Before each flight, the remote PIC must perform tasks to ensure that the sUAS is in a condition for safe operation. This preflight inspection should be conducted in accordance with the sUAS manufacturer’s inspection procedures when available (usually found in the manufacturer’s owner or maintenance manual) and/or an inspection procedure developed by the sUAS owner or operator.
Such inspections should focus on evaluating equipment for damage or other malfunction(s). The preflight check should be performed prior to each flight and include an appropriate UAS preflight inspection that is specific and scalable to the sUAS, the program, and the operation. This should encompass the entire system in order to determine a continual condition for safe operation prior to flight. If manufacturers do not provide a preflight checklist or guide, remote PICs should create their own guidelines to properly check all components critical to the safety and operation of flight.
An example of a common issue with sUAS is propeller damage or installation issues. Propeller blades can have nicks, cracks, bends, etc., that significantly degrade the structural integrity of the blade and could potentially impact the controllability and overall safety of the sUAS. Also, propeller installation must be done per the manufacturer guidelines. Failure to do so can lead to separation of the blade inflight, loss of control, damage to the sUAS, and/or injury to the user or other persons in the area.
Another important item to consider during the preflight inspection is the security of panels, doors, and other components as well as the security of attachments of object such as the camera, antennae, and the battery. Batteries should be inspected for damage or malfunctions. If a battery is “bloated” or looks abnormal in anyway, it should not be used or charged. A good practice is to turn on the engine(s)/motor(s) to ensure they are working properly followed by a brief, low altitude test flight to verify controllability, radio link, and system integrity.
At minimum, the preflight inspection should include a visual or functional check of the following items:
The FAA requires that the remote PIC and other crewmembers coordinate to:
To achieve this goal, the remote PIC should:
One way to accomplish effective communications procedures is to have a VO maintain visual contact with the sUA and maintain awareness of the surrounding airspace, and then communicate flight status and any hazards to the remote PIC and person manipulating the controls so that appropriate action can be taken. The remote PIC should evaluate which method is most appropriate for the operation and should be determined prior to flight.
Aviation has a language all its own to facilitate communication between all participants. These participants include both ATC and pilots, often communicating in a busy and noisy environment. The most important component to effective communications is understanding between the parties involved. Brevity is important, and contacts should be kept as brief as possible. Basic communication procedures include:
The phonetic alphabet is used in aviation communications by both ATC facilities and pilots. Use the phonetic equivalents for single letters and to spell out groups of letters or difficult words during adverse communications conditions. See Figure 5-1.

Figure 5-1. Phonetic alphabet
Figures indicating hundreds and thousands in round numbers as used in weather reports or for altitudes should include both the first number of the hundred/thousand and then followed by the quantity descriptor(s). For example, “500” should be spoken “fife hundred.” Another example, “4,500” should be annunciated “four thousand five hundred.” The number nine is spoken “niner” and the number five is spoken “fife” to further help alleviate confusion over the radio waves and to avoid confusion among languages (“nine” sounds like the German word for no: “nein”).
The three digits for course, heading or wind direction should be magnetic and spoken individually. The word “true” should be added when it applies. For example, magnetic heading 360 would be spoken “three six zero.”
Speed should be followed by the words “knots” or “mile per hour.” For example, the speed 87 knots is spoken “eighty-seven knots.”
Time is measured in relation to the rotation of the Earth. A day is defined as the time required for the earth to make one complete revolution of 360°. Since the day is divided into 24 hours, it follows that the earth revolves at the rate of 15° each hour. Thus, lines of longitude may be expressed as 90° apart, the first of which is 6 hours west of Greenwich. Twenty-four time zones have been established. Each time zone is approximately 15° of longitude in width, with the first zone centered on the meridian of Greenwich. For most aviation operations, time is expressed in terms of the 24-hour clock (for example, 8 a.m. is expressed as 0800; 2 p.m. is 1400; 11 p.m. is 2300) and may be either local or Coordinated Universal Time (UTC). UTC is the time at the prime meridian and is represented in aviation operations by the letter “Z,” referred to as “Zulu time” and is not adjusted for daylight savings time. For example, 1500Z would be spoken as “one five zero zero Zulu.”
Initial transmissions to ATC should contain the following elements:
Call signs should be spoken in their entirety the first time. Never abbreviate on initial contact or any time other aircraft call signs have similar numbers/sounds or identical letters/numbers. Standard phraseology should be used at all times. See Figure 5-2.

