ASTi was selected to design the audio systems for a number of F-16 manned flight simulators as part of the F-16 Mid-Life Update (MLU) program.

This F-16 simulator is, essentially, a productized flight simulation system complete with motion platform, full visual system, and ASTi's environmental aural cue and communications systems. Many of these simulators are installed for training in Norway, Belgium and The Netherlands.

Each F-16 simulator features an embedded Digital Audio & Communications System (DACS) that handles both the environmental aural cues and radio/intercom traffic for that simulator. Since all of the F-16 simulators are identical, there is no need to reconfigure the individual custom sound models within the DACS. Changes made to sound models at the manufacturer (via ASTi's development platform) are forwarded to each location, and the resident DACS is updated. By opting to install embedded platforms, ASTi simplified configuration management and delivered the systems at a considerably reduced price.

Up to four F-16 simulators can be networked together via local or wide area network, as shown above. Each DACS processing node contains two high-performance Waveform Synthesizer DSP cards. One is used to deliver environmental aural cues via a set of five speakers positioned around and above the pilot. The other is used to transfer audio to and from the pilot(s), instructor(s) and observer(s). Each DACS system also provides network interfaces to the DIS and Host control networks.

Radio Communications
The simulated radio environment for the F-16 simulator is processed by the DACS & ASTi's Model Builder software. When multiple simulators are networked together, each pilot can communicate with other pilots over a DIS-compatible voice network. In addition to the standard radio propagation effects (like background noise, signal strength, AM/FM band interference, etc.), the F-16 simulated radio environment features a unique method of determining radio signal degradation due to terrain occlusion. The ASTi DACS processing nodes interface directly with the Thomson visual system on the host computers to account for line-of-sight and terrain interference.

The ASTi DACS processing node also provides NavAids, Aircraft ICS and Threat Audio in addition to the simulated radio environment.

Intercom Systems
Each trainer includes instructor and observer stations. When networked, each instructor has access to various intercom buses that not only connect him to pilots-in-training, but to other instructors and observers.

Each F-16 simulator's environmental sound aural cues are generated by one of the two high-performance Waveform Synthesizer DSP cards in the DACS. These include:

• Engine/turbine noise
• Wind rush
• Gear up/gear down
• Runway rumble
• Flap & wing adjustments
• and more

The Waveform Synthesizer receives instructions from ASTi's Model Builder software toolkit, and generates the corresponding audio signals. Then, according to the instructions from Model Builder, the audio is routed to one or more of the five speakers surrounding the pilot, offering a truly realistic flight simulation environment.