Active Parallel Actuation Subsystem, An Alternative Approach to Tactile Cueing Without Fly By Wire

After supplying a first-generation Active Inceptor System (AIS) for the Boeing Vehicle Management Systems Integration Technology for Affordable Lifecycle cost (VITAL) AH-64 Apache helicopter, BAE Systems has produced a range of flightworthy AIS products for several military and commercial aircraft. The latest fifth-generation AIS is in development for the civil marketplace. Most recently, BAE Systems worked collaboratively with Boeing Helicopters to define a new type of tactile cueing solution, the Active Parallel Actuation Subsystem (APAS) that provides the benefits of tactile cueing to vehicles that are not Fly-By-Wire (FBW). Initially aimed at the H-47 Chinook platforms, the APAS equipment provides synthetic force feedback and tactile cues to pilots of any aircraft having mechanically interconnected pilot stations and displacement-trim flight controls. The solution leverages Commercial-Off-The-Shelf (COTS) components, software, and civil certification artifacts from the fifth-generation AIS. Already proven in ground-based evaluations, flight demonstrations of APAS using a MH-47G Chinook are planned in 2015 with the intent of bringing APAS into production as a retrofit kit for the Chinook towards the end of this decade. The APAS implementation presented some specific challenges to ensure that the cues, feel, safety and performance were all acceptable while minimizing the impacts to the legacy mechanical controls installations and existing electrical interfaces. This paper presents a summary of the APAS approach, potential benefits to the Chinook helicopter, and compares some of the pros and cons to that of a full FBW AIS implementation.