What happened
On October 19, 2001, an EMB-810C Seneca, registration PT-EUQ, was conducting a pilot proficiency check near Teresina, PI. The flight involved two pilots being evaluated and an inspector (checker). During the flight, the checker requested a real engine shutdown of the right engine to simulate an emergency, a procedure that deviated from the aircraft's operational manual.
Following the engine shutdown, the pilot attempted to restart the engine. After multiple unsuccessful attempts, the aircraft experienced a total electrical failure. During the subsequent descent for an emergency single-engine landing, the pilot cycled the battery switch to check the landing gear indicators. This action triggered blue smoke from the throttle pedestal, followed by black smoke emerging from the instrument panel. An explosion occurred, and intense flames engulfed the cockpit.
The aircraft landed on runway 02 while on fire. The checker and a passenger (the second pilot) managed to bail out of the aircraft while it was still in motion. The pilot remained in the cockpit and subsequently died from smoke inhalation and burns. The aircraft veered off the runway and collided with a ditch, resulting in two fatalities and one serious injury.
The investigation
CENIPA investigators examined the wreckage and found evidence of continuous burning in the baggage compartment near the battery housing. The battery showed signs of overheating and deformation, specifically with a melted positive terminal.
Technical analysis revealed that the electrical system contained non-aeronautical components, including a wiring splice made with domestic-grade wire. Furthermore, the investigation found that the aircraft was not in compliance with Airworthiness Directives (AD) and Service Bulletins (SB) regarding the replacement of aluminum terminals and cables with copper to prevent battery pole fires. The use of a carbon steel terminal and the presence of aluminum wiring were identified as critical non-conformities.
Findings
- Deficient Maintenance: The use of non-aeronautical materials and the failure to comply with mandatory Service Bulletins and Airworthiness Directives allowed the fire to originate at the battery's positive pole.
- Deficient Planning and Judgment: The crew decided to perform a real engine shutdown during a check flight, contradicting the aircraft's manual and the inspector's manual, which recommends simulating engine failure via power reduction rather than actual shutdown.
- Deficient Supervision: The operator failed to properly supervise maintenance and operations, allowing the aircraft to fly with non-compliant electrical components and failing to ensure the pilot was adequately trained in emergency procedures.
- Human Factors: High levels of stress and anxiety, combined with a sense of invulnerability in the pilot, influenced the decision to perform the high-risk engine shutdown procedure.
Safety action
CENIPA issued several recommendations, including:
- The operator must revise pilot training programs and oversight processes to ensure proficiency in emergency procedures.
- The operator must implement stricter maintenance supervision and tool control to prevent foreign object debris (such as maintenance wrenches) from being left in aircraft.
- The airport authority must review its Aeronautical Emergency Plan to improve fire and rescue response times.
- Regulatory bodies (DAC and SERAC) must disseminate the report findings to all flight checkers to prevent the use of unauthorized testing parameters.