Navy F-35C Prepares for Ship Trials, Faces Headwinds

By Sandra I. Erwin

Naval aviators plan to fly the F-35 Joint Strike Fighter from an aircraft carrier at sea this fall. Pilots who have operated the aircraft say they are cautiously optimistic about its future despite a string of technical setbacks.

During carrier tests scheduled for October, officials will have an opportunity to examine the performance of the airplane following a recent redesign of the arresting hook that catches the airplane when it lands on the carrier deck. Aviation commanders also hope the tests will provide early answers to questions about the role of the F-35C as part of an air wing.

The F-35C faces several more years of tests before it is ready to join carrier air wings. Whereas the Marine Corps is determined to start operations with its vertical-takeoff F-35B as early as 2016, the Navy is in less of a hurry. At the earliest, the Navy has said the F-35C would be operational in 2019, although that goal appears to be in flux.

“We are only half way through the initial development plan,” says Navy Lt. Cmdr. Michael Burks, a test pilot with 150 hours in the cockpit of the F-35C and B.

Flight tests are planned through 2017, and operational-level trials would begin later.  The $400 billion Joint Strike Fighter program includes three variants: one for the Air Force, one for the Marine Corps and one for the Navy.

The priorities for the Navy’s F-35C are to finish software development and to fix glitches in the helmet-mounted displays, Burks says during a recent industry conference in San Diego. Then the Navy will have to decide how to incorporate the F-35C into an already crowded air wing.

“There will be some challenges integrating the F-35 on the carrier. Most have been identified,” he says. A carrier air wing typically has anywhere from 44 to 54 fighter jets. The Navy expects that for the foreseeable future, most of the fighters in the air wing will be Super Hornets, and that the F-35C will have a niche role as an airborne intelligence nerve center.

The F-35C will be predominantly an “information collector and distributor in the air wing,” says Burks. As the Navy’s only “stealth” aircraft that can fly undetected by radar, it will be prepared to “go alone into highly contested areas,” he adds. But most of the time it will serve as the hub of a “network centric” air wing.

“It may not matter what weapon we have on board,” Burks says.  F-35 pilots will pass information over the network that would allow other aircraft to engage targets. “I may pull the trigger in the cockpit but the weapon may come from a different platform,” he explains.

Routine aircraft operations and maintenance aboard the carrier will change dramatically when the F-35C joins the fleet, says Burks. The high-tech materials that give the F-35 stealth properties require special care. “There will have to be a paradigm shift … in the grimy flight deck environment,” he says. “Maintainers are going to have to come into the 21st century when it comes to maintaining these technologies,” says Burks. “No longer can we allow our aircraft to get grubby and grimy from wear and tear, and wash them once a month. They will require daily support, the effort of the entire squadron, especially on cruise,” he says. “That's different from the current mindset when we let the airplanes get dirty because of the operational environment.” In test squadrons, aircraft are kept indoors and in hangars, so maintenance problems at sea have yet to be experienced.

Another issue will be coping with louder than usual engines. “It is a very noisy jet,” Burks says of the F-35C. “We are looking at having to use noise-cancellation headsets for maintainers” and other operators.

The Pentagon’s Director of Test and Evaluation Michael Gilmore says in his 2014 annual report that engine noise is a “potential risk to personnel on the flight deck and one level below the flight deck.”

Projected noise levels one level below the flight deck will require at least single hearing protection, he says. On most carriers this is a berthing area, but on the new carrier CVN-78 this is a mission planning space, Gilmore says. “Personnel wearing hearing protection in mission planning areas will find it difficult to perform their duties.”

A more significant concern is the performance of the redesigned tail hook, which has been tested six times so far. “It's a bit early to say we have definitely nailed this problem,” says Burks. “The tail hook has been a major issue for the development of this airplane. It was unexpected until it was discovered in 2011.” The first problem was not being able to catch the arresting wire. There was also a structural flaw that caused excessive stress to the bulkhead where the tail hook attaches to the airframe. The redesign took a year and a half. Manufacturer Lockheed Martin Corp. has so far delivered one F-35C with the new tail hook at the Navy’s test site at Patuxent River, Md.

