Researchers use mathematical modeling to explain complete destruction of Germanwings Flight 9525

20 Feb 2017 by Simon Davies A supercomputer-simulation of a pulverizing airplane crash over a ravine, produced by Texas A&M mathematician Goong Chen and his team. Credit: Cong Gu, Texas A&M University.

An international team of researchers, led by Texas A&M mathematician Professor Goong Chen, has used the latest in visualization technology and their collective scientific expertise to chart the final moments of Germanwings Flight 9525, deliberately crashed in the French Alps on March 24, 2015.

Although it happened almost two years ago, the crash is still fresh in the minds of many, if not for the extenuating circumstances that occurred in the Airbus A320-211’s cockpit prior to the catastrophic event that killed all 150 people on board, then for the absolute and complete destruction of the aircraft in the equally tragic aftermath.

With little more to go on than the aircraft’s flight data and cockpit voice recorders, area topography and the debris scattering pattern, Professor Chen and his collaborators across the United States and in France, China and Saudi Arabia used computational mechanics and mathematical modeling to produce a visualization of Flight 9525 — specifically, the type of impact that would lead the plane to pulverize in the way it did.

Their results are published today (February 20) in Physica Scripta, the physics journal of the Royal Swedish Academy of Sciences.

“Based on our simulations and the evidence from the flight data recorder, we found the most likely scenario is that Flight 9525 crashed head-on into a hard-rock impact area of the ravine, pulverizing upon impact and scattering the debris up the ravine, away from the initial impact point,” Professor Chen said.

Professor Chen, an applied mathematician in Texas A&M Department of Mathematics, previously studied the disappearance of MH370 in the Indian Ocean. He used similar mathematical modeling expertise to support his team’s theory that the aircraft had entered the water vertically, thereby accounting for the lack of floating debris and the main wreckage’s total disappearance — a theory which is somewhat consistent with the Australian Transport Safety Bureau’s November 2016 assessment report stating that MH370 spiraled downward vertically and into the Indian Ocean.

Unlike MH370, however, Chen said with regard to Flight 9525, most of the causes and flight details related are well known and understood.

“Both the crash and the aircraft’s disintegration happened so fast that the large amount of aviation fuel did not burn or explode,” Professor Chen said.

“During the crash, a huge amount of energy transfer was made violently and destructively within tenths of a second, transforming from kinetic energy into fracture energy and effectively pulverizing the aircraft.”

Beyond vastly improved visualization technology in the three years since MH370, Professor Chen and his team also benefited from a novel hybrid finite element and smoothed-particle hydrodynamics method they developed specifically to better simulate the Flight 9525 crash.

“What we had hoped to understand was, under what conditions will that happen to a plane?” Professor Chen said. “We wanted to uncover and also provide a visualization of the dynamics of the impact and the crash damage.”

He noted that the challenges in measuring, experimenting with and analyzing large, high-speed impact dynamics are many. In addition to accurately modeling the aircraft and mountain terrain, he and his team also had to validate their data. They ran more than 500 supercomputer simulations on Texas A&M High Performance Research Computing’s EOS and ADA iDataPlex Clusters – with each run taking about three days – before reaching their conclusion.

But even with supercomputers at their disposal, Professor Chen said deciphering what actually happened to Flight 9525 was a task as monumental as the potential impact of the answers.

“Our simulations and visualization show the devastating effects of pulverization in several crashing scenarios,” Professor Chen said. “Ultimately, this kind of assessment is a forensic study – an analysis to try to piece together what actually happened.

“We’re on the cusp of a new era where visualization is critical to better understanding many complex scenarios and industries. It’s a tool that can help increase the body of knowledge and, in this case, possibly improve aviation safety and aircraft design. We hope the work here can also help and be applicable to the design of a real-time aircraft crash simulator that can educate pilots about the highly destructive effects of colliding with or ditching into land, mountains and obstacles.”