What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
During an IFR flight (night, IMC conditions) the #1 inverter failed.
The pilot switched to the #2 inverter, but it failed to power the aircraft systems.
The result was loss of many of the engine instruments, some primary flight indicators and navigational capability.
The pilot declared an emergency and received vectors and a descent out of the weather to VMC. The pilot elected to divert, VMC, to an appropriate nearby airfield (eug), descended and landed without further incident.
Post incident maintenance revealed the #1 inverter had failed. Upon replacement, the aircraft systems worked normally, including the #2 inverter and switching between inverters.
It is company policy to use the inverter on alternate days (#1 on odd days of the month, and #2 on even days of the month). There was no report of previous problems with either inverter.
It is unknown why, when the pilot switched to the #2 inverter inflight, that it did not provide power to the aircraft.
As the FAA filed it
DURING AN IFR FLIGHT (NIGHT, IMC CONDITIONS) THE #1 INVERTER FAILED.
THE PILOT SWITCHED TO THE #2 INVERTER, BUT IT FAILED TO POWER THE AIRCRAFT SYSTEMS.
THE RESULT WAS LOSS OF MANY OF THE ENGINE INSTRUMENTS, SOME PRIMARY FLIGHT INDICATORS AND NAVIGATIONAL CAPABILITY.
THE PILOT DECLARED AN EMERGENCY AND RECEIVED VECTORS AND A DESCENT OUT OF THE WEATHER TO VMC. THE PILOT ELECTED TO DIVERT, VMC, TO AN APPROPRIATE NEARBY AIRFIELD (EUG), DESCENDED AND LANDED WITHOUT FURTHER INCIDENT.
POST INCIDENT MAINTENANCE REVEALED THE #1 INVERTER HAD FAILED. UPON REPLACEMENT, THE AIRCRAFT SYSTEMS WORKED NORMALLY, INCLUDING THE #2 INVERTER AND SWITCHING BETWEEN INVERTERS.
IT IS COMPANY POLICY TO USE THE INVERTER ON ALTERNATE DAYS (#1 ON ODD DAYS OF THE MONTH, AND #2 ON EVEN DAYS OF THE MONTH). THERE WAS NO REPORT OF PREVIOUS PROBLEMS WITH EITHER INVERTER.
IT IS UNKNOWN WHY, WHEN THE PILOT SWITCHED TO THE #2 INVERTER INFLIGHT, THAT IT DID NOT PROVIDE POWER TO THE AIRCRAFT.
Other reports on N4299A · 5
Matched to the same aircraft by N-number and date.