ALTAIR, a Massachusetts-based avionics company, has introduced the first health and usage monitoring system for light turbine and piston helicopters.

The Altair HUMS, weighing less than 1kg, has already been fitted to Enstrom 480 and Bell 206 helicopters and is scheduled for the Robinson R22 and the McDonnell Douglas Helicopter Systems MD520N by mid-1995 as production increases.

Company president Peter Bransfield says: "This is the first in a line of avionics we're developing for enhanced flight safety in general aviation. We believe HUMS is the right place to start because, although there are lots of products for the higher end of the market, the numbers are astronomical at the lower end."

The HUMS is a passive system made up of a microprocessor connected to a variety of sensors, which monitor and report on critical engine speed, engine temperature and main-rotor speed excursions above known safe limits. The system gives an alert of any exceedances, with a light in the cockpit, and downloads data to a ground-based system for inspection by maintenance staff.

The "tamper-proof" system records any attempts to disconnect the power supply or sensors and will indicate to ground staff if anything out of the ordinary happened during the previous flight. Altair developed the HUMS after surveying light-helicopter users. "Some 90% of them came back and said 'give me TOT [turbine operating temperature], torque and cycles. Just keep it simple."

The turbine HUMS, is being sold for "under $5,000", while the piston system, measuring manifold pressure, engine temperature, Rpm and cycles, sells for between $2,000 and $3,000, depending on application. Further enhancements being developed, include gearbox and engine vibration, low and high g events, crash worthiness and fuel flow monitoring.

Source: Flight International