What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) The aircraft, N731SJ a Lancair iv-p departed from krmn for a local flight at approx 0915. Upon reaching a cruise altitude of 3000 feet the PIC turned on the aft aux battery in order to charge it with the alternator. A short time later he detected smoke and immediately turned off all electrical power. PIC immediately returned to the airport and landed uneventfully. There were no injuries to PIC or passenger other than minor complaints of smoke and fume inhalation. Upon inspection of the aircraft by the FAA, substantial damage was found in the aft section of the aircraft where the aft battery was located. The fire severely damaged the aft battery mounting structure and caused severe deformation and delamination to the surround composite fuselage structures within an approximate 3 foot radius of the battery mounting position.
As the FAA filed it
(-23) THE AIRCRAFT, N731SJ A LANCAIR IV-P DEPARTED FROM KRMN FOR A LOCAL FLIGHT AT APPROX 0915. UPON REACHING A CRUISE ALTITUDE OF 3000 FEET THE PIC TURNED ON THE AFT AUX BATTERY IN ORDER TO CHARGE IT WITH THE ALTERNATOR. A SHORT TIME LATER HE DETECTED SMOKE AND IMMEDIATELY TURNED OFF ALL ELECTRICAL POWER. PIC IMMEDIATELY RETURNED TO THE AIRPORT AND LANDED UNEVENTFULLY. THERE WERE NO INJURIES TO PIC OR PASSENGER OTHER THAN MINOR COMPLAINTS OF SMOKE AND FUME INHALATION. UPON INSPECTION OF THE AIRCRAFT BY THE FAA, SUBSTANTIAL DAMAGE WAS FOUND IN THE AFT SECTION OF THE AIRCRAFT WHERE THE AFT BATTERY WAS LOCATED. THE FIRE SEVERELY DAMAGED THE AFT BATTERY MOUNTING STRUCTURE AND CAUSED SEVERE DEFORMATION AND DELAMINATION TO THE SURROUND COMPOSITE FUSELAGE STRUCTURES WITHIN AN APPROXIMATE 3 FOOT RADIUS OF THE BATTERY MOUNTING POSITION.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.