Technology Focus Area: Explosive Effects and Survivability

The research conducted in this technology area is focused on the protection of commercial aircraft from catastrophic structural or critical system failure due to an in flight explosion or other terrorist initiated event. The efforts of the Explosive Effects & Survivability group (EESG) are focused on determining and identifying the minimum size explosive that would result in immediate catastrophic aircraft loss. The data collected in this research has been used to validate and refine explosives detection standards for checkpoints, checked luggage and air cargo. In addition, methods and technologies that can be applied to the current and future fleet of commercial aircraft to decrease the level of vulnerability to internal explosive effects have also been a topic of study. Finally, in addition to internal explosive threats, the EESG is tasked with the assessment of other intentional threats to the aircraft including Man Portable Air Defense Systems (MANPADS), and small arms fire. The EESG is currently organized into three distinct technical areas which include vulnerability assessment, explosive mitigation, and advanced threats.

Working with aircraft manufacturers and the Department of Defense (DOD), the EESG has researched the effects of internal blast on the current fleet of commercial aircraft. Since 1992, the program has conducted over 200 explosive tests on commercial aircraft. Explosive testing on the subject airframes has been conducted within both passenger cabin and cargo hold areas under pressurized conditions to simulate aircraft cruise altitude conditions, as well as testing under unpressurized conditions in order to determine equivalent damage. The data and assessments generated as a result of the commercial aircraft explosive vulnerability assessment program have allowed the EESG to develop a family of aircraft survivability curves, each dependent upon aircraft class and explosive threat mass. These curves are used to determine if explosives detection standards are appropriate and, if not, to what extent they may need revision. Aircraft vulnerability testing has also allowed the EESP to conduct full-scale testing of potential explosive mitigation technologies, thus providing a uniform method of validating the effectiveness of aircraft based explosive mitigation concepts and designs.

The aircraft vulnerability assessments and associated testing conducted to date by the EESP have provided sufficient data to identify, investigate, and develop measures and associated technologies that increase the survivability of commercial aircraft to internal explosive detonations. Blast mitigation concepts investigated by EESP include hardened containers, commonly known as Hardened Unit Load Devices (HULD’s), explosive resistant aircraft passenger cabin and cargo hold liners and hardened overhead stowage bins.

In order to facilitate the conduct of full-scale aircraft vulnerability and explosive mitigation research, EESP maintains explosive test range facilities at the U.S. Army Aberdeen Proving Ground (APG) in Maryland. Through an interagency agreement, APG provides support in conducting explosives tests to determine system vulnerabilities and demonstrate the feasibility of protection concepts. Basic explosives research is also conducted to establish measures for damage equivalency between various types of explosives.

TSL also maintains the on-site Explosive Effects Laboratory where fundamental and applied research to characterize improvised explosives and explosive devices and their effects on personnel and structures takes place. The research areas of this laboratory include (1) gaining a comprehensive understanding of the sensitivity, stability, elemental composition, explosive potential, and/or detection probability of liquid and solid energetic materials of interest, (2) conducting tests and executing computer simulations to qualify and quantify characteristics of explosives of interest and performing analyses of resultant test/simulation data, (3) modeling and simulation of explosive events using available commercial and noncommercial finite element software to determine material and structural response due to explosion, and (4) development of new instrumentation and data acquisition techniques for explosive events.