As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BRASS 1/4" HOSE COUPLING CAME DISCONNECTED INSIDE THE COCKPIT WHERE THE PITOT LINE ENTERS THE CABIN. THIS RESULTED IN A LOSS OF INDICATED AIRSPEED DURING CRUISE FLIGHT. LIKELY CAUSE OF FAILURE WAS IMPROPER ASSEMBLY WHEN ORIGINALLY INSTALLED. A NEW COUPLING WAS INSTALLED AND THE SYSTEM WAS PRESSURE TESTED AFTER RETURNING TO HOME BASE OF KLXT