The heavy-lift C-5a aircraft has been providing critical airlift capability for the U.S. Air Force to move oversized strategic cargo long distances since 1969. It is the largest military transport in the American fleet and one of the largest military aircraft in the world.
CACI International, meanwhile, is part of a team developing a next generation rotary wing aircraft. And this new larger helicopter must be airlifted by the C-5a.
To ensure proper fit of the new prototypical vehicle inside the cargo bay of the C-5a, CACI International, under direction from the Navy, contracted Direct Dimensions to provide an accurate three dimensional CAD model of the actual cargo bay interior. This digital data will then be used by the Navy to perform loading and interference analysis.
Using conventional metrology tools to accurately measure a space as large and complex as the cargo compartment of the C-5a, would be a very difficult and time consuming project - especially at the requested accuracy of +/-.125”. So Direct Dimensions utilized a new high-accuracy 3D laser scanning system called the Surphaser 25HSX. The extreme resolution and accuracy combined with its very fast data acquisition rate provided a level of performance not available even a year ago.
Three DDI engineers traveled to the Westover AFB in Mass. to perform the scanning using the Surphaser and a FARO Laser Tracker for position coordination. With this raw data back at the DDI facility, the engineers then created detailed 3D CAD models using PolyWorks and CAD modeling software.
The final model of the interior space, delivered for use in Catia, will allow the Navy/CACI team to plan for the cargo loading of the new helicopter into the C-5A aircraft.
*Factoid: at 121 feet long, the C-5a cargo compartment is actually a foot longer than the length of the Wright Brothers’ first flight.