Rolls-Royce has achieved FAA certification of an enhanced full-authority digital engine control (FADEC) system for the Model 250-C47B turboshaft. This enhanced FADEC will benefit operators of the Bell 407 helicopter.

The new EMC-35R FADEC system is identical to the original EMC-35A with the exception of the Electronic Control Unit (ECU). The major difference between the two units is that, while the original EMC-35A ECU utilizes a single electronic channel unit, the new EMC-35R ECU features a dual electronic channel unit. The EMC-35R’s Primary Governor (PG) channel is functionally similar to the EMC-35A’s single channel, while the use of a Reversionary Governor (RG) channel introduces a back-up electronic control.

When fitted with the new EMC-35R ECU, the Model 250 FADEC system still retains its manual hydraulic back-up control system. The effort to certify this new Model 250-C47B FADEC results from an extensive and detailed engineering test program, during which Rolls-Royce was able to demonstrate that the probability of a ‘reversion to manual’ scenario is reduced by 60 percent. This improvement will provide an increased operational benefit to the pilot, allowing continued flight in an automatic governed mode.

To assist with the introduction of the new FADEC system, Rolls-Royce has issued two Customer Support Letters (CSL's 6113 and 6117) which provide further details, and which request that affected operators register in order to allow all affected operators to be identified. The new EMC-35R ECU will be provided to operators at no cost, provided that they have registered in accordance with these CSLs and that the existing core ECU is returned. The new ECUs will be supplied with a new 24-month/1,000-hour (whichever comes first) warranty.

This new FADEC system will also be certified on the Model 250-C47M turboshaft later in 2006, extending the same benefits to operators of the MD Helicopter Inc. MD 600N.

FMI: www.rollsroyce.com