SWISS airline demonstrates the role of Dillon Dynamometers in aircraft maintenance

A video produced by Swiss International Airline’s (SWISS) Technical Division shows how the Dillon AP Dynamometer and bootstrap kit is used to lift the company’s 2.5 tonne engines and measure stress on the hoists and mounts.

SWISS serves over 100 destinations in 43 countries, carrying more than 16.5 million passengers a year.  In addition to their fleet of 91 aircraft, the SWISS Technical Services division is one of the leading maintenance, repair and overhaul providers in the regional aircraft sector. Qualified specialists service all of the aircraft in the SWISS fleet at regular intervals, all of which involves the use specialist equipment such as the dynamometer featured in the video.  

The video, which shows an engine being completely overhauled, shows how the engine is removed using bootstrap equipment. The engine cradle is positioned under the engine then lifted until the mount point can be attached to the engine. Once the fuel and electrics etc have been disconnected, the engine mount bolts are loosened and the engine is removed ready for maintenance. The process is reversed when hoists these huge engines back into position.   

The critical factor when removing and replacing engines, whether for maintenance or replacement, is pre-tensioning the hoists used to lift the engine. Too little tension can mean that the weight of the engine causes it to drop at the point when it is disconnected, while too much can damage the pylon and mounts. With engine mounts alone supporting the entire 2.5 tonne weight of the engine, plus in-flight forces adding further stress, ensuring that they are not subject to undue stress is a critical safety measure.

Originally designed to measure the tension on telephone wires, the Dynamometer has proven to have limitless versatility as a tension and weight measuring instrument. It is used for such diverse jobs as suspended weighing; mounting cables for bridges; adjusting tension on guy wires; field testing chain, rope, wire—anything requiring precision force or tension measurement.

Watch the video to see how the AP Dynamometer is used by SWISS to pre-tension the hoists for aircraft maintenance.