On June 10, 2016, a CESSNA 310 G (registration N8943Z) was involved in an aviation accident near Apopka, FL. No fatalities were reported. Investigators recorded the probable cause as: The intermittent failure of the left brake master cylinder, which resulted in asymmetric braking and the subsequent loss of directional control during the landing roll. This summary draws on records from NTSB; 12 related events involving the same aircraft type or operator are linked below.
A Cessna 310G, N8943Z, departed the runway at Orlando Apopka Airport on June 10, 2016, after a brake malfunction during a post-maintenance test flight. The pilot was uninjured, and the aircraft sustained substantial damage.
Accident Overview and Flight Details On June 10, 2016, at approximately 1610 eastern daylight time, a Cessna 310G, registration N8943Z, collided with a berm while landing at Orlando Apopka Airport (X04) in Apopka, Florida. The aircraft was registered to SOFI, LLC, and was being operated by a private individual under 14 Code of Federal Regulations as a Part 91 local, post-maintenance test flight. The airline transport pilot was not injured, and the airplane was substantially damaged. Visual meteorological conditions prevailed, and no flight plan was filed for the flight, which departed from X04 at 1515. This was the aircraft's first flight after an annual inspection, and it had not been operated in the previous two years. ## Pilot Account and Sequence of Events The pilot reported that after the inspection, he performed a preflight inspection and noted several discrepancies, none of which were related to the aircraft's brake system. After removing the airplane from the hangar, he started the engines and taxied to a fueling area, during which he did not indicate any issues with the brakes. Following fueling, he taxied to runway 33, a 3,987-foot-long asphalt runway, and initiated takeoff. He remained in the traffic pattern and performed two touch-and-go landings on the same runway. After the second touch-and-go, the pilot intended to perform a full-stop landing but had to initiate a go-around because another airplane was on the runway. On his return, he reported that the touchdown was normal and in the typical location. After touchdown, he retracted the flaps and allowed the airplane to slow aerodynamically to the end of the runway. As the airplane approached the end of the runway, the pilot applied the normal brakes; however, the left brake did not function. The airplane began drifting to the right, and as it slowed to a slow taxi speed, the right deviation became more pronounced. The pilot pumped the left brake and applied pressure, but the left brake pedal went to the floor with no pressure or effect. When it became evident that the airplane would depart the runway, he secured the engines and attempted to maintain control while applying the right brake in an effort to slow the airplane. The airplane went off the right side of the runway at the end and contacted upsloping terrain, which caused spar damage to the left horizontal stabilizer. ## Post-Accident Examination and Findings Operational testing of the pilot's side brakes by a Federal Aviation Administration (FAA) operations inspector following recovery revealed no discrepancies; however, operational testing of the brakes on the copilot's side revealed a discrepancy with the right brake. No brake system leaks were noted, and the fluid levels in both brake master cylinders were at the correct level. The airplane was retained for further examination. Further examination of each brake master cylinder was performed by an FAA airworthiness inspector. Following removal from the airplane, the left brake worked once but on the second actuation, the actuating rod slowly leaked internally to the bottom. The right brake worked perfectly when removed. Both cylinders had an acceptable fluid level after removal. Disassembly of the brake master cylinders revealed that all o-rings were in a reasonable condition with no visible cuts or tears. The left brake had a dark crusty compound and a small washer in the reservoir, while the right brake had the same compound including the washer, but was not as contaminated as the left. It was not possible to determine part numbers or serial numbers of either brake master cylinder as the data plates were damaged by hydraulic fluid. ## Maintenance and Inspection Context According to the facility that performed the inspection, they utilized a generic twin-engine checklist to perform the inspection. The owner/general manager of the facility where the inspection was performed stated there were no discrepancies related to the brakes during the engine run-ups prior to the inspection.