SD3-60 AIRCRAFT MAINTENANCE MANUAL z AMM 31.0.0.0COLD WEATHER PROTECTION DESCRIPTION & OPERATION 1. General This section details precautions necessary to protect the aircraft on the ground during cold weather conditions. Details are also given of the recommended methods of removing snow, slush and ice. During the removal of snow, slush or ice only the equipment detailed in this section or approved alternative equipment, should be used to avoid damaging the aircraft. When spraying de-icing fluids the engine and air conditioning should not be running. Avoid fluid entering the engine and air conditioning intakes. WARNING: THE PRESENCE OF ICE OR SNOW ANYWHERE ON THE FLIGHT SURFACES CAN SERIOUSLY IMPAIR THE PERFORMANCE CHARACTERISTICS AND UTMOST CARE MUST BE TAKEN TO CLEAR THE SURFACES OF ANY DISCERNABLE HAZARD. NOTE: Aircraft certificated for flight in icing conditions are not certificated for take-off or flight with ice formed as a result of ground storage or operations. Such ice must be removed and the aircraft maintained in a clean condition prior to take-off. The use of the aircraft de-icing/anti-icing systems is not recommended for removing deposits of ice accumulated during ground storage or operations. 2. Equipment and materials Refer to Table 1. This details suggested equipment and materials for clearing the effects of cold weather from the aircraft. Other approved manufacturer's equivalents may be used Table 1 Item Description Manufacturer Tool No. 1 Bung, air intake Short Bros. PLC. T360-10-06 2 Cover, pitot head Short Bros. PLC. T360-10-04 3 Jet, fullcone square spray Spraying Systems Co. - 4 Lance, trigger-operated spray (9 feet long) Rollasan Aerocessories Ltd. - 5 Gun, adjustable jet spray, type 'Fixum' Firma Gebruder Holder 6 Spraying unit, hot defrosting, (50 lmp.gal.) Rollasan Aerocessories Ltd. 7 Spraying unit, hot defrosting (self-propelled, hydraulic platforms, fully equipped) Simon Engineering Co., Ltd. or Bernh. Schulze-Echel 8 Pump, de-icing Silmen and Hinsche 9 Hose, 2-wire braided Willcox and Co. Page 1
z SD3-60 AIRCRAFT MAINTENANCE MANUAL Item Description Manufacturer Tool No. 10 Hose, Hi-flex Oil Feed Eng. 212-0463 or 112-1163 *11 Kilfrost ABC 3 Kilfrost Limited 11A Standard de-icing fluids equivalent to item 11 12 Cart, pneumatic starter 13 Soft brooms, brushes, Operator's supply NOTE: *Kilfrost ABC 3, or equivalent conforming to 'AEA TYPE 2' AMS 1428 or ISO 11078 specifications 3. Precautions If cold conditions exist, or are forecast, as many as possible of the following precautions should be taken: A. Hangar the aircraft. B. On snow or ice, taxi, rather than tow, the aircraft to a parking position. C. If towing, load the aircraft as lightly as possible. D. Reduce the possibility of tyre/ground adhesion by removing snow and slush from ground around the wheels. E. Park into wind. F. Fit all bungs and covers. 4. Storage of de-icing/anti-icing fluids Store in accordance with supplier/manufacturer's instructions. Page 2
SD3-60 AIRCRAFT MAINTENANCE MANUAL z AMM 32.0.0.0COLD WEATHER PROTECTION - SERVICING 1. Freezing weather - Precautions A. Aircraft to take-off within 6 hours. (1) Observe general precautions in Description and Operation. (2) Park the aircraft. Refer to 10-11-00, pb201. (3) Close all doors and hatches and fit covers and bungs (Items 1 and 2.). (4) Anti-ice the aircraft as detailed in para 1.C. B. Aircraft to remain parked for longer than 6 hours. (1) Repeat para 1.A.(1), (2) and (3). (2) Drain the water containers in the galley or remove the containers to a warmer environment. (3) Add any high-quality ethylene glycol based automotive anti-freeze to the toilet tank charge and flush to mix. NOTE: Do not use aircraft de-icing ethylene glycol because foaming may occur when mixed with toilet fluid. Do not store flushing fluid for more than 10 days after automotive anti-freeze has been added, as the anti-foam inhibitor can deteriorate. For recommended amounts of anti-freeze, Refer to Table 301. Ambient Temp. Anti-freeze (US quarts) Table 301 +10 F 0 F -15 F -34 F -59 F (-12 C) (-18 C) (-26 C) (-37 C) (-51 C) 3 4 5 6 7 (4) If ambient temperature is expected to be below 5 F (-15 C) and the aircraft is to stay in the open for more than 8 hours, remove the aircraft batteries to a warm storage place. (5) Anti-ice the aircraft as detailed in para 1.C. Page 301
