The US Navy admitted that delivery of the USS Gerald R Ford (CVN 78) will not occur in 2016 as the navy must determine the cause of problems with two main turbine generators (MTGs) on the next-generation aircraft carrier.
The USN has been working to determine the root cause of the problem, and how to fix and prevent recurrence of these issues.
The problem with the MTGs is an isolated incident, Vice Admiral Thomas Moore, commander Naval Sea Systems Command, said on 2 November, at the Washington, DC, Navy Yard.
“We are just about done getting through root cause analysis and putting some fixes in place and I expect us to be back in testing in the next couple of weeks, Vice Adm Moore said.
The Navy should know by Christmas when it plans to take possession of the aircraft carrier Gerald R. Ford, a $12.9 billion ship with an on-again, off-again delivery schedule due to several technical problems.
Vice Adm. Tom Moore said the Navy is making progress on isolating and fixing a troublesome electrical issue that has been blamed on a defective component. Clearing that hurdle will allow testing to continue on the propulsion plant.
“I would expect before the end of the year we’ll be able to set a date certain on when we think the ship will be delivered,” said Moore, the commander of Naval Sea Systems Command, during a roundtable discussion with reporters Wednesday in Washington.
The electrical problem was among five issues cited in an August memo from Frank Kendall, a Defense Department undersecretary and lead weapons buyer. Navy Secretary Ray Mabus responded days later, citing “design vulnerabilities” that required a fix before the ship’s delivery.
Kendall, who has commissioned a 60-day review of the Ford carrier program, also cited ongoing concerns with the Ford’s advanced arresting gear (AAG). It combines energy-absorbing water turbines and an induction motor to bring aircraft to a controlled stop.
It is designed to require less maintenance and be more flexible in accommodating whatever future aircraft might land on the Ford, which is intended to serve for 50 years.
The advanced arresting gear, already installed in Ford, is still undergoing testing at a land-based site in Lakehurst, N.J. The Navy recently announced it had conducted a dozen “fly-in” landings of an F/A-18E Super Hornet.
That was a first. Prior to that, it had tested the system with “roll-in” landings.
Moore said testing on AAG is 56 percent complete. Referring to the dozen fly-in landings, he said, “We thought that would take a week and we did it in a day.”
The Navy is currently studying whether to continue with AAG on the next Ford-class carrier. That ship is more than 20 percent complete at the Newport News shipyard. If the Navy abandons AAG, it would return to an older-style arresting system.
Moore said if progress continues on AAG, he believes “there is a very strong and viable path forward” to use it on future Ford-class ships.
In June and again in July, two of Ford’s electricity-generating main turbines experienced issues. Capt. Thurraya Kent, a spokeswoman for the assistant secretary of the Navy for research, development and acquisition, said the problem originated with a voltage regulator.
A Pentagon inspector general’s report released in July said mismanagement, software issues, cost overruns and hardware failures had delayed the Ford’s testing of its advanced arresting gear, the system that helps land aircraft on the flight deck. The Navy will determine by December whether to go forward with the system on the next two carriers in the Ford class.
According to a June 28 memo, Michael Gilmore, the Defense Department’s director of operational test and evaluation, said the most expensive warship in history [the new Gerald Ford aircraft carrier] continues to struggle launching and recovering aircraft, moving onboard munitions, conducting air traffic control and with ship self-defense.
“These four systems affect major areas of flight operations,” Gilmore wrote in his report to Pentagon and Navy weapons buyers Frank Kendall and Sean Stackley. “Unless these issues are resolved … they will significantly limit CVN-78’s ability to conduct combat operations.
Fixing these problems would likely require redesigning the carrier’s aircraft launch and recovery systems, according to Gilmore, a process that could result in another delay for a ship that was expected to join the fleet in September 2014.
Commanders said delays to the USS Gerald R. Ford have resulted in extended deployments for the operational carriers in order for the Navy to meet its commitments around the world, placing additional stress on sailors and crew members.
The report comes just days after the Navy announced the Ford will not be delivered before November 2016 due to unspecified testing issues, walking back testimony from April in which Stackley told Congress the Ford would be ready by September.
Now that delivery date could be pushed to 2017, according to the Navy.
To date, construction on the Ford is 98 percent complete with 88 percent of the test program finished.
Despite delays to the USS Gerald R. Ford’s delivery, the Navy says that the Ford-class carriers will yield a $4 billion reduction per ship cost as compared to its predecessor, the Nimitz Class.
The next carrier in the Ford class, the USS John F. Kennedy (CVN 79), is scheduled to launch in 2020.
The Navy estimates the arresting gear could be operated for approximately 25 consecutive landings, or cycles, between critical failures. That means it has a “negligible probability of completing” a 4-day surge “without an operational mission failure,” Gilmore wrote.
The electro-magnetic launch system’s reliability is higher but “nonetheless I have concerns,” Gilmore wrote. Recent Navy data indicates the carrier can conduct only 400 launches between critical failures, “well below the requirement” of 4,166 takeoffs, Gilmore wrote.
Gilmore said the system would have to increase its reliability to 1,600 launches between critical failures “to have a 90 percent chance of completing a day of sustained operations.” The Navy program office’s determined that the carrier “has less than a 7 percent chance of completing the four-day combat surge” plan, Gilmore wrote.
The current MK 7 hydraulic arresting system outfitted on the ten Nimitz-class aircraft carriers will be replaced on the Gerald Ford-class carriers by the Advanced Arresting Gear (AAG) unit for recovery operations. The AAG is designed for a broader range of aircraft, including UAVs, while reducing manpower and maintenance. Rotary engines which use simple energy-absorbing water turbines (or twisters) coupled to a large induction motor provide finer control of the arresting forces.
Existing water twister systems are fixed in their capacity to absorb energy. For AAG there is a variable energy dissipation by the water twister. There is an actual moving plate inside the water twister that adjusts how much resistance to the water is generated. Initially there was an underestimation of the forces involved inside the water twister because it is a three-dimensional flow field. Internal plates that take the force of the water weren’t strong enough and finding a solution has taken some time
In 2016 the Office of the Inspector General, U.S. Department of Defense found that the AAG remained unproven.
SOURCES – Bloomberg, Wikipedia, Pilot Online, US Navy, wikipedia