What Are the Different Steps of Removing an Aircraft Engine?

When removing an aircraft engine, there are several steps that must be taken before it can be fully removed. As engines work at extremely high temperatures with multiple moving parts, it is important to take great care when removing one for repair or replacement. This includes preparing a hoisting mount, as well as securing surrounding components. In this article, we will be discussing the various procedures that take place when removing an engine.

Before carrying out the bulk of engine removal, there are a number of key precautionary measures to be taken, and one should follow the procedures detailed in your aircraft manufacturer’s guide. As such, the steps mentioned in this blog are for general information purposes only and should not be used as a guide for the exact steps to be taken. With that said, though the methods will change dependent on the aircraft, the following steps are usually taken to properly prepare for engine removal:

The magneto switch is in the off position to prevent accidental starting of the engine due to propeller movement.
All fuel selectors or solenoid-operated fuel shutoff valves are closed to protect against fuel leaks.
The battery is disconnected to eliminate the possibility of a hot wire starting a fire.
There is a fire extinguisher on hand that has been checked to ensure that it has not been discharged.
The wheel chocks have been evaluated to make sure they will stay in place and prevent accidental wheel movement.
If the aircraft has tricycle-style landing gear, the tail should be supported so that the aircraft cannot tip back when the weight of the engine is removed.
The landing gear shock struts are deflated as well to prevent them from extending as the engine weight is removed.
The cowling is removed, cleaned, and checked for cracks so that necessary repairs can be made while the engine change is in progress.
After removing the cowling, the propeller is also removed for inspection and repair, as applicable.

Draining the Engine

After taking the necessary precautions, there are several larger steps which will typically take place during engine removal. The first of these steps is to drain the engine of any oil and/or corrosion-preventative mixture. Generally, this process includes opening the various drainage valves and letting the system drain completely before closing the valves and plugs once again. There are several points at which the system can be drained, including the oil cooler, oil return line, and engine sumps.

Electrical Disconnects

When the engine is being removed, it is important to disconnect all electrical leads and related accessories to prevent the risk of engine fire. Electrical disconnections are usually made at the engine firewall, and when disconnecting them, it is a good safety habit to disconnect the magnetors first and ground them. Most firewall disconnections are made easy by the use of specialized connectors that consist of a plug assembly and receptacle assembly. Sometimes there will also be various safety devices installed to prevent accidental disconnection due to vibration mid-flight. These mechanisms must be removed or broken in some cases to begin disconnecting the various electrical connections.

Disconnection of Engine Controls and Lines

The engine controls must also be disconnected from the engine before removal, and they typically include engine control rods and cables. The controls are sometimes disconnected by removing the turnbuckle that joins the cable ends, but this is not always the case. Additionally, there are several different lines between the units within the aircraft, including flexible hose or aluminum-alloy tubes joined by lengths of additional hose clamped to them. Most lines leading from a basic engine are secured to a threaded fitting at the firewall by a sleeve nut around the tubing. Hoses may also be secured in this manner, but can also be secured by a threaded fitting on the unit to which they are connected to, or by hose clamp. Depending on the type, these connections may be quickly disconnected by loosening the hose clamps, or by way of another method.

Conclusion

Often during engine maintenance and repair, new parts are needed to replace worn out components. Here on Stacked Hardware, we offer an array of engine parts, alongside other quality aircraft parts. We are proudly an AS9120B, ISO 9001:2015, and FAA AC 00-56B accredited enterprise, meaning that we go to great lengths to uphold a high standard of service and quality for our customers. If you are currently on the search for reliable aircraft parts, we invite you to browse our online catalog of available products and make use of our Instant RFQ service to receive competitive quotes for your comparisons. Our team of experts are available 24/7x365 to answer customer inquiries and will reply to RFQ forms in just 15 minutes or less!