New carrier island is a heart of higher sortie rates for CVN 21

Sea Power, Jun 2003 by Keeter, Hunter

The island, or superstructure, of the Navy's new CVN 21 aircraft carrier is at the heart of numerous improvements planned for the ship. The new carrier, scheduled for launch in 2014, is to have an improved aircraft sortie rate, a crew that is far smaller than that of the Nimitz-class vessels, and lower life-cycle costs.

The means to achieve those goals began with a smaller, redesigned island that is made partly of composites and moved aft, or further back, on the deck relative to islands of the 10 Nimitz-class carriers. Rear Adm. Dennis M. Dwyer, program executive officer for aircraft carriers, said the redesign of CVN 21's island is "the real transformational part of the 'airport'" operations on board the carrier.

Slimming down the island and moving it about 100 feet aft created space on deck for the creation of a centralized re-arming and re-fueling location the Navy has dubbed the "pit stop," after the similar process in auto racing. It enables the crew to service the aircraft and get them quickly back into the air for another tactical mission. "That is the concept," said Dwyer. At present, "we do a lot of ... pushing planes around the deck and that takes a lot of time. They don't push cars in a NASCAR race. They drive them into the pit and they get out in 14 seconds. We [could be] doing that."

CVN 21, to be built by Northrop Grumman's Newport News Operations, Newport News, Va., is the Navy's first new carrier design since 1965. The ship is expected to last 50 years, and the CVN 21 carrier class of ships will be the centerpiece of the Navy's expeditionary strike force for more than 100 years. Therefore, the Navy wants quantum improvements in capability in a hull design that is about the same size as the Nimitz class: approximately 1,092 feet in length; a beam of 134 feet; and a flight deck width of 252 feet. A larger hull would have brought penalties in size and cost. Anything larger than a Nimitz CVN would have required new, larger drydocks, for example.

However, CVN 21 will have a new nuclear reactor that produces 25 percent more power. Steam produced by the reactor will generate three times the electrical power of the Nimitz, which suffers from chronic overloading of its electrical generators.

The new reactor and other changes permit substantial reductions in crew size. Overall, the CVN 21 will have a crew of 2,100 to 2,500 men and women. The Nimitz crew totals approximately 3,000 personnel. That reduction should bring substantial cuts in life-cycle costs of the CVN 21, relative to the Nimitz class, but Dwyer is reluctant to estimate the savings at this early point in the ship's development.

But the Navy's excitement about the new carrier stems in large part from the improvement in operations to be derived from the redesigned island and the airplane 'pit stop' that will generate aircraft sorties of 140 to 160 per day, with a surge capability to 220 sorties per day. The Nimitz's normal sortie rate is about 120 per day. Ordnance, fuel, and electronic support systems all will be located at or near the pit stop, eliminating the need to drag fuel hoses across deck to the planes and push ammo dollies through long distances on the flight and hangar decks.

On the Nimitz class, "we go through a two-hour cycle and quarter of a mile hauling bombs throughout the hangar bay and the mess deck" to get them to an upper stage elevator and onto a deck staging area, said Dwyer. That made re-arming planes "the long leg" in sortie rates on the Nimitz.

On the CVN 21, ordnance will moved by robotic devices from the magazines to re-located weapons elevators and then to "little bomb farms" near the pit stops, said Dwyer. Thus, re-arming a plane will probably be measured in "minutes instead of hours."

"We can pull [the aircraft] in once . . . and do everything [we need] to them, and they can cycle right out, get to the catapult and go again," Dwyer said.

As is the case for ordnance, the movement of JP5 aviation fuel around today's flight decks is a cumbersome process, accomplished by dragging long hoses from hatches and catwalk stations on deck. The CVN 21 design would place shorter fuel hoses directly in the aircraft pit. Diagnostic stations also will be positioned at the pit for maintenance troubleshooting.

In addition, Navy tactics have changed, reducing the number of sorties flown against most targets. The "whole philosophy of what a sortie is has changed ... because of technology," said Dwyer. When Nimitz was designed, carrier air wings included A-4s, A-6s, A-7s, F-4s, and F-Ss. Multiple sorties were then launched to release large numbers of usually unguided munitions against single targets. Since the 1991 Persian Gulf War, the strike platforms in the typical carrier air wing have evolved and now are based on the F/A-18 Hornet series of tactical aircraft. The ordnance delivered by the airplanes also has changed, and now includes larger numbers of precision-guided munitions, such as the GPS-assisted Joint Direct-Attack Munitions series and various laser-guided bombs. Therefore, aircraft involved in Operation Enduring Freedom, over Afghanistan, and Operation Iraqi Freedom often engaged multiple targets.