ABOARD THE USS GEORGE H. W. BUSH, Persian Gulf -- The U.S.S. George H. W. Bush in January became the first East Coast-based carrier to deploy with a specialized piece of medical equipment aboard: a hyperbaric chamber, or "transportable recompression system," designed to treat pilots who experience hypoxia-like symptoms in the cockpit.
Fewer than four months into the deployment, it has already been used twice for that purpose.
Back in the States, Naval Air Forces launched a service-wide review in April of cockpit physiological episodes affecting pilots who fly the Navy's T-45 Goshawk trainers and F/A-18 Hornets. The review was launched after instructor pilots at the Navy's three training commands refused to fly, citing safety concerns with the T-45.
In the Persian Gulf, where pilots of Hornets and E/A-18 Growlers routinely conduct 10-hour missions over Iraq and Syria in support of the ground fight against Islamic State militants, the stakes are even higher. And though the aviation community aboard the carrier has found new and innovative ways to treat and detect cockpit incidents, they continue to happen.
Capt. James McCall, commander of Carrier Air Wing 8, told Military.com that the first of two episodes happened in February, affecting the two-person crew of a Growler attached to the wing's Electronic Attack Squadron 131.
The aircraft was returning from a long mission in support of Operation Inherent Resolve, the coalition fight against ISIS, and was nearing the carrier when the crew experienced what McCall called an "abnormality" with the aircraft's environmental control system. That system affects air supply and pressurization, among other factors.
On that occasion, the crew members were able to safely complete a tailhook landing onto the carrier and were immediately taken for medical care, including consultations with stateside doctors.
"The decision was made to put them in the hyperbaric chamber, with the resolution of their symptoms immediately," McCall said. "And [they were kept] in a down status for a period of time per medical protocol. Both those aircrew are back flying today."
The second incident came in April, McCall said, and involved a single-seat F/A-18 attached to the air wing. As in the first episode, the pilot physically experienced changes in the environmental control system, this time shortly after takeoff. He was able to return to the carrier immediately, McCall said, and seek treatment. Again, a medical team prescribed the use of the on-board hyperbaric chamber, and the pilot's symptoms subsided.
In both incidents, the pilots involved were fortunate in that the episodes occurred near the carrier, allowing them to land quickly and seek treatment. If an episode had begun above an urban ground fight over Iraq or Syria, the available options might have been more limited, and certainly more complex.
Having the recompression chamber aboard to treat pilots' symptoms was a measure that emerged from aviators' feedback, McCall said.
"Really that was in response to, frankly, aircrew who said, 'We need a capability like this so we don't have to try and find medical transport somewhere where we're deployed halfway around the world,' " he said. "And I think the naval aviation enterprise listened to that and said, 'Hey, let's see if we can come up with a solution in a very short period of time.' "
Mitigating the Effects
Both the Bush and the San Diego-based carrier Carl Vinson, which deployed within days of each other in January, departed port with one of the $250,000 chambers aboard. The systems are traditionally used to treat Navy divers for symptoms related to decompression, though hyperbaric oxygen therapy has been used to treat a variety of other illnesses as well.
"DCS symptoms are significantly improved when medical treatments are quickly administered, and these portable chambers provide that immediate medical care in the event of a physiological episode," Cmdr. Dave Hecht, a spokesman for Naval Air Force Atlantic, told Military.com. "Deploying with them aboard was a decision based on our number-one priority, safety. The significant mitigation measures we've taken allow us to safely execute our assigned warfighting missions."
McCall said the decision to deploy the system -- an egg-shaped pod six to seven feet long -- aboard the Bush was made just weeks before the carrier departed port.
"That would not have happened without a dialogue from aviators in squadrons right to the three-star level," he said. "I'll be honest, we've moved that dialogue fairly quickly."
Other mitigation and detection measures also represent firsts for the carrier. McCall said the carrier was the first to deploy its fighters equipped with "slam sticks," small devices that measure cockpit air pressure and other factors, and can provide diagnostics following a mission.
"They can come back, plug it in a computer and measure that," McCall said. "So even if they didn't notice there was a problem [while they were flying], that's detail they may not have had before."
Another measure, designed to help pilots detect cockpit problems before they can physically feel them, is a true improvisation: the wearing of commercially available Garmin watches, equipped with altimeters and barometric sensors, that can be set to sound alarms when certain thresholds are reached.
"Some of our aircrew had Garmin watches that they had bought, watches with little altimeters on them," McCall said. "I think somebody was just like, 'Hey, this would make sense.' And so we offered up discussions with one of my [commanding officers] and myself, and we said, 'Let's pitch this up the chain of command.' "
The watches are now specially authorized for members of the wing's Strike Fighter Squadron 37, which still flies the F/A-18C Hornet, an older airframe than that employed by the wing's three other squadrons, which all fly F/A-18 E/F Super Hornets.
"I can't speak to the Navy enterprise, their intention to do that for all type-model-series, but I know our guys wear them and like the capability they provide," McCall said.
Finding a Solution
McCall said he didn't want to sugarcoat the fact that it is troubling that cockpit episodes continue to affect pilots, particularly those flying combat missions in the Middle East. But he said he's heartened by the level of direct communication between pilots in the fight and the Navy aviation enterprise, as well as the education that aviators are receiving.
"They've given us a lot of opportunity for real-time feedback. And again, that doesn't mean there aren't problems with the aircraft, and I think they've been really responsive to us trying to get some mitigations there," McCall said. "The crew understand that, 'Hey, now we may have some tools that may help us as we deal with these issues.' What I've seen is, the unfettered communication has allowed leadership to take some actions that hopefully have some meaningful mitigation."
The Navy's 30-day review of cockpit episodes began April 24. At the end of the review period, according to Navy officials, U.S. Pacific Fleet Commander Adm. Scott Swift will provide top Navy leadership with recommendations about whether the actions the service is taking to determine why the problems are happening are sufficient, and whether additional efforts are warranted to solve the problem and safety operate its fighter aircraft.