Aircraft engines wear out due to high temperatures, vibration, friction, corrosion, and damage from the ingestion of foreign objects. All of this combined with the stress of high-speed rotating engine parts can cause mental fatigue over time. To extend the life of the engine and ensure its reliability and durability, you need to routinely perform engine maintenance. Maintenance, repair, and overhaul operations can increase the life of the engine limiting the need for more extensive and expensive repairs.
Modern commercial jet engines are big and heavy. A Boeing 777 jet engine will weigh around 18,000 pounds. These engines are attached to the aircraft wing with pylons. To remove them for maintenance they have to have to lifted and placed on an engine dolly. These engines are lifted by engine hoists or cranes with slings. This job requires careful handling and expertise.
Before attaching the sling to the hoist, one must be confident that the hoist is capable to lift the engine safely. The lifting should be balanced and the engine’s center of gravity should also be taken into account as the engine is hoisted. Often a manually operated hoist is used which is mounted on a portable frame. These hoists are specifically made to remove engines and other large assemblies from aircraft. Some of these hoists are electrically powered. These hoists should be used with care since considerable damage can be done to the engine and the aircraft if the operator is not experienced enough and mishandles the operation.
The hoist and the frame should also be checked for their condition for any previous damage before it is used to lift the engine.
Before the hoist is hooked onto the engine sling, check that the aircraft wheels are secured in place and there is tail support for the aircraft. Fix safety lines to the engine, at points on the sides or rear, so that the engine movement can be controlled as it is being hoisted. Hook the hoist onto the sling and hoist the engine just enough to release the engine weight from its mounting pylons. Remove the nuts from the pylon mount attachments as per the procedure for that aircraft.
Once the engine is free from the aircraft structure, the engine should be eased gently forward, away from the aircraft, and placed on the engine dolly. The engine should be fastened to the dolly stand and prepared for the removal of other parts.
This procedure applies to the removal of most common aircraft engines. Any variation in details is outlined in the manufacturer’s instructions. Before attempting any engine removal, always consult these instructions for the aircraft concerned.
All slings and hoists should meet the general design and installation requirements specified by ASME B30.2-1. All slings and hoists should be installed according to the manufacturer’s specifications and inspected by a qualified technician before initial use. An inspection shall be conducted before the sling or hoist is put into service each day. The frequent inspection also includes observations made during daily sling and hoist operations. Visually inspect wire ropes, slings, chains, and all components of the hoist.
Follow the manufacturer’s recommendations for preventative maintenance and lubrication. All replacement parts shall be equivalent to the original manufacturer’s specifications. All maintenance work should be meticulously recorded and placed in the relevant record-keeping files.
The following precautions, if applicable, shall be taken before performing maintenance on a crane or hoist:
Any condition identified as hazardous for operation shall be corrected by repair or replacement before using the sling or hoist. Replacement of wire ropes and alloy chains, as components of a hoist, shall be done as per the specified procedure.
The maintenance manager is responsible for ensuring the elimination of these identified hazards by repair or replacement before the sling or hoist is placed back into service. All repairs shall be performed by technically qualified persons.
e2b calibration is an ISO/IEC 17025:2017 accredited laboratory. We specialize in cost-effective repair and maintenance services of all types of slings and hoists. We are registered with ANAB. We are also ANSI/NCSL Z540-1-1994 certified. Please contact e2b calibration for repair and maintenance of all of your slings and hoists.