What happened
On January 25, 2000, an EMB-110E Bandeir． registered as PT-FRF, operated by the Brazilian Federal Police, departed from Congonhas Airport (SBSP) for Brasília (SBBR) carrying two crew members and seven passengers. During the flight, the aircraft experienced a progressive loss of hydraulic pressure. After reaching cruise altitude, the hydraulic pump for the right engine failed. Approximately one hour later, the hydraulic pump for the left engine also lost pressure.
In response to the dual failure, the crew transitioned the hydraulic selector to the emergency position and utilized the alternative landing gear extension system for arrival. Upon landing at Brasília, the crew attempted to use the main brakes and subsequently the emergency brakes, but neither system provided effective deceleration. The crew lost directional control, causing the aircraft to exit the left side of the runway, striking small bushes. The aircraft sustained light damage to the landing gear, right wing, and right engine propeller, but all nine occupants remained uninjured.
The investigation
CENIPA investigators examined the hydraulic system and found that while the lines and fluid levels were within limits, metal shavings were present in the high and low-pressure filters and the hydraulic fluid. The hydraulic pumps showed internal damage to the pistons and swashplates.
Further inspection revealed that the hydraulic system accumulator had a leak at the filling valve, which introduced air into the lines and caused the pumps to operate dry. Additionally, the accumulators for both the main and emergency braking systems exhibited internal leaks. Investigators also noted that while the aircraft had previously reported hydraulic issues in flight logs, there was no evidence of corrective maintenance being performed. The investigation also highlighted that the operator lacked a formal Flight Safety Program (PPAA) and a qualified safety representative.
Findings
- Deficient maintenance: Internal leaks in the hydraulic and braking accumulators led to the loss of braking effectiveness.
- Deficient supervision: The operator failed to ensure that previously reported hydraulic malfunctions were properly corrected.
- Lack of safety oversight: The absence of a formal safety doctrine and a certified safety professional prevented the detection of substandard maintenance quality.
Safety action
- The maintenance provider was directed to disseminate the report findings to all mechanics.
- The Federal Police were advised to implement procedures for the effective monitoring of aircraft malfunction reports and to evaluate the quality of contracted maintenance services.