Figure 5-2. Standard aviation phraseology
When ATC authorization is required (at or near an airport with a control tower and/or when operating within controlled airspace), such permission must be requested and granted before any operation in that airspace. When ATC authorization is not required (at or near an airport without a control tower and/or when operating within uncontrolled airspace), remote PICs should monitor the CTAF to stay aware of manned aircraft communications and operations. Manned pilots will self-announce their position and intentions on the CTAF, consistent with recommended traffic advisory procedures. It is helpful to announce sUAS operations on the CTAF to increase local pilots’ situational awareness, as well as potentially increase the safe interaction among manned and unmanned aircraft. Use standard phraseology at all times so as not to confuse manned pilots or other operators on the frequency.
Automatic Terminal Information Service (ATIS) is a continuous broadcast of non-control information in selected high-activity terminal areas. ATIS frequencies are listed in the Chart Supplement U.S. To relieve frequency congestion, pilots are urged to listen to ATIS, and on initial contact, to advise controllers that the information has been received by repeating the alphabetical code word appended to the broadcast. For example: “information Sierra received.”
At airports with operating air traffic control towers (ATCT), approval must be obtained prior to advancing an aircraft onto the movement area. Ground control frequencies are provided to reduce congestion on the tower frequency. They are used for issuance of taxi information, clearances, and other necessary contacts. If instructed by ground control to “taxi to” a particular runway, the pilot must stop prior to crossing any runway. A clearance must be obtained prior to crossing any runway. Aircraft arriving at an airport where a control tower is in operation should not change to ground control frequency until directed to do so by ATC.
The key to operating at an airport without an operating control tower is selection of the correct CTAF, which is identified in the Chart Supplement U.S. and on the Sectional Chart. CTAF is the frequency on which pilots (manned and unmanned) announce their intentions, location, or other pertinent information and monitor the intentions, location, etc. conveyed by other pilots in the area. If the airport has a part-time ATCT, the CTAF is usually a tower frequency. Where there is no tower, UNICOM, (if available) is usually the CTAF. UNICOM is limited to the necessities of safe and expeditious operation of private aircraft pertaining to runways and wind conditions, types of fuel available, weather, and dispatching. UNICOM may also transmit information concerning ground transportation, food, lodging and services available during transit. When no tower, FSS, or UNICOM is available, use the MULTICOM frequency 122.9 for self-announce procedures.
Often, there is more than one airport using the same frequency. To avoid confusion, be sure to state the airport name, followed by the term “traffic” (addressing other aircraft in the area) as part of the beginning and end of the transmission. For example, “Manatee traffic, unmanned aircraft XYZ is operating at 200 AGL approximately 3 NM south of the airport, Manatee traffic.” See Figure 5-3.

Figure 5-3. Summary of recommended communications procedures
Although it is unlikely that ATC will be able to track unmanned aircraft in the near future, they may issue information about traffic that is in the vicinity of sUAS operations. Traffic advisories given by ATC will refer to the other aircraft by azimuth in terms of the 12-hour clock, with twelve o’clock being the direction of flight (track), not aircraft heading. Each hourly position is equal to 30°. For example, an aircraft heading 090° is advised of traffic at the three o’clock position. The remote PIC (and any VO or crew) should look 90° to the right of the direction of flight of the sUAS, or to the south of the area of operation/sUA. Remote pilots should be aware that traffic information is based upon the track observed on radar, thus if traffic advisories about your operation are conveyed to manned aircraft, they may indicate a slight difference in the perceived location of observed aircraft and the actual location of such aircraft. See Figure 5-4.

Figure 5-4. Traffic advisories are issued based on direction of flight, not the aircraft heading
Most sUAS use radio frequencies to establish the data link between the control station and the small unmanned aircraft.
Considerations for radio frequencies used in sUAS operations include:
The most commonly used sUAS frequencies are 2.4 GHz and 5.8 GHz. These unlicensed radio frequency bands are regulated by the Federal Communications Commission (FCC). These frequencies are also used for computer wireless networks. Therefore, frequency interference can cause problems when operating an unmanned aircraft in areas with many wireless signals (e.g., near dense housing or office buildings). Lost links and flyaways are some of the reported problems with sUAS frequency implications. To avoid frequency interference many modern sUAS operate using a 5.8 GHz system to control the sUAS, and a 2.4 GHz system to transmit video and photos to the ground. Consult the sUAS operating manual and manufacturers recommended procedures before conducting sUAS operations
Both sUAS radio frequency bands (2.4 GHz and 5.8 GHz) are considered line-of-sight. Be aware that the command and control link between the control station and the sUAS might not work properly when barriers are between the control station and the unmanned aircraft.
