What happened
On May 18, 2009, at approximately 20:42 UTC, a Piper PA-32-300, registration PT-DPD, operated by Tok Táxi Aéreo Ltda, departed from Zumbi dos Palmares Airport (SBMO) in Maceió, Brazil. The flight was intended for a cargo transport mission to Recife (SBRF) with one pilot and two passengers on board.
The incident began earlier that evening following a previous landing in Maceió. The pilot failed to shut down certain onboard equipment and the battery after the prior arrival. Consequently, the battery was depleted, preventing the engine from starting during pre-flight preparations. Although the pilot used an external power source to start the engine, the battery failed to recharge sufficiently.
Prior to departure, the pilot contacted the Aeronautical Information Service (AIS) via telephone to inquire about departing without radio capabilities due to the electrical failure. After receiving authorization to taxi and take off from the Control Tower (TWR-MO), the aircraft experienced a total electrical failure, resulting in the loss of all radio communications. Because the aircraft's navigation and anti-collision lights were unpowered, air traffic controllers were unable to visually identify the aircraft during its night departure.
Shortly after takeoff, the pilot used a mobile phone to contact the AIS office to coordinate an immediate return to Maceió due to the electrical outage. Upon landing at SBMO at 20:52 UTC, the aircraft veered off Taxiway B and came to a stop on the grass. There were no injuries to the three occupants and no damage to the aircraft.
The investigation
CENIPA's investigation focused on the pilot's decision-making process and the violation of air regulations regarding night operations and radio equipment. The investigation examined the sequence of events following the battery depletion and the pilot's use of non-aviation communication (mobile phone) to coordinate with ATC. The investigators also reviewed the compliance of the aircraft's maintenance and the pilot's certifications, which were all found to be in order.
Findings
- The pilot failed to follow standard checklists, specifically neglecting to turn off onboard equipment after a previous flight, which led to the battery depletion.
- The pilot elected to proceed with a night departure despite knowing the aircraft had a total electrical failure and no functional radio communication.
- The aircraft was operating in violation of air regulations (ICA 100-12) because it failed to display required anti-collision and navigation lights during night flight.
- The pilot's low situational awareness regarding the risks of operating at night without lights or communication compromised flight safety.
- The pilot utilized a mobile phone to coordinate with the tower, which is not a standard aeronautical communication method for flight coordination.