Larry J. Yount

Sidestick controllers for advanced aircraft cockpits

Utilization of sidestick controllers for pitch and roll is examined for advanced cockpit configurations for commercial transport aircraft. Specifically, information on active sidesticks which are servo coupled for dual sidestick cockpit configurations is presented. Hardware development status is presented along with results of evaluations. The sticks are coupled such that when one of them is displaced the other one will track that displacement. Autopilot or flight control inputs will cause each stick to displace, thereby providing a visual cue on how much control authority is being implemented. The autopilot can be overridden by applying pressure to the stick or pressing a disengage button on the grip. The sidesticks incorporate the following feel features: break-out forces, linear force gradients, softstop steps, and hardstops. The softstop-to-hardstop region provides a tactile cue to tile pilot that stick displacement limits are being reached and provides the capability of modifying the control laws in this region of sidestick displacement when approaching the aircraft limitations.<<ETX>>

Digital flight control systems: some new commercial twists

The exponential increase in the number and complexity of aircraft digital electronic systems over the last decade has brought to light a number of fault and failure mechanisms not encountered with traditional mechanical and analog systems. One approach to handling these problems on future commercial aircraft is through the use of integrated modular avionics (IMAs). The issues and concepts associated with commercial IMAs are discussed. Some integration concepts for future fly-by-wire/fly-by-light commercial aircraft are considered. It is likely that highly integrated commercial modular avionics systems will be in service by the late 1990s or early twenty first century. It is expected that the extent and rapidity of modular avionics applications on commercial transport will depend largely on the flexibility and fault tolerance achievable at a reasonable cost as well as on the need for incorporation of new highly integrated systems.<<ETX>>

Development of fly-by-light systems for commercial aircraft

Fly-by-wire/Flybylight (FBW/FBL) controls are in the process of supplanting traditional mechanical control technology for commercial transport aircraft. Douglas Aircraft Company in cooperation with its suppliers is actively pursuing a comprehensive program to develop and validate advanced flight control concepts and technologies. This paper details the various perceived technical barriers associated with fly bylight as well as the work in progress to overcome them. The advantages of flybylight technology are discussed with particular attention to its potential to help prevent and/or tolerate electromagnetic effects.

Honeywell optical investigations on FLASH program

The increasing performance and reduction of life cycle cost requirements placed on commercial and military transport aircraft are resulting in more complex, highly integrated aircraft control and management systems. The use of fiber optic data transmission media can make significant contributions in achieving these performance and cost goals. The Honeywell portion of Task 2A on the Fly-by-Light Advanced System Hardware (FLASH) program is evaluating a Primary Flight Control System (PFCS) using pilot and copilot inputs from Active Hand Controllers (AHC) which are optically linked to the primary flight Control Computers (PFCC). Customer involvement is an important element of the Task 2A activity. Establishing customer requirements and perspectives on productization of systems developed under FLASH are key to future product success. The Honeywell elements of the PFCS demonstrator provide a command path that is optically interfaced from crew inputs to commands of distributed, smart actuation subsystems commands. Optical communication architectures are implemented using several protocols including the new AS-1773A 20 Mbps data bus standard. The interconnecting fiber optic cable plant is provided by our Task 1A teammate McDonnell Douglas Aerospace (West). Fiber optic cable plant fabrication uses processed, tools and materials reflecting necessary advances in manufacturing required to make fly-by-light avionics systems marketable.