Advanced Arresting Gear

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.

Design and development
The AAG is being developed by General Atomics for the U.S. Navy's newest Gerald R. Ford-class aircraft carriers.

AAG tests have yet to involve real aircraft. Rather, dead loads simulating the weight of aircraft have been used to test the system at a jet car track installed at Joint Base McGuire-Dix-Lakehurst, New Jersey. The first deadload arrestment was March 27, 2011.

To date, that site has executed 537 dead loads. Testing has been delayed four and a half years due primarily to a serious problem with the water twisters, discovered early in 2012.

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