What happened
On April 22, 2013, an Embraer EMB 110 operated by Tail Táxi Aéreo Itaituba Ltda departed from Val de Cans Airport (SBBE) in Belém, Brazil, bound for Almeirim (SBMD) under instrument flight rules. The aircraft was carrying two crew members and 15 passengers.
Shortly after takeoff, the flight crew identified a drop in hydraulic system pressure. The pilots coordinated with Belém Tower to return to the departure airport. To prepare for landing, the crew deployed the landing gear using the emergency system. However, during the landing roll on runway 06, the aircraft experienced a loss of braking effectiveness. This caused the aircraft to exit the runway to the right, coming to a stop in a grassy area adjacent to the runway. There were no injuries to the 17 occupants and no damage to the aircraft.
The investigation
CENIPA's investigation focused on the mechanical failure and the aircraft's weight configuration. Investigators determined that an internal failure in the left engine's hydraulic pump caused the pressure drop. While there were no external fluid leaks, the failure prevented the brakes from functioning effectively once the applied pressure exceeded the remaining residual pressure in the system.
Furthermore, the investigation revealed significant weight and balance discrepancies. The aircraft's takeoff, ramp, and landing weights all exceeded the manufacturer's maximum allowable limits. This was due to an error in the weight and balance manifest, which recorded only 795 kg of fuel on board, whereas the actual fuel load was approximately 1,226 kg. This discrepancy resulted in the aircraft operating significantly above its maximum ramp weight of 5,630 kg, maximum takeoff weight of 5,600 kg, and maximum landing weight of 5,300 kg.
Findings
- An internal failure of the left engine hydraulic pump caused the loss of system pressure.
- The aircraft exceeded all manufacturer-established weight limits for ramp, takeoff, and landing.
- The weight and balance calculation was inaccurate due to an underestimation of the actual fuel onboard.
- The loss of braking effectiveness during the landing roll led to the runway excursion.
- The pilot did not declare an emergency until after the aircraft had come to a complete stop outside the runway.