A different JLENS blimp is seen at  at the Utah Test and Training Range in 2014.

A different JLENS blimp is seen at at the Utah Test and Training Range in 2014. Senior Airman Tiffany DeNault/Air Force file photo

US Military Blimp Down Over Pennsylvania

The Army lost control of its 3.5-ton multi-billion-dollar air-defense JLENS for four hours on Wednesday.

UPDATE: NORAD has confirmed the JLENS is down and deflating in Moreland Township, Pennsylvania.

A 240-foot U.S. Army blimp has broken loose from its moorings at Aberdeen Proving Grounds and is drifting northeast above the fall foliage of Pennsylvania.

The Air Force has scrambled two F-16s from the Atlantic City Air National Guard base to track the blimp, which officials say is holding at 16,000 feet. The blimp broke free at 12:20 p.m. Eastern time.

“NORAD officials are working closely with the FAA to ensure air traffic safety, as well as with our other interagency partners to address the safe recovery of the aerostat,” the agency said in a statement.

The aircraft is part of a Pentagon plan to create a net to hunt enemy drones and cruise missiles along the Eastern seaboard of the United States. The Pentagon has spent $2.55 billion on the program.

The much-maligned Joint Land Attack Cruise Missile Defense Elevated Netted Sensor System, or JLENS, is not technically a blimp because it it has no propulsion; rather, it is a tethered aerostat. Similar but smaller aircraft have been used for overwatch surveillance to protect overseas U.S. bases for years, including in Afghanistan and Iraq.

The JLENS has been in testing since 2009. Raytheon, the manufacturer, has billed the JLENS program as a meant to detect missile and large drones via radar. Raytheon demonstrated that the X-band radar could pick up multiple ballistic missiles back in 2012. The JLENS’s ability to track other other objects like drones is much less clear.

Earlier this year, when a Florida man flew a gyrocopter from Pennsylvania to the steps of the U.S. Capitol, NORAD declined repeated requests for information about whether the JLENS detected the slow-moving helicopter as it made its way toward Washington, D.C. They also have yet to respond to a Defense One Freedom of information Act Request for information about the matter.

Kevin Baron contributed to this report.