SOUTHLAKE, Texas, 22 Oct. 2007. Deployment of the IEEE 1394 FireWire databus in the future Lockheed Martin F-35 Lightning II joint strike fighter is providing guaranteed quality of service with predictable latencies in real-time control applications on the aircraft, say officials of the 1394 Trade Association in Southlake, Texas.
More than 70 1394 devices are delivering information about mission details, communication systems, weapon systems, engine controls, and flight controls on the F-35 fighter. Prime contractor Lockheed Martin Corp. chose 1394b after a trade study of other networking options including USB, Fibre Channel, and MIL-STD-1553, association officials say.
The 1394 Trade Association's announcement on F-35 use of the databus comes shortly after market researcher In-Stat in Scottsdale, Ariz., predicted last summer that IEEE 1394 faces major challenges and a stagnating market share. The peak year for 1394 devices will be 2008, In-Stat reports, and a slow decline will set in beginning in 2009, In-Stat analysts predict.
The F-35 program
evolved in response to the need to deploy fewer types of more cost-efficient tactical aircraft. Current plans call for production of 2,458 F-35 aircraft in three versions: conventional (CTOL), short take-off/vertical landing (STOVL), and carrier (CV). A total of 14 Lightning IIs are now in various stages of assembly.
The AA-1's (CTOL) first flight was last December, and the first three STOVLs are scheduled to fly in 2008. According to Lockheed Martin, the 1394b-equipped AA-1 has completed 19 successful flight tests to date.
The IEEE 1394b databus is installed in the F-35's vehicle systems network based on its speed, bandwidth and long distance capabilities, and also because 1394b enables operational software downloads to network components without the need to remove any component after installation, association officials say.
Main F-35 flight control and subsystem processing are completed in a trio of the vehicle management computers (VMCs), which act as the master for each bus. There are triplex VMCs that are cross-channeled and data-linked together. Most of the 1394b buses are looped to provide additional redundancy, so if one cable fails, there is an alternate path for communication.
1394b helps the VMC to house all flight control algorithms and all utilities in a centralized structure. While there are still some distributed processing functions handled by legacy buses such as 1553, it is 1394b that's carrying the bulk of the processing load, association officials say.
The VMC incorporates flight-control systems, utilities, and subsystems processing that has been done separately on legacy aircraft. Components on the F-35's 1394b network serve the VMC; remote input/output units); flight-control systems with all flight control surfaces; utilities and subsystems such as weapons bay door drives, power system controllers, brake controllers, power thermal management system controllers; propulsion systems such as main digital engine controller; mission systems such as standby flight display, display management computer, helmet display management computer, integrated core processor, lighting controller, communications/navigation/identification, and GPS; and flight test Instruments like the high-speed data acquisition unit on each bus for capturing flight test data.
The F-35 design team lengthened the distances between 1394b units on the F-25 with physical enhancements like active transformers, quad cabling, connectors, and termination method. The enhancements also enhance operation in harsh-temperature and -vibration environments.
For more information contact the 1394 Trade Association online at www.1394ta.org.