Chapter 5: Weather and Environmental Factors

5.1 Impact of weather on sUAS operations

Weather conditions can significantly impact the performance and safety of sUAS operations. Factors such as wind speed, temperature, humidity, and precipitation can affect the stability, endurance, and overall functionality of the aircraft. Strong winds can cause the sUAS to drift off course or become difficult to control, while extreme temperatures can impact battery life and electronic components. Precipitation, such as rain or snow, can damage the aircraft and impair visibility for the operator.

5.3 Identifying and mitigating weather-related risks

Identifying potential weather-related risks is essential for maintaining the safety of sUAS operations. Operators should conduct a thorough pre-flight assessment of the weather conditions and consider factors such as wind speed and direction, temperature, humidity, and the presence of precipitation or other hazards, such as fog or dust. Based on this assessment, operators should develop and implement appropriate risk mitigation strategies, such as adjusting flight paths, postponing operations, or using alternative equipment better suited to the prevailing conditions.

Impact of weather on sUAS operations
Understanding and interpreting weather reports and forecasts
Identifying and mitigating weather-related risks
Environmental considerations, such as temperature and wind

5.4 Utilizing weather resources and tools

To support effective weather-related decision-making, sUAS operators should be familiar with and utilize a range of weather resources and tools. These may include official government sources, such as the National Weather Service or the Federal Aviation Administration, as well as specialized aviation weather websites and mobile applications. By leveraging these resources and staying informed about current and forecasted weather conditions, operators can make informed decisions and ensure the safety and success of their sUAS operations.

5.2 Understanding and interpreting weather reports and forecasts

To ensure safe and efficient sUAS operations, it is crucial for operators to understand and interpret weather reports and forecasts accurately. This includes familiarizing oneself with key terminology, such as METAR (Meteorological Terminal Aviation Routine Weather Report) and TAF (Terminal Aerodrome Forecast), and understanding how to read and interpret the information provided. Operators should also be aware of the limitations of weather forecasts and be prepared to adapt their plans accordingly.

Scenario Example

Michael, an experienced sUAS operator, was excited to fly his new FPV drone to capture stunning aerial footage of the local countryside. He had been planning this flight for weeks and had carefully studied the weather reports and forecasts to ensure optimal conditions.

On the morning of the flight, Michael arrived at the designated location and began his pre-flight checklist. He noticed that the wind speed was slightly higher than he had anticipated, but still within the acceptable range for his drone. Michael double-checked his equipment, ensuring that everything was in proper working order, and then took off.

As he piloted the drone through the sky, Michael marveled at the breathtaking views displayed on his FPV goggles. The rolling hills, lush forests, and winding rivers looked even more impressive from above. However, as he continued his flight, he noticed that the wind speed had increased significantly, causing the drone to drift off course.

Remembering his training, Michael quickly adjusted his flight path and reduced the drone's altitude to minimize the impact of the wind. He also kept a close eye on the battery level, knowing that the increased wind resistance could drain the battery more quickly than expected.

Suddenly, Michael noticed a rapidly approaching storm cloud on the horizon. He had been so focused on capturing the perfect footage that he had failed to notice the changing weather conditions. Realizing the potential danger, Michael immediately began to navigate the drone back to his location, carefully monitoring its progress and making necessary adjustments to maintain control.

As he brought the drone in for a landing, Michael felt a sense of relief wash over him. He had successfully identified and mitigated a weather-related risk, thanks to his understanding of weather reports and his ability to adapt to changing conditions.

Upon reviewing the footage, Michael was thrilled with the stunning visuals he had captured, but he also recognized the importance of remaining vigilant and prepared for unexpected weather challenges. He made a mental note to be even more thorough in his pre-flight weather assessments and to always prioritize safety over the perfect shot.

METAR

which stands for Meteorological Terminal Aviation Routine Weather Report, is a standardized format for reporting weather observations at airports. METARs are typically issued hourly and provide information about current weather conditions, including wind speed and direction, visibility, cloud cover, temperature, dew point, and barometric pressure.

