FAA Part 107 study guide with diagrams — part of the Sky107 UAG knowledge test preparation course.
Flight Operations and Emergencies
Overview
This chapter covers the operational rules and emergency procedures a remote pilot in command (Remote PIC) must follow during small unmanned aircraft system (sUAS) operations under 14 CFR Part 107. The material focuses on maintaining visual line of sight (VLOS), yielding right-of-way to manned aircraft, conducting adequate preflight inspections, responding to lost-link and lost-GPS events, handling in-flight emergencies, managing pilot fitness and environmental hazards, and documenting maintenance after an incident.
The core principle is that the Remote PIC is directly responsible for the safe operation of the sUAS at all times. Whenever an abnormal condition threatens the safety of persons, property, or other aircraft, the Remote PIC must take immediate corrective action, up to and including terminating the flight.
Key Regulatory Foundations
The following regulations form the backbone of safe flight operations and emergency response under Part 107:
14 CFR §107.15 – Condition for safe operation: No person may operate a small UAS in a careless or reckless manner, and the aircraft must be in a condition for safe operation.
14 CFR §107.17 – Medical condition: No person may operate a small UAS if they have a physical or mental condition that would interfere with safe operation.
14 CFR §107.19 – Remote PIC responsibility: The Remote PIC is directly responsible for the operation and safety of the small UAS and must ensure the operation does not create an undue hazard to persons or property.
14 CFR §107.23 – Hazardous operation: No person may operate a small UAS in a careless or reckless manner that endangers life or property.
14 CFR §107.31 – Visual line of sight: The Remote PIC, person manipulating the controls, and visual observer, if used, must maintain unaided visual contact with the aircraft throughout the flight.
14 CFR §107.37 – Right-of-way: Each small unmanned aircraft must yield the right-of-way to all other aircraft, airborne vehicles, and launch or reentry vehicles.
14 CFR §107.49 – Preflight inspection: Before each flight, the Remote PIC must inspect the sUAS to ensure it is in a condition for safe operation.
14 CFR §107.51 – Operating limitations: Provides visibility and cloud clearance requirements, including a minimum flight visibility of 3 statute miles.
14 CFR §107.45 – Prohibited or restricted areas: Prohibits operations in prohibited or restricted areas unless authorized.
14 CFR §91.3(b) – Emergency authority: In an emergency, the pilot in command may deviate from any rule to the extent required to meet that emergency.
Visual Line of Sight (VLOS) and Visual Contact
VLOS Requirement
The Remote PIC must be able to see the small unmanned aircraft at all times using natural or corrected vision only. This means:
Eyeglasses or contact lenses are allowed.
Binoculars, telescopes, or other magnifying devices are not permitted for satisfying VLOS.
A First-Person View (FPV) camera or video feed does not satisfy VLOS by itself.
If a visual observer is used, the Remote PIC and the observer must both be able to maintain visual contact with the aircraft and communicate effectively.
Losing Visual Contact
Losing sight of the aircraft is a serious operational violation and a safety hazard. Common causes include:
Sun glare or the aircraft being silhouetted against the sky
Flying behind a tree line, building, hangar, or terrain
Fog, haze, or other reduced visibility conditions
Distraction or visual impairment
Flying the aircraft too far away
If VLOS is lost, the Remote PIC must immediately take action to either:
34.Regain visual contact by repositioning the aircraft or moving the pilot/observer to a better position, or
35.Land the aircraft safely as soon as practicable.
Continuing a mission solely by watching the FPV feed is not acceptable. The aircraft must never be operated beyond visual range without an appropriate waiver.
Video Link Failure
A failure of the live video feed is not normally an emergency under Part 107 because the remote pilot’s primary obligation is to maintain VLOS. If the control link remains functional and the aircraft is still visible:
The flight may continue.
The Remote PIC should continue to fly using direct visual observation.
No immediate landing is required solely because the video link failed.
If the video loss is combined with loss of control link, GPS, or visual contact, the situation becomes an abnormal or emergency event requiring immediate corrective action.
