A to Z of Aviation Terminology - (S)

|   A   |   B   |   C   |   D   |   E   |   F   |   G   |   H   |   I   |   J   |   K   |   L   |   M  
 N   |   O   |   P   |    |   R   |   S   |   T   |   U   |   V   |   W   |   X   |   Y   |   Z   |

Scheduled air transportation refers to the provision of regular and pre-arranged commercial air services between designated airports, using aircraft that operate on a published schedule. These air services are usually operated by airlines and are designed to carry passengers and cargo from one place to another on a regular basis. Scheduled air transportation provides a reliable and convenient mode of transportation for travelers and is often used for both business and leisure purposes. The frequency and timing of flights are set in advance, allowing passengers to plan their trips with certainty.
In aviation, a segment refers to a single portion of a flight journey, usually between two consecutive stops, that are part of a larger itinerary. It can refer to either a single trip taken by an aircraft from one airport to another, or a portion of a passenger's journey from their origin to their destination. For example, if a passenger travels from city A to city B with a stopover in city C, then the journey can be considered as two segments - A to C and C to B. The concept of segments is used for a variety of purposes, including flight scheduling, ticket pricing, and tracking of frequent flyer miles.
Sideslip refers to the sideways movement of an aircraft in relation to its intended flight path, caused by a difference in airspeed or angle of attack between one wing and the other. Sideslip can be intentional, as when a pilot uses it to align an aircraft with a runway during a crosswind landing, or unintentional, as when it results from incorrect control inputs or a malfunction of the aircraft's systems. Too much sideslip can cause a loss of lift and a reduction in control effectiveness, potentially leading to a stall or spin. Pilots are trained to recognize and correct sideslip, and aircraft are designed with features such as winglets and vortex generators to reduce its occurrence. Sideslip is a key aspect of aircraft handling and must be properly managed for safe and efficient flight
SIGMET (Significant Meteorological Information) is a type of aviation weather advisory issued by meteorological agencies to provide information on significant weather phenomena that may affect the safety of air navigation. It is typically issued for hazardous weather conditions such as thunderstorms, icing, turbulence, and volcanic ash clouds.

SIGMETs are an important source of information for pilots, air traffic controllers, and aviation meteorologists, as they provide up-to-date information on weather conditions that can affect flight safety. This information is critical for flight planning and for making real-time decisions during flight.

SIGMETs are issued by regional meteorological centers and are broadcast to pilots and air traffic controllers via satellite and other communication channels. They typically include information on the location, movement, and intensity of hazardous weather conditions, as well as any potential impacts on flight operations.

In addition to their importance for flight safety, SIGMETs are also used by meteorologists and weather forecasters to monitor and track the development of severe weather events, and to issue forecasts and warnings to the aviation community.

Overall, SIGMETs play a critical role in ensuring the safe and efficient operation of aircraft, and they are an essential tool for flight planning and real-time weather decision making in aviation.
A skid is a type of uncontrolled flight condition that occurs when an aircraft loses its directional control on the ground during takeoff or landing. A skid can be caused by a number of factors, including a slippery runway surface, sudden changes in wind direction, or a sudden loss of engine power. During a skid, the aircraft may slide or slide sideways on the runway, rather than moving forward in the direction of its intended path.

Skids can be dangerous, as they can cause damage to the aircraft and can increase the risk of a runway excursion, which is a situation in which an aircraft leaves the runway during takeoff or landing. To minimize the risk of a skid, pilots and air traffic controllers must be aware of the conditions of the runway and take steps to maintain control of the aircraft during takeoff and landing. This may include using anti-skid brakes or other systems designed to increase traction and stability on the runway.

In aviation, skids are considered a critical safety issue and are addressed by regulatory agencies and the aviation industry through the development of standards, training programs, and safety initiatives aimed at reducing the risk of skids and other uncontrolled flight conditions.
Slip refers to a condition in which an aircraft is not aligned with its direction of motion, resulting in sideways movement relative to the ground. This occurs when the aircraft's wings generate more lift on one side than the other, causing the aircraft to "slip" or yaw in the direction of the lower-lift wing.

