Current Regulations Do Not Include Adequate Safety Standards For The Type, Agency Says

The FAA has posted a Notice of Proposed Special Conditions for the Bell 525 Relentless helicopter in the Federal Register. The agency says that the helicopter will have a novel or unusual design feature associated with fly-by-wire flight control system (FBW FCS) functions that affect the pilot awareness of the flight control modes while operating the helicopter. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These proposed special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

According to the notice, the Relentless will be equipped with a four-axis full authority digital FBW FCS that provides for aircraft control through pilot input and coupled flight director modes. Current regulations are inadequate in the area of pilot awareness of the flight control modes while operating the helicopter. The proposed special condition will require that suitable mode annunciation be provided to the flight crew for events that significantly change the operating mode of the system but do not merit the traditional warnings, cautions, and advisories.

The FAA says that a means must be provided to indicate to the crew any mode that significantly changes or degrades the handling or operational characteristics of the rotorcraft.

These special conditions are applicable to the BHTI Model 525 helicopter. Should BHTI apply at a later date for a change to the type certificate to include another model incorporating the same novel or unusual design feature, the special conditions would apply to that model as well.

Comments on the proposed special conditions must be received by the FAA by January 22, 2018.

(Image from file)

FMI: Federal Register Notice