Pinnacle Armor Milestones

USA Armoring, awarded sole source emergency status contract for:

APU Armor Assemblies applicable to the CH-47D aircraft system.

Commerce Busines Daily Issue of November 5, 1999 PSA#2470

U.S. Army Aviation and Missile Command, Acquisition Center, Bldg 4488, Redstone Arsenal, AL 35898-5280

28 -- APU ARMOR ASSEMBLIES APPLICABLE TO THE CH-47D AIRCRAFT SYSTEM -- QTY 340 SOL DAAH23-00R-0059 DUE 113099. POC Brenda Robinson, Contract Specialist, AMSAM-AC-SA-FC, (256) 313-3377. J.W. Sheats, Contracting Officer, AMSAM-AC-SA-FC, (256) 313-3225. Synopsis # 0020-99. -- Effort is sole source to USA Armoring, P. O. box 5839, Fresno, CA 93755-5839. -- Authority for other than full and open competition is 10 U. S. C. 2304(c)(2), Unusual and Compelling Urgency. Posted 11/03/99 (W-SN397655). (0307)

Background: The CH-47F ICH is a service life extension program for the aging CH-47D Chinook helicopter, which is being managed by the Product Manager, ICH (PM ICH).

Overview: The CH-47 T-62 APU has experienced a catastrophic failure of the centrifugal compressor resulting in large fragments being thrown as far as 900 feet. A ballistic containment and/or retention unit needs to be procured as a possible means to attenuate the fragment’s velocity and energy thereby precluding these fragments from exiting the aircraft and endangering ground or flight crew. The size of the fragment coupled with the speed with which the fragment travels, would cause irreparable damage to a rotor, the rotor assembly or other internal systems of the aircraft if struck.

Objective: To develop, test and manufacture under an emergency deployment necessary requirement timeline, an armored unit to surround the housing of the turbine compressor assembly of the auxiliary power unit, in the CH-47D helicopter. The system shall be able to withstand high continuous heat operating temperatures, have resistance to jet fuels and hydraulic fluids, and be non-hydroscopic. This unit shall be light in weight, easy in initial installation and removal for repairs or maintenance to the compressor section. The unit shall be non-flammable and designed to allow for visual inspection of the turbine compressor assembly. The critical resistance criteria is for the armor assembly unit to initially resist an unimpeded “Ballistic Threat” of a 1.1 pound tri-lobe compressor wheel fragment with a velocity of 600 miles per hour.

Description: The composite armor unit was initially tested utilizing a 76mm smooth bore cannon. The composite test sample dimensions were 18”x18”. This was used along with a fabricated sabot to house the tri-lobe compressor wheel fragment. The initial composite (shot # T62-12) stopped the 1.1 pound fragment at a velocity of 890 feet per second / 607 miles per hour. The velocity was measured through two (2) sets of screen/breaks. The kinetic energy developed was 13,639 FPE (foot pounds of energy). The following formula was used in the calculation: (KE) in ft-lbs: K. E. =1/2 mV2, where m=w/g; w=1.01lbs, g=32.174 ft/sec2. The impact of the fragment did not cause penetration further that approximately 28% into the composite. The fragment sprung back and fell to the ground. Minimal rearward velocity was attained.

The project coordinator then requested that the T-62 compressor housing be shot to determine the impeded velocity of the fragment. The striking velocity was 700ft./sec. With a residual velocity of 390 ft./sec., indicating an approximate 45% reduction.

The next tests were to be at a lower impeded velocity within the design dimensions of the first form fit and function unit of 6”x18”. This second shot was with an aluminum inner liner. It was later decided that the aluminum was to be added to preclude possible abrasion of the composite due to the excessive vibration in the aft area of the helicopter. The second composite (shot # T62-16) stopped the 1.1 pound fragment at a velocity of 759 feet per second / 518 miles per hour. The velocity was measured through two (2) sets of screen/breaks. The kinetic energy developed was 9,758 FPE (foot pounds of energy). The fragment was stopped center of the 6” width with a progressively controlled delamination of the material. This test result is particularly impressive as there was only minimal, approximately 20% of the composite actually penetrated.

Conceptual Design, Research and Development, Testing and Evaluation, 85 days to completion.
Manufacturing and Production 341 armor units, 4 months to completion and outfit.

The final units met the following production criteria:

• 300+° F continuous operating temperature rating.
• Non-hydroscopic finished composition.
• Non-flammable, self-extinguishing finished composition.
• Resistant to hydraulic fluids and jet fuels.
• Light weight – 10.44 pounds bare completed composite unit, 13.47 pounds completed composite unit with aluminum inner liner.
• Ballistic threat reduction criteria exceeded, without composite unit being destroyed.

• This photo shows the 2 velocity screens, 2 start/stop grids, 1" solid steel sabot shield and containment trap.

• 76mm smooth-bore cannon utilized to fire sabot containing compressor turbine wheel fragment projectile.

• 1.1 lb. compressor turbine wheel fragment within sabot.

• Exterior profile of sabot.

• 1.1 lb. compressor turbine wheel fragment post-shoot photo.

• Strike face of 18" x 18" composite subsequent to impact.

• Back face of 18" x 18" composite subesequent to impact.

• Strike face of 6" x 18" composite with aluminum inner ring post-shoot photo.

• Back face of 6" x 18" composite with aluminum inner ring post-shoot photo.

• Side profile of 6" x 18" composite with aluminum inner ring post-shoot photo.

• Strike face of 6" x 18" composite with aluminum inner ring, mounted in target frame assembly, post-shoot photo.

• Back face of 6" x 18" composite with aluminum inner ring, mounted in target frame assembly, post-shoot photo.

The following photos show completed components and assembly of the armor shield for the CH-47D APU containment armor*

*Taken from LOI CH-47-2000-01
CH-47 LETTER OF INSTRUCTIONS (LOI)
FOR Installing Safety Containment Device on CH-47 APU 08 Feb 2000
NSN # 2835-01-092-2037 PART # 160150-10 and -100

PATENT # 6,647,856 B1