July 25, 2016

New super aircraft cannot land or recover aircraft for four days without failing and fixing this would require a redesign

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. That ship was 18% percent complete as of March.

Arresting Gear

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

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