Ada Used for the Boeing 777 Brake Control System Boeing 777 Brake Control System

Form U150-0794 CRANEHY.TXT

Ada Information Clearinghouse, 1-800/AdaIC-11, 703/685-1477

Through the implementation of Ada, Hydro-Aire is able to assure maximum productivity for their programmers while supporting their requirements for code quality, complete configuration control, and extensive testing and documentation to mee FAA certification requirements.

Ada Used for the Boeing 777 Brake Control System


Founded in 1943, Hydro-Aire is a recognized supplier of skid control systems and hydraulic controls for the aerospace industry. As a division of Crane Co., its capabilities are backed by the substantial resources of the parent company. Hydro-Aire's products can be found operating effectively on most all commercial aircrafts. Hydro-Aire's skid control units installed on today's jets are the most technically advanced systems obtainable. By using integrated microcircuit, Hydro-Aire has developed a compact, reliable system which allows the pilot maximum possible braking capability under all landing conditions.

The Ada System

In April 1993, Alsys' Ada software development tools were selected for the development of the brake control system of the Boeing 777 aircraft. Hydro-Air chose AdaWorld cross compilers with the Smart Executive and Certification package to ensure meeting real-time and FAA requirements. Hydro-Aire uses the AdaWorld compilers on Hewlet-Packard HP 9000/300 platforms, targeting the new Motorolla 58333 microcontroller, Hydro-Aire is one of the first companies to use the new chip.


Each 777 aircraft's brake control system includes two Motorolla 58333 microcontrollers programmed entirely in Ada. The processors control the built-in test (BIT) and auto-brake functions. The BIT includes both an on-line interface to the central maintenance computer and off-line maintenance capability. The auto-brake automatically applies the correct amount of brake pressure during landing. It also applies the maximum amount of braking during aborted takeoffs while assuring not too much brake which causes a tire blow-out. The brake system also includes additional hardware and software to prevent skids, sensors and transducers to various external systems and the hydraulic valves for the braking system. "We find Ada an excellent language for the development of real-time applications; Alsys demonstrated a superior understanding and ability to support the safety-critical market", said Harry Hansen, Hydro-Aire's Manager of Software Engineering.

Alsys' SMART Executive and FAA Certification package are designed to be used in real-time safety-critical applications. SMART is designed to be very small and extremely fast. Alsys tools, along with SMART, assure that only the portion of the executive that are used are linked to the application. Literally no dead code from the executive is linked to the application. The SMART specification package comprises the source code for SMART, an extensive documentation package and several test suites supporting FAA certification process. SMART and its certification package also provide benefits to developers of other safety-critical and high reliability software.

Hydro-Aire plans a sophisticated software development environment to assure maximum productivity for their programmers while supporting their requirements for code quality, complete configuration control, and extensive testing and documentation to meet FAA certification requirements.

For further information, please contact:

Sally Burke or 
Barbara Sherlock 
Alsys, Inc.  
57 South Bedford Street 
Burlington, MA 01803 
Tel: + 517 270 0030 
Fax: + 517 270 5882


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