M-20 K (231) / Encore
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Commercial
Flight Crew Last 90 Days 10; Flight Crew Total 2230; Flight Crew Type 1900
Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Maintenance; Ground Event / Encounter Ground Strike - Aircraft; Ground Excursion Runway
Flight Crew Became Reoriented
Environment - Non Weather Related; Human Factors
Landed on Runway 33 at night; ending a flight that had begun before sunset.  Had landing/taxi light switch 'on'; but upon touchdown discovered the lights were off.  Taxied down the runway looking for a taxiway turn-off; but with no lights could not see the yellow lead line to either of the turn-offs ahead of me.  I knew the last turn-off was at the end of the runway; but when I got there I could not determine where to start my right turn.  I turned too soon and missed the asphalt turn-off; rolling onto the grass beside it instead.  I then attempted a right U-turn on the grass; to get back onto the runway.  Halfway through the U-turn; when I was headed approximately 150 degrees; the nose wheel and prop impacted a plastic sign located in the grass.  The front side of the sign was lighted; but the rear side was not.  Approaching the sign from its rear; it was dark and impossible to see.The aircraft had just come out of its annual inspection; which required removal of the engine cowling.  To remove the lower cowling; the landing/taxi lights must be disconnected; and I suspect they were not reconnected when the cowling was put back in place.  Otherwise; it would be highly unlikely that both bulbs would fail simultaneously.This would have been discovered in a thorough pre-flight; but unfortunately this item was missed.
The pilot of a Mooney reported inoperative landing and taxi lights that resulted in a runway excursion and contact with a ground object. The pilot suspected that the lights were not reconnected when the cowling was reinstalled during the annual inspection.