and increase the mass airflow in the piccolo tubes. The wing  leading edge is constructed of two skin layers separated by a  narrow passageway.  [Figure 15-8]  The air directed against  the leading edge can only escape through the passageway,  wing inboard area. The ejector discharges the bleed air into  piccolo tubes for distribution along the leading edge. Fresh  ambient air is introduced into the wing leading edge by two  flush-mounted ram air scoops in each wing leading edge,  one at the wing root and one near the wingtip. The ejectors  entrain ambient air, reduce the temperature of the bleed air,  15-5 Figure 15-7.  Thermal WAI system. Figure 15-8.  Heated wing leading edge. Figure 15-6.  Aircraft with thermal WAI system. Leading edge diaphragm Inner skin Inner skin Front spar Deicing  air  duct Exhaust Contour-etched outer skin MASTER STBY BATT FAIL ARM ON BATT TEST O F R H L O A D B U S Normally closed (NC) 41 psi regulator shutoff valve 3.5 psi switch Thrust lever 60% switches Overboard outlet Overboard outlet 350 °F overtemp switch 350 °F overtemp switch 140 °F operation switches 212 °F overtemp switches 212 °F overtemp switches