NAV CANADA’s 2025 Airspace Study: What the Future of ADS-B Means for Canadian Drone Pilots

By: Colonel (ret) Bernie Derbach, KR Droneworks, 19 Dec 25

If you fly a drone in Canada—whether for commercial inspections, filming, or advanced BVLOS operations—you need to keep your eyes on the horizon. While most of the chatter regarding airspace regulations usually comes from Transport Canada, a new study by NAV CANADA could fundamentally reshape the low-level airspace we share with manned aviation.

NAV CANADA is currently conducting its Level of Service Study (2025 National). While the immediate focus is on General Aviation (GA) aircraft, the ripples of this study will undoubtedly reach the RPAS community.

Figure 1: The core conflict of the NAV CANADA study: ground-based vs. space-based surveillance in Canada's low-level airspace, affecting both general aviation and RPAS.

The Context: Bringing Surveillance to the "Lower" Skies

Currently, Canada’s ADS-B (Automatic Dependent Surveillance-Broadcast) mandate only applies to high-level airspace (Class A and B)—essentially, airliners and business jets flying above 12,500 feet.

However, the 2025 National Study is assessing the feasibility of expanding this mandate into Class C, D, and E airspace. This is the low-level controlled airspace where many complex drone operations take place, such as near airports or along busy flight corridors.

NAV CANADA has stated that any new rules resulting from this study would not take effect until 2028 at the earliest. However, the decisions made now regarding technology standards will dictate how accessible the sky is for the next decade.

The "Antenna Diversity" Problem: A Warning from General Aviation

The biggest controversy emerging from this study for manned pilots is the requirement for Antenna Diversity. Because NAV CANADA utilizes the Aireon space-based system (satellites) rather than ground stations, aircraft are best seen when they have an antenna on top of the fuselage.

However, most General Aviation aircraft are equipped for the US (FAA) system, which uses ground stations and bottom-mounted antennas. To comply with a potential Canadian mandate, pilots might have to rip out working avionics and install expensive dual-antenna (diversity) systems.

Why this matters for RPAS: If NAV CANADA decides that "Antenna Diversity" is the absolute standard for low-level airspace, this sets a daunting precedent for future drone certification.

Figure 2: A potential "Antenna Diversity" mandate could pose a significant Size, Weight, and Power (SWaP) challenge for small drones, which may not be able to carry large, power-hungry transponder units.

1. Size, Weight, and Power (SWaP): Installing two transponder antennas (top and bottom) on a Cessna is expensive. Installing them on a drone is a physics challenge. Most RPAS have limited battery power and payload capacity. A mandate requiring heavy, power-hungry diversity transponders could make many current enterprise drones obsolete for controlled airspace work.

2. The "Electronic Conspicuity" Debate: Regulators globally are trying to figure out how drones should "electronically squawk" their location. If Canada commits strictly to a space-based diversity standard, we may lose the ability to use lighter, cheaper, low-power ADS-B solutions that are popular in other jurisdictions.

The Double-Edged Sword for BVLOS

For Beyond Visual Line of Sight (BVLOS) operators, this study presents both a massive opportunity and a significant barrier.

The Opportunity (The Carrot): If the study leads to a mandate where all manned aircraft in Class C, D, and E airspace must have ADS-B, the sky becomes "cooperative."

• Easier DAA: Detect-and-Avoid systems on drones work much better when the incoming Cessna is broadcasting its position clearly via ADS-B.

• Safety: A fully known airspace environment reduces the risk of mid-air collisions, potentially making it easier for Transport Canada to approve complex BVLOS SFOCs (Special Flight Operations Certificates).

The Barrier (The Stick): If the mandate is a "pay-to-play" model, access to airspace could be restricted.

• Airspace Lockout: If NAV CANADA mandates that all entrants into Class C, D, or E must be ADS-B equipped (to the diversity standard), unequipped drones could be effectively barred from these zones.

• Forced Retrofits: Commercial operators might face high costs to equip their fleets with satellite-capable transponders to legally enter control zones for routine jobs like roof inspections or surveys near airports.

Figure 3: Two potential futures for BVLOS operations. On the left, unequipped drones face an airspace barrier. On the right, equipped drones operate safely within a cooperative airspace environment.

What Should Drone Pilots Do?

The study implies that the architecture of Canadian low-level airspace is under construction. While the changes are aimed at manned aviation today, they will define the "Digital Sky" that drones will inhabit tomorrow.

1. Watch the 2028 Timeline: While no immediate changes are coming, business plans for drone delivery or long-range survey requiring airspace access post-2028 need to account for potential equipage costs.

2. Monitor the "Diversity" Verdict: If GA pilots win the fight to allow single (bottom) antennas, it opens the door for lighter, drone-friendly transponders. If diversity is enforced, the hardware requirements for drones will be steep.

3. Stay Vocal: Organizations like COPA are fighting for practical solutions for manned pilots. RPAS associations need to ensure that the unique constraints of drones (battery, weight, size) are considered in these high-level infrastructure studies.

The sky is getting crowded. Whether you are in a cockpit or on the ground holding a controller, the rules of who gets to be seen—and how much it costs—are being written right now.