By Rita Hess, USAEC ContractorMarch 11, 2015
Creating and launching a new product--or modifying an existing one--isn't as easy as it appears on television shows like Shark Tank. That definitely holds true when the product is for the U.S. Army and Soldiers' lives will depend on it.
The Halon Extinguisher Replacement Program for Aviation Weapon Systems Integrated Product Team (IPT) can vouch for that. The IPT, which included representatives from many organizations, spent several years of researching, developing and testing to replace the current aviation hand-held fire extinguisher (HHFE) charged with the ozone depleting substance (ODS) Halon 1301. Their efforts won them a Secretary of the Army Environmental Award for Environmental Excellence in Weapon System Acquisition.
The Halon HHFE, currently mounted in rotary wing weapon systems (H-60s, H-47s and OH-58s), uses a Class I ODS that was banned from production by the Montreal Protocol in 1994. Thus, the Aviation Ground Support Equipment (AGSE) Product Office within the Program Executive Office for Aviation qualified a non-ODS fire suppression agent and an associated hardware configuration. The AGSE Product Office led a group of subject matter experts within the U.S. Army Aviation and Missile Command and the U.S. Army Test and Evaluation Command to spearhead a team of stakeholders, at which time the IPT was created, thoughtfully including representatives of all affected aviation project managers. And so it began . . .
HHFEs are required for mission readiness. All Army rotary wing aircraft must have them installed during the pre-flight checklist to be mission capable. But more than that, it must be an effective fire suppression tool and perform as expected when needed.
Using the Halon 1301 as a guide, the IPT wanted to provide warfighters with a replacement that had the same fire-fighting capability, while not increasing size or operational difficulty and with only minimal increase to the weight. The goal was to provide a drop-in replacement for extinguishers mounted on rotary-wing aircraft while meeting other requirements, such as strict environmental parameters for aviation weapon systems.
Although the early hardware and agent configurations developed were more effective than commercially available configurations using the same agents, they did not perform as well as the Halon 1301. The team thus tested with a standard sodium bicarbonate powder, which then led to the use of special sodium bicarbonate (SBCS) produced at a very small particle size: less than 2 microns in diameter. At this size, the powder didn't cake, toxicology concerns were eliminated and the suspendability of the SBCs in the HFC-227ea allowed the agent mixture to discharge at a consistent composition ratio, which allowed for optimal firefighting capability.
Using five percent by weight of the SBCS with the HFC-227ea, the team exceeded the capabilities of other available non-Halon clean agents of the same quantity. The blend also presented no visual obscuration for crewmembers during flight operations. When agent development was finalized, two types HFC-227ea/SBCS blends met the JP8 fuel pan fire capabilities of the Halon 1301 configuration being replaced, which was critical to developing a drop-in replacement.
The team then developed accelerated aging test protocols to ensure the quality of the agent (the SBCS constituent) would not degrade when subjected to temperature cycling. No test like this existed, so the team developed accelerated aging test criteria, including high-pressure glassware and fixturing hardware.
Next up, the team tested nozzles but discovered that the best extinguishing performance was with ones they developed--commercial nozzles were simply not as effective in fire suppression tests using the new agent mixture. The team also worked with specialized commercial labs to develop tests to measure critically important quality parameters of SBCS and measure moisture content. To measure and document the cross-sectional area and throw range of the replacement discharge, the team developed a test that was also useful when comparing agent throw range of developed configurations to the Halon configuration.
Other test considerations were environmental factors such as high altitude, temperature shock and rough usage; corrosion and compatibility concerns with the new agent and whether it would corrode aviation unique materials; and whether the agent mixture would be compatible with materials in the extinguisher over an HHFE's expected lifetime. Still other tests determined whether the final configuration would fit in the bracket that holds the existing HHFE and would remain strapped in if subjected to a variety of forces, including projectile impacts.
The final configuration was documented in a technical data package that included 42 drawings. The final test report and supporting documentation was shared with all IPT members and ultimately submitted to the Defense Logistics Agency for procurement. The non-ODS HHFE obtained a safety confirmation and an airworthiness release for fielding. Core IPT members and other subject matter experts played a vital role in the review and coordination of the specifications developed and finalized in December 2012.
The team has fit-tested the new HHFE on all aviation weapon systems and has developed an audio-visual tool outlining the proper use and maintenance of the non-ODS HHFE. It will launch on the consolidated aviation portal and storage website and possibly others when sufficient quantities of the extinguisher are in stock to support fielding.
The contract for the first production of the non-ODS HHFE should occur soon; fielding to the aviation community should follow about one year after contract award (expected early of FY16). Implementation of the non-ODS HHFE will ultimately eliminate 30,000 pounds of Halon from Army aviation systems.
Team members gave presentations documenting the early development to the International Fire Protection System Working Group; they also submitted technical papers documenting the program's successes to the leading fire suppression research experts at the 2013 Federal Aviation Administration (FAA) Triennial Fire Research Conference and the 2014 National Fire Suppression Association (NFPA) Suppression/Detection Research Symposium. NFPA Fire Technology Journal editors requested a manuscript of the work performed for publication consideration in a special issue in 2015.
Test equipment and configurations developed during this program will be used at the Aberdeen Test Center to evaluate aging hand-held extinguishers used on the Abrams main battle tank. Also, Naval Aviation Systems Command personnel in the IPT have expressed interest in the non-ODS HHFE once Navy testing is conducted. The FAA Fire Research Branch invited team members to attend meetings with FAA contractors and assist in discussions related to fire suppression.
The IPT will later compete in the Secretary of Defense Environmental Awards.
This project required the team to balance testing, schedules, materials, test resources, and personnel to best use funding, meet management requests and keep the program on track. The team used Army test facilities, laboratories, airfields, specialized equipment and other resources to the fullest extent possible, including those made available by the U.S. Army Public Health Command, U.S. Army Test and Evaluation Command, U.S. Army Redstone Test Center, the Army National Guard, and Air Warrior and Army Soldier Systems Centers.