On Monday, September 21, 2026, flights stopped at five airports in the Northeast. Newark, Teterboro and Philadelphia were stopped at around 10 a.m.; JFK and LaGuardia were added at around 1 p.m. A construction crew in New Jersey had cut a fiber line that air traffic control (ATC) relied on as its backup, while the main line was also down. The head of the Federal Aviation Administration (FAA) said the break would probably take 13 hours to repair.
Our company builds sensing technology for excavation. Our team was not at that site, and this article is not about who is at fault. New Jersey’s Board of Public Utilities has opened an investigation, which may take weeks or months. We are writing about something the outage made visible, and it matters to everyone who is building a more automated sky.
The Sky Runs on Buried Cable
The outage showed that ATC depends on cables in the ground. A sky with more drones and air taxis in it is likely to lean on those links even more. Those cables share the ground with water, gas and power lines and with every road, rail and building project that digs near them. Each of those projects presents a chance to hit one.
A Mark is a Prediction
Before a crew digs in the United States, it is required to call 811, so locators can mark where the buried lines run. Contractors say they do call. In a survey published in January 2025 by the Associated General Contractors of America, 99% of firms said they use 811 before they start excavation work. The crew then works around the marks.
New Jersey’s investigation falls under the state law that requires buried lines to be marked before a dig. Whether the markings at this site were accurate is not known.
What is known is how often marks and lines disagree across the industry. In the same survey, 64% of the firms that answered said the lines they had struck in the past year were at least two feet from where locators had marked them after a call to 811.
Marking a buried line is hard work. Greg Finkle, a licensed engineer who owns the utility locating firm Trinity Subsurface, told NJ.com after the outage that paint wears off under traffic and weather, that flags and stakes get moved and that rails and their power systems create electromagnetic noise. “A mark-out is only as good as the locator’s ability to detect the line and the records behind it,” he said.
A paint mark on the ground shows where a cable is supposed to be. It does not show where the cable really is.
Not a Rare Event
The Common Ground Alliance estimates about 669,000 utility strikes in the U.S. in 2025, at a cost of $83.2 billion a year. For every dollar spent on repairs, nearly $16 more is lost to delays and disruption.
Few of these strikes reach the national news. This one stopped flights.
What Autonomy Calls It
Readers who work in autonomy will recognize the problem. A self-driving car carries a map, and it still watches the road. Drone builders have a name for the same idea: detect and avoid (DAA). A flight plan says where other aircraft should be. DAA exists because they are not always there.
Digging still depends on the map, which consists of paint on the ground and the records behind it. New Jersey’s rules require hand digging or vacuum excavation within two feet on either side of a marked line. Rules like this one protect a line that sits where the mark says it sits. A line that sits more than two feet from its mark is outside that protection.
What Has to Change
Two things have to change. One is how we treat the mark. It is where the checking starts, and it should be treated that way.
The other is that the excavator has to be able to see. The answer is to see what is under the bucket while the crew is digging in real time. The technology to do that from the machine itself is already in use on job sites, and it should be standard wherever crews dig near lines that a region depends on.
That technology is ground-penetrating radar, or GPR. It sends short radio pulses into the ground. When a pulse meets something with different electrical properties from the soil around it, such as a pipe or a cable duct, part of the pulse bounces back. The time it takes to return shows how deep the object sits. Not every buried line is metal. Federal rules require plastic gas mains, the pipes that run under the street, to be laid with a wire, or another way of finding them once they are buried. Radar does not depend on that wire. It reacts to the difference between the line and the soil around it.
Used from the surface, a standard GPR generates data that, once translated by an expert, gives an estimated utility location in the pre-dig phase, within the limitations of depth and orientation. Mounted in the excavator bucket, it allows the crew to get an immediate alert, with no expert needed, as the dig goes deeper, which is when a line is at risk. No sensor sees everything. Wet clay, for example, limits how deep a surface radar can see. A radar built into the bucket changes that: detections appear live on the operator’s screen in the cab. GPR embedded in the bucket can also solve the wet soil challenge.
None of this replaces the call to 811. That call is mandatory, and it shows where lines are supposed to be. It doesn’t detect them or give their exact location and depth. Radar assembled into the bucket adds that last line of defense at the moment that matters.
The investigation will show what happened at this site. The wider lesson does not need to wait for it. We are building a more automated sky on top of ground where we still dig by paint marks.
Moshe Dalman is Co-founder and CEO of RodRadar, the maker of Live Dig Radar®, the first ground-penetrating radar integrated directly into an excavator bucket.