The Navy is preparing to launch the first ship-board tests of a new Electromagnetic Aircraft Launch System designed to replace steam catapults and propel fighter jets and other aircraft off the deck of an aircraft carrier and into the sky over the ocean, service officials said.
The EMALS system, which uses an electromagnetic field to propel aircraft instead of the currently used steam catapult, is slated for the new Ford-class aircraft carriers. The first EMALS system has been under construction for several years aboard the USS Gerald R. Ford (CVN 78), the first in class of the new carriers expected to deliver to the Navy in 2016, Navy officials said.
This summer, the Navy will start incremental testing on board the USS Ford wherein “dead loads” placed on weighted sleds are catapulted by the EMALS system into the river, said Capt. Jim Donnelly, program manager for aircraft launch and recovery equipment.
“As things get connected they will increase the number of tests. The first aircraft launch will be after the ship gets to sea,” Donnelly said.
Ship integration and testing for the EMALS technology will mark a substantial milestone in a program which, until now, has largely been conducting land-based flight tests at a Navy facility in Lakehurst, N.J.
“We’ve conducted 452 aircraft launches and just finished up our second phase of aircraft compatibility testing,” Donnelly explained.
The ground-based EMALS catapult tests have launched EA-18G Growlers, F/A-18 Super Hornets, C-2 Greyhound planes and E2D Advanced Hawkeyes, among others. In fact, EMALS even launched an F-35 Joint Strike Fighter at Lakehurst, Donnelly added. The USS Ford has been under construction in recent years at Newport News Shipbuilding, a division of Huntington Ingalls.
Equipment for the EMALS system has been in development on board the ship for several years, Navy officials said. General Atomics was awarded a $573 million deal from the Navy in 2009 for EMALS development.
“We’ve been making component deliveries to the ship in Newport News since 2011. It started early because for EMALS, some of the equipment such as the motor-generators are lower in the ship so they had to be part of the super-lift early on,” Donnelly added. “At this point we’re delivering components to be installed in the catapult trough which is up on the flight deck.”
Metal decking is slated to be placed over the trough on the flight deck. Donnelly said cabling and linear induction motor sections are still being installed on board the USS Ford. The linear motors are engineered to help create a sequentially activated rolling magnetic field or wave able to thrust or propel aircraft forward, Donnelly explained.
“It is the same type of technology that you see in a rollercoaster except this one is designed for critical launch reliability. It has to work every time you press the launch button. You are getting an electromagnetic field by turning on linear motor sequentially so we don’t energize the whole field in one shot,” he explained.
The electromagnetic field acts on a large 22-foot long aluminum plate, he added. The aluminum plate runs in between stationary sections of 12-foot long linear motors. Electricity runs through the two sides of the motors, creating an electromagnetic wave, Donnelly explained.
“The aircraft motors are kicked in at the beginning. There’s a hydraulic piston that pushes a shuttle forward. The shuttle is what connects to the aircraft launch bar,” Donnelly said.
The EMALS system is engineered to be both steady and tailorable, meaning it can adjust to different aircraft weights and configurations, Donnelly said. For example, EMALS is configured such that it could launch a lighter weight aircraft, such as an unmanned aircraft system, he added.
This is particularly useful because the amount of thrust needed to launch an aircraft depends upon a range of interwoven factors to include size, shape and weight of the aircraft, wind speed on the carrier deck and the speed of the aircraft carrier in the water, Donnelly explained.
“EMALS better supports the air wing now and in the future. As you may know we’ve changed the make-up of the carrier wing over the years. We’re getting to an air wing that requires higher energy launches and EMALS is much more capable when it comes to higher launch energy requirements,” Donnelly said.
