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X-43 Team uses Safety Days for training exercise
X-Press Editor P281 turns red, indicating the purge pressure in the X-43A is below the minimum safe value. An engineer in the control room sees the change and calls the simulated B-52 carrying the X-43A stack and asks if the crew sees a pressure drop too. The B-52 crew confirms the pressure drop, which indicates that it is not an instrumentation error. On a different area of the panel in the control room another line of information turns red. The flow control valve registers 3 volts where it should read 0 volts. The implication is that gas is flowing when it shouldn't be. PV12, the hydrogen sensor turns red, indicating hydrogen is present in the X-43A. Then, 30 seconds apart, a first, then a second thermal couple reaches 400 degrees, indicating there is a fire aboard the X-43A – and it's spreading. The chase aircraft radios to the control room that smoke is visible. The X-43A stack is dropped into the ocean. It's not real and it's not expected, but a number of scenarios need to be practiced. Prior to Safety Days, the X-43A Team was preparing to simulate missions in the control room. Jim Lester, Kalman and Company X-43A systems safety engineer, worked with simulation engineers and the control room to prepare several scenarios during which the X-43A would experience "problems." The idea was to observe the team's reactions and to log valuable training in situations that could be encountered during actual flights. Lester worked with Jeanette Le, Dryden's lead X-43A simulation engineer, and Karla Shy, a Dryden simulation engineer and a backup on the Hyper-X. The X-43A is part of the Hyper-X Program. The group's idea was to make it possible for people in the control room to be fed information – and simulated problems – to make the experience much like a real research mission. "We wanted to make it as realistic as possible during the training. To make it more realistic we had engineers substitute for a B-52 crew and placed them in a different room. Through headsets the B-52 crew could hear communication amongst the staff in the control room as if it were the day of flight. This type of control room training is the standard at Dryden," said Le. In the second simulated exercise, new problems began occurring every 25 seconds. The response of those in the exercise was to shut down the aircraft computer systems and return to base because it was acting squirrelly. "The computer could be bad, so we powered it down. It's not what I would have thought of, but it was a good response," Lester said. The simulation included random failures across a number of disciplines. "The simulated failures were not safety critical, but they were mission critical," Lester said. The two exercises took a couple of months to plan, set up and complete with some dry runs to ensure everything would work as expected. "Clearly the time and effort put into supporting this exercise was well worth it. It's great to see how this capability is being used within the project. I believe this capability can only add to the future success of the Hyper-X Project and other projects to come," Shy said. Another training session is planned to simulate from power-up to launch, Lester said. The exercise is expected to be broader in scope and include more areas of simulation. It also will include the B-52 flying and looking more at the time elements in the launch. "The F-15B, the SRA (F-18 Systems Aircraft) and other projects fly many times, but the Hyper-X will fly one or two captive flights and then the flight to launch it. Engineers have to be prepared to react quickly and confidently without the benefit of several envelope expansion flights," Lester said. More people will be involved in future training sessions and the timing of events leading to launch will be closely monitored. If there is a problem discovered in time, it could mean the difference between canceling for the day and earning another shot later in the day to conduct a successful launch, he said. The exercise conducted during Safety Days also looked to train project people on another routine occurrence in flight research. When researchers were faced with new problems every 25 seconds in the second simulation, it made that point – researchers have to continue looking for anomalies, even when only one is discovered and the team is working to resolve it. "Sometimes you get so wrapped up in failures that you don't look for additional ones. When there is one problem, there usually is another," Lester said. |
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Responsible NASA Official: John Childress For questions, contact: Dryden Web Group Page Curator:WD-Team Modified: January 24, 2001 |
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