Slips can be intentional or unintentional. Intentional slips are often used by pilots to increase the rate of descent during an approach to landing or to compensate for crosswinds that may be present on the runway. Unintentional slips, on the other hand, can result from factors such as incorrect use of the rudder, incorrect engine power settings, or wind shear.

In general, slips are considered an uncontrolled flight condition and can be dangerous if not properly managed. To avoid slips, pilots must maintain proper control of the aircraft and correct any misalignment as soon as it is noticed. Training programs and safety initiatives aimed at preventing slips and other uncontrolled flight conditions are critical components of the aviation industry's efforts to ensure safe and efficient flight operations.
The speed of sound is the speed at which sound waves propagate through a medium. It is a fundamental physical constant that depends on the properties of the medium, such as its temperature, pressure, and density.

In air at sea level and a temperature of 15°C, the speed of sound is approximately 340 meters per second (m/s) or 1225 kilometers per hour (km/h). This value increases with temperature and decreases with pressure, which means that the speed of sound can vary significantly depending on the conditions.

In aviation, the speed of sound is an important factor in determining the performance of aircraft and in understanding the effects of supersonic flight. At high altitudes, the speed of sound decreases due to the reduced air pressure, which allows aircraft to fly faster than the speed of sound. Supersonic flight is the flight of an aircraft at speeds greater than the speed of sound, and it can have significant impacts on the environment, including sonic booms and other sonic disturbances.

As a result, supersonic flight is regulated by international and national aviation authorities to minimize these impacts and to ensure the safety and efficiency of air travel.
Sport jet charter refers to the use of private jets for recreational or sporting activities. This type of private aviation service is often used by individuals or groups who want to attend sporting events, such as golf tournaments or horse racing events, or to engage in outdoor activities, such as hunting or fishing trips. Sport jet charter provides an efficient and convenient way for individuals to reach remote destinations for their sporting activities, bypassing the hassle and delay of commercial air travel. This type of service is typically provided by private jet charter companies and can be tailored to meet the specific needs and requirements of each individual or group.
Squawk is a code assigned by air traffic control (ATC) to identify an aircraft on radar. This code, also known as a transponder code, is used by ATC to monitor the position, altitude, and speed of aircraft and to provide separation between them. When an aircraft is assigned a squawk code, it enters the code into its transponder, a device that sends electronic signals to ATC's radar system. The squawk code helps ATC to differentiate between different aircraft and to provide efficient and safe control of air traffic. The term "squawk" is often used as a verb, as in "the pilot has been instructed to squawk code 7600," which means the pilot has been told to set the transponder code to 7600.
A stabilized approach refers to a consistent and controlled descent of an aircraft towards a landing runway, with the goal of ensuring a safe and efficient landing. A stabilized approach is an important part of safe flight operations, as it reduces the risk of a landing accident and helps to ensure that the aircraft is in the correct position and configuration for landing.

In a stabilized approach, the aircraft is flown in a controlled manner, with the speed, altitude, and other flight parameters monitored and adjusted as needed to ensure that the aircraft is in the correct position and configuration for landing. This typically involves establishing and maintaining a constant descent angle, airspeed, and landing configuration, such as flaps and landing gear, throughout the approach to the runway.

A stabilized approach is important because it reduces the risk of a landing accident, as the aircraft is flown in a consistent and controlled manner, with the pilot able to make adjustments as needed to ensure a safe landing. Additionally, a stabilized approach can improve landing performance, reduce the workload of the pilot, and conserve fuel, as the aircraft is flown in a more efficient manner.
Stage length refers to the distance between two consecutive points on a flight route, typically expressed in nautical miles or kilometers. It is used to calculate the fuel consumption and the payload capacity of an aircraft for a specific flight segment. Stage length is one of the key factors that airlines and aircraft operators consider when planning their flight operations and determining the feasibility of a route.
A stall is a condition where the airflow over an aircraft's wings is disrupted, resulting in a loss