Prototype Well Received
When it comes to warfighting, survivability has topped comfort for the past few decades, but that doesn’t mean comfort isn’t a factor, especially when comfort issues degrade aircrew endurance and mission performance.
In the MH-60S Seahawk, aircrew can spend hours at a time in the helicopter’s gunner seat, which was designed for crashworthiness, but not necessarily operator endurance. Among MH-60S aircrews, the seat is notoriously uncomfortable, to the extent that it can be detrimental to long-term aircrew health, and fielding a replacement is Naval Aviation’s No. 2 safety priority, right behind resolving physiological episodes.
“You were able to crash in [the current seat], but you weren’t able to sit in it for extended periods of time,” said Rabea Shaiboon, student control and curriculum chief petty officer at Helicopter Sea Combat Squadron (HSC) 2. Shaiboon, who is more than six feet tall, has been serving as the stand-in for the end user for the program office team.
In May, the Aircrew Systems Program Office debuted its second prototype (PT2) of the new MH-60S gunner seat at the Naval Helicopter Association Symposium (NHA) in Norfolk, Virginia, where it was met with excitement and gratitude on the part of the Navy sailors who sat in it. New features on PT2 include: height adjustability, lumbar support, adjustable additional leg room, the ability to recline, a flip-up seat bottom, redesigned restraints, a redesigned headrest to accommodate the night-vision goggle battery, and tracks to allow the seat to move to and from the window.
The same week that PT2 was unveiled at NHA, flight and ground testing began at HSC-2 in Norfolk. Air Test and Evaluation Squadron (HX) 21, Air Test and Evaluation Squadron (VX) 1 and the Naval Air Warfare Center Aircraft Division’s (NAWCAD) Crashworthy and Escape Systems Branch continued flight, ground and lab testing, all of which was completed June 15.
“With flight test completed, the team will continue to tweak the design to incorporate issues learned during test,” said Fillip Behrman, integrated product team (IPT) lead of the project. “While the engineering and design teams nailed it on the feature set, component tolerances needed some work.
“Also, based on fleet feedback during test, we learned that we gave the fleet a little too much leg room, so the design team will add in additional seat movement capability back toward the window.”
Ultimately, the team wants to field a seat that will increase both safety and comfort while improving aircrew mission performance and endurance.
In May 2017, the team got the green light that the effort could commence. Once funding was identified, one of the key organizations tapped to support the effort was NAWCAD’s AIRWorks Division.
“AIRWorks is a key component of this effort. They have rapid prototyping capabilities, as well as contract vehicles in place that allowed us to accelerate the effort,” Behrman said.
In addition, a 10-person Gunner Seat Fleet Task Force (GSTF) was created to allow the fleet to provide real-time input during each step of the prototype’s development. The GSTF is also a resource the IPT uses to vet ideas, support fit checks and provide the conduit into the gunner community, Behrman said.
In June 2017, the design kick-off meeting was held in San Diego. The effort was supported by the GSTF, Naval Air Systems Command/NAWCAD program team and HSC-3. Most of the features incorporated into PT2 were borne out of that initial design meeting.
Depending on the mission, the gunner operates the externally mounted gun-or a hoist during search-and-rescue missions-and sits for extended periods of time.
It’s a role and an environment to which conventional design standards do not neatly apply. That’s why the program office has been working closely with the fleet to determine the optimal dimensions, features and functionality for the new seat, said Lindley Bark, head of the crashworthy and escape systems branch.
“The different occupants’ sizes, the mission profiles, the evolutions—what they have to do with the seat is unlike anything you’ll find in an ergonomic standard,” Bark said. “So we needed to work with them in order to get this right.”
In the back of the helicopter’s cramped cabin are three seats, two gunner seats and a rear-facing center seat. Working with the H-60 program office, the gunner seat team was able to eliminate the rear-facing seat to free up additional space, allowing the two gunner seats to move farther away from the window, Behrman said.
The team is incorporating design tweaks into an updated drawing package in preparation for the critical design review (CDR). Once the CDR is complete, production representative test articles are expected to be manufactured this fall. Test articles will be put through a rigorous set of environmental and destructive tests, leading to a new round of flight testing.
Once those tests are complete, the program will transition to the production phase, which includes the building of gunner seat kits to support all aircraft and fleet trainers.
An engineering change proposal and technical directive will be developed for incorporation of the new gunner seats into the MH-60S at the organizational level. Initial operating capability is planned for the third quarter of fiscal 2019, when initial gunner seat kits will have been delivered to the fleet.
Written by the Aircrew Systems Program Office.