# NTSB SEA05LA121: Cessna 188A, N2133U, Fairview, MT, June 20, 2005 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: June 20, 2005, 09:30 local (15:30 UTC) - Place: Fairview, MT - Coordinates: 47.863887, -104.633056 - Nearby events: https://openairdocs.org/map.md?lat=47.8639&lon=-104.6331&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report December 20, 2005 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 61744 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA05LA121 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/61744/pdf - Page: https://openairdocs.org/ntsb/SEA05LA121 ## Probable cause While in cruise flight a separation of a propeller blade as a result of a propeller hub crack. Factors contributing to the accident included the installation of an unapproved propeller, and the failure to properly service the propeller with red dyed oil for crack protection. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Propeller failure/malfunction, cruise - maintenance,installation - not approved, unknown (contributing factor) - maintenance,service of aircraft/equipment - not performed, unknown (contributing factor) - propeller system/accessories,hub - cracked (cause) - propeller system/accessories,blade - separation (cause) - Forced landing, descent - uncontrolled - terrain condition - open field ## Analysis While en route at approximately 100 feet above the ground during an aerial application operation, one of the airplane's two propeller blades separated from the propeller hub. Subsequently, the remaining propeller blade and hub separated from the airplane, culminating with the pilot making a forced landing to an open field. Examination of the propeller assembly revealed that the propeller blade model was the correct blade for the propeller; however, the propeller model was not approved for the Cessna 188A with a TCM IO-520 engine. It was also revealed that the propeller should have been filled with red dyed oil for crack detection. A visual inspection of the aircraft revealed no evidence of red dyed oil on the surface of either propeller blade or the propeller hub. A further inspection of the separated propeller blade indicated that the failure occurred within the outboard blade retention threads. ## Factual narrative On June 20, 2005, approximately 0930 mountain daylight time, a Cessna 188A, N2133U, sustained substantial damage following a forced landing after experiencing a propeller failure about 27 nautical miles west of Fairview, Montana. The certificated commercial pilot, the sole occupant, received minor injuries. Visual meteorological conditions prevailed for the aerial application flight, which was being operated in accordance with 14 CFR Part 137, and a flight plan was not filed. The flight had departed the Fairview Airport at approximately 0915. According to a Federal Aviation Administration (FAA) airworthiness inspector, who traveled to the accident site and conducted the preliminary investigation, the pilot was en route to spray a field at an altitude of about 100 feet when one of the two propeller blades separated from the propeller hub. After dumping the load the pilot reported that the remaining propeller blade and propeller hub assembly separated from the airplane after the engine's crankshaft failed. The pilot subsequently made a forced landing to an open field, during which the right main landing gear separated, followed by the airplane spinning around 180 degrees to the right before coming to rest in an upright position. The FAA inspector reported to the NTSB investigator-in-charge (IIC) that further examination of the aircraft revealed the aircraft was equipped with a McCauley propeller, model D2A34C49-N, blade model 90A-2. According to a representative from McCauley Propellers, the model 90A-2 blade is the correct blade for the D2A34C49-N propeller; however, it is not an approved model propeller (or blade) for the Cessna 188A with a TCM IO-520 engine. It is only approved on O-470 or IO-470 engines with four 6th order dampers. Additionally, the propeller should have been filled with red dyed oil for crack detection. The FAA inspector confirmed that there was no indication that the propeller had been filled with the red dyed oil, and that there was no visible evidence of red dyed oil on the surface of either propeller blade or the propeller hub. A further inspection of the separated propeller blade indicated that the failure occurred within the outboard blade retention threads. The inspector also reported to the IIC that the registered owner refused to provide the FAA with all pertinent aircraft records and logbooks as requested. ## Aircraft - Registration: [N2133U](https://openairdocs.org/deregistered/N2133U-2017-03-24), registration cancelled 2017-03-24, S/N 18800653, built 1970 (OpenAirDocs) - Reported make and model: Cessna 188A - Registry model: [Cessna A188A](https://openairdocs.org/model/cessna-a188a) (registry code 2073008) (OpenAirDocs) - Registry engine: [Continental IO-520 series](https://openairdocs.org/engine/continental-io-520-series) (registry code 17032, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 18800653 - Engines: Continental IO 520 300 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Airworthiness certificate: Special, Restricted (Special) - Departed: 5U6, Fairview, MT ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 22; injuries: minor; commercial; airplane ratings: single-engine land; medical: class 2, without waivers/limitations; last flight review October 1, 2004; seat: center ## Weather - Conditions: Visual (VMC), Day - Wind: 140° at 4 knots - Visibility: 9 statute miles - Lowest ceiling: none - Temperature: 73 °F, dew point 57 °F - Altimeter: 30.13 inHg - Observed at: SDY, 27 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 20050620011279A](https://openairdocs.org/incident/20050620011279A), Jun 20, 2005: Cessna A188A, Fairview, MT, Substantial damage. (-23) Prior to the accident, the aircraft propeller hub failed and prop separated from the aircraft in flight. The aircraft continued on a westerly heading for… ## Other investigations on N2133U (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 MIA73DKG03](https://openairdocs.org/ntsb/MIA73DKG03), Jul 3, 1972: Cessna A188 (N2133U), Sylvester, GA, 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.