Right-of-Way and Collision Avoidance
Small UAS Must Always Yield
Under 14 CFR §107.37, a small unmanned aircraft must yield the right-of-way to all other aircraft, including:
Manned airplanes
Helicopters
Gliders
Ultralights
Balloons
Other small unmanned aircraft
The rule is stricter than the traditional manned aircraft right-of-way rules because sUAS are smaller, less visible, and not occupied by an onboard pilot. A small UAS does not have right-of-way over any other aircraft, even if it is approaching from the right or appears to have the traditional right-of-way priority.
Manned Aircraft Encounters
When a manned aircraft approaches the sUAS at the same altitude or on a converging path:
The Remote PIC must immediately maneuver the sUAS to avoid the manned aircraft.
The sUAS must give way and must not pass over, under, or ahead of the other aircraft unless well clear.
In a head-on situation, the Remote PIC should take early and positive avoidance action; a common response is to turn right or otherwise increase separation. The key requirement is that the sUAS must yield and avoid being a collision hazard.
There is no fixed distance that automatically requires action. If a manned aircraft is nearby and could become a conflict, the Remote PIC should increase separation immediately.
Manned Aircraft Near the Operating Area
Even when the manned aircraft is some distance away—for example, one mile away but descending toward the sUAS—the Remote PIC’s first response should be to increase separation and be prepared to take evasive action. The sUAS must always be the give-way vehicle.
Between Small Unmanned Aircraft
When two small UAS approach each other head-on or converging at the same altitude:
Both aircraft are expected to yield under 14 CFR §107.37.
Each Remote PIC should adjust the aircraft’s path to avoid a collision.
There is no “stand-on” or “right-of-way” sUAS when two Part 107 aircraft conflict; both must take positive separation action.
Preflight Inspection and Aircraft Condition
The Preflight Inspection
Before each flight, 14 CFR §107.49 requires the Remote PIC to determine that the small UAS is in a condition for safe operation. This includes:
Inspecting the aircraft structure and propulsion system
Checking propellers for cracks, nicks, bends, or other damage
Verifying that all fasteners, landing gear, and components are secure
Inspecting the control station and flight controls
Checking battery condition and proper installation
Assessing the operating environment, including weather and airspace
A preflight inspection is not merely a visual glance. It must be systematic enough to detect defects that could cause an in-flight failure.
Propeller Damage
A crack, nick, bend, or other significant defect in a propeller is an immediate grounding condition. Propellers operate under high stress and can fail suddenly if damaged.
Actions required:
Replace the propeller with a manufacturer-approved part.
Do not attempt to sand, glue, tape, or otherwise patch a cracked propeller.
If the manufacturer’s maintenance manual does not provide a repair procedure, replacement is the only acceptable action.
The fact that the Remote PIC is also a certificated aircraft mechanic does not authorize an unapproved propeller repair.
This is consistent with general aeronautical guidance such as FAA Advisory Circular AC 43.13-1B, which cautions that cracked propeller material is generally cause for replacement.
Structural Damage and Missing Hardware
Cracks in airframe components such as arms, motor mounts, or landing gear are serious defects. Hairline cracks can grow rapidly under vibration and flight loads, leading to structural failure.
If a structural crack is found and no manufacturer-approved repair procedure exists, the affected component must be replaced.
A missing screw, bolt, retainer, or other hardware must be corrected before flight.
Flying with missing hardware or damaged structure may violate the requirement that the aircraft be in a condition for safe operation and may also constitute hazardous operation.
Battery Inspection and Battery Fire
Preflight should include checking the battery for swelling, excessive heat, punctures, damaged connectors, or any burning smell. Smoke or a burning odor from the battery compartment before or after flight is an immediate emergency.
If a lithium battery begins smoking or catches fire while the aircraft is on the ground:
96.Power off the aircraft only if it is safe to do so.
97.Move away from the aircraft and keep other people away.
98.Use a fire extinguisher rated for electrical or battery fires, such as a Class B or battery-rated extinguisher.
99.Isolate the aircraft on a non-combustible surface if possible.
100.Contact emergency services if necessary.
Lithium battery thermal runaway can be violent and may release toxic gases. Do not attempt to remove the battery with bare hands. Do not rely on ordinary water or improvised firefighting methods unless the manufacturer’s emergency guidance specifically directs otherwise.
