Chapter 71. Power Plant

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1 Chapter 71 Power Plant PAGE 1

2 Table of Contents Chapter Title COWLING ENGINE MOUNT Shock Mounts AIR BAFFLES PAGE 2

3 COWLING Description The engine cowling is divided into two parts: The upper (1, Figure 1) and lower (2) cowling made of GFRP or CFRP honeycomb sandwich. The upper cowling features a hinged hatch (3) for access to the oil dip stick. This hatch is opened by two slotted head flush type Camloc retainers. Both cowling parts are attached to each other and the airframe by means of truss head screws (4) and special washers (5). The interior surface of both cowling parts is coated with a fire protection paint which is sealed by varnish coating. Additional aluminized heat blankets are placed in the lower cowling. Figure 1; Engine Cowling PAGE 3

4 Removal/Installation NOTE It is favourable to remove the cowling with two persons. WARNING Before rotating the propeller in the most convenient position for removal of the cowling, make sure that the ignition switch is in the OFF position. 1 Rotate the 3 or 4 blade propeller in the most convenient position. 2 Remove the related truss head screws (4)&(5) of the upper cowling (see Figure 1). 3 Remove upper cowling. 4 Remove the remaining truss head screws (4)&(5) of the lower cowling (see Figure 1). 5 Remove lower cowling. 6 Install in reverse sequence of removal. PAGE 4

5 ENGINE MOUNT Description The engine is mounted on the airframe via the engine mount. The engine mount is constructed of welded steel tubes and is bolted to the firewall at 4 attachment points. The tubes of the engine mount structure are provided with an internal anti corrosion treatment. The engine mount itself carries the oil cooler and is used as a support for various hoses of the oil system as well as electrical wiring. The engine is nested into the engine mount on a system of rubber shock mounts, each of which comprises two rubber elements and one tubular spacer (ref. Figure 2). The shock mounts reduce the transmission of engine vibrations to the airframe. PAGE 5

6 Figure 2, Engine Mount & Shock Mount Installation PAGE 6

7 Removal This paragraph describes the removal of the engine mount from the engine (instructions in brackets for double oil cooler system only!) 1 Disconnect (aft) oil cooler assembly (and separator) from its supports at the engine mount by removing the connection bolts and nuts, remove baffles if necessary. 2 Unscrew locknuts of the mounting bolts (refer to Detail A on Figure 2) at the shock mounts. 3 Separate engine including oil cooler (and separator) from engine mount. If necessary, push bolts outwards for removal. Installation Install in reverse sequence of removal Torque locknuts of connection bolts to engine shock mounts with 55 Nm (40.5 ft. lbs.) Shock Mounts Description The shock mounts serve as dampers to reduce the transmission of vibrations induced by the engine to the aiframe. The shock mounts consist of bonded rubber material with a metal spacer at the center. Each of the 4 shock mounts consists of two rubber halfs and one tubular spacer (ref. Figure 1, Detail A) fixed by a single bolt. PAGE 7

8 Removal CAUTION Replace the extracted shock mount before proceeding with the removal of the next. 1 Support engine at its designated lifting lugs (ref. Lycoming Maintenance Manual). 2 Unscrew locknut of the mounting bolt at one shock mount (ref. Figure 1, Detail A). 3 Push bolt backwards to remove it. 4 Remove forward half of the shock mount. 5 Remove tubular spacer. 6 Extract aft half of the shock mount. If necessary, lower respectively lift the engine a little to get the needed clearance for removal of the aft shock mount half. Installation Install in reverse sequence of removal Torque locknuts of connection bolts with 55 Nm (40.5 ft. lbs.). PAGE 8

9 AIR BAFFLES Description Refer to Figure 2. Air baffles are screwed to the engine to achieve optimum engine cooling. These baffles are multi section items designed for separate removal of each section. They are manufactured of plated aluminium sheets. The interface to the engine cowling is sealed by rubber stripes, which are riveted to the outer edge of the baffles. Furthermore the forward LH baffle has a circular cutout, serving as a cooling air inlet that is connected with the exhaust s heat exchanger air intake via an air ducting. Single oil cooler system: The aft RH baffle has a rectangular cutout to provide airflow to the oil cooler. Dual oil cooler system: The aft LH baffle has a circular inlet to provide airflow to the aft oil cooler, which is connected to the baffle by an air ducting. In addition to the circular inlet described above, the forward LH baffle has a rectangular cutout to support the forward oil cooler. PAGE 9

10 Figure 3, Air Baffles Removal Refer to Figure 3 (Instructions in brackets for dual oil cooler system only). 1 Disconnect bowden cable of RPM-control from engine (refer to Chapter 61). 2 Disconnect fuel pressure sensing line at bulkhead of aft RH baffle. 3 Disconnect ignition harness. PAGE 10

11 4 Disconnect air ducting to exhaust heat exchanger at air intake of forward LH baffle (to aft oil cooler at rear LH baffle). 5 (Disconnect forward oil cooler assy at forward LH baffle). 6 Unscrew grommets for ignition harness and RPM bowden cable from their cutouts and pull out ignition harness and RPM bowden cable. 7 Unscrew baffle plates. Installation Install in reverse sequence of removal. NOTE Minor cracks in the plating can be stopped by drilling a hole at the end of the crack. Serious damage requires replacement of the baffle concerned. PAGE 11

Chapter 79. Oil System

Chapter 79. Oil System Chapter 79 Oil System PAGE 1 TABLE OF CONTENTS Chapter Title 79-00-00 GENERAL.................................. 3 79-00-10 Christen Inverted Oil System..................... 3 79-00-11 Valve Balls...................................