Radio transmissions, such as those used to control an sUA and to downlink real-time video, must use frequency bands that are approved for use by the operating agency. The FCC authorizes civil operations. Some operating frequencies are unlicensed and can be used freely (e.g., 900 MHz, 2.4 GHz, and 5.8 GHz) without FCC approval. All other frequencies require a user-specific license for all civil users, except federal agencies, to be obtained from the FCC. For further information, visit fcc.gov/licensing-databases/licensing. It is recommended that the remote PIC utilize a frequency spectrum analyzer prior to operation to ensure that there are no potential interfering transmissions in the area.
Follow any manufacturer guidance for appropriate response procedures in abnormal or emergency situations prior to flight. In case of an inflight emergency, the remote PIC is permitted to deviate from any rule of Part 107 to the extent necessary to meet that emergency. FAA may request a written report explaining the deviation. Review emergency actions during preflight planning and inform crewmembers of their responsibilities.
The remote PIC must be prepared to respond to abnormal and emergency situations during sUAS operations. Refer to the manufacturer’s guidance for appropriate procedures in the following situations:
Without an onboard pilot, sUAS crewmembers rely on the command and control link to operate the aircraft. For example, an uplink transmits command instructions to the aircraft and a downlink transmits the status of the aircraft and provides situational awareness to the remote PIC or person manipulating the controls. Lost link is an interruption or loss of the control link between the control station and the unmanned aircraft, preventing control of the aircraft. As a result, the unmanned aircraft may perform pre-set lost link procedures. Such procedures ensure that the unmanned aircraft:
A lost link is an abnormal situation, but not an emergency. A lost link is not considered a flyaway.
Follow the manufacturer’s recommendations for programming lost link procedures prior to the flight. Examples of lost link procedures may include, when applicable:
Plan contingency measures in the event recovery of the sUAS is not feasible.
Remote PICs should conduct a thorough preflight briefing with crewmembers to discuss all lost link procedures including crewmember responsibilities and all contingency plans for abnormal and emergency situations. Contingency planning should include an alternate landing/recovery site to be used in the event of an abnormal condition that requires a precautionary landing away from the original launch location. Incorporate the means of communication with ATC throughout the descent and landing (if required for the flight operation) as well as a plan for ground operations and securing/parking the aircraft on the ground. This includes the availability of control stations capable of launch/recovery, communication equipment, and an adequate power source to operate all required equipment. Take into consideration all airspace constructs and minimize risk to other aircraft by avoiding persons, congested areas, and other aircraft to the maximum extent possible.
Flight termination is the intentional and deliberate process of performing controlled flight to the ground. Flight termination may be part of lost link procedures, or it may be a contingency that you elect to use if further flight of the aircraft cannot be safely achieved, or if other potential hazards exist that require immediate discontinuation of flight. Execute flight termination procedures if you have exhausted all other contingencies. Flight termination points (FTPs), if used, or alternative contingency planning measures must:
A flyaway often begins as a lost link—an interruption or loss of the control link prevents control of the aircraft. As a result, the unmanned aircraft is not operating in a predicable or planned manner. However, in a flyaway, the pre-set lost link procedures are not established or are not being executed by the unmanned aircraft, creating an emergency situation. In rare instances, software or hardware malfunctions may induce a flyaway. If a flyaway occurs while operating in airspace that requires authorization, notify ATC as outlined in the authorization.
GPS tools can be a valuable resource for flight planning and situational awareness during sUAS operation. However, as with manned aviation, remote PICs in sUAS operations must avoid overreliance on automation and must be prepared to operate the unmanned aircraft manually, if necessary.
Battery fires pose a significant hazard to sUAS. Because sUAS often utilize high energy density, rechargeable batteries, the risk for battery malfunction or failure are real concerns for sUAS operations. The charge/discharge cycle involves significant changes in temperature which can stress internal components of the battery. Before each flight, batteries should be inspected for any obvious damage, bloating or deformation, and excessive heat.
Both lithium metal and lithium-ion batteries are:
Thermal runaway usually occurs during a rapid discharge event such as a short or structural failure within in battery cell. During thermal runaway, lithium batteries generate sufficient heat to cause adjacent cells to also go into thermal runaway. Once in thermal runaway, the battery may hiss (release gas), smoke, catch fire, or explode. Fires with these types of batteries are very difficult to extinguish. Because lithium can react with water, it is inadvisable to use water to aid in extinguishing the fire. Type D fire extinguishers, designed for chemical and combustible metal fires are recommended to assist in fire suppression. Covering the battery in sand can also help smother the fire. Batteries should be charged and stored in battery bags specifically designed to contain battery failures. As with any component, follow manufacturer guidelines and cautions prior to and during use.
