AD FAA-2008-0955

The FAA is adopting a new airworthiness directive (AD) for certain Harco Labs, Inc. part numbers 100435-39, 100435-39-001, 100435- 40, and 100435-40-001 pitot/angle of attack (AOA) probes installed on, but not limited to Eclipse Aviation Inc. Model EA500 airplanes. This AD requires you to incorporate information into the Limitations section of the airplane flight manual (AFM) that will allow operation only under day visual flight rules (VFR) and allow only a VFR flight plan. This AD also requires you to test the pitot/AOA probes for heater performance and replace the pitot/AOA probe if it fails the heater performance test. This AD results from several reports of airspeed disagree caution indication due to blockage from freezing condensation within the pitot/ AOA system. We are issuing this AD to detect and correct improperly performing pitot/AOA probe heaters, which could result in blockage within the pitot/AOA system from condensation freezing with consequent incorrect indication of impact air pressure (airspeed/AOA). This blockage could lead to the stall warning becoming unreliable and the stick pusher, overspeed warning, autopilot, and yaw damper to malfunction.