VICKSBURG, Miss.— Since aircraft have been used as wartime weapons, the U.S. Army Engineer Research and Development Center (ERDC) has led the charge of creating tools that allow those planes to land anywhere in the world. Today, that mission has not changed, and the Geotechnical and Structures Laboratory (GSL) is using a unique machine to better understand the Navy’s P-8 Poseidon and how it distresses temporary, rapidly constructed runways.
“What we do is measure how long it will be before an airfield surface fails,” explained Dr. Tim Rushing, a research civil engineer in GSL’s Airfields and Pavements Branch. “Why is that important? Our military operators need to know how long an airfield is going to last.”
Rushing and his team are using a Heavy Vehicle Simulator-Aircraft (HVS-A), one of the largest of its kind in the world, to pull a wheel back-and-forth and side-to-side, mimicking the way aircraft wheels roll across the ground and strain a runway during taxi, takeoff and landing.
“Pilots, just like drivers on the highway, aren’t perfect, so the wheel doesn’t land in the same place every time. We can apply traffic in the same way, just like reality,” Rushing said, adding that for the experiment, the HVS-A will simulate 90,000 pounds of load applied to two wheels rolling across the ground.
Used as a maritime patrol aircraft, the P-8 excels in hunting enemy submarines, intelligence, surveillance and reconnaissance, as well as search and rescue. According to Boeing, the P-8’s performance and reliability delivers confidence in an uncertain world—“in any condition, anywhere, anytime.”
Military aircraft must be able to land anywhere, but a functional runway does not always exist. With that challenge in mind, GSL researchers worked with DOD agencies to develop AM2, an expedient matting system, made of interlocking structures that can be assembled by hand in a matter of hours and result in a fully serviceable runway.
“This system has been a workhorse for the United States government since the 1960s,” Rushing said. “It was designed in support of the Vietnam War, landing fighter jets in very soft soils and keeping them from sinking into the mud. This system has been in our inventory and used by all our military services since then.”
“It’s pretty amazing to know that our military can go build an airfield anywhere on the face of the planet in a matter of hours and start operations with this expedient transportation system,” Rushing said.
And despite GSL’s involvement with expedient matting systems for decades, the Poseidon experiment is the first time Rushing’s team has ever used the HVS-A to test the matting system.
“This is a really unique capability,” Rushing explained of the HVS-A, typically used by the ERDC to test bridges, highways and more permanent airfields. “There are only two of these in the nation that are used on airfields, this one and one that belongs to the Federal Aviation Administration.”
With the ability to test up to 100,000 pounds of vertical load, the ERDC’s HVS-A can run for 23 hours a day and can be controlled remotely. At such a rate, the machine can apply 20 years of design traffic in only a few months. This enables GSL researchers to get quick answers when testing new materials and designs.
“We’ll apply passes, then stop and collect data, and then start it up again,” Rushing said. “We want to monitor the deterioration of the mats, the fatigue and breaking, and the deformation of the soil underneath the mats.”
For the Poseidon experiment, Rushing’s team has another one-of-a-kind tool in its arsenal—the ERDC’s Directorate of Public Works. Home to plumbers, welders, electricians, carpenters and other tradesmen, the shop has the ability to make any custom parts needed in house. Their handmade aircraft axles, which are an exact replica of the Poseidon’s, were fitted to the HVS-A and became a key part of the testing and data collection.
According to Rushing, the experiment is useful for expedient matting systems currently in use by the military, as well as those being designed for future use.
“We’re using this machine (HVS-A) to rapidly evaluate new systems that we’re currently designing so we can really understand how this aircraft operates on pavements,” Rushing explained. “Because of this research, we’ll really be able to rewrite the textbook on the design and evaluation of our airfields.”