It was a mission so perilous D-Day’s head of airborne operations predicted 70% of the planes and up to half the men involved would be lost, according to NOVA (Reconstructing the D-Day Gliders). The mission was to deliver an advanced force behind enemy lines to secure some of the bridges and crossings before the primary assault began on D-Day. The idea was to have C47 planes tow a series of gliders across the English channel. Upon reaching the landing site, the tow ropes would be cut to let the glider pilots land the planes, made of mostly wood and fabric. What’s worse? The pilot would have to land the unwieldy gliders in the dark, in about three minutes.
Seventy years later, a few people from Dassault Systemes got to experience what it was like to land a WWII-era glider in the tree-strewn French countryside. They were part of the production team that helped NOVA recreate the D-Day landing for a documentary series.
The first business of order was to build a virtual replica of the glider. Mehdi Tayoubi, Dassault’s VP of digital & experiential strategy, and his colleagues couldn’t easily extract meaningful volumes and measurements out of poorly preserved WWII blueprints of the gliders. Their best hope was to find a surviving aircraft. They found a match in the American heartland, 4,000 miles away from Normandy. At the Fagen Fighters World War II Museum, Tayoubi and his team set out to capture the dimensions of a restored glider hanging in the museum using Faro Focus3D laser scanning equipment.
“It took two days to scan the museum plane,” Tayoubi said. “It was in point cloud with colored points — more than seven million points. Three hundred and fifty million points were captured in an open ascii format file. The point cloud was converted to 3D-editable mesh and we recreated [the digital glider] manually using the different references we had. It helped a lot to understand the full structure of the glider and to make some measurements directly to the point cloud.”
To virtually recreate the landing operations, the team also needed a virtual landscape that closely matches the French countryside that greeted the WWII-era glider pilots. To get their landing site, they rebuilt inside the computer the Arromanches Artificial Harbor. The area was considered a high priority target by the allied forces during D-Day. An artificial port set up there served to supply the invading forces with ammunition. Today, it serves as a tourist attraction.
“No gliders were used there during the [D-Day] Overlord operation,” explained Tayoubi, “but it looks quite the same as the Normandy bocage with hedgerows and small fields. We also used a mix of maps and original aerial pictures taken in 1944 by the Allies [as reference]. It gave us a lot of accurate information, such as the height of the hedgerows and field size. The vegetation was a real obstacle for the glider and made the landing part very dangerous.”
Tayoubi and his team used CATIA, part of Dassault’s 3D Experience Platform, and CATIA Dynamic Behavior Modeling in order to compute the flight dynamics in real time. “We succeeded almost 50% of the time at the end of the trial,” observed Tayoubi. While maneuvering a virtual plane behind a joystick, he came to have a better understanding of the difficult faced by the WWII pilots.
The glider landing recreation was part of a larger project that aims to turn D-Day operations into a virtual experience.
For more, watch the NOVA video below: