Airworthiness Directives; Liberty Aerospace Incorporated Model XL-2 Airplanes

We are adopting a new airworthiness directive (AD) for certain Liberty Aerospace Incorporated Model XL-2 airplanes. This AD requires you to repetitively inspect the exhaust muffler for cracks and to replace the exhaust muffler when cracks are found. This AD is the result of reports that cracks have been found in the exhaust muffler during maintenance and service inspections. We are issuing this AD to detect and correct cracks in the exhaust muffler, which could result in carbon monoxide entering the cabin through the heating system. Carbon monoxide entering into the airplane cabin could lead to incapacitation of the pilot.