The Rescue Winch

(Airwaves Issue 6 Spring / Summer 2008)

An in-depth look at some of the specialist equipment, vital to the operation of our rescue helicopter services.

The physical capabilities of a rescue helicopter to access difficult terrain are well documented. Speed and manoeuvrability allow a helicopter to reach areas that land-based ambulances and rescue teams cannot.

But it is in the use of an electric cable winch to deliver and extract people and equipment to and from terrain where the aircraft cannot land, that the rescue helicopter really comes into its own.

The Christchurch Westpac Rescue Helicopter BK117 carries a fixed electric Breeze winch on its port side which is manually operated from a hand held control by the winch operator, inside the helicopter.

After the winch is swung from its fixed flight position close to the fuselage out on a boom clear from the aircraft, it can deliver or retrieve loads of up to 250 lbs on its steel cable operationally up to 240 feet.

The variable speed winch can deliver a single person at a speed of up to 200ft per minute or perform a two-person lift at the rate of 100ft per minute.

The winch itself has a breaking strain of 600 lb (although this has thankfully never been tested on the Christchurch Westpac Rescue Helicopter).

As with all equipment on the rescue helicopter, the winch is meticulously cleaned and maintained to ensure its operational performance. This becomes doubly important after maritime rescues where the steel cable is exposed to salt water and becomes susceptible to corrosion.

An extended winch cable adds another dimension to an operational helicopter, especially one which may already be working in a precarious position, and overall safety and control is paramount. For that reason, the handheld controls which operate the winch are duplicated in the cockpit and, if necessary, can be overridden by the pilot who has ultimate control of the aircraft.