Ensure careful storage of spare (uninstalled) lithium batteries. Take the following precautions to prevent a battery fire:
When preparing to conduct sUAS operations, do not charge or use any battery with signs of damage or defect. For example, check carefully for small nicks in the battery casing and be alert for signs of bubbling or warping during charging. Once the battery is installed and the sUAS takes flight, the remote PIC or ground crew might not observe a battery fire until it is too late to land the aircraft safely. If a battery fire occurs, follow any manufacturer guidance for response procedures. Following flight, allow the battery to cool prior to charging or storing (allow it to return to room temperature).
When disposing of a used or damaged battery, follow the manufacturer and local trash collection guidelines, as these types of devices are typically considered hazardous materials and should not be treated as regular trash for disposal.
A remote PIC should use a variety of different resources to safely operate an sUAS and needs to be able to manage these resources effectively. An sUAS operation may involve one individual or a team of crewmembers, as follows:
A culture of safety must be established with all commercial sUAS operations. Many techniques from manned aircraft operations apply to the operation of unmanned aircraft. Examples include situational awareness, risk-based aeronautical decision making (ADM), crew resource management (CRM), and safety management systems (SMS).
The remote PIC attains situational awareness by obtaining as much information as possible prior to a flight and becoming familiar with the performance capabilities of the sUAS, weather conditions, surrounding airspace, privacy issues, and ATC requirements. Sources of information include a weather briefing, ATC, FAA, local pilots, local laws and ordinances, as well as landowners.
Technology, such as GPS, mapping systems, and computer applications, can assist in collecting and managing information to improve your situational awareness and risk-based ADM. ADM is a systematic approach to the mental process used by pilots to consistently determine the best course of action in response to a given set of circumstances.
CRM is the effective use of all available resources—human, hardware, and information—prior to and during flight to ensure a successful outcome of the operation. The remote PIC must integrate CRM techniques into all phases of the sUAS operation. Many of these techniques traditionally used in manned aircraft operations are also applicable for sUAS, such as the ability to:
Risk management is part of the decision-making process which relies on situational awareness, problem recognition, and good judgment to reduce risks associated with each flight. Sound risk management skills will help prevent and break the final “link” in the accident chain.
An SMS is a formal, top-down business-like approach to managing safety risk, which includes a systemic approach to managing safety, including the necessary organizational structures, accountabilities, policies, and procedures.
The remote PIC identifies, delegates, and manages tasks for each sUAS operation. Tasks can vary greatly depending on the complexity of the sUAS operation. Supporting crewmembers can help accomplish those tasks and ensure the safety of flight. For example, VOs and other ground crew can provide valuable information about traffic, airspace, weather, equipment, and aircraft loading and performance. The remote PIC:
Hazardous attitudes can affect unmanned operations if the remote PIC is not aware of the hazards, leading to situations such as:
Operational pressure is a contributor to becoming subject to these pitfalls. Studies have identified five hazardous attitudes that can interfere with the ability to make sound decisions and properly exercise authority: anti-authority, impulsivity, invulnerability, “machoism,” and resignation. See Figure 5-5. Remote PICs should be alert to recognize hazardous attitudes (in themselves or in other crewmembers), bring attention to and label actions deemed to be hazardous, and correct the behavior.
Identifying associated hazards is the first step to mitigating the hazardous attitude. Analyzing the likelihood and severity of the hazards occurring establishes the probability of risk. In most cases, risk management steps can be taken to mitigate, even eliminate, those risks. Actions such as using VOs, completing a thorough preflight inspection, planning for weather, familiarity with the airspace, proper aircraft loading, and performance planning can mitigate identified risks. Take advantage of information from a weather briefing, ATC, the FAA, local pilots, and landowners. Technology can aid in decision making and improve situational awareness. Being able to collect the information from these resources and manage the information is key to situational awareness and could have a positive effect on your decision making.
It is also beneficial for remote PICs to assess risk for each mission or type of operation. Guidance on how to conduct such an evaluation is available from the U.S. Geological Survey and can be found in the reader resources at asa2fly.com/TPUAS. This can focus attention on actions or parts of the mission that may entail the highest risk and therefore can be actively mitigated with proper planning, ADM, and CRM.

Figure 5-5. Hazardous attitudes
[10-2024]