Incident Overview
On Sunday, December 18, 2011, a private Cessna 182 registered as F-BLEC departed from Couhé-Vérac aerodrome at approximately 16:35 local time. The flight was intended for Toussus-le-Noble under Visual Flight Rules (VFR). Around 17:40, while in cruise near Chartres, the pilot lost radar contact with air traffic control. Shortly after receiving this notification, the pilot observed that the red battery warning light was illuminated.
Emergency Procedures and Navigation
The pilot reported an electrical issue to the controller but subsequently lost communication. To conserve power, the pilot switched off the radios, transponder, pitot heating, and onboard GPS. The decision was made not to divert because the pilot lacked the means to activate lighting at other aerodromes and assumed Toussus-le-Noble lights were active due to the filed flight plan.
Attempts to navigate using VOR signals failed as reception was lost before reaching the EPR navaid. The pilot then decided to return toward Chartres, considering it easily identifiable at night. To access a portable GPS unit located on the rear seat, the pilot engaged the autopilot, which is powered by the pneumatic circuit. With no interior lighting and likely no landing lights, the pilot used a headlamp and flashlights for visibility.
Landing and Investigation Findings
Upon approaching Toussus-le-Noble, the pilot observed another aircraft in the traffic pattern. The pilot overflew the control tower, joined the final approach for runway 25 Left, and landed without deploying flaps. No injuries were reported.
Maintenance inspections revealed that the alternator charge breaker had tripped, preventing the alternator from supplying power to the electrical circuit. The specific cause of the trip could not be determined. The red overvoltage warning light, which illuminated during the flight, indicates either an alternator failure or low voltage at the electrical regulator.
Contributing Factors
The pilot admitted to not using a checklist and failing to inspect the breaker panel located under the dashboard. The standard checklist for this type of failure did not include checking the breakers. The pilot had previously experienced an alternator failure on a different aircraft type and may have prematurely concluded that the alternator was faulty again, rather than investigating the electrical circuit further.