Incident Overview
On 7 May 2016, a Cessna T207A aircraft was conducting a parachute jump flight in the TRA59 temporarily reserved area near Białystok-Krywlany Airport (EPBK). The crew consisted of a pilot-in-command and a second pilot. Six occupants were on board, none of whom were injured.
Crew Actions
During the climb from flight level 80, the crew observed intermittent low voltage warnings. After reducing the electrical load, the warnings ceased. Following the parachutists' exit from the aircraft, the low voltage indication became continuous, and the digital EDM 700 indicator showed a gradual decrease in battery voltage. In accordance with the checklist, the crew disconnected the alternator. The aircraft subsequently landed without incident at EPBK.
Post-Flight Findings
A preliminary inspection by maintenance personnel revealed significant play between the two halves of the alternator housing. The ground wire had broken due to vibration, and metal filings had accumulated in the engine compartment.
Cause
The cause of the incident was alternator damage from an undetermined reason.
Safety Measures
As a preventative action, the event was recorded in the operator's internal safety management system (SMS) and was scheduled to be discussed with maintenance personnel and instructional staff.