Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Short Brothers Model SD3-60 airplanes. This proposed AD would require deactivation of auxiliary fuel tank systems installed in accordance with Supplemental Type Certificate (STC) SA00404AT. This proposed AD results from fuel tank system review requirements done in accordance with Special Federal Aviation Regulation No. 88 (SFAR 88), which identified potential unsafe conditions. We are proposing this AD to prevent the potential of ignition sources inside fuel tanks, which, in combination with flammable fuel vapors, could result in fuel tank explosions and consequent loss of the airplane.