AEDC implements night ops for fourth year to lower costs

  • Published
  • By Philip Lorenz III
  • AEDC/PA
ARNOLD AIR FORCE BASE, Tenn. --  AEDC has significantly lowered the cost to the customer since the organization's leadership first implemented a night operations testing schedule for the summer months in 2007.

"Five weeks into it [this year] we've saved our customers slightly more than $1 million in energy costs," said Gary Bryant, manager of ATA's Integrated Scheduling branch. "The cyclic nature of power usage in our larger facilities works to drive a rate structure with TVA that makes it financially beneficial for both AEDC and our test customers to operate those facilities during off-peak periods. Off peak are those weekday clock hours during the summer when the energy demand across the Tennessee valley is lowest, which translates to lower energy costs."

Bryant said it helps to understand how the process works.

"Night ops is a scheduling methodology we've put in place during the summer months, June through September, which shifts the operation of our plant supported wind tunnels and altitude test cells away from periods of peak power demand across the area served by TVA," he explained. "By moving this operation out of the peak demand hours, we are able to pass significant energy costs savings on to our test customers."

2010 marks the fourth year AEDC has used this scheduling option.

"Test cells normally operating 24 hours per day don't see a great deal of change, but things are different for those with a typical two-shift schedule," Bryant said. "In particular, operations folks begin to feel the effects of a different sleep pattern within the first few days of night ops. Circadian rhythms are altered, and we all need to pay particular attention to that from a fatigue risk management standpoint. Safe operation remains the primary goal."

Garry Blaisdell, the Pratt & Whitney site manager at AEDC, described a typical ground testing cycle on an aircraft engine during the summer.

"During night ops, the altitude and RAM tests are [conducted] from 8 p.m. to 10 a.m. the next day, a 14-hour test period," he said. "When we are off summer rates, as of Oct. 1, we'll go back to our normal 8 a.m. to midnight, a 16-hour test window."

RAM is a term describing test conditions in which inlet pressures are above ambient or atmospheric conditions.

"There are some other positive impacts for the facility to meet cooler flight conditions with the cooler night air, than processing the hotter daytime air to meet some flight conditions that approach minus 50 degrees Fahrenheit," he added. "The cost savings is in the combination of testing facility and plant operations, benefiting both the customer and AEDC."

Tim Layton, ATA's Aeropropulsion Plant Operations branch manager, said night ops provide another cost benefit to AEDC.

"Night operations allows the workers at the Engine Test Facility to more efficiently meet process air conditions for C, J, and T cell testing due to lower air temperatures at night," he said. "Plant coolers and refrigeration systems require less energy to condition the air from an initial ambient temperature of 80 degrees rather than the normal 95 degree day time temperature."