Flight testing of an automatic ground collision avoidance system (AGCAS) is under way using a Lockheed Martin Block 50 F-16D fighter assigned to the US Air Force Flight Test Center at Edwards AFB, California.

The AGCAS involves three main components. The first is an updated data transfer unit that hosts the terrain management and scanning software logic and receives terrain data from the mega data transfer cartridge.

The cartridge carries preplanned mission data and detailed terrain data, the aircraft response model and terrain reference navigation software developed by British Aerospace.

The final component is the fly-up coupler software, which resides in the digital flight control computer. Other avionics, including an inertial navigation system, global positioning system and radar altimeter, help pinpoint the aircraft's position in reference to the stored digital terrain map.

With AGCAS, the pilot selects a minimum height above terrain for a mission. The safety device computes the aircraft's position while predicting its trajectory. If the trajectory goes below the preset minimum clearance, a warning is issued and the flight control system automatically levels the aircraft and executes a 5g pull up until the aircraft is clear of terrain.

Lockheed Martin is handling system integration with support from Swedish engineers. The project is managed by the USAF Research Laboratory with assistance from Sweden's defence procurement executive. The AGCAS evaluation is sponsored by the USAF and Swedish air force.

Meanwhile, over 400 USAF Block 40/42 F-16C/Ds are receiving the 40T5 software upgrade designed to make the aircraft more capable in the close air support role. The next software change for the Block 40 F-16 is the 40T6, which will be fielded in 2001.

Source: Flight International