Lost Link, Lost GPS, and Flyaway Procedures
Lost Command and Control Link
A lost link occurs when the remote controller and the sUAS are no longer communicating. Many small UAS have a manufacturer-provided lost-link procedure, often based on GPS, such as:
Return-to-home (RTH) to the launch point
Fly to a designated waypoint
Hover in place
Execute a controlled descent and landing
The correct initial response to a lost link is to:
112.Follow the manufacturer’s programmed lost-link procedure.
113.Maintain visual line of sight with the aircraft.
114.Monitor the aircraft’s behavior.
115.Be prepared to take manual control when the link is restored or if the automation places the aircraft in an unsafe condition.
The Remote PIC must not:
Randomly turn off the transmitter or repeatedly cycle power.
Make unplanned control inputs that could conflict with the automated recovery.
Climb or change altitude without a clear reason.
Abandon the aircraft and stop monitoring it.
A lost link does not automatically require the remote pilot to intentionally crash the aircraft or shut it down. It is a serious abnormal condition, but the first priority is to support the aircraft’s preplanned recovery and regain control.
Re-Establishing the Link
If the command link is restored while the aircraft is executing its lost-link procedure:
The Remote PIC should continue monitoring the aircraft.
The lost-link procedure should be allowed to continue if it is functioning correctly.
Manual control should be taken only if the automated procedure is placing the aircraft in an unsafe situation.
Interrupting a properly functioning return-to-home procedure without situational awareness can create a new hazard.
Loss of GPS Signal
Loss of GPS is not necessarily a total emergency if the aircraft remains stable and responsive to control inputs. GPS is used for position holding, automatic return-to-home, and many autonomous flight modes. If GPS is lost:
The aircraft may drift from its position.
The aircraft may enter a non-GPS or manual flight mode.
The Remote PIC should switch to a stable manual or attitude flight mode if available.
Maintain VLOS and land or return to the launch point as conditions permit.
If GPS loss is combined with loss of video, uncommanded movement, or loss of control response, the Remote PIC must prioritize placing the aircraft over the least hazardous terrain available. For example, an open lake or clear field may be safer than power lines, buildings, or populated areas.
Flyaway and Loss of Control
A flyaway is an uncontrolled condition in which the aircraft is not responding to commands and is drifting toward an unsafe area. The Remote PIC should:
137.Attempt to regain control using all appropriate methods, such as selecting return-to-home or a different flight mode.
138.Maintain VLOS as long as possible.
139.If control cannot be regained, direct the aircraft toward the least hazardous area available.
140.If the aircraft has a flight termination system or other approved emergency recovery feature, use it when necessary to avoid injury or property damage.
141.If no other option exists, an intentional controlled descent in a clear area may be preferable to allowing the aircraft to fly uncontrolled into people or structures.
The Remote PIC must not simply allow the aircraft to fly away without action. All available means should be used to reduce the risk to persons and property.
In-Flight Emergencies and Immediate Actions
Structural Failure or Uncontrollable Flight
If the aircraft suffers a structural failure, violent pitching, or an uncontrollable descent:
The Remote PIC should immediately use the aircraft’s emergency recovery systems if available.
If a ballistic parachute system is installed, deploy it within the manufacturer’s recommended recovery envelope.
Do not delay deployment until the aircraft is near the ground, because the parachute may not have time to fully deploy and reduce impact energy.
Cycling flight modes is unlikely to help if the aircraft has already suffered structural failure.
The Remote PIC may need to deviate from normal operating rules to the extent necessary to meet the emergency, prioritizing the safety of persons and property.
Unexplained Oscillation or Altitude Loss
An unexplained oscillation, vibration, or loss of altitude can indicate a control system fault, motor imbalance, propeller damage, or structural issue. The safest initial response is:
Land as soon as practicable.
Do not continue the mission.
Do not rely on automation to correct the problem.
Inspect the aircraft after landing to identify and correct the fault before further flight.
Low-Battery Warning
A flashing or audible low-battery warning indicates that the aircraft has limited endurance remaining. The Remote PIC should:
Follow the manufacturer’s low-battery procedure.
Land as soon as safely possible.
Avoid delaying until the battery reaches a critical level, because this can lead to an uncontrolled descent.
Continue to maintain VLOS and positive control during the landing.
Battery Fire After Landing or During Ground Operations
If a battery fire occurs after landing:
Power off the aircraft if safe.
Back away immediately.
Use a battery-rated or Class B extinguisher if available.
