COVART is capable of modeling several penetrators: a single missile fragment, a set of missile fragments, a single Man Portable Air Defense (MANPAD) missile, a single Armor Piercing Incendiary (API) projectile, and a single High Explosive Incendiary (HEI) projectile. The penetrator data used within COVART for vulnerability analyses is documented within the Gun Pedigree report and the Missile Pedigree report.

COVART is capable of modeling the damage mechanisms induced by threat penetrators. Damage is modeled using several methods. Analysts’ selection of the damage mechanism modeling method is dependent upon the penetrator type and failure modes of the equipment being modeled. Physical damage criteria, such as hole size or damage distance, are preferred because they can be directly related to tests. Distance criteria are used to model blast and hydrodynamic ram induced damage. Hole size criteria is used to model functional failures due to liquid leaking from a container. Air-gap distance criteria are used to model sustained fires from threat induced leaks of flammable materials. Other equipment damage is modeled using penetrator impact mass and velocity relationships. A given component may be vulnerable to several damage effects. The COVART model uses failure analysis trees (fault trees) to assess the cascading effects of damage. The fault trees use data obtained from ground simulators (flight controls simulators, hydraulic system simulators, avionics coolant simulators, fuel system simulators, electrical power simulators) to enhance the robustness and quality of failure predictions.

The COVART configuration control is defined in the configuration control plan. Modifications / improvements to the COVART code are made through the model manager. Configuration control is obtained by periodic releases on CD-ROM. The model manager has authority to implement three-digit version control numbers. While two-digit version control numbers require configuration control board approval. Users are encouraged to inform SURVIAC or the model manager when they find code errors. Users need to document errors using the Software Change Request (SCR) form. Additionally, users are requested to document projects usage. This documentation provides the model manager with data to justify requests for headquarters funding.

The COVART User’s Manual, Analyst’s Manual, Programmer’s Manual are comprehensive documents that outlines model usage. The COVART documentation is available with the model.

Detail and robust verification and validation (V&V) is difficult to complete. COVART routines are based upon a combination of empirical equations, test data, and expert rules. COVART has been spot-checked over many years and many different applications. Therefore, the Model Manager has a reasonable confidence in the code. Currently the documentation of these V&V activities is incomplete. The COVART report contains a small set of test cases. These test cases were designed to highlight specific COVART features. These test cases were small in size to simplify testing. Therefore, test cases did not demonstrate code functions using a full-up target description database. This type of verification is very difficult and time consuming.

The Joint Aircraft Survivability Program Office is funding the development of selected test cases. These test cases will be compared against COVART and Advanced Joint Effectiveness Model (AJEM).

Input
COVART requires data characterizing the threat; velocity, material etc. The model also needs specific data on the materials and thicknesses of aircraft components. Required inputs for the critical components, for the kill level being analyzed, include Pcd/h data and fault tree data for redundant components. COVART accepts line-of-sight data from FASTGEN and BRL-CAD computer programs. See the FASTGEN section for further information on the relationship between the FASTGEN and COVART Models.

Output
The COVART model determines the vehicle vulnerable area as a function of the kill level. Numerous kill levels could be modeled. The following sets of kill levels are related to operational capabilities: KK kill level (immediate), K kill (less than 30 seconds), pilot has time to eject, A kill (less than 5 minutes), B kill (less than 30 minutes) and mission kill. A listing and the location of vulnerable components can be displayed.