Precision without precedent
The tech the US Navy will use to land unmanned tankers on carriers
The same technology that will help safely guide naval aviators onto the decks of aircraft carriers in roiling seas will also help the U.S. Navy’s future unmanned tanker perform similar landings.
The Navy will use the Joint Precision Approach and Landing System, or JPALS for short, to land the MQ-25 unmanned aircraft onto carriers without a human at the controls. Known as the Stingray, the Navy’s future unmanned carrier aviation air system will provide inflight refueling to the U.S. fleet’s fighters, allowing them to operate at far greater ranges than before.
“When you’re talking about auto-landing a flying unmanned tanker onto an aircraft carrier, then the system has to be infallibly accurate, which JPALS is,” said Mark Maselli, Raytheon JPALS deputy program manager.
JPALS is a differential, GPS-based precision landing system that guides aircraft onto carriers and amphibious assault ships in all weather and surface conditions up to the rough waters of Sea State 5. It uses an encrypted, jam-proof datalink, connecting to software and receiver hardware on the aircraft and an array of GPS sensors, mast-mounted antennas and shipboard equipment.
The first Marine Corps F-35 Squadron will deploy in early 2018 with an early operational capability JPALS unit aboard ship. The system is slated to go into production in 2019 and will be outfitted on the U.S. Navy’s newest fighter — the F-35 Lightning II — allowing pilots to land with accuracy.
“JPALS is a critical enabler...providing unprecedented landing accuracy and precision in all weather environments through 2040 and beyond," said U.S. Navy Captain Joseph B. Hornbuckle III, PMA-213 program manager, Naval Air Traffic Management Systems Program Office.
Landing a jet on the deck of an aircraft carrier is a high-stakes, harrowing business even on calm seas.
"A jet landing on the deck of an aircraft carrier goes from about 150 mph to zero in seconds. There's little to no margin for error, and JPALS makes one of the most dangerous activities on a ship a lot safer," Maselli said. "We’ve got a 20-centimeter vertical accuracy requirement, so that hook hits the wire every time. We never want the pilot to miss that and have to bring the jet back around again."
In 38 attempts in one test, Maselli said, the aircraft captured the wire every time.
JPALS will also provide shipboard air traffic controllers with information on the exact location of outfitted unmanned and low-observable aircraft. This will create a hybrid environment, in which both manned and unmanned aircraft can be rapidly marshaled and recovered during flight operations.
Maselli described how a pilot might typically land an F-35 using JPALS. After returning from a mission and at about 200 nautical miles out from the ship, a pilot will start receiving range and bearing from the ship, telling the pilot in what direction to head and how far away the ship is. At about 60 nautical miles out, the jet will automatically log into the JPALS queue, receiving more data and exchanging information. At 10 nautical miles out, the pilot starts receiving precision data for landing.
“To the pilot, it’s just needles on their head’s up display,” Maselli said. “They’ve got the horizon line and cross hairs and they’re just honing in on the target. This isn’t like a tractor beam with the jet bouncing up and down in rhythm with the ship — instead, it uses an algorithm that allows for a very smooth approach.”
The F-35 can ingest the data from JPALS and autonomously land the aircraft on the carrier without the assistance of the pilot, according to Maselli.
“In theory," he said, "the pilot could just put his or her hands up in the air and the plane could land itself.”