Getting fit for your jet fighter helmet
“You’re gonna like the way you look, I guarantee it,” was what the guy in the old Men’s Wearhouse commercials promised customers who got fit for a suit in his stores. Anyone who has been fitted for a suit, a tux, or even a set of golf clubs knows the difference the fitting can make. It’s no different for warfighters. As technology gets more sophisticated it’s essential that pilots, Marines, soldiers, and sailors be properly fitted for their gear.
This summer I was fitted for a new set of golf clubs and was fascinated by the fitting technology that analyzed swing speed, side spin, ball speed, you name it, but the process pales in comparison to how F-35 fighter pilots are fitted for their Helmet-Mounted Display System (HMDS). A F-35 helmet fitting is so granular it measures the distance between your eyes and how your pupils react to light. Makes figuring out the lie angle on a 9-iron seem quite mundane.
I was given a tutorial on the process during the Air Force Association (AFA) event last month in Washington from Martin Gunther, product marketing manager for Airborne Marketing at Rockwell Collins. Gunther, a former Navy fighter pilot, has been designing fighter helmets more than 30 years.
The HMDS, designed and developed by Rockwell Collins ESA Vision Systems, places a virtual Head Up Display (HUD) and other critical flight data directly onto the helmet’s visor, he says. It has a bi-ocular, 40 by 30 field of view, and a high-resolution, high-brightness display, with integrated digital night vision. It is also integrated with multiple sensors on the aircraft such as the Distributed Aperture System (DAS), designed by Northrop Grumman, that enables pilots to essentially see through the structure of the aircraft for a 360-degree view and see a direct picture of the ground beneath them, Gunther notes.
The only people authorized to assemble and custom-fit a helmet to an F-35 pilot are Rockwell Collins employees (pictured) – Dan Kalsow, a senior systems engineer, and Rodney Breuer, a senior customer support manager – according to Rob McKillip, senior director of F-35 programs for Rockwell Collins. They have fitted more than 120 pilots from the U.S. Air Force and Navy, as well as three foreign national pilots from the Netherlands since 2011. To fit F-35 pilots for the helmet, [Kalsow and Breuer] start by laser scanning the pilot’s head so the helmet’s optics package on the display visor is within two millimeters of exact center of each of the pupils, Gunther says.
This part of the process takes about four hours per helmet and involves spending two days with each pilot, he continues. On the first day, measurements are taken of the pilot’s head, including a 3D head scan and the use of a pupilometer to measure the distance between the pupils, Gunther adds.
Once the measurements are made they begin assembling the helmet. This process includes custom-milling each helmet liner so the helmet sits comfortably on the pilot’s head while maintaining stability under high gravity (G) maneuvers so the optics continue to match up to the individual’s field of view, explains McKillip. “They custom fit the pads in the helmet based on head size,” Gunther says.
Once the helmet is assembled, the pilot comes in for a final fitting on the second day. During this time the optics are aligned to the pilot’s pupils and the display visor is custom contoured – a process that must be done precisely so the pilot has a single focused image at infinity, says McKillip. Many would assume that people’s eyes are aligned, but that is not the case, Gunther says.
Rockwell Collins engineers have developed the third generation of the HMDS (Gen III), which is scheduled for flight-testing at Edwards Air Force Base in California this fall, Gunther says. For the Gen III version the team made improvements to night vision acuity, the latency of the DAS imagery displayed on the visor, and solved a jitter challenge. The jitter – a symptom of the aircraft shake generated during a high G turn – has been totally eliminated in Gen III, Gunther says. “The big difference between the Gen II and the Gen III helmets is the improved optical design performance across the exit pupil,” Gunther notes. “Gen III also has blacker blacks and no green glow that was associated with previous models.”
Gunther says if he had this type of helmet back in the 1970s it would have made landing on aircraft carriers at night a lot less complicated.
It would have also made the fitting process more fun for the pilots. Whether you fly jets, need a new suit, or want to lower your handicap with new irons, don’t buy off the rack. Get fitted.