AIRCRAFT OPERATIONS MANUAL | 2.6. SYSTEM OPERATION 787 2.6.8 Ice and Rain Protection 01 NORMAL PROCEDURES 1.1, General Window heat must be on for all normal flight conditions. Early application during pre-flight checks, or maintaining it on during transit stops will ensure correct operating temperatures are achieved prior to take-off. 1.2. Before Starting < wiindow Healey Sectates ons csnpieienne + von Check: . Window heat switches on. + POWER LIGHTS button is depressed and light on. POWER lights cycle on or out. + WINDOW 1 OVHT light is not illuminated. > Probe Heat ........... i pee + Left and Right Probe Heaters Switches Check: . MAIN PITOT lights out. + AUX PITOT lights out. + TAT PROBE lights out, PROBE HEAT light out, FMAPSL Le ANE —Ioe.,, S52 saniae sinainew vee a orF Check: . Nacelle anti“ice switches off. + (NACELLE) VALVE OPEN lights out. + (UASUG] STATOR VALVE OPEN lights out. 1.3, Before Taxi (or during push-back with all engines running) - Nacelle Anti-Ice eas ee ON or OFF Refer to: Use of Nacelle Anti-Ice, AOM 2.6.8 page 2. 1.4, Before Towing/After Parking - Anti-Icing ....., ee cicsincaineteg ansevicile CFR. + Nacelle Anti-Ice Switches, one at a time 1.1) Orr Check: . (NACELLE) VALVE OPEN light out. UA-UG] STATOR VALVE OPEN light out. + Wing Anti-Ice Switch .........csecee +++ Check OFF - Probe Heat .. EWES, SR, «SA RAEI SEIEN eee: Select Left and Right probe heaters switches to OFF. 1.5. Termination At terminating stations, where the ground time exceeds 14hrs: - Window Heat .... ++ OFF => FL Date =: 1 JUL 1984 747 ROM: 2.6.8 Issue No. : 12 Page: 7séee KLM 266 SYSTEI OPERATION aircraft operations manual Boeing 747 2.6.8 Ice and Rain Protection 02 CONDITIONAL PROCEUDRES 2.1. Icing Conditions ~ Icing conditions exist when OAT (on ground and for take-off) or TAT (in flight) is 10°C or below and visible moisture in any form is present, such as clouds, fog with visibility of 1 St.M. or less, rain, snow, sleet and ice crystals. = Icing conditions also exist when OAT (on ground and for take-off) is 10°C or below, when operating on ramps, taxivays or runways where surface snow, ice, standing water or slush may be ingested by the engines or freeze on engines, nacelles or Pt2 probes. 2.2. Operation in Icing Conditions Nacelle anti-ice must be on during all ground and flight operations when icing conditions exist or are anticipated, except during climb and cruise when SAT is below -40°C. Nacelle anti-ice must be on prior to and during descent in all icing conditions, including temperatures below -40°C SAT. NOTES: 1. (JTID) erratic or abnormal EPR indications may be an indication of engine icing. I 2. Do not operate nacelle anti-ice at OAT (on ground) or TAT (in flight) above 10°C, except as required for Engine Operation I in Heavy Precipitation, refer to AOM 2.6.2-2.8. When using nacelle anti-ice on ground during icing conditions, refer to | Engine Run-up during Icing Conditions, AOM 2.6.8-2.4. When using nacelle anti-ice during flight, the following applies: - Maintain pneumatic duct pressure at 15 psi or above. = When penetrating or operating in icing conditions, maintain a minimum of: + 508 NI at or above 10.000 ft, or + 458 NI below 10.000 ft, except as required for landing. ‘The above minimum thrust settings must also be maintained when operat ing in clouds at temperatures below -40°C SAT with nacelle anti-ice on or off to prevent ice forming internally in the engine. Under these conditions, visible moisture will normally be in the form of ice crystals which do not adhere to the nacelle or other aircraft surfaces. NOTES Under no circumstances should engines be operated at idle other than momentarily for aircraft operational reasons. 2. PMS retards power levers to appropriate minimum Nl if nacelle anti-ice is on. = If a HIGH STAGE light remains out at low thrust, maintain a minimum of 708 Nl on the affected engine in level flight, or accelerate periodically to this value during descent, to provide sufficient heat for nacelle anti-ice. > pate 15 JUL 1988 747 KOM: 2.6.68