AD FAA-2008-0147

The FAA is superseding an existing airworthiness directive (AD), which applies to certain Boeing Model 737-600, -700, and -800 series airplanes. That AD currently requires repetitive inspections to detect damage of the aft strut insulation blanket, and eventual replacement of the insulation blankets with new, improved blankets. This new AD adds airplanes to the applicability and requires installation of a new heat insulation blanket and new cover plate on the left and right side engine struts. This new AD does not retain the requirements of the existing AD but does terminate the requirements of the existing AD. This AD results from reports of damaged heat insulation blankets on the engine struts. We are issuing this AD to prevent exposure of the lower surface of the strut to extreme high temperatures, consequent creation of a source of fuel ignition, and increased risk of an uncontrollable fire and possible fuel tank explosion.