi-plane, N8891H, was substantially damaged during a forced landing following a partial loss of engine power, while maneuvering near Tallulah, Louisiana. The private pilot, soul occupant, sustained minor injuries. The airplane was registered to and operated by the pilot. Visual meteorological conditions prevailed for the 14 Code of Federal Regulations Part 137 agricultural flight for which a flight plan was not filed. The local flight originated from the Red Beard Dusting Service Airport (9LS5), near Tallulah, Louisiana, approximately 1100. According to the 2,697-hour pilot, at the completion of an east to west spray pass over a field, the airplane's engine experienced a loss of power and developed an unusual vibration. The pilot turned the airplane to a southerly direction in an attempt to fly back to the originating airport. Realizing that the airplane was not developing sufficient power to return to the airport, the pilot turned the airplane approximately 180-degrees towards a road that he thought would make a suitable landing area. Before the pilot could reach the road, the engine started making "popping" noises, trailing smoke, and experienced a further reduction of power. The pilot then elected to land in a cotton field. During the landing roll, the left main landing gear collapsed and the airplane nosed-over coming to rest in an inverted position. A Federal Aviation Administrator inspector, who responded to the accident site, reported the airplane sustained structural damage during the mishap. The inspector further reported that an examination of the engine revealed the number five-cylinder exhaust valve rocker arm mounting boss was fractured approximately 180 degrees around its circumference. This fracture allowed the exhaust valve to remain closed. ## Aircraft - Registration: [N8891H](https://openairdocs.org/deregistered/N8891H-2012-11-15), registration cancelled 2012-11-15, S/N 1561, built 1975 (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: 1561 - Airframe hours: 5091 - Engines: Pratt & Whitney R-1340-AN-1 600 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Registered owner: John C Hopkins - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, March 1, 2005, 4 hours before - Departed: 9LS5, TALLULAH, LA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 55; private; airplane ratings: single-engine land; medical: class 3; seat: center; flight hours: 2,697 total, 1,750 in this make and model, 7 in the last 90 days, 7 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 290° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 208 °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 20050721015629A](https://openairdocs.org/incident/20050721015629A), Jul 21, 2005: Scwzer G164A, Tallulah, LA, Substantial damage. (-23) Pilot was conducting aerial application and had just completed second pass and pullup when engine vibration/shudder was felt and engine began to lose… ## Other investigations on N8891H (1) 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. - [NTSB FTW76DRJ42](https://openairdocs.org/ntsb/FTW76DRJ42), Aug 17, 1976: Grumman G-164A (N8891H), Lake Providnce, LA, substantial damage 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.