No fatalities

26 Dec 2022: CESSNA 210N (N210CU) — Morgan, UT

Morgan, UT, United States

On 26 Dec 2022, a CESSNA 210N (registration N210CU) was involved in an aviation accident near Morgan, UT. No fatalities were reported. Investigators recorded the probable cause as: Failure of the brake system O-rings on the left landing gear trunnion, which allowed the hydraulic fluid to drain from the left brake system, resulting in a runway excursion and impact with a fence. This summary draws on records from NTSB; 12 related events involving the same aircraft type or operator are linked below.

SourcesNTSBPrimary reportUpdated 1778583330Data APIEditorial standards

A Cessna 210N, N210CU, was substantially damaged after departing the runway and impacting a fence at Morgan County Airport, Utah, due to a left brake failure. The pilot was uninjured.

Introduction

On December 26, 2022, at 1645 mountain standard time, a Cessna 210N, registration N210CU, was substantially damaged when it was involved in an accident at Morgan County Airport (42U), Morgan, Utah. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

Accident Sequence

According to the pilot, after an uneventful flight to Spanish Fork, Utah, he flew to Morgan County Airport. He landed normally, and after the nose landing gear touched down, he began to apply the brakes. The pilot reported that the left pedal “had zero pressure” when he applied the brakes. He pumped the left brake in an attempt to “pump the brake up,” but that did not work. At that point, the pilot stated there was not enough time to safely reconfigure the airplane for a go-around. He maintained runway centerline using steering and the right brake until the airplane eventually departed the runway surface and impacted a fence. The empennage, right elevator, and horizontal stabilizers sustained substantial damage.

Pilot Report

The pilot stated that there had been a recurring issue with the left brake and maintenance was performed to correct the malfunction. Since that time, he had flown more than 10 hours with over 25 takeoffs and landings without any issue. The pilot further reported that he did not see hydraulic fluid on the airplane’s undercarriage.

Postaccident Examination

Postaccident examination of the brake system revealed that when the left brake was actuated there was no pressure and it did not function properly. The right brake operated normally when brake force was applied. The seats and floor panels were removed to facilitate further inspection. The left brake master cylinder was removed and disassembled with no evidence of a hydraulic fluid leak from the master cylinder or brake lines in the forward cabin subfloor area. However, the left master cylinder reservoir was completely empty of hydraulic fluid. The O-ring and master cylinder were in a serviceable condition. The brake system was reassembled and serviced with fluid. The left brake was activated with maximum pressure applied for 5 minutes with no failure or leakages identified.

The left landing gear leg and pivot assembly were removed, and the O-rings from the brake fluid transition assembly were undamaged, normally shaped, and flexible to the touch. The main landing gear pivot trunnion was disassembled, and the O-rings did not have visible damage; however, they appeared “flattened and stiff.” There was a significant amount of brake fluid under the aft cabin floor in front of the bulkhead forward of the landing gear door and brake line pivot fitting.

Contributing factors

Landing gear brakes system — FailureInoperativeFluid levelAttain/maintain not possible