Intelligent cargo hook lifts angel safely onto church spire

The church was built in the 1950s and the statue was added as part of a recent major refurbishment and extension project. The cargo hook was fitted with a HeliNav LoadMaster made by Sensor Technology Ltd. This presents the pilot with live information about the load hanging beneath the aircraft, making complex operations safer, easier and more efficient.

Additionally the system logs data on load, distance, location and flight path, giving the operating company a complete set of information for its client billing and aircraft maintenance scheduling.

Helicopters are now regularly used for lifting statues and large crosses so that they can be mounted atop church spires, or for removing them for maintenance and repair. Aerial lifting can prove the most efficient, safest and cost-effective way of lifting ecclesiastical statues. The first recorded use in the UK was at the then newly built Coventry Cathedral in the early 1960s and today heli-cranes are particularly popular in America where new churches are regularly built.

The primary reason for using aerial lifting is often a financial one - a helicopter can typically lift up to 1.9 tonnes and can work out at a fraction of the cost of hiring a crane.

A ground-based craning operation will require a team of people working closely together because the driver will not have line of sight, and road closures and traffic management may be required. There may also be costs associated with locating the crane in a suitable position, in a third-party's car park, for example. Typically the crane will be required for at least a day, whereas a helicopter often performs the lift in a matter of minutes.

Tony Ingham of Sensor Technology says: "The lift required a brief stoppage of the traffic on the nearby A-road, but nothing else. The whole operation was carried out quickly and efficiently and the few safety issues were addressed in the early planning stages.

"The pilot was highly experienced at lifting and flew the angel straight into position, ready to be secured with some suitably large bolts. The whole job was completed very quickly and the waiting traffic had quite a spectacle to watch during its short stop."

The load sensing and monitoring technology provided by Sensor Technology's HeliNav LoadMaster is simple yet accurate. Significantly it is a wireless system that means a hole does not have to be drilled in the aircraft's body to accommodate a cable from the hook to the cockpit.

HeliNav LoadMaster is based on Sensor Technology's wireless load sensor - a strain gauge-based stainless steel tension-type sensor. It has the capability of wirelessly transmitting its data to a readout where it both displays live readings and records them to build up an exact profile of each operation. Its inbuilt 32MBit memory can hold up to 280 hours of data, which can then be downloaded to a PC via a USB cable. The load sensor transmits using the worldwide licence-free frequency of 2.4GHz using two built in antennae.

The cockpit-mounted readouts provide the pilot with precise real-time information in an easy-to-understand graphical format. The hook can also send signals to other handheld readouts so assistants on the ground have the same information.

The HeliNav TrackMaster controller provides position information through an on-board GPS (global positioning system), inclinometer and accelerometer to help plot flight paths, flight times, fuel requirements, etc. It also logs the weight of the load and the distance travelled so the helicopter operating company can provide the client with accurate work reports and precise billing as well as schedule timely maintenance.

Tony Ingham concludes: "I can remember the national television coverage of the first job at Coventry Cathedral. It was fraught and tense because the lack of live information meant the whole operation relied on the fantastically skilled pilot. Little did I know then that more than 50 years later our HeliNav Systems would make similar operations so much more straightforward that they would become almost the de facto preferred method for precision heavy lifting."