Summary
This document proposes to adopt a new airworthiness directive (AD) that would apply to all Mooney Aircraft Corporation (Mooney) Models M20B, M20C, M20D, M20E, M20F, M20G, and M20J airplanes that are equipped with an O & N Bladder Fuel Cell that was installed prior to February 1, 1998, in accordance with Supplemental Type Certificate (STC) SA2277CE or STC SA2350CE. The STC's apply to all of the affected airplane models except for the Model M20B airplanes; the Model M20B airplanes could have one of the STC's incorporated by field approval. The proposed AD would require inspecting the drain valve to assure that it was inserted fully into the drain nipple and modifying any drain valve found not to be inserted fully into the drain nipple. The proposed AD would also require certain modifications and replacements on the affected fuel cells to reduce the chances of water/ice contamination. The proposed AD is the result of reports of rain water entering the fuel bladders and the information from the subsequent evaluation of the fuel systems. The actions specified by the proposed AD are intended to assist in preventing water from entering the fuel bladders, which could result in rough engine operation or complete loss of engine power.