The Air Force Participating Test Unit: Keeping the Battlefield Secure Published Sept. 23, 2021 By Don Sturges, Dexter Baird, Les Lee & Anna Schriebl AF Participating Test Unit JOINT BASE LANGLEY-EUSTIS, Va. -- It’s a battlefield scenario: two Air Force pilots have intercepted an enemy aircraft. One pilot transmits a command to engage the hostile aircraft through encrypted data link communication with minimal voice communication. The second pilot responds through the same data link, complying with the order, and begins to engage the aircraft. Meanwhile, other ground, air, and ocean platforms receive these messages and follow the action as it unfolds on their display. The Tactical Data Link network is now alive with activity. You’re not eavesdropping on a conversation between two pilots – what you are witnessing is the AF Participating Test Unit doing what it does best: Tactical Data Link Certification Testing. Located at Langley Air Force Base, and established in the late 1970s, the AFPTU is the Air Force’s only facility of its kind. Its mission is to test for certification of the Air Force’s Command, Control, Communications, Computers and Intelligence aircraft and weapons systems via the Air Force System Interoperability Test process to ensure timely distribution of battlespace information to the Warfighter. “When the speed and accuracy of information makes the difference between mission success and failure, you need systems to perform as they should,” said Lt. Col. Jeremy Coffman, Air Combat Command Communications Support Squadron commander. Testing is based on the tactical data link mission capabilities of a System Under Test. For example, a system such as the Airborne Warning and Control Systems may perform a command, control and communications mission capability. A B-52 Combat Network Communications Technology bomber, may perform interceptor, strike and bombing mission capability. The process typically runs between two to five weeks. SUTs can connect remotely or bring a system with a small tactical data link footprint to the AFPTU’s state of the art Data Link Interoperability Test Center here. The center provides simulation and support equipment, radios, terminals, digital switching systems, display technology, and voice conferencing equipment. “Using real-world communications in attenuated radio frequency networks, virtual internet protocol networks, simulated sensors and direct communications, the Tactical Data Link Interoperability Test Center provides the environment necessary to test even the most complicated Air Force platform,” said Terry Elhajj, chief engineer, TDLITC. Once test participants are confirmed, connected and ready to test, the test lead will direct operators to execute scenarios that exchange system and theater-specific TDL messages with the system(s) being tested. “These messages create an area of responsibility operational picture that can include the kind of armaments currently in range, weather conditions, and the complicated structures of coordinating weapon attacks,” said Lester Lee, AFSIT test manager. While the operators are busy employing scenarios, they watch the raw data being transmitted and received and monitor the displays that translate these messages into a man-readable picture. “The whole process requires intense concentration and years of training,” said Coffman. “The work being done by our dedicated team of professionals cannot be overstated.” Once the AFSIT is completed, post-test data analysis begins, and Trouble Reports are consolidated and presented to each system’s fielding authority for review. Finalized reports are discussed during an online meeting with the Test Analysis Group. The final product of the TAG’s discussion becomes the test report and recommended certification decision. “As one system exits the AFSIT process, others are on the schedule to take its place,” said Don Sturges, AFSIT test manager. The AFPTU tests a total of 59 Air Force TDL systems with 20-24 systems tested per year. The team is already forecasting test scheduling for 2023. “It’s a busy and fulfilling mission -- knowing lives are saved by rigorously testing the tactical data link systems used by the warfighter,” said Dexter Baird, AFSIT test manager.