Maintaining Visual Line of Sight During Drone Operations

• Losing awareness of the drone’s location or direction of travel
• Flying behind buildings, trees, terrain, or equipment
• Relying only on the camera or controller display
• Failing to see approaching crewed aircraft or other hazards
• Losing visibility in glare, haze, darkness, or poor weather
• Continuing outward after the aircraft becomes difficult to identify

Visual line of sight allows the flight crew to judge the drone’s position, altitude, attitude, direction, and movement while watching for aircraft, people, structures, and changing conditions.

Under normal Part 107 operations, the drone must remain within unaided visual sight of the remote pilot or visual observer. Corrective lenses may be used, but binoculars and similar devices do not replace the basic visual-line-of-sight requirement.

The controller display provides useful information, but it only shows part of the operating environment. Camera views can hide side hazards, approaching aircraft, wires, obstacles, and changes outside the frame.

Buildings, tanks, trees, bridges, terrain, cranes, and other obstructions can block both visibility and command signals. The route should be planned so the aircraft does not disappear behind an obstruction.

Distance should be limited by actual visibility, not by the advertised range of the aircraft. A drone may still have a strong signal even after it becomes too small to identify or safely control by sight.

Glare, haze, clouds, low contrast, shadows, dusk, and background clutter can make the aircraft difficult to see. Visibility should be reassessed throughout the flight rather than only at takeoff.

The pilot should begin the return before visual contact becomes uncertain. Waiting until the aircraft is nearly lost leaves little time to respond to wind, battery use, or an approaching hazard.

If the crew cannot clearly determine the aircraft’s position and movement, the operation should be safely terminated unless it is being conducted under specific approval and procedures that allow otherwise.

• Keep the drone visible throughout normal operations.
• Do not rely only on the camera or controller display.
• Avoid routes behind buildings, trees, terrain, or equipment.
• Limit distance based on actual visibility, not signal range.
• Watch for glare, haze, shadows, and changing background contrast.
• Start the return before the aircraft becomes difficult to identify.
• Land safely if visual awareness cannot be maintained.

• Can the crew clearly identify the drone’s position and direction?
• What obstructions could block visual contact during the route?
• Could glare, weather, or background clutter reduce visibility?
• At what point will the pilot begin the return?
• What will the crew do if visual contact is lost?