What was found
(CAN) LANDING LIGHT ASSEMBLY MOUNTING RING (MADE OF ALUMINUM, RIVETED INTO COWLING NOSE BOWL) CRACKED THROUGH SEVERAL RIVET HOLES AND ANCHOR NUT HOLES. THESE RINGS ARE PRONE TO CRACKING, BUT THIS ONE HAS LASTED ONLY 20 MONTHS/1100 HOURS. MATERIAL MAY BE TOO BRITTLE. OTHER FACTORS: FREQUENT LANDING LIGHT CHANGES, VIBRATION, POSSIBLE HEAT FROM LIGHTS, POSSIBLE OVER TIGHTENING OF SCREWS.