Keep the aircraft isolated on a non-combustible surface if possible.
Contact emergency services if the fire is not quickly controlled.
Pilot Fitness, Weather, and Environmental Hazards
Remote PIC Medical Condition
Under 14 CFR §107.17, no person may operate a small UAS with a medical condition that could interfere with safe operation. Symptoms that require immediate termination of the flight include:
Nausea
Faintness or dizziness
Headache
Slowed reaction time
Difficulty focusing or maintaining attention
Severe heat stress
If the Remote PIC becomes impaired during flight:
182.Land the aircraft immediately.
183.Secure the aircraft and control station.
184.Stop operations and recover.
185.Do not hover, continue the mission, or hand controls to an unqualified person.
Fatigue and heat-related illness degrade decision-making and reaction time. The Remote PIC must recognize personal impairment and take action before it leads to a hazardous operation.
Weather and Visibility
Part 107 operations require a minimum flight visibility of 3 statute miles and compliance with cloud clearance requirements. Weather conditions that reduce visibility threaten the Remote PIC’s ability to maintain VLOS and see other aircraft.
If fog begins to form or visibility drops:
Terminate the operation and land.
Land while conditions still allow a controlled recovery.
Do not wait until the aircraft is invisible from the ground.
Wind and Manufacturer Limitations
The Remote PIC must know and respect the aircraft manufacturer’s maximum demonstrated wind speed and other operating limitations. If the forecast includes gusty winds exceeding the manufacturer’s limit:
Cancel or postpone the operation.
Do not attempt to “fly through” winds that exceed aircraft performance limits.
Operating outside the manufacturer’s limitations can cause loss of control and may violate hazardous operation rules.
Temporary Flight Restrictions and Airspace Incursions
A small UAS must not operate in prohibited or restricted areas unless authorized. Temporary flight restrictions (TFRs), such as those issued around wildfires, are also binding.
If the Remote PIC discovers that the aircraft has entered a TFR:
Land as soon as practical.
Do not continue the incursion by reversing course through restricted airspace.
Do not attempt to obtain an in-flight waiver; a TFR authorization cannot be granted in that manner.
The primary concern is to minimize the hazard to manned firefighting or emergency aircraft.
Post-Incident Maintenance and Documentation
After an emergency landing, crash, motor failure, or other abnormal event, the Remote PIC must ensure the aircraft is safe before the next flight. Even if there are no injuries or property damage, the aircraft must be inspected for:
Fractured motor mounts
Cracked propellers
Bent landing gear
Damaged wiring or connectors
Battery damage
If damage is found:
Replace damaged components with manufacturer-approved parts.
Do not attempt field repairs unless the manufacturer’s maintenance manual provides a specific approved procedure.
Being a certificated aircraft mechanic does not authorize unapproved repairs to a small UAS when the manufacturer’s instructions control maintenance.
A logbook entry or equivalent record should be used to document the discrepancy and the corrective action taken. Part 107 does not require an FAA Form 337 for a small UAS without an approved type certificate, but documenting the repair and verifying the aircraft is in a condition for safe operation is essential. A structural failure does not automatically require retiring the aircraft unless the manufacturer’s service bulletin or airworthiness directive requires it.
Common Relationships Between Concepts
Several recurring relationships appear throughout the Part 107 operations and emergencies material:
VLOS is the foundation of see-and-avoid. If the Remote PIC cannot see the aircraft, the Remote PIC cannot reliably yield right-of-way, avoid collisions, or respond to an abnormal situation.
Video link failure is not the same as VLOS failure. A lost FPV feed is not an emergency if the aircraft is still visible and controllable.
Lost control link and lost GPS can occur separately or together. A lost command link requires following the manufacturer’s programmed lost-link procedure. A lost GPS signal may only require switching to manual control and landing.
A small UAS never has the right-of-way over a manned aircraft. Regardless of approach direction or altitude, the sUAS must yield.
Preflight defects that seem minor can become in-flight emergencies. A cracked propeller or missing screw may fail under load. When no manufacturer repair exists, replacement is required.
The Remote PIC’s personal fitness is a safety-of-flight issue. Illness, fatigue, or heat stress is a valid reason to terminate a flight.
Emergency priorities are consistent: first reduce risk to persons and property, then recover the aircraft, and then document and correct any defects.
