What happened
On October 4, 2009, an EMB-810C aircraft, registration PR-ETT, departed from Blumenau, SC, bound for Campos dos Amarais, SP. The flight was carrying a pilot and three passengers. During the cruise phase, the pilot identified a malfunction in the aircraft's electrical supply. Specifically, the alternators were not charging the battery.
As the flight progressed, the pilot attempted to conserve power by disabling non-essential electrical equipment. Due to the lack of electrical power, the pilot was unable to use the aircraft's primary communication systems and relied on a portable VHF radio to coordinate with Campinas Approach (APP-KP) near Sorocaba, SP. The pilot also navigated using two portable GPS units attached to the control columns.
During the approach to Campos dos Amarais, the pilot commanded the landing gear to the down position. However, because of the total electrical failure, the cockpit indicator lights and the landing gear warning horn were inoperable, leaving the pilot without visual or auditory confirmation of the gear's status. The aircraft subsequently performed a gear-up landing on runway 16. The aircraft slid approximately 200 meters along the asphalt, resulting in severe damage to the engines and propellers. All four occupants escaped without injury.
The investigation
CENIPA investigators examined the aircraft's electrical system and found that loose wires in the alternators had been damaged by the induced component, rendering the alternators inoperable during flight. The investigation also reviewed the pilot's flight experience, the aircraft's maintenance history, and the operational decisions made during the emergency.
Findings
- The primary cause of the electrical failure was the inoperability of the alternators due to internal wiring damage.
- The pilot's decision to continue the flight under IFR (Instrument Flight Rules) conditions while experiencing an electrical failure contributed to the depletion of the battery, which eventually prevented the hydraulic pump from operating the landing gear via normal means.
- The pilot failed to use the emergency checklist and did not verify the gear position using the auxiliary mirror located on the left engine nacelle.
- The pilot's lack of recent emergency training, attributed to the aircraft being used for private leisure rather than commercial operations, hindered effective emergency management.
- Stress from the deteriorating flight conditions likely impacted the pilot's cognitive ability to process critical information.