What happened
On September 17, 2010, a Cessna 500, registration PT-LCC, was performing a proficiency check flight involving two pilots and two passengers. After completing a series of touch-and-go maneuvers at Cabo Frio Aerodrome (Seredo), the aircraft returned to Jacarepaguá Aerodrome (SBJR) for landing.
During the landing roll, the pilot flying initially applied the brakes normally but subsequently released pressure on the pedals to allow the aircraft to accelerate and clear the runway. When the pilot attempted to reapply the brakes, the pedals depressed without resistance, indicating a loss of braking effectiveness. Despite attempts by the crew to cycle the brakes, the aircraft failed to stop within the runway limits, eventually exiting the pavement and coming to a rest 147 meters beyond the threshold. All four occupants escaped the incident uninjured, and the aircraft sustained light damage.
The investigation
CENIPA investigators examined the aircraft's braking systems, including both normal and emergency functions. While maintenance records for the airframe and engines were found to be outdated, technical tests revealed no mechanical discrepancies or failures in the braking systems. There were no cockpit alarms or indications of low pressure reported by the crew during the flight.
Investigators identified a common but non-standard practice among pilots of this aircraft type: disconnecting the Anti-Skid system circuit breaker (CB) during flight to prevent the noise of the hydraulic pump cycling. If this CB is left disconnected, it can lead to reduced braking effectiveness. Furthermore, the investigation found that the crew mistakenly attempted to use the emergency gear extension lever instead of the emergency brake lever when the aircraft approached the end of the runway. Although sufficient pressure remained in the emergency braking system, the pilot's error prevented its use.
Findings
- The pilot's error in activating the emergency gear extension lever instead of the emergency brake lever.
- Improper pilot judgment regarding the use of the brakes during the landing roll.
- The practice of disconnecting the Anti-Skid circuit breaker during flight, which is not a standard operating procedure and can impact braking performance.