Ever wonder why copper sleeves are used on aircraft cables? Cable-based control systems are common in the aviation industry. Many small and midsize airplanes use them to move flight control surfaces. When the pilot turns the yoke or presses a rudder pedal, a cable will move the respective control surface. These cables, however, are often equipped with copper sleeves.
What Are Copper Sleeves?
Copper sleeves are exactly what they sound like: hollow sleeve-like components made of copper. They are commonly used to terminate cable ends. Rather than wrapping the end of a cable around an anchor point, you can use a copper sleeve to create a loop. The newly looped end can then be securely attached to the anchor point.
Benefits of Copper Sleeves for Aircraft Cables
Aircraft cables are used to connect various parts, such as flight control surfaces like rudders and ailerons. These parts often have specialized anchor points designed for cables. Copper sleeves allow for the creation of looped ends that can easily and securely attach to these anchor points.
You can’t just tie a cable end around an anchor point. Control cables are typically too stiff. If you tie the end into a knot, the cable will likely deform or kink.
Furthermore, the knot will create sharp bends that can reduce the cable’s breaking strength by as much as 50%. This loss of strength can compromise the cable’s integrity, increasing the risk of failure. Copper sleeves offer a solution. You can run the end of a cable through a copper sleeve to create a loop that’s suitable for the anchor point.
How Copper Sleeves Are Installed on Aircraft Cables
Copper sleeves are relatively straightforward to install. The end of a cable or wire rope is inserted through the copper sleeve. A loop is then formed around a thimble, after which the cable or wire rope is returned through the sleeve.
Most copper sleeves require the use of a swaging tool to install. A pair of pliers typically won’t provide enough pressure, nor will they apply consistent pressure. A swaging tool, though, solves these problems. It will apply a series of controlled compressions so that the copper sleeve grips the enclosed cable.
In Conclusion
Copper sleeves play an important role in aircraft cable systems. They provide a practical way to form secure cable loops without relying on knots that can kink the cable or reduce its strength. When installed around a thimble and compressed with a swaging tool, copper sleeves create secure loops that can connect the cable to an anchor point.
