HUMS for Light Helicopters in Rescue and EMS Operations

The Swiss Air Ambulance - Rega - operates a 24 hour a day, 7 days a week helicopter rescue and air ambulance service, using 15 Agusta 109k2 helicopters. The operation covers all of Switzerland and some areas in neighboring countries. Rega’s primary goals are 100% accident free mission completion, a high state of readiness, mission availability, and minimum consumption of aircraft life limited parts. In accomplishing this goal, Rega is equipping the fleet with HUMS, which is expected to streamline the maintenance process and lead to achieving these goals. The HUMS is composed of two parts, an On Board System which records data from each flight, and a Ground Based System which stores the recorded data in a relational database. The data can then be used for reports, tracking of life limited parts, determination of the condition of a particular component or aircraft, and communications with the manufacturer on courses of action when the airworthiness of a part is questionable. This paper will also discuss some aspects of flight testing of a new HUMS. A HUMS needs to be utterly reliable and at the same time unobtrusive. It must warn the pilot or maintenance when something is wrong, but not give false indications which would reduce its creditability. Rega hopes to gain immediate benefit from the HUMS in the area of operations improvements, pilot awareness, better maintenance, and a reduction in insurance premiums. Long term goals will be a reduction in maintenance costs, and more serviceable aircraft.