Page: 1 / 8 1. General information This instruction defines the principles and procedure for the application of the ACF-50 anticorrosion compound, which is applied in the form of spraying, usually on the inert parts of the airplane 1.1. Basic terms Corrosion is spontaneous disintegration of metals or of even non-metallic organic or inorganic materials by the effect of a chemical, electrochemical or biochemical reaction with the surrounding environment Corrosion of steel Corrosion of aluminium alloy ACF-50 is an anti-corrosion lubricant compound, specially developed for the aviation industry. It is approved as meeting the aviation standards MIL-SPEC 81309 type II and III, which means that it is approved for ferrous and non-ferrous metals, electric systems and electronic components. The principle of the protection is in the application of an ultra thin protective film (5-12µm) of the treated surface. After the application of the ACF-50, moisture is squeezed out to the surface, where it subsequently evaporates (no water = no corrosion) and ends the electrolytic activity in the location of the starting corrosion. The ACF-50 compound does not contain any water. It is designed as prevention against corrosion and its extra advantage is that it is capable of significantly slowing the already existing corrosion. It has strong capability to penetrate structures, while it does not attack the structure of the metal. The spray is able to penetrate downwards even micrometer gaps around screws, nuts, and rivets and between sheets riveted together. It is also a very good lubricant. It is compatible with plastics and coatings. By default, the ACF-50 compound is applied to new aircraft and then cyclically at recommended intervals for the prevention of corrosion. The recommended interval of application depends on the corrosion environment severity and presence of specific corrosion on aircraft in a particular geographical area. A suitable tool for decision to set the repeat interval spraying is circular DoT US FAA AC No: 43-4 Date: 07/25/91. Maps for three stages of corrosive environment severity for the continents are listed in Chapter 4 Paragraph 4.12 of this circular. Aircraft manufacturer recommends the following cycles for repeated application of the ACF-50 compound for Viper SD-4 aircrafts (with reference to the circular mentioned above): Corrosion environment severity stage Recommended interval of application MILD 24 months MODERATE 12 months SEVERE 6 months
Page: 2 / 8 1.2. Occupational Safety 1.2.1. Basic information: The ACF-50 compound is non-toxic, non-flammable and transparent. 1.2.2. Application: If the conditions allow it, apply the ACF-50 formula in an open area, away from the hangar 1.2.3. Settings: Adjust the output pressure on the compressor to 4-6 bars Mist must be created by spraying the ACF-50 formula must not drip, flow or foam 1.2.4. Prevention: Avoid the spray from getting into eyes and the inhalation of the sprayed mist. During the application of the compound, do not eat or drink. Under normal conditions, when the application is done in an open area, no protective equipment is necessary. If the spraying is done in a closed area, the use of a respirator, suitable eye protection and glows is recommended. Wash thoroughly after application. 1.2.5. Reaction: After inhalation: Move the victim to fresh air and leave to rest in a position that facilitates breathing. After contact with eyes: Rinse the eyes thoroughly with water with eyelids wide open. After contact with skin: Remove excess substance by wiping off and then wash with water and soap. After ingestion: Immediately wash the mouth with water. Drink 1/2 l of water. Excessive contact with the ACF-50 compound may cause drying and cracking of the skin. It can also cause eye irritation. 1.2.6. Storage: Avoid sources of ignition. Store at temperatures up to 70. Store the containers well closed in a dry, cold, and well ventilated place. Keep away from the reach of children. 1.2.7. Disposal: None
Page: 3 / 8 2. Application of the ACF-50 compound 2.1. Preparation of the airframe Cover the canopy with a protective film. Demount the laminate wing root fairing ( scarves ) and the cover of the rear fuselage. Remove the covers of the access holes in the outer skin of the airplane. Protect the aileron trim servo, the flap servo and the elevator servo. If they are already installed, protect the autopilot servos against the spray (right wing and rear fuselage). Demount the seats and the removable upholstering. Cover the glued-on upholstering. Cover the instrument panel, central panel, harness, and parachute. Protection of the canopy Removal of the cover + Protection of the servo Unscrew and demount the laminated cover of the empennage and the wing root fairings
Page: 4 / 8 2.2. Places of the application of the ACF-50 compound airframe * CAUTION: In the marked access holes protect the control servos! - Do not spray ACF-50 directly on a protected servo! - In the place of the removed wing root fairing, spray also on the main wing spar, the bolt of the auxiliary spar and flap control. - Apply on the bolt (attaching a parachute cable) only with a brush. - Do not spray ACF-50 directly on the BPRS parachute harness and container Left and right wing through 3 access holes Aileron with trim through 1 access hole Rear fuselage through 2+2 access holes Elevator with trim through 1 access hole Floor 2 access holes to the landing gear beam well * * * * Wings through the holes in the end rib from the side of the fuselage (after the removal of the wing root fairing) Ailerons and flaps gaps on the trailing edge (from both sides) Rear fuselage through 2 holes in the rear wall of the tail top
Page: 5 / 8 Horizontal stabilizer holes in the root rib on the side of the demounted rear cover (on both sides) Elevator gaps on the trailing edge (on both sides) gaps on the leading edge in the place of the hinge bearing eye Elevator trim gap on the trailing edge Vertical stabilizer through the holes in the bottom rib on the side of the demounted rear cover Rudder through the holes on the leading edge in the place of the hinge bearing eye 2.3. Places of the application of the ACF-50 compound power plant compartment Engine mount attachments of the engine mount (5x) + attachments of the vibration dampers (4x on both sides) Fuselage bottom side edges through the technological hole in the rib (on the bottom of the firewall on both sides) 2 x On both sides CAUTION: 1. Apply ACF-50 on the connecting elements of the engine mount with a brush 2. Avoid direct spraying of belts or filters 3. Do not apply on the exhaust muffler or the exhaust piping
Page: 6 / 8 2.4. Places of the application of the ACF-50 compound cockpit CAUTION: 1. Demount the seats 2. Demount the upholstering (attached by velcro fasteners) 3. Protect against spraying: safety belts, BPRS harness fixed upholstering of the luggage area, instrument panel, central panel flaps servo Flaps servo Space below the luggage area Landing gear beam well Floor + fuselage sides (on both sides) Wingbox (main bolts) Longitudinal + lateral control mechanism Central tunnel Rudder control BPRS Parachute container
Page: 7 / 8 2.5. Spraying of the ACF-50 compound Spraying pistol with a container and spraying nozzle Compressor Protective spraying through access holes Protective spray through gaps on control surfaces
Page: 8 / 8 3. Cleaning and reassembly Remove the protection of the canopy (acrylic glass) Remove the protection elements of the cockpit interior (BPRS parachute container and harness, safety belts, upholstering, instrument panel, central panel,) Remove the protection on all control servos. Wipe off the excessive drained oil from the outer surfaces of the airplane (focus on the bottom parts of the airplane). Wipe off the possible spraying of the acrylic glass and of the laminate parts (focus on the surfaces that come into contact with hands or clothes). Reinstall and attach with screws the empennage and the wing root fairings (scarves). Reinstall the covers of access holes. Reinstall the seats and upholstering.