Summary
The FAA proposes to supersede an existing airworthiness directive (AD) that applies to all Dassault Model Falcon 10 series airplanes. The existing AD currently requires revising the airplane flight manual (AFM) and installing a placard in the flight deck to prohibit flight into known or forecasted icing conditions. In lieu of the AFM revision and placard installation, that AD allows identifying the part number of each flexible hose in the wing (slat) anti-icing system, performing repetitive inspections of each hose for delamination, and performing corrective actions if necessary. That AD allows the following actions (also in lieu of the AFM revision and placard installation): new repetitive inspections for delamination at reduced intervals, corrective actions if necessary, and an additional AFM revision to include a statement to track flight cycles when the slat anti-icing system is activated. That AD also provides optional terminating action for the repetitive inspection requirements. This proposed AD would mandate the previously optional terminating action. This proposed AD results from a report of in-service delamination of a flexible hose in the slat anti-icing system at a time earlier than previously reported. We are proposing this AD to prevent collapse of the flexible hoses in the slat anti-icing system, which could lead to insufficient anti-icing capability and, if icing is encountered in this situation, could result in reduced controllability of the airplane.