Narrative:

On aircraft right wing tail position light assembly, I removed light assembly to change the top position bulb. The assembly must be removed for this job as the bulb is 'hard wired.' I took the unit into the shop to change the bulb and upon returning to the aircraft, hooked up cannon plug and slid the unit into the wingtip. Note: on removal of the unit, I had laid the 8 securing screws on top of the wing. Before I secured the unit into the wingtip, I wanted to be sure it worked. I went into the cockpit and activated the lights. I went out to the wingtip to find them working properly and returned to cockpit to shut them off as the lights would be blinding while securing the unit. After shutting lights off from cockpit, I stopped for 3-4 mins to talk to a mechanic who was doing aircraft interior work. After leaving interior of aircraft, I was thinking I wanted to finish all exterior work quickly, as it was 18 degrees F with the wind chill factor. A ladder I had out on the left engine caught my eye as I was coming down the stairs. I was running through my mind items I had to complete to get inside out of the WX. With the wingtip light fixed, all I had to do was put ladders away. I put the ladder away on the left engine that had caught my eye, then put away the ladder on the right wingtip. I never had installed the 8 screws to secure the light assembly. The aircraft departed the field and upon arrival at the next station, a preflight walkaround by someone revealed the right wing tail position light assembly missing.

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Original NASA ASRS Text

Title: MECH FAILS TO SECURE WINGTIP LIGHT ASSEMBLY.

Narrative: ON ACFT R WING TAIL POS LIGHT ASSEMBLY, I REMOVED LIGHT ASSEMBLY TO CHANGE THE TOP POS BULB. THE ASSEMBLY MUST BE REMOVED FOR THIS JOB AS THE BULB IS 'HARD WIRED.' I TOOK THE UNIT INTO THE SHOP TO CHANGE THE BULB AND UPON RETURNING TO THE ACFT, HOOKED UP CANNON PLUG AND SLID THE UNIT INTO THE WINGTIP. NOTE: ON REMOVAL OF THE UNIT, I HAD LAID THE 8 SECURING SCREWS ON TOP OF THE WING. BEFORE I SECURED THE UNIT INTO THE WINGTIP, I WANTED TO BE SURE IT WORKED. I WENT INTO THE COCKPIT AND ACTIVATED THE LIGHTS. I WENT OUT TO THE WINGTIP TO FIND THEM WORKING PROPERLY AND RETURNED TO COCKPIT TO SHUT THEM OFF AS THE LIGHTS WOULD BE BLINDING WHILE SECURING THE UNIT. AFTER SHUTTING LIGHTS OFF FROM COCKPIT, I STOPPED FOR 3-4 MINS TO TALK TO A MECH WHO WAS DOING ACFT INTERIOR WORK. AFTER LEAVING INTERIOR OF ACFT, I WAS THINKING I WANTED TO FINISH ALL EXTERIOR WORK QUICKLY, AS IT WAS 18 DEGS F WITH THE WIND CHILL FACTOR. A LADDER I HAD OUT ON THE L ENG CAUGHT MY EYE AS I WAS COMING DOWN THE STAIRS. I WAS RUNNING THROUGH MY MIND ITEMS I HAD TO COMPLETE TO GET INSIDE OUT OF THE WX. WITH THE WINGTIP LIGHT FIXED, ALL I HAD TO DO WAS PUT LADDERS AWAY. I PUT THE LADDER AWAY ON THE L ENG THAT HAD CAUGHT MY EYE, THEN PUT AWAY THE LADDER ON THE R WINGTIP. I NEVER HAD INSTALLED THE 8 SCREWS TO SECURE THE LIGHT ASSEMBLY. THE ACFT DEPARTED THE FIELD AND UPON ARR AT THE NEXT STATION, A PREFLT WALKAROUND BY SOMEONE REVEALED THE R WING TAIL POS LIGHT ASSEMBLY MISSING.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.