News | Dec. 19, 2023

Ergonomics Enables Longer Sorties, Improves Aircraft Habitability

By Jacquelyn Tolbert-Millham

E-2D Advanced Hawkeye pilot, copilot, and three naval flight officers (NFO) may soon be able to endure longer flights, across greater distances and in greater comfort due, in part, to a recently developed ergonomically-designed seating system initially funded by the Naval Air Systems Command’s (NAVAIR) Small Business Innovation Research (SBIR) Program.
The technology is called the Multi-Axis Vibration Reduction Increased Comfort (MAVRIC) seats, designed by small business partner Safe, Inc. It reduces the impact of the E-2D’s three-axis, whole-body vibration, as well as improves its seating ergonomics. The need for this solution became critical following the Hawkeye’s aerial flight refueling system installation, which extended the length of its sorties to 6 to 8 hours according to the project’s technical point of contact William Glass, a Naval Air Warfare Center Aircraft Division (NAWCAD) Senior Engineer and NAVAIR Associate Fellow, working out of the NAWCAD Human Systems Engineering Department’s Crashworthy and Escape Systems Branch.

“Ergonomics, the applied science of equipment design intended to maximize productivity by reducing operator fatigue and discomfort, is just as essential to warfighter performance as training or experience,” he said. “The MAVRIC seat effort was initiated to provide the pilots and aircrew of the E-2D with a seating system that addressed deficiencies with the previous seat, and to provide a platform that greatly enhances their ability to conduct extended duration missions without suffering from physical pains or discomforts.”
MAVRIC for E-2Ds required two different designs, one for pilots and another for cabin crew. Both reduce vibration input along all three axes and recline without lifting the occupant's feet from the floor. This ergonomic design enables users to adjust the seat into a comfortable position during extended flights. The cabin seat for the NFOs features a lever that rotates the seat 90 degrees so that they are facing forward during launch and recovery and can move the seat for optimal equipment reach during operations. The seat also includes thicker, topographical contoured cushions covered with a breathable cover ergonomically designed to provide improved support to users’ thighs to alleviate pressure points at the hips and under the pelvis during long missions.
One feature, commonly referred to as “the lift,” is game changing, according to pilots and aircrew.
“A clever mechanism at the rear of the seat, which can be adjusted for any occupant’s weight, carries the PSE mass on the seat rather than the occupant. That means the E-2D’s occupants no longer have to bear all of that weight for hours at a time,” Glass said. 

The pilot seat was installed in an Air Test Evaluation Squadron (VX) 1 E-2D aircraft. Operational Test Director Lt. Cmdr. Hunter "Sheriff" Fahey flew the aircraft during a prototype flight test.
“I was also the project officer for MAVRIC when I was at VX-20. It’s coming at an absolute opportune time as the E-2D missions are beginning to be extended,” he said. “The current results of testing are showing significant benefits to aircrew both physically and mentally after a four-hour mission in the MAVRIC seat.”
“The design and continued development of this piece of equipment are driven heavily by the input from E-2 aircrews,” said Lt. Chad “Angus” Milam, aerospace and operational physiologist/aeromedical safety officer (AMSO) at Airborne Command Control Logistics Wing Detachment Norfolk, Virginia, where MAVRIC was tested in the fleet. His primary responsibility as the aeromedical safety officer is to advocate for aircrew and ensure that the MAVRIC seat meets their operational needs while and effectively addressing the aeromedical safety concerns identified during the assessment of the current E-2 seating.
“I act as an intermediary between various agencies, both civilian and military, communicating the fleet's requirements, reporting on the progress of the program to stakeholders and providing aeromedical guidance as needed. We want our aircrews to express a sense of ownership in the development of MAVRIC and to make every effort, when available, to see, experience and provide feedback on the seat now so that we can incorporate today’s knowledge and technology to reduce headaches and backaches caused by yesterday’s design,” Milam said.

