# NTSB FTW01LA210: Cessna T188C, N4629J, Aiken, TX, September 27, 2001 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 27, 2001, 09:05 local (14:05 UTC) - Place: Aiken, TX - Coordinates: 34.123332, -101.518333 - Nearby events: https://openairdocs.org/map.md?lat=34.1233&lon=-101.5183&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report August 26, 2002 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 53520 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW01LA210 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/53520/pdf - Page: https://openairdocs.org/ntsb/FTW01LA210 ## Probable cause the application of silicon sealant to the crankcase mating surfaces by maintenance personnel, which resulted in improper torque on the bolts which mate the crankcase halves, vibration, and the subsequent failure of the #2 main crankshaft bearing. A 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(total) - mech failure/malf, maneuvering - aerial application - maintenance,installation - improper, other maintenance personnel (cause) - engine assembly,crankcase - foreign material/substance - engine assembly,crankcase - undertorqued - engine assembly,crankcase - vibration - engine assembly,bearing - shifted - engine assembly,bearing - failure - Forced landing, emergency descent/landing - In flight collision with terrain/water, landing - flare/touchdown - terrain condition - crop - terrain condition - none suitable (contributing factor) ## Analysis The pilot was maneuvering the agricultural airplane to enter a field and commence spraying, when at 120 feet agl, the engine lost power. The pilot attempted to restart the engine; however, the engine did not restart. During the ensuing forced landing, the airplane contacted circular rows of cotton, before coming to rest upright. The engine was examined at the manufacturer's facility and silicon sealant was observed on the base flanges of the #1, #2, #4, and #6 cylinders and on the crankcase mating surfaces. Fretting was observed on the base flanges of the cylinders, on the mating surface of the crankcase halves, and on the main bearing bosses. The #2 main bearing was observed fragmented and the bearing's bore was cracked and damaged. Additionally, it was observed that the crankshaft was fractured between the #2 main bearing and #3 crankshaft cheek. According to a TCM metallurgist, the fatigue fracture's origin was determined to be at the aft radius of the #2 main bearing. The silicon sealant prevented proper torqueing of the bolts that mate the crankcase halves and led to vibration at the crankcase mating surfaces. The #2 main bearing then shifted and failed, resulting in a loss of engine power. ## Factual narrative On September 27, 2001, at 0905 central daylight time, a Cessna T188C agricultural airplane, N4629J, was substantially damaged during a forced landing following a loss of engine power while maneuvering near Aiken, Texas. The airplane was registered to a private individual and was operated by Addison Spraying Service, of Plainview, Texas. The commercial pilot, sole occupant of the airplane, was not injured. Visual meteorological conditions prevailed, and a flight plan was not filed for the 14 Code of Federal Regulations Part 137 aerial application flight. The local flight originated from the Hale County Airport, Plainview, Texas, at 0900. According to the pilot, the flight was part of the boll weevil eradication program. The pilot was maneuvering the airplane to enter a field and commence spraying, when at 120 feet agl, the engine lost power. The pilot attempted to restart the engine; however, the engine did not restart. During the ensuing forced landing, the airplane contacted circular rows of cotton, the left main landing gear separated from the airplane, and the left wing's rear spar was damaged. The airplane came to rest upright. The Teledyne Continental Motors (TCM) TSIO-520-T engine was examined by an FAA inspector. The propeller rotated when it was manipulated by hand; however, none of the accessory drive gears rotated as the propeller was turned. The engine was sent to the TCM Factory in Mobile, Alabama, for further examination. The engine was examined under supervision of an NTSB investigator at TCM. The oil sump was removed and ferrous debris was observed in the sump. The oil pump was removed, disassembled, and observed to be lubricated and intact. The engine crankcase and cylinders were disassembled. A silicon residue was observed on the base flanges of the #1, #2, #4, and #6 cylinders and on the mating surface of the crankcase halves (backbone). Fretting was observed on the base flanges of the cylinders, on the crankcase mating surfaces, and on the main bearing bosses. The crankshaft was observed to be fractured between the #2 main bearing and #3 crankshaft cheek. According to a TCM metallurgist the fatigue fracture's origin was determined to be at the aft radius of the #2 main bearing. The #2 main bearing was fragmented, and the bearing's bore was cracked and damaged. According to the engine maintenance logbook, on May 3, 1999, the engine underwent its last field overhaul, during which the crankshaft was installed in the engine. On May 10, 2001, the engine underwent its most recent annual inspection at a time of 664.0 hours since overhaul. At the time of the accident, the engine had accumulated 777.0 hours since overhaul. ## Aircraft - Registration: [N4629J](https://openairdocs.org/deregistered/N4629J-2004-04-09), registration cancelled 2004-04-09, S/N T18803757T, built 1980 (OpenAirDocs) - Reported make and model: Cessna T188C - Registry model: [Cessna T188C](https://openairdocs.org/model/cessna-t188c) (registry code 2073012) (OpenAirDocs) - Registry engine: [Continental TSIO-520 series](https://openairdocs.org/engine/continental-tsio-520-series) (registry code 17040, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: t18803757T - Engines: Continental TSIO-520-T 310 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Addison Spraying Service, doing business as N/A - Registered owner: John Wesley Addison - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, May 10, 2001, 113 hours before - Departed: PVW, Aiken, TX ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 41; injuries: none; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; last flight review June 16, 2000; seat: single; flight hours: 4,500 total, 3,500 in this make and model, 110 in the last 90 days, 100 in the last 30 days, 8 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 180° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 72 °F, dew point 45 °F - Altimeter: 30.12 inHg - Observed at: LBB, 42 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 20010927031359A](https://openairdocs.org/incident/20010927031359A), Sep 27, 2001: Cessna T188C, Aiken, TX, Substantial damage. (-23) The engine stopped operating during a turn while agricultural spray operations were being conducted. The pilot continued the turn into the wind and tried… 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.