Seeking Technology Available Soon To Harden Scout And Utility Birds

The US Army has identified three survivability technologies that it would like to incorporate in its helicopters. Survivability, in military-aircraft terms, is the ability of the aircraft to take hits from enemy weapons systems without any vital damage to the aircraft and its crew. For most military technologies, like vehicles, survivability means hardening the item with armor. But aircraft can only carry so much armor -- which makes this field ripe, the Pentagon thinks, for technological improvement.

Certainly current helicopters are more vulnerable than the Army would like. The illustrated OH-58D Kiowa Warrior made it back to its base at Baghdad, miraculously, but even the Army's best-armored helicopter, the AH-64 Apache, has proven vulnerable to small arms and light fragmentation weapons. Once in Afghanistan and once in Iraq, the Army had Apache squadrons rendered non-mission-capable by enemy fire (although the Apache's cockpit did keep the crews alive). And cargo, scout and utility helicopters are flimsy, compared to the Apache.

Army experts at the Aviation Applied Technology Directorate (AATD) have identified three technologies which might help current and future Army helicopters go to Downtown Bulletsville and get home safely. Those technologies, all targeted against rifle-caliber machine-guns, are SIMS, MFS and SPS.

The directorate is offering development contracts for each of these technologies, with varying amounts of dough available for the contracts, which are expected to run about two years long, give or take a few months.

Responses to the solicitation are due in to AATD by October 31, 2005, which is already a month into the first available contract month (FY2006 begins October 1).

SIMS is Structural Integrity Monitoring System. "Having a clear understanding of an aircraft’s structural integrity will enable the pilot to safely fly within the aircraft’s limits as well as notify the crew when maintenance actions are required," AATD suggests. It wants to see a system for tracking the structural stresses on aircraft and reporting failures before they happen. Think of this as the pressurized fault-detection system in rotorblades, writ large.

The Army wants to see contractors using off-the-shelf sensors for SIMS and it expects that multiple organizations will share early development money.

BPS is Ballistic Protection System. Now, cargo and utility helicopters have a structural floor, which is protected by non-structural armor.

The solicitation lays out the problem: "Current parasitic armor has a significant weight penalty that limits range and payload of the aircraft. This weight penalty arises from the use of separate components for the functions of carrying loads (structure) and providing ballistic protection." The AATD thinks that with proper design, one part can do double duty as structural floor and armor protection, suitable for defeating the 7.62mm rounds fired by the world's light and general purpose machine guns -- which protection would also stop rifle bullets.

SPS is Spaced-Armor Protection System. This is designed to take advantage of the physics of rifled-gun projectiles, which are moving forward at supersonic speed while spinning at very high RPM. The spin, imparted by the rifling in the weapon's bore, makes the projectile stable in the air.

SPS would use a stand-off plate to destabilize and tumble the projectile, turning its armor-piercing tip away from the internal armor which is designed to trap the projectile and absorb its energy without allowing it to penetrate. (The projectile tumbles because rifling only imparts enough spin to keep it stable in materials of low density such as air. Passing through a higher density material upsets the bullet).

The stand-off plate may serve not only to tumble the projectile but to fragment it. Multiple lighter projectiles lose velocity (and therefore energy) much faster than single, heavier projectiles.

Overall, the AATD has about $1.3 million to allocate to developers that respond to its solicitation for protective technologies.

FMI: www.aatd.eustis.army.mil