UA.V.C.K3: Loss of aircraft control link and fly-aways.

ACS Area V — Operations Task C: Emergency Procedures References: ACAdvisory CircularCloseFAA guidance that explains acceptable ways to comply with rules or understand FAA procedures. 107-2; FAAFederal Aviation AdministrationCloseThe U.S. aviation regulator responsible for Part 107 rules, airspace, and pilot certification processes.-H-8083-25; FAAFederal Aviation AdministrationCloseThe U.S. aviation regulator responsible for Part 107 rules, airspace, and pilot certification processes.-G-8082-22; SAFOsSafety Alert for OperatorsCloseFAA safety alert that shares operational safety information. 09013, 10017, 15010

Key Concepts

Preflight Planning to Prevent and Contain Lost-Link/Fly-Aways (§ 107.49)

A thorough preflight is crucial to prevent control link loss and fly-aways. Before flight, complete familiarization, inspection, and actions, including crew briefings, to ensure everyone knows the plan if the aircraft stops responding (§ 107.49). The preflight assessment must include local weather, airspace, flight restrictions, location of nonparticipants, potential overflight of open-air assemblies, and other ground hazards. Use the FAAFederal Aviation AdministrationCloseThe U.S. aviation regulator responsible for Part 107 rules, airspace, and pilot certification processes.’s B4UFLYB4UFLYCloseFAA-recognized planning tool for checking nearby airspace and flight restrictions before a drone flight. app or a current aeronautical chart to select a site with fewer hazards and better containment options in case of link loss. Contingency procedures should be part of the briefing to enable the crew to clear the area, protect nonparticipants, and track the aircraft’s last known flight direction if control is lost.^[3]

Choose launch and recovery points that direct any uncommanded drift away from people and traffic, avoid operations near busy roads or open-air assemblies, and identify safe areas for aircraft termination if link quality degrades. The assessment requires considering persons and moving vehicles throughout the operation, so select an area where brief unplanned transit over nonparticipants is minimized while re-establishing control.^[3]

Remote ID as a Locating and Status Tool During a Fly-Away

Standard Remote IDRemote IdentificationCloseRemote ID broadcast requirements for most drones operating in U.S. airspace. helps monitor and recover a fly-away. The aircraft must broadcast its identity, latitude/longitude, geometric altitude, velocity, UTC time mark, and emergency status; it must also broadcast the control station’s latitude/longitude and geometric altitude. The control station location in the broadcast must match the person manipulating the controls, and the time mark must be synchronized with other message elements. Standard Remote IDRemote IdentificationCloseRemote ID broadcast requirements for most drones operating in U.S. airspace. includes self-testing and monitoring before takeoff, supporting system awareness.^[2]

If the control link is lost, the broadcast UA position, altitude, velocity, and time mark provide near-real-time situational awareness to help visually reacquire the aircraft and assess its flight path. The emergency status element indicates abnormal conditions, aiding coordination and deconfliction. The control station location in the broadcast allows responders to validate the operator’s position if assistance is needed to recover the aircraft.^[2]

Over-People and Moving Vehicle Constraints During Lost-Link Events

Even in emergencies, overflight rules apply. Outside closed or restricted-access sites, a small unmanned aircraft must not maintain sustained flight over moving vehicles. For Category 1–3 aircraft, only brief transit over moving vehicles is allowed—no lingering. Within closed/restricted-access sites, operations over moving vehicles are permitted when participants are directly involved, and nonparticipants must be notified, subject to the applicable category’s allowances. Category 4 aircraft may operate over moving vehicles if not prohibited by the FAAFederal Aviation AdministrationCloseThe U.S. aviation regulator responsible for Part 107 rules, airspace, and pilot certification processes.-approved Flight Manual or other Administrator-specified limitations. Category 1 applies to aircraft weighing 0.55 pounds (250 grams) or less on takeoff and throughout the operation.^[7]

For lost-link planning, design flight geometry and contingency plans to avoid roads and traffic lanes, preventing sustained flight over vehicles. If a fly-away results in unavoidable crossing, minimize time over traffic consistent with the “transit only” limitation, and use the crew to clear and cordon areas until control is regained or the aircraft comes to rest.^[7]

Manufacturer Instructions and Modes That Matter in Emergencies

Understand your aircraft’s operating modes and limitations. For Category 2 operations, the applicant must provide remote pilot operating instructions, including a system description with required components and limitations, permissible modifications, and instructions for verifying and changing the mode or configuration. The aircraft must not cause injury equivalent to or greater than 11 foot-pounds of kinetic energy on impact, have no exposed rotating parts that could lacerate human skin, and contain no safety defects. A label indicating Category 2 eligibility must be permanently affixed to the aircraft.^[1]

These operating instructions contain manufacturer procedures to verify and change configurations relevant to abnormal situations—information you must review and brief before flight. Understanding how to verify current mode/configuration and system limitations helps you respond decisively if link quality deteriorates or the aircraft behaves unexpectedly.^[1]