Fahey said Navy Acquisition is listening to the needs and concerns of the fleet as exemplified in the development of MAVRIC. “There's been a significant amount of data collected and several ideas presented—remember the seat currently is a prototype and there’s room for improvement—but we've made incredible progress in the overall aircrew accommodation and comfort."
MAVRIC represents a keystone effort in the development and procurement of a revitalized aircrew station and equipment ensemble, according to Milam.
“As we pursue this program, we must harness the momentum to tackle other critical needs of E-2 aircrew members, such as a modernized parachute and harness,” he said.
Capturing NFO feedback is key to MAVRIC’s ergonomic design, according to Bob Gansman, director of technology development for Safe, Inc. and one of the seat’s developers.
“Companies follow the equipment specifications written by the military but it is a challenge to convey all of the nuances of what aircrew need to best support their mission,” he said. “You don’t know for sure until it is put into the aircraft. This is why we installed the prototypes at VX-1 and V-20 where it was tested by the users. We can ensure it does what it’s designed to do and it’s an opportunity for us to learn firsthand what they need and want.”
VX-20 E-2 Project Officer and NFO Lt. Nicholas “Reek” Jahrmarkt, who also tested MAVRIC, was impressed with the simplicity of the design.
“When we test a prototype like MAVRIC, we have to think of it in the [aircraft] carrier environment and how it will be used in flight,” he said. “For example, the levers on the seat were moved to allow for better leg movement. Also, the locking mechanism for the parachute lever was placed on the outside rather than on the inside to prevent [users] from pulling the wrong tab.”
Sometimes, Gansman said, specific requirements must be modified when the prototype equipment is installed at point of use. For example, the round of testing at VX-20 identified a need for a protective cover for the lift adjustment mechanism button. The company is also looking to reduce the number of parts used in the seat overall based on maintenance concerns.

Human subject testing with MAVRIC has been completed at the Air Force Research Laboratory on a human-rated vibration table, which simulates aircraft vibrations, at Wright-Patterson Air Force Base, Ohio. Tests also included ground evaluations of the pilot seat were conducted at Naval Air Station (NAS) Point Mugu, California; and more than 55 hours of fight demonstration testing of the cockpit seat was successfully completed with 13 pilots at NAS Patuxent River, Maryland.
Glass said that empirical data from this testing show a considerable reduction in aircraft vibration transmitted through the seats. Pilots are now able to remain seated for extended periods of time without experiencing pain commonly felt in the neck, back and down through the legs. They can also achieve a comfort position known as “max relax” without experiencing reduced blood flow to the back of the upper legs—all with improved functional reach.
“Aircrew testing MAVRIC noted less fatigue and musculoskeletal pain as well as a sense of better personal well-being. The effort to bring the same level of relief to the aircrew is also well underway. NAVAIR intends to conduct flight demonstration of the cabin seat version of the MAVRIC sometime in the first quarter of the 2024 fiscal year,” Glass said.
Some of the MAVRIC’s benefits were buoyed by efforts to mitigate vibration on other platforms. H-60 gunners also complained of prolonged exposure to aircraft vibration as a source of fatigue and discomfort. With funding from the Rapid Innovation Fund (RIF), MH-60S transitioned to an in-seat vibration system, similar to the one built into the MAVRIC seating system, to reduce the impact of the aircraft’s vibration along the vertical axis. RIF is a technology transition program administered by the Under Secretary of Defense for Research and Engineering Small Business and Technology Partnerships that facilitates the rapid insertion of innovative technologies into military systems or programs that meet specific defense requirements. It provides up to $3 million for development of the technology over a two-year period.

“The H-60 effort is extremely noteworthy in that it demonstrated military usefulness and robustness could be designed into an in-seat vibration isolation system,” Glass said. MAVRIC will also undergo testing for static load and dynamic load (simulated crash load testing), environmental conditional and service life characterization (endurance) testing.
Safe, Inc. is continuing its work on applying ergonomics to mitigate the effects of vibration on aircrews. In addition to MAVRIC, the small business is developing a passive anti-resonance vibration isolator system, which isolates an entire helicopter crew seat at its floor attachments, as well as innovative seat restraints for troops aboard rotorcraft. Safe, Inc. is also developing the Crash Safety Data Recorder, a device that can measure and record rotorcraft crash dynamics to improve design standards for crash protection technology such as seats and restraints.
Glass said MAVRIC seating system has exceeded the original intent of the call for proposals.
“Pilot feedback has been unambiguous and it’s clear that MAVRIC has greatly improved performance in the number of areas. It goes beyond addressing vibration—a top concern among aircrew,” he said. “Improved aircraft habitability not only greatly increases the aircrew’s ability to conduct extended duration missions without experiencing pain and discomfort, but is an enabler in mission accomplishment and key factor in users’ better long-term health outcomes.”
Jaquelyn Tolbert-Millham is a member of the NAVAIR Small Business Innovation Research (SBIR)/Small Business Technology Transfer (STTR) Program Public Affairs Team.