# NTSB LAX04LA230: Cessna T210M, N121JR, Santa Rosa, CA, May 30, 2004 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 30, 2004, 13:55 local (20:55 UTC) - Place: Santa Rosa, CA - Coordinates: 38.508888, -122.812774 - Nearby events: https://openairdocs.org/map.md?lat=38.5089&lon=-122.8128&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 6 uninjured - Status: Completed, report December 28, 2004 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 59344 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX04LA230 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/59344/pdf - Page: https://openairdocs.org/ntsb/LAX04LA230 ## Probable cause Maintenance personnel's improper installation and servicing of a retaining ring, which resulted in the failure of the landing gear door actuator and failure of the landing gear extension system during landing. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, approach - landing gear,normal retraction/extension assembly - failure,total (cause) - miscellaneous,bolt/nut/fastener/clamp/spring - improperly serviced (cause) - maintenance,installation - improper, other maintenance personnel (cause) - Wheels up landing, landing - flare/touchdown - landing gear,normal retraction/extension assembly - inoperative - Loss of control - on ground/water, landing - roll - directional control - not possible, pilot in command - On ground/water collision with object, landing - roll - object - airport sign/marker ## Analysis The airplane landed with the main landing gear retracted after a main landing gear door actuator failure. The pilot attempted to extend the landing gear for landing, and stated that the main landing gear would not extend, and the landing gear down-and-locked light did not illuminate. The pilot noted that the hydraulic motor continued running and that there was plenty of hydraulic fluid in the reservoir. After performing all of the recommended emergency procedures for landing gear malfunctions to no avail, the pilot landed with the nose landing gear extended and the main landing gear only partially extended. Upon landing, the airplane tilted and drifted to the left of the runway, where it impacted a sign. Post-accident examination of the landing gear revealed the right main landing gear door actuator failed, and the retaining clip was installed improperly. The failed landing gear door actuator was worked on 10.7 hours prior to the accident. ## Factual narrative On May 30, 2004, at 1355 Pacific daylight time, a Cessna T210M single-engine airplane, N121JR, landed with the main landing gear retracted at the Charles M. Schulz - Sonoma County Airport (STS), Santa Rosa, California. The pilot owned and operated the airplane under the provisions of 14 CFR Part 91 as a personal flight. The private pilot and five passengers were not injured; the airplane sustained substantial damage. The flight departed Upper Lake, California, approximately 1300, and was terminating when the event occurred. Visual meteorological conditions prevailed, and a flight plan had not been filed. During a telephone interview with the pilot, he stated that he landed at Upper Lake earlier in the day. Prior to takeoff, the pilot conducted a walk around inspection of the airplane and noted no anomalies. Upon arriving at STS, the pilot noticed that when he went to extend the landing gear, the hydraulic power pack motor kept running and the landing gear down-and-locked light did not illuminate. The pilot looked at the reservoir and noticed that there was plenty of hydraulic fluid in the tank. He attempted to retract and lower the landing gear again, to no avail. He then performed the Pilot Operating Handbook's recommended procedures for landing gear malfunctions, also to no avail. The pilot contacted the STS control tower and notified them of the situation. Another aircraft flew by the accident airplane, and examined the landing gear. The pilot of the other aircraft notified the accident pilot that the nose landing gear was extended, but the main landing gear remained only partially extended. The pilot briefed his passengers of the ensuing landing scenario. He performed a soft-field landing on runway 19 with crash/fire rescue personnel standing by. Upon touchdown, the airplane tilted and veered to the left. The airplane continued to the left where it departed the runway and impacted a taxiway sign before coming to rest upright. According to the pilot, the hydraulic power pack motor was replaced with a repaired motor 3 months prior to the accident. In addition, approximately 1.5 weeks prior to the accident, the right main landing gear door actuator was repaired due to a leaking o-ring. According to a mechanic located at the STS airport, the left wing, horizontal stabilizer, and elevator sustained structural damage. The mechanic noted that the right main landing gear door actuator had come undone, and hydraulic fluid was along the right side of the airframe aft of the door. He also noticed that the retaining snap-ring that holds the actuator together had been installed improperly (the rounded, or pressed, side of the snap-ring was facing away from the actuator piston). A work order, dated May 11, 2004, indicated that at an aircraft total time of 4,492.3 hours, the "starboard main gear door actuator" was leaking. The same work order indicated that mechanics "removed the right gear door actuator. Found o-rings worn. R&R [Removed and Replaced] with new o-rings. Reinstalled actuator with new locknuts. Ops check good, leak check good." The airplane accumulated 10.7 hours since the right main landing gear door actuator work. ## Aircraft - Registration: [N121JR](https://openairdocs.org/aircraft/N121JR), registered now, S/N 21061726, built 1977 (OpenAirDocs) - Reported make and model: Cessna T210M - Registry model: [Cessna T210M](https://openairdocs.org/model/cessna-t210m) (registry code 2073451) (OpenAirDocs) - Registry engine: [Continental TSIO-520 series](https://openairdocs.org/engine/continental-tsio-520-series) (registry code 17040, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 21061726 - Airframe hours: 4503 - Engines: Continental TSIO-520-R 310 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Geoffrey B. Klotz - Airworthiness certificate: Standard, Normal - Last inspection: Annual, May 19, 2003, 91 hours before - Departed: 1Q5, Upper Lake, CA - Destination: STS, Santa Rosa, CA - Airport: STS, Charles M. Shultz - Sonoma Co., runway 19, 5,001 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 41; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; last flight review May 1, 2002; seat: left; flight hours: 1,365 total, 1,050 in this make and model, 1,302 as pilot in command, 19 in the last 90 days, 11 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: variable at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 84 °F, dew point 48 °F - Altimeter: 30.01 inHg - Observed at: STS ## 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 20040530010479A](https://openairdocs.org/incident/20040530010479A), May 30, 2004: Cessna T210M, Santa Rosa, CA, Substantial damage. (-23) Aircraft departed lake pillsbury airport (IQ5) direct to Santa Rosa (sts). Pilot observed that aircraft main landing gear had failed to extend during… 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.