# NTSB SEA02LA046: Cessna 421C, N421DG, Hailey, ID, March 2, 2002 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 1, 2002, 19:36 local (Mar 2, 2002, 02:36 UTC) - Place: Hailey, ID - Coordinates: 43.505001, -114.296669 - Nearby events: https://openairdocs.org/map.md?lat=43.5050&lon=-114.2967&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report April 8, 2003 - Report: Approved by Office Director - Parties: FAA Flight Standards District Office - NTSB case key (mKey): 54294 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA02LA046 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/54294/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=54294 - Page: https://openairdocs.org/ntsb/SEA02LA046 ## Probable cause Water contamination within the aircraft's landing gear hydraulic line(s) which froze and blocked the line(s) preventing extension of the right main gear. A factor was the below freezing environmental conditions which the aircraft was operating in prior to and during the approach and landing. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, approach - hydraulic system - contamination,water (cause) - hydraulic system,line - blocked(total) - weather condition - temperature,low (contributing factor) - Wheels up landing, landing - flare/touchdown ## Analysis While on approach to the Friedman Memorial airport (Hailey, Idaho), the pilot of the Cessna 421C lowered the landing gear but failed to receive a gear down and locked indication on the right main gear. He attempted to lower the landing gear utilizing the nitrogen blow down system, again without success. The pilot then executed a landing with the nose and left main gear extended. Post-crash examination revealed a small amount of water in the landing gear hydraulic lines. When the landing gear system was purged and replenished with uncontaminated fluid the gear operated without malfunction both normally and with the use of the blow down system. Temperature at Hailey, Idaho, remained well below freezing before and after the accident. ## Factual narrative On March 1, 2002, at 1936 mountain standard time, a Cessna 421C, N421DG, registered to and being flown by a private pilot, sustained substantial damage during a gear up landing on runway 31 at the Friedman Memorial airport, Hailey, Idaho. The pilot and passenger were uninjured. Visual meteorological conditions existed and an IFR flight plan had been activated. The flight, which was personal, was operated under 14CFR91, and originated from Santa Monica, California, earlier in the day, and was destined for Hailey. As the aircraft approached Hailey, the pilot reported that he was unable to obtain a down and locked status on the right main landing gear. He then attempted a manual extension of the landing gear using the nitrogen blow down system, but again was unable to get a down and locked indication on the right main gear. The aircraft was landed with the nose and left main gear extended and during the initial landing roll the right wing impacted the runway. An examination and testing of the aircraft's landing gear and associated hydraulic systems was conducted under the oversight of an inspector from the Federal Aviation Administration's (FAA) Flight Standards District Office (FSDO) at Boise, Idaho. The hydraulic system was drained and the fluid was captured. Examination of the fluid yielded no particulate contaminants but a small amount of water was found in the fluid. The hydraulic system was subsequently replenished and the aircraft was placed on jacks. The landing gear was then cycled up and down repeatedly with no malfunction noted. The landing gear was then extended utilizing the emergency extension system, again with no malfunction (refer to ATTACHMENT FAA-I). The surface temperature at Friedman airport was well below freezing several hours before and after the accident. ## Aircraft - Registration: [N421DG](https://openairdocs.org/aircraft/N421DG), registered now, S/N 421C0456, built 1978 (OpenAirDocs) - Reported make and model: Cessna 421C - Registry model: [Cessna 421C](https://openairdocs.org/model/cessna-421c) (registry code 2076016) (OpenAirDocs) - Registry engine: [Continental GTSI0-520-F-K](https://openairdocs.org/engine/continental-gtsi0-520-f-k) (registry code 17031, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 421C0456 - Airframe hours: 3898 - Engines: Continental GTSIO-520-L 375 horsepower reciprocating; Continental GTSIO-520-L 375 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Benjamin, Mark J. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, December 5, 2001, 50 hours before - Departed: SMO, Santa Monica, CA - Destination: SUN, Hailey, ID - Flight plan: IFR - Airport: SUN, Friedman Memorial, runway 31, 6,602 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 51; injuries: none; private; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; last flight review January 19, 2002; seat: left; flight hours: 1,680 total, 1,232 in this make and model, 1,635 as pilot in command, 68 in the last 90 days, 21 in the last 30 days ## Weather - Conditions: Visual (VMC), Night - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 16 °F, dew point 7 °F - Altimeter: 30.10 inHg - Observed at: SUN ## 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 20020301003899A](https://openairdocs.org/incident/20020301003899A), Mar 1, 2002: Cessna 421C, Hailey, ID, No damage. (-23) The pilot departed santa monica, California IFR for Hailey, Idaho. The temperatures at altitude were -40 degrees and the surface temperature at Hailey… ## Docket (3 files) The files NTSB released with the investigation on December 24, 2002, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=54294. 668 KB in all. - Supplement S (item 1, .PDF, 26 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40173933&FileExtension=.PDF&FileName=Supplement%20S-Master.PDF - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 2, .PDF, 587 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40391592&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Attachment FAA-I (item 3, .PDF, 54 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40173935&FileExtension=.PDF&FileName=Attachment%20FAA-I-Master.PDF 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.