We’ve seen quite a few changes in aviation in the last few years, both in the commercial and military sectors. New technologies, such as drones, have made regulating air space more complicated.
Security has become an even greater concern, too. There were reportedly fewer than 100 air marshals in 2001, while today they number as many as 5,000. Customer service and overbooking issues have been hot topics lately as well.
A new technology for launching aircraft from U.S. Navy aircraft carriers has now been making headlines, too. This new technique demonstrates a fundamental shift in the way the U.S. is getting its planes into the air.
The New Fighter Jet Technology
For the last 60 or so years, aircraft carriers have used steam to get aircraft off the ground. In this system, somewhere around 1,350 pounds of live steam propels a piston along an opening in the flight deck, pulls the aircraft along and sends it into the air. Often, this steam is diverted from the nuclear-powered turbines on board.
The USS Gerald R. Ford (News - Alert) recently became the first aircraft carrier to complete a successful test launch of an aircraft using a new technology — an electromagnetic launch system, or EMALS.
How the Digital Catapult Works
The EMALS works similarly to the steam catapult system, except it uses power electronics. A linear induction motor (LIM), consisting of a row of stator coils, moves the carriage and the aircraft along the track.
To get enough power for a launch, the system uses a kinetic energy storage system that is made up of four disk alternators. The storage system can recharge in 45 seconds and releases all of its stored energy in two to three seconds using a cycloconverter.
The system can monitor the speed of the aircraft during the launch process and make adjustments as necessary. This is a distinct advantage of steam-powered systems, which don’t have feedback control systems and can’t adjust speeds mid-takeoff.
Challenges of an Electronic System
The electronic system has had its share of problems. During an earlier test launch of F/A-18s with wing-mounted fuel tanks, it caused so much vibration in the wings the Navy worried about safety. The Navy and tech company General Atomics created a patch for the software to fix the vibration problem, which has been successfully tested but not applied yet.
Scaling the components to the large scales needed also presents challenges. The motor generator required, for instance, weighs over 80,000 pounds. The software needed for the system will also likely need continued updates and fixes.
The Future of EMALS
The Navy expects the USS Gerald R. Ford to receive the software update to fix the vibration problem in 2019, after which final tests will be conducted. Despite calls from President Trump to go back to using steam, all future aircraft carriers will likely use EMALS to launch their aircraft. The Navy says it hasn’t received any orders from the White House about the systems and plans to continue developing and installing them.
Although the Ford is the first in its class and the first new U.S. aircraft carrier design in the last 40 years, a new carrier, the USS John F. Kennedy, is currently under construction. The Navy has also started work on the USS Enterprise.
Although developing and implementing the new digital system has presented challenges and proved to be quite expensive, EMALS and other similar advancements are estimated to save the Navy $4 billion in maintenance costs over the lifetime of the Ford and run more efficiently than the steam-powered systems.
That’s likely enough to keep pushing forward with such innovations. It’s hard to argue with savings and efficiency.