By Aviation and Missile Command G-4

A team sustainment effort focused on Hexavalent Chrome primer replacement has won AMCOM G-4 an environmental team award from its senior command.

Paul Robinson, AMCOM G-4 (Logistics) Technology Integration Branch subject matter expert, accepted the Army Materiel Command's Green Innovation Award on behalf of the AMCOM G-4 Environmental Quality Team during a presentation at AMCOM headquarters at Redstone Arsenal. Robinson also received a two-star note from AMCOM commander Maj. Gen. Doug Gabram in recognition of his efforts.

AMCOM's G-4 Environmental Division is responsible for ensuring processes utilized by the aviation and missile community are sustainable at all aviation and missile maintenance installations. The Environmental Division has personnel at four different locations: Redstone Arsenal; Letterkenny Army Depot, Pennsylvania (LEAD); Fort Rucker, Alabama; and Corpus Christi Army Depot, Texas (CCAD).

AMCOM G-4 monitors the sustainability of maintenance operations at CCAD and LEAD, including the painting of helicopters and ground vehicles/equipment. The Redstone Arsenal Team helps develop and implement new technologies to reduce the Army's environmental footprint and provides oversight for the environmental activities at LEAD, Fort Rucker and CCAD. AMCOM G-4 onsite personnel at CCAD, Fort Rucker and LEAD implement the new technologies in a real world environment.

For this award, the AMCOM G-4 Environmental Quality Team worked on several projects, but the primary focus of their effort was on hexavalent chromium primer replacement and a complete rewrite of TM 1-1500-345-23 Painting and Marking of Army Aircraft. Robinson has served as the subject matter expert on both projects since their inception.

In 2011, the AMCOM G-4 Environmental Quality Team began coordinating with the Naval Air System Command to assess the performance of non-chromate (Class N) based aviation primers. The effort was supported by the Department of Defense's Environmental Security Technology Certification Program.

As part of this initiative the AMCOM G-4 Environmental Quality Team developed a new test protocol and test article that better replicates the conditions experienced by the depot technicians during repair or refurbishment of Army aircraft. The new test protocol more thoroughly assesses the performance of the latest generation of Class N primers. Using this new test protocol will ensure the replacement primer provides adequate corrosion protection, therefore reducing the maintenance burden on aircraft maintainers.

AMCOM depots have been authorized to apply currently qualified Class N primers over trivalent chromium conversion coatings for aircraft exterior mold lines since 2009.

However, even when conditions are ideal, the overall performance of the new primers has not been equivalent to the hexavalent chrome-based primer products. Continued research and development efforts have remained crucial to identify and test promising new materials and technologies to meet or exceed the performance of the hexavalent chrome-based products. Another item of concern for the maintenance community is the ability to demonstrate effectiveness of qualified non-hexavalent chrome coating system on aviation interior mold lines and aviation components.

The AMCOM G-4 Environmental Quality Team has accomplished the following in pursuit of hexavalent chromium substitute materials and validation of the new testing protocol and test article configuration:

• Worked closely with NAVAIR coatings team to identify promising new technologies and evaluated the performance of the potential replacements.
• Developed the new testing protocol and test article to better represent normal depot repair actions.
• Identified potential demonstration facilities and coordinated with Aviation Program Management Offices and Program Executive Office for Aviation to obtain approval for on-aircraft testing.
• Tested the new "metal-rich" Class N primers over the new test articles using non-hexavalent chromium pretreatments to assess galvanic and overall corrosion resistance.
• Exposed the test articles to neutral salt-fog for 3,000 hours, removed and inspected them. The aluminum-rich primer formulas developed by NAVAIR were shown to outperform the chromated coatings significantly.
• Revised TM 1-1500-345-23 to include the latest environmentally compliant coating technologies, including Class N primer products.
The achieved goals have more than tangible impacts on the environment. They also have a positive effect on AMCOM, Army aviation/missile maintenance facilities, and the entire Army and its Soldiers by ensuring improved readiness.