AEDC's Hypervelocity Ballistic G-Range return to service is complete

David Brown, an ATA outside machinist, loads a high fidelity projectile into the barrel of a two-stage gas gun at the center’s Hypervelocity Ballistic G-Range during recent ongoing high-velocity impact testing.

David Brown, an ATA outside machinist, loads a high fidelity projectile into the barrel of a two-stage gas gun at the center’s Hypervelocity Ballistic G-Range during recent ongoing high-velocity impact testing.

Milton Boyer, an ATA operating engineer, works with an installation crew to put a large valve into place above the repaired upper ducting for G-Range. He was on hand to inspect the alignment of the valve to ensure the crane operator had it correctly positioned. A mishap in November 2004 severely damaged the original valve.

Milton Boyer, an ATA operating engineer, works with an installation crew to put a large valve into place above the repaired upper ducting for G-Range. He was on hand to inspect the alignment of the valve to ensure the crane operator had it correctly positioned. A mishap in November 2004 severely damaged the original valve.

ARNOLD AIR FORCE BASE, TENN -- Arnold Engineering Development Center's (AEDC) Hypervelocity Ballistic G-Range is now fully-mission capable as a result of the recent completion of a significant repair project. In November 2004 a mishap occurred in which combustion of hydrogen gas in the facility's vacuum ducting severely damaged a pump, a couple of coolers and a large valve.
"It took about six weeks to get G-Range back into temporary operation," said Larry Campbell, Aerospace Testing Alliance's (ATA) lead and systems engineer at the facility. "We were able to circumvent the damaged section -- because we could operate without it."
After safety reviews and looking at what happened, they developed an interim configuration to get the facility back into service. The completion of the recent repair project resulted in significant modifications and improvements in both the operational process and the configuration of the facility.
"For the full return to service we added some things to the system, changed some of the ways we did business--all of that was important," explained Larry Davis, the AEDC asset manager of G-Range. "Also, another thing worth mentioning is the approach that was taken to get us back into full capability. What was done actually put us into a position to have additional safeguards in place and to be more efficient, maintenance-wise, than we were before the mishap. We've had nothing but success and improvement since the beginning of this process."
To bring G-Range up to full service capabilities, the team expanded an existing hydrogen gas detection system by adding sensors to the upper-level ducting. The addition of a nitrogen gas wash system, which provides an inert operating atmosphere and the installation of a large valve, which provides better protection and requires considerably less maintenance were key changes made to improve the safety of the entire facility.
Davis emphasized the significance of both the interim and recent full return to service, "What this team accomplished is noteworthy; they initially got us back into the interim level of operation very quickly with minimal disruption, actually with no impact on our customer's schedule for critical testing. We were able to get back rapidly into a configuration that would allow us to continue the work and now with this recent repair project we're in a position to begin the next phase of this testing."
Davis said another challenge the team faced and tackled with efficiency and creativity was meeting the requirements of a mishap board to ensure an event like the one, which occurred in 2004 would not happen again.
"A lot of good suggestions came out of that mishap board," said Campbell. "We worked as a team to try and come up with the best answers for all these issues that we had."