Incident Overview
A pilot reported that after departing under Instrument Flight Rules (IFR) for The Florida Keys Marathon Airport in Marathon, Florida, he canceled his IFR clearance and completed the pre-landing checklist. While on the base leg over water during a dark night, he became distracted by the failure of the landing light.
With the landing gear and flaps extended for landing and power set to 15 inches of manifold pressure, the pilot did not recognize that the airplane was descending. When the aircraft impacted the water, the pilot stated he believed they were at 1,000 feet. He also attempted to activate the runway lights using the common traffic advisory frequency but could not see them. In hindsight, he said he must have been too low to see the runway lights.
Runway Lighting Status
According to the County of Monroe Assistant Director of Airports, the runway lights at Marathon Airport come on automatically at night and remain at "step 1." As a 14 CFR Part 139 airport, a complete night inspection is performed each Friday and Monday, and a daily morning continuous inspection is conducted on the runway lighting circuit. Daily Self Inspection Reports indicated that the airfield runway lights were functioning properly during the weekend, with no issues reported. However, the runway end identifier lights for runway 7 were out of service at that time.
Summary
The incident involved a night water impact following a distraction from a landing light failure. The pilot reported no awareness of descending until impact. The runway lighting system was reported functional except for the runway 7 end identifier lights.