Abstract: Method and apparatus for reducing thrust reverser lock switch malfunctions by ducting slipstream air into the compartment containing the thrust reverser door hydraulic lock assembles and lock switches. The slipstream air is ducted into this chamber by ducts mounted on the outer wall of the thrust reverser itself just forward of the locks and the lock switches, the air being ducted in opposition to any tendency of the engine exhaust to flow into this region during operation of the thrust reverser. The installation of the scoops to purge the latch switch areas with outside air has been reported during testing to solve the switch fouling problems, and has been shown to be an effective solution to the problem. The ram air introduced into the latch switch area pressurizes that area and prevents the flow of contaminated air over the latch switches.