The Test & Evaluation community has used Distributed Live Virtual Constructive (LVC) based environments for many years.  Using LVC environments provides a cost-effective way to conduct repeatable testing, spans different environments and conditions, and allows tests to be performed that can not be safely conducted live.  When possible, the system under test is wrapped in an operationally realistic environment using modeling and simulation.  When the live system is not available or practical for a given test, a digital twin may be a suitable solution.  For aircraft, a digital twin may be selected if the test could impact the aircraft's flight worthiness.

Redstone Test Center (RTC) is the US Army's organization tasked with testing aviation systems.  Much of this testing is conducted by flying the aircraft.  However, in some tests, it is advantageous to use LVC environments.  One type of testing that requires LVC environments is Aircraft Survivability Equipment (ASE) testing.  ASE is the set of sensors and countermeasures used to protect the aircraft from threat systems.  RTC can not conduct this testing using a full aircraft because of limited availability and the potential to affect the aircraft's airworthiness certification.  RTC created a hybrid digital twin using a flight simulator, selected sensors, and aircraft processors to address this limitation.  This hybrid digital twin includes two of the aircraft MIL-STD-1553B buses, sensors, and other hardware components.  The hybrid digital twin allows the evaluation of human-in-the-loop and hardware-in-the-loop issues in the testing.  This paper reviews the steps involved in creating this hybrid digital twin and the lessons learned from this process.  The paper describes the distributed LVC environment developed to support this test.