# NTSB SEA95LA229: Piper PA-18A, N1953P, Roberts, ID, September 30, 1995 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: September 30, 1995, 15:15 local (21:15 UTC) - Place: Roberts, ID - Coordinates: 43.729225, -112.260063 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=43.7292&lon=-112.2601&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 3 minor, 1 uninjured - Status: Completed, report April 29, 1996 - Report: Approved by Office Director - NTSB case key (mKey): 42260 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA95LA229 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/42260/pdf - Page: https://openairdocs.org/ntsb/SEA95LA229 ## Probable cause an improperly performed major rebuild and inadequate inspection of the aircraft by maintenance personnel. Inadequate preflight inspection by the pilot contributed to the accident. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, landing - roll - landing gear,wheel - loose part/bolt/nut/clamp/etc (cause) - maintenance,rebuild/remanufacture - improper, other maintenance personnel (cause) - maintenance,inspection - inadequate, other maintenance personnel (cause) - aircraft preflight - inadequate, pilot in command (contributing factor) - inadequate recurrent training, pilot in command - landing gear,wheel - separation - Nose over, landing - roll - seat belt - not used, passenger ## Analysis The pilot reported that while landing on his private airstrip the left main wheel separated from the aircraft and the aircraft nosed over. According to a county sheriff report, the left main wheel retaining nut and cotter pin were missing from the axle, and there was no cotter pin securing the right main wheel retaining nut. The airplane had undergone a major rebuild and annual inspection about 5 months (12 flight hours) before the accident. The pilot stated that he performed a preflight inspection on the day of the accident but did not check the cotter pins, which are visible if installed. A statement in the sheriff report indicated that shortly before landing, the adult passenger in the rear seat unfastened his seat belt because two children in his lap were interfering with control stick travel. ## Factual narrative On September 30, 1995, approximately 1515 mountain daylight time, a Piper PA-18A, N1953P, received substantial damage when it nosed over following a main landing gear wheel separation on landing roll at the pilot's private airstrip near Roberts, Idaho. The private pilot-owner of the two-seat airplane, an adult passenger, and one child passenger (5 years old) received minor injuries. One passenger, a two-year-old child, was not injured. The flight was a local 14 CFR 91 flight originating from the pilot/owner's airstrip, where the accident occurred. Visual meteorological conditions prevailed and no flight plan had been filed. The pilot reported: "On landing, plane touched down and a gust of wind lifted plane off ground about three feet. Left front wheel fell off at this time. On second touchdown, left landing gear dug into dirt runway causing plane to flip upside down." Statements from the pilot, adult passenger, witnesses, and responding law enforcement officials, contained in the Jefferson County sheriff's report of the accident, indicated that after the accident, the wheel retaining nut and cotter pin were not observed to be in place on the left main gear axle. Additionally, the statements in the report indicated that the individuals at the scene observed that there was no cotter pin securing the retaining nut on the right main landing gear wheel although the right main wheel retaining nut was still in place. The left main wheel was located about 50 feet from the airplane after the accident. The sheriff's report statements indicated that a search was made on the airstrip for the left wheel retaining nut but that it was not located. The pilot's NTSB accident report indicated that the airplane's last annual inspection was on April 12, 1995, 12.16 flight hours before the accident. The pilot stated in a telephone query by the investigator on March 11, 1996, that Hart Enterprises of Rexburg, Idaho, had recently rebuilt the aircraft, and that the annual inspection was performed in conjunction with this rebuild. He also stated during this telephone query that he performed a preflight inspection on the day of the accident but had not checked the main wheel cotter pins, and that there are no wheel covers installed on the main wheels. In a telephone inquiry to Hart Enterprises on March 8, 1996, a representative of the company stated to the investigator: "Three people missed the checking of the cotter key, if you can figure that out." The adult passenger reported in his sheriff's report statement that shortly before the accident landing, he unfastened his seat belt since the children, who were riding in his lap, were interfering with the travel of the control stick. ## Aircraft - Registration: [N1953P](https://openairdocs.org/aircraft/N1953P), registered now, S/N 18-4180, built 1955 (OpenAirDocs) - Reported make and model: PIPER PA-18A - Registry model: [Piper PA-18-150](https://openairdocs.org/model/piper-pa-18-150) (registry code 7101828) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 18-4180 - Airframe hours: 4173 - Engines: LYCOMING O-320 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Linden J. Butikofer - Registered owner: Linden & Lois Butikofer - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 12, 1995, 13 hours before - Airport: Private, runway 17, 2,640 × 80 ft, dirt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 59; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: front; flight hours: 800 total, 700 as pilot in command, 11 in the last 90 days, 1 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 190° at 10 knots - Visibility: 50 statute miles - Lowest ceiling: none - Temperature: 57 °F, dew point 34 °F - Altimeter: 30.00 inHg - Observed at: IDA, 10 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 19950930030679A](https://openairdocs.org/incident/19950930030679A), Sep 30, 1995: Piper PA18150, Roberts, ID, Substantial damage. Left wheel fell off on ballooned landing. No cotter pins main gear retaining nuts. Passenger had two babys in lap. 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.