Turbofan Powerplant QECA Removal

in Engine Removal and Replacement

The powerplant may be removed from the aircraft by either of two methods. One method involves lowering the powerplant from the nacelle by using an engine dolly. The other method requires hoists and a special sling to lower the powerplant to a movable engine stand. The following preliminary steps are applicable to either method of removal:

1. Adequately secure the aircraft either with wheel chocks or tiedown provisions; attach ground wire or cable to aircraft.

2. Open the nacelle doors and support them with the struts. Verify that no external power is connected to the aircraft and that the electric power switch is off.

3. Remove the mount access plates from both sides of the nacelle structure.

4. Remove the engine’s pneumatic ducts as needed.

5. Disconnect the turbine electrical wiring connections, thermocouple lead. [Figure 8-18]

Figure 8-18. Electrical disconnect.

Figure 8-18. Electrical disconnect.

6. Disconnect the fuel line by removing the bolts from the hose flange. [Figure 8-19]

Figure 8-19. Fuel line disconnect.

Figure 8-19. Fuel line disconnect.

7. Disconnect the hydraulic lines and connections. [Figure 8-20]

Figure 8-20. New hydraulic connections (Boeing).

Figure 8-20. New hydraulic connections (Boeing). [click image to enlarge]

After the engine has been disconnected, except for the engine mounts, and a dolly is being used to remove the engine, position it under the engine. Attach it to the engine and raise the dolly until all the weight is relieved from the wing. If hoists are used, connect the hoists to the engine mounts through the accesses on the pylon. When lowering the engine with hoists, operate them simultaneously to exert tension on the hoist cables at all times. Position a movable engine stand under the engine before lowering it.

With either the hoists or dolly attached and the stand in place, the engine is now ready to be lowered.

Remove the rear engine mount bolt and bushing and the front engine mount nuts and washers. Start lowering the engine, constantly observing the engine clearance with the nacelle to prevent damage to the engine or nacelle. Secure the engine to the dolly or stand. If hoists are used, detach them from the engine. Roll the engine clear of the aircraft. Care must be taken while moving the engine clear to prevent damage to the pylon or pod. Cap or plug all lines, hoses, and outlets. With the engine removed, inspect the power control rod bracket and crank assembly for bearing looseness and the nacelle area for structural damage. Inspect for cracks or openings in the area where the pylon structure joins the nacelle structure.

Removal of QECA Accessories

When an aircraft engine is to be replaced, the aircraftfurnished accessories and equipment may be removed either for installation on the replacement engine or for overhaul, as required. Note carefully the locations and attachments of all units before removal to aid in the assembly of the replacement powerplant. When accessories are to be sent to overhaul or storage, preserve them in accordance with the manufacturer’s instructions and attach all pertinent data and the proper accessory record cards.

After removal of these accessories and equipment, cover all exposed drives and ports. Prepare the engine for shipment, storage, or disassembly as directed in applicable manufacturer’s instructions.