The FAA has issued an airworthiness directive that supersedes a previous AD for a series of combustion heaters made by Kelly Aerospace Power Systems. The AD applies to heater models B1500, B2500, B2030, B3040, B3500, B4050, and B4500, which are found on various Beechcraft Baron, Duke, and Duchess aircraft, and Cessna 208, 310, 320, 337, 340, 414, and 421-series aircraft, but may include other aircraft as well. The FAA said the AD resulted from reports that the new ceramic-coated combustion tubes are subject to the same distress as the non-ceramic-coated combustion tubes. The AD becomes effective November 19 and requires repetitive testing of the system. For more, see AOPA Online.
