Johns Hopkins APL Research Helps Shape Landmark Federal Expansion of Unmanned Aircraft Operations

The Federal Aviation Administration’s long-awaited proposal to expand drone operations beyond visual line of sight marks a step toward transforming how unmanned aircraft operate in the nation’s skies — and one of the most consequential elements of the guidance emerged from pioneering work at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland. This new expansion of operations could accelerate use cases from rural package delivery to life-saving emergency response, while giving American companies a competitive edge in a global race for drone technology.

For roughly seven years, APL analysts had been running hundreds of thousands of computer simulations, seeking to answer a deceptively simple question: How do you keep unmanned aircraft from colliding in increasingly crowded skies?

APL’s research built on work led by NASA and the Federal Aviation Administration (FAA) to evaluate two technical safeguards — strategic deconfliction and conformance monitoring — that are central to integrating drones safely into shared airspace. Strategic deconfliction prevents drones from being assigned overlapping flight paths before they take off, while conformance monitoring alerts operators when an aircraft deviates from its planned route once airborne.

Through extensive simulations, APL demonstrated how these systems, when used together, can dramatically reduce the risk of midair collisions — a finding that helped inform the FAA’s proposed new rule expanding beyond visual line-of-sight (BVLOS) operations, in which the pilot cannot directly observe the vehicle.

“This is foundational work,” said Sebastian Zanlongo, the project manager at APL for this research effort. “The FAA was deciding whether these features should be recommended or required, and our analysis helped show the value of making them part of the proposed rule.”

Testing Safety at Scale

The challenge is urgent. Drones are poised to transform how Americans receive medical supplies, inspect infrastructure, monitor crops, and respond to disasters. Yet opening the skies to these new operations raises complex safety questions. How do regulators ensure that swarms of small, fast-moving aircraft can coexist with one another — and with manned aviation — while maintaining acceptable levels of safety?

APL’s study was staggering in scope. Researchers conducted more than 450,000 simulations, equal to 94 million flight hours. These modeled not just open skies but dense urban environments filled with variable te​rrain, tall buildings, and diverse mission profiles ranging from package delivery to medical transport.

Lab experts tested how drones of different performance classes would interact with one another, and what might happen when human operators, weather, or unexpected malfunctions caused deviations from planned routes.

The analysis showed that safety hinged on two factors. First, strategic deconfliction had to be universally adopted; if even 25% of operators opted out, most of the benefits disappeared. Second, conformance monitoring was indispensable for detecting when drones deviated from their planned paths and alerting operators to potential safety risks.

These findings directly shaped the proposed BVLOS rule, released last Aug. 9. For the first time, these capabilities would be required in designated airspace where small unmanned aircraft operate under federated or third-party traffic management systems.

A Decade in the Making

APL’s involvement in unmanned aircraft safety traces back to its earlier work on collision avoidance for manned aviation. Researchers supported the FAA’s development of the Airborne Collision Avoidance System, helping to design and validate algorithms that became the safety net for pilots worldwide.

As commercial drone activity accelerated in the mid-2010s, APL scientists began applying that expertise to a new class of vehicles, focusing on collision avoidance principles that could enable drones to safely operate beyond the sight of a human pilot. This safety foundation was essential for the FAA to even consider expanding drone operations.

“The business case for beyond visual line of sight depends on not having human observers stationed everywhere,” explained Charles Leeper, a program manager who has led APL’s work on collision avoidance systems for uncrewed aircraft for more than 15 years. “Industry has been clamoring for this rule for nearly a decade. The FAA needed credible, quantitative evidence to underpin new requirements. That’s where APL came in.”

From the outset, the Laboratory worked across the government–industry divide. Collaborations with Airbus’ A³ (Acubed) and SkyGrid, a Boeing joint venture, helped validate scenarios and ensure realism, while APL’s trusted role on FAA committees provided the independent technical analysis regulators needed.

For Andy Oak, APL’s mission area executive for Homeland Defense, the collaboration reflects the Laboratory’s mission and broader national priorities.

“Our work on unmanned aircraft integration shows how APL can partner with federal regulators and industry to anticipate challenges, deliver trusted solutions, and help ensure safety and resilience in the systems our nation depends on,” Oak said. “This is not just timely — it’s the right thing to do.”

What Comes Next

The public comment period on the FAA’s proposed rule closed on Oct. 6. The agency will now review thousands of responses from industry, government, and the public before issuing a final rule. If adopted as written, it will clear the way for widespread BVLOS operations across industries.