Service difficulty report · Bulb

Difficulty date
July 3, 2026
Submitted
July 3, 2026
Operation
General aviation
Part
Bulb
Part number
NLI751224
Condition
Burned Out
Stage of operation
IN
How discovered
V
Nature of condition
O
Precautionary procedure
K

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

WE HAVE DISCOVERED THAT THE NAVIGATION LIGHT BULBS ARE OF VERY POOR QUALITY AND ARE NOT RELIABLE. WE HAVE USED THESE BULBS IN THE PAST WITHOUT ISSUE, BUT THE PAST TWO BATCHES HAVE BEEN CONSISTENTLY PROBLEMATIC. SOME HAD BROKEN FILAMENTS STRAIGHT OUT OF THE BOX, AND THE REST FAIL VERY VERY QUICKLY. SOMETIMES IN LESS THAN 1 DAY, BUT THEY LAST NO LONGER THAN A WEEK. THIS HAS BEEN OBSERVED FOR EVERY SINGLE BULB USED OUT OF A COUPLE DOZEN. IT IS CAUSING THE NAV LIGHT SYSTEM ON OUR PLANES TO BE NOT FUNCTIONAL.