Your Friends Name:
Your Friends Email:
By Bernard Choi
In April, the average temperature in Florida is about 70 degrees Fahrenheit. So, why is the 787 Dreamliner in the "Sunshine State" testing for freezing temperatures?
BOEING PHOTO BY BERNARD CHOI
There's a good explanation: Florida is home to the largest refrigerated hangar in the world. Located at Eglin Air Force Base, the McKinley Climatic Laboratory can simulate temperatures as low as -65 degrees Fahrenheit or as high as 165 degrees Fahrenheit.
"This is really the only place in the world we could go in April that would give us the kind of cold temperatures that we need," said Tom Sanderson, the flight test director for the third 787 test bed. "We have a lot of new systems on this aircraft and we want to make sure it's all functioning properly in extreme situations."
A crew of about 100 engineers, technicians and support staff traveled from Seattle to support the test operations. For many of them, the wintry weather requires an adjustment.
"I've never experienced -40 degrees before so it's a new experience," said Julie Plessner, a flight test engineer. "I just feel fortunate to be a part of this, not many people get to do this."
"It feels like the way I would think Siberia would be. It's definitely cold," Derek Wright, a Boeing Field Service employee.
Before the tests can begin, the 787 goes through what's called a cold soak where the plane is left in freezing temperatures for hours until the structure is cold enough. Throughout the process, engineers closely track the thermometer.
Meanwhile, onboard the plane, the team set up a makeshift tent in the middle of the cabin to protect the finely tuned instrumentation equipment. This is the one part of the plane that has to stay warmer than the outside.
"This way you don't see any loss of data. And that's really why we're here is to get the data and to figure out if there's any anomalies within our system," said flight test engineer Derek Muncy.
BOEING PHOTO BY BERNARD CHOI
Every degree counts because the test plan is very precise, one that the whole team reviews page by page. "We won't test until the temperatures are where they need to be for the data," explained flight test engineer Renee Esch.
After the airplane is stabilized at either the hot or cold temperatures, flight test technicians will follow the 787 Airplane Maintenance Manual to perform the steps required to prepare the airplane for flight release and operate under these conditions. Sensors and monitors will allow the test team to determine if all systems hardware and software operate as expected.
After engineers complete cold testing, they will move on to the other extreme: very hot temperatures. In the nearly two weeks of testing expected in Florida, the 787 will see a temperature swing from -45 degrees Fahrenheit to 115 degrees Fahrenheit.
"We want to validate that the airplane recovers when we go to start it so that airline customers, when they're in a similar situation, they have confidence the airplane will do what we said it will do," said Sanderson.