DEN00LA020
1999-11-20 · SHERIDAN, Wyoming, United States · None · 1 aircraft · Status: Completed
Airport SHR
Aircraft involved
Probable cause & findings
The partial failure of the engine driven hydraulic pump.
Factual narrative
On November 20, 1999, at 2100 mountain standard time, a Cessna 210D, N3928Y, was substantially damaged during landing at Sheridan County Airport, Sheridan, Wyoming. The private pilot, the sole occupant in the airplane, was not injured. The airplane was being operated by the pilot under Title 14 CFR Part 91. Visual meteorological conditions prevailed for the local flight which originated approximately 35 minutes before the accident. No flight plan had been filed. The pilot said that this was the first flight after the annual inspection. He was flying from Billings, Montana, to Sheridan, Wyoming, and had put the leading gear handle down for landing. He didn't get a positive gear lock light, so he cycled the landing gear several times in an attempt to get a positive gear down and locked indication. He then attempted to hand pump the gear down, but still had no positive down and locked light. He landed the airplane, and during the landing roll the right main landing gear collapsed. Subsequently, the right horizontal stabilizer and the right wing tip were bent when they struck the ground. Postaccident examination of the engine driven hydraulic pump pressure revealed that its output was 200 pounds per square inch (psi). The maintenance personnel that worked on the airplane said that normal pump pressure output should be 2,725 psi. The hydraulic pump was replaced, and the landing gear cycled normally. The pilot said that this was the first flight after the annual inspection. When he put the leading gear handle down for landing, he didn't get a positive gear lock light, so he cycled the leading gear several times in an attempt to get a positive gear down and locked indication. He attempted to hand pump the gear down, but still had no positive down and locked light. He landed the airplane, and during the landing roll the right main landing gear failed. Postaccident examination of the engine driven hydraulic pump pressure revealed that its output was 200 pounds per square inch (psi). The maintenance personnel that worked on the airplane said that normal pump pressure output was 2,725 psi. The hydraulic pump was replaced, and the landing gear cycled normally. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12
Verbatim from NTSB's published report. Source file
NTSB_1999_DEN00LA020.txt.
Findings + structured fields enriched from FAA avall.mdb.
Full investigation docket on
data.ntsb.gov ↗.
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Related research
Matched on aircraft type or causal vocabulary (maintenance). All research papers
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