Gilmore says the arresting hook system “remains an integration risk as the JSF development schedule leaves no time for new discoveries.” He cautions about the “potential for gouging of the flight deck after a missed cable engagement due to an increase in weight of 139 pounds and the potential for sparking from the tail hook across the flight deck because of the increased weight and sharper geometry of the redesigned hook.”

One of the most anticipated features of the F-35C is an automated landing system called “delta flight path” that would take the pressure off aviators to nail landings on moving ships. “The delta flight path for the F-35C will make carrier landing so easy,” Burks says. “It will be a new era of carrier aviation. … Night landings will not be the number one task to focus on.” The system has been tested ashore but has yet to be tried at sea.

The glitches of the $500,000 F-35 pilot helmet have been well documented, but problems have yet to be fixed. Having a helmet-mounted display is central to how air warfare will be conduced with the F-35 because it eliminates the heads-up display in the cockpit, and everything is projected on the visor of the helmet.

“When it gets to the fleet and it's working right, it will provide a great capability,” says Burks. It would allow for a smooth transition from day to night, with no need for night vision goggles. The pilot would have a 360-degree view of his surroundings from the cameras around the aircraft. The helmet, though, has been plagued by the jitters. When the display is fixed to the aircraft, it is easy for the human eye to compensate for head motion. “It so happens now that your head is bobbing around when you're pulling G's, it's not quite as easy to stabilize the symbology on the visor,” he says.

“We've been through many fixes.” The contractor built a tiny electronic device to sense aircraft vibration and buffeting. “It turns on filters in different regimes of flight to filter out the noise we're seeing in the display,” says Burks.

The redesigned helmet is now undergoing tests. The helmet’s night camera also will require major changes. “It continues to be a show stopper at night,” he says. One problem is that it leaks light at night when the pilot is trying to dim the display down. “You get a lot of leakage of light in the optics around the eyes. It's distracting,” says Burks. He predicts the transition from cockpit to helmet-mounted displays will be hard for most pilots. “It took me about 50 flying hours to adjust.”

William Gigliotti, F-35 test pilot at Lockheed Martin Corp., says glitches are to be expected in any major weapon development. During a panel discussion at the Navy’s West 2014 conference in San Diego, Gigliotti suggests that “nits” in the F-35 program get blown out of proportion. “It's the most scrutinized program around,” he says. “We can't afford to hide anything.”

Being in the middle of the flight test program, he says, “our job is to stress the aircraft, find problems and fix them.”

He says Lockheed engineers have come up with novel ideas for how to maintain sensitive stealth aircraft at sea. “When we go to the carrier this year, we have to see the normal wear and tear.”

A potential weakness of the F-35 is not the aircraft but its weapons, Gigliotti says. He worries about future conflicts where U.S. aviators may have to engage in dogfights against well-equipped enemies. “We have air-to-air missiles. But it's important we acknowledge that in the United States we need a new AIM 120,” he says referring to the newest air-to-air weapon used by the U.S. military.

“We need a longer range air-to-air weapon. … As an industry, we need to get active in supplying a longer and more kinematic air-to-air weapon,” Gigliotti says. “That is a current limitation under some scenarios. … It is the Achilles’ heel across the U.S. Fighter fleet. We need better kinematics.”

The Pentagon plans to buy nearly 100 F-35s of the three variants by 2018. When the program’s schedule collapsed in 2009 and its costs started to soar, Pentagon officials halted development and directed all branches of the military to beef up the testing program to ensure problems were fixed before more airframes were produced.

The projected price tag of $391.2 billion for an eventual fleet of 2,443 F-35s is a 68 percent increase from the estimate in 2001. The officer in charge of the F-35, Air Force Lt. Gen. Christopher Bogdan, says in a 60 Minutes interview that the price tag of at least $115 million per aircraft is too high, but the Pentagon intends to stick with the plan. “I don’t see any scenario where we’re walking back away from this program.”

Topics: Aviation, Joint Strike Fighter, Test and Evaluation

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