An open-architecture real-time operating system developed by BAE Systems has been selected for use on the newest version of the U.S. Army’s CH-47 Chinook heavy-lift transport helicopter, the CH-47F. The CsLEOS operating system will underpin the helicopter’s digital flight control system.
The digital control will replace analog flight controls on CH-47D helicopters as Boeing upgrades 300 of the aircraft to the F-model standard under contract to the U.S. Army. Its digital design will provide significantly greater reliability, maintainability, and flexibility than the existing analog control. The system also will incorporate a built-in diagnostic system for detecting and analyzing system failures and faults.
“The operating system that runs an aircraft flight control computer must be exceptionally robust,” said Milan Dedek, CsLEOS product manager for BAE Systems Aerospace Controls. “Our operating system was developed specifically for use on flight control and other mission-critical aircraft systems and is ideally suited to this use. We are proud that CsLEOS has been chosen to demonstrate its capabilities on this important Army program.”
An ARINC-653-compliant, fault-tolerant, hard-real-time operating system, CsLEOS was designed from the ground up for safety- and mission-critical applications that place a premium on security, predictable real-time response, and safety. Utilizing hardware memory protection, CsLEOS provides “Brick-wall” time, space, and resource partitioning between the kernel and applications operating on the same hardware platform. It also assures resource availability in both the time and space domains.
This combination facilitates the robust partitioning defined in ARINC 653, enabling applications with different DO-178B safety levels to run concurrently on the same processor. CsLEOS also supports “on-the-fly” application rescheduling, giving it the flexibility needed to meet a broad range of today’s safety-critical applications.
To assure fast recovery for time-critical events without compromising system safety, CsLEOS synchronizes all redundant channels on a frame-by-frame, lock-step basis, ensuring that all channels process the same data concurrently. In the event of a fault on one of the channels, the RTOS restarts the channel within milliseconds. To further enhance fault tolerance, CsLEOS provides a built-in health monitor.
To streamline application development, upgrades, and D0-178B certification, CsLEOS supports independent loading of application modules. Unlike approaches in which a portion of the kernel must be linked to each application, CsLEOS interacts exclusively with applications through its applications programming interface. This enables existing applications to be modified and new applications to be built and installed without the entire system having to be recompiled and rebuilt.
Digital Flight Control System on U.S. Army CH-47Fs Helicopters to Use BAE Systems CsLEOS