z SD3-60 AIRCRAFT MAINTENANCE MANUAL C. Anti-ice the aircraft To cater for existing or forecast icing conditions, the aircraft should be subjected to anti-ice treatment as detailed below. NOTE: Treatment should be applied as near departure as is reasonable to assure that the recommended hold-over times defined in the anti-icing fluid specification prior to takeoff are not exceeded. If a further coating of anti-icing fluid is necessary, the aircraft must be de-iced before a further coating is applied. An aircraft should not receive a further cold anti-icing coating on top of an existing film. Particular attention should be afforded to the following critical surfaces: - Top surface of nose of fuselage forward of windshield - Wing struts - Stub wings - Propellers - Wings - Rudder horns - Aileron mass balances - Tailplane - Fins - Top surface of fuselage aft of air conditioning intakes The attention of ground crew is also drawn to representative surfaces i.e. those visible to pilots whilst seated in the flight compartment. The representative surfaces are: Upper surface of nose fuselage forward of windshield Outer wing leading edges Wing strut leading edges If snow has accumulated before anti-icing, clear the aircraft as detailed in para 2. CAUTION: IRRITATION TO THE EYES MAY RESULT FROM DIRECT CONTACT WITH DE- ICING FLUIDS. HANDS SHOULD BE WASHED BEFORE TOUCHING THE FACE IN THE VICINITY OF THE EYES. (1) Procedure (a) Ensure that covers and bungs are fitted (para 3.A.(3)). (b) Remove any frozen deposits (para 3.). Page 302
SD3-60 AIRCRAFT MAINTENANCE MANUAL z CAUTION: DO NOT SPRAY DIRECTLY ON THE AIRCRAFT STATIC PORTS. WIPE CLEAN THE REGION OF THE PORTS AFTER APPLICATION. (c) Spray apply approved anti-icing fluid to the aircraft surfaces commencing with the representative areas. Fluid mix and application is to be in accordance with the fluid manufacturer's guidelines. 2. Snow and slush removal A. Sequence of snow and slush removal (1) Top of fuselage, starting at wing intersection and working aft to the tail, and forward to the nose. (2) Stub wing landing gear fairing and wing strut. (3) Horizontal stabilizer. (4) Flight control surfaces. (5) Main and nose landing gear assemblies and bays. B. Remove snow and slush (1) Remove loose snow layers using long handled brooms etc. (Item 13). On wings work forward and aft from the front spar. (2) Remove frozen snow as detailed in para 3. (3) Anti-ice the aircraft as detailed in para 1.C. (4) Carry out a freedom of movement check of all flight control surfaces. 3. De-icing and de-frosting De-icing and de-frosting may be accomplished by the application of a diluted approved de-icing fluid (preferably heated), by hot air blowing using a ground heating unit, or, when the ambient temperature is above freezing, by hot water spraying. After hot air or hot water spraying, anti-ice the aircraft as detailed in para 1.C. to prevent re-freezing. WARNING: GLAZE ICE MAY BE DIFFICULT TO DETECT. CAUTION: DO NOT USE SHARP TOOLS TO REMOVE ICE. NOTE: It is permissable to use de-icing fluids that conform to all aspects of AMS1428. The aircraft critical and representative surfaces are defined in para 1.C. A. De-ice with approved de-icing fluid. Page 303
z SD3-60 AIRCRAFT MAINTENANCE MANUAL (1) Ensure de-icing mixture is prepared in accordance with the fluid manufacturer's guidelines. NOTE: If cold water is used, some form of mechanical agitation is needed to achieve complete solution. (2) Ensure that covers and bungs are fitted (Items 1 and 2). (3) Spray apply de-icing mixture to the aircraft surfaces in accordance with the fluid manufacturer's guidelines. (4) On completion of de-icing allow the residual fluid to remain on the surface for further protection. (5) Check all drainage holes and static vents for freedom from ice or other obstruction. (6) Carry out function and freedom of movement checks on all flight control surfaces. Page 304