What happened
On November 16, 2009, an Embraer EMB-810C, registration PT-OBL, operated by JAD Táxi-Aéreo, departed from Salgado Filho Airport in Porto Alegre, Brazil, bound for Santa Maria. The flight was conducting a cargo operation with two crew members on board. Shortly after takeoff, the pilots noticed that the landing gear had failed to retract. Consequently, they decided to return to the origin airport for an emergency landing.
During the approach, air traffic control observed that the landing gear was in an irregular position and instructed the crew to execute a go-around. However, the crew did not receive this instruction and proceeded with the landing. The aircraft touched down with the landing gear unlocked, resulting in a belly landing. The aircraft slid approximately 100 meters along the runway, causing substantial damage to the propellers, engines, and the lower fuselage. Both crew members were unharmed.
The investigation
The investigation focused on why the landing gear failed to retract and why the crew failed to identify a potential electrical failure. Investigators examined the aircraft's electrical systems, noting that while the landing gear and radio systems functioned normally during subsequent ground tests, the crew had experienced a simultaneous loss of radio contact.
It was determined that the aircraft may have been started with the alternators turned off, leaving the systems to rely solely on battery power. As the battery depleted, the electrical supply became insufficient to operate the electric pump required for the landing gear hydraulic system. The investigation also noted that the red landing gear indicator light and the audible warning alarm failed to alert the crew to the gear's transit status, which was consistent with a lack of electrical power.
Findings
- The crew failed to use the aircraft's emergency checklist to diagnose the situation.
- There was a lack of cockpit coordination, as the crew did not consider that the gear failure and radio loss were linked to an electrical supply issue.
- The pilots did not monitor other electrical instruments, such as ammeters or loadmeters, which could have confirmed a power failure.
- The crew's judgment was impaired by a failure to recognize the emergency as an electrical issue, leading them to bypass necessary emergency procedures.
- The investigation suggested that a rush to depart may have led to errors in executing pre-takeoff procedures, specifically regarding the verification of the alternators.