Here's an example of a METAR report:

KORD 121151Z 22015G25KT 180V250 1SM R32L/3000VP6000FT -RA BR BKN007 OVC015 12/11 A2990 RMK AO2 PK WND 22029/1128 SLP120 P0002 T01220106

Let's break down the key components of this METAR:

- KORD: The station identifier for Chicago O'Hare International Airport.

- 121151Z: The date and time of the observation (12th day of the month, 11:51 UTC).

- 22015G25KT: The wind direction and speed. In this case, the wind is coming from 220 degrees at 15 knots, with gusts up to 25 knots.

- 180V250: The wind direction variability, indicating that the wind direction varies between 180 and 250 degrees.

- 1SM: The visibility is 1 statute mile.

- R32L/3000VP6000FT: The runway visual range for runway 32L is between 3,000 and 6,000 feet, with varying conditions along the runway.

- -RA: Light rain is present.

- BR: Mist or fog is present.

- BKN007 OVC015: There is a broken layer of clouds at 700 feet AGL and an overcast layer at 1,500 feet AGL.

- 12/11: The temperature is 12°C (54°F), and the dew point is 11°C (52°F).

- A2990: The barometric pressure is 29.90 inHg.

- RMK: The remarks section, which includes additional information such as peak wind speed and sea-level pressure.

Pilots and sUAS operators use METARs to assess current weather conditions and make informed decisions about the safety and feasibility of their flights.

METARs follow a standardized format that allows for easy interpretation by pilots, air traffic controllers, and other aviation professionals. The format includes the following elements in a specific order:

Station Identifier: A four-letter code identifying the airport or weather station.
Date and Time: The day of the month and the time of the observation in UTC, followed by the letter "Z" to denote Zulu time (UTC).
Wind Information: Wind direction in degrees (true) and speed in knots, followed by "G" and the gust speed if applicable.
Visibility: Reported in statute miles or meters.
Present Weather: Descriptions of current weather conditions, such as rain, snow, or fog, using standardized abbreviations.
Sky Condition: Cloud cover and height reported in feet above ground level (AGL) using abbreviations such as FEW (few), SCT (scattered), BKN (broken), or OVC (overcast).
Temperature and Dew Point: Reported in degrees Celsius.
Altimeter Setting: Barometric pressure adjusted to sea level, reported in inches of mercury (inHg) in the U.S. and hectopascals (hPa) elsewhere.
Remarks: Additional information, such as recent weather phenomena, sea-level pressure, or temperature/dew point in tenths of a degree Celsius.

METARs are typically issued hourly at most airports and weather stations. However, if conditions change significantly between hourly reports, a special METAR (SPECI) may be issued to provide more timely information.

In the United States, METARs are produced by the National Weather Service (NWS) and disseminated through various channels, including the Federal Aviation Administration (FAA) and the Aviation Weather Center (AWC). The observations are made by certified weather observers or automated weather stations, which are equipped with sensors to measure various weather parameters.

Internationally, METARs are produced by the respective countries' meteorological authorities and distributed through the World Meteorological Organization (WMO) and the International Civil Aviation Organization (ICAO).

Pilots and other aviation professionals access METARs through various means, such as:

Aviation weather websites and mobile applications
Direct communication with air traffic control or flight service stations
Onboard weather systems in aircraft
Airport terminal information systems

By staying informed about the most current METAR information, pilots and sUAS operators can make informed decisions about the safety and feasibility of their flights based on the prevailing weather conditions.

Chapter Quiz

This quiz is designed to assess your ability to read and interpret METAR reports accurately, which is essential for pilots, sUAS operators, and other aviation professionals to make informed decisions based on current weather conditions.By the end of this quiz, you will have demonstrated your proficiency in reading and interpreting METAR reports, a crucial skill for ensuring safe and efficient aviation operations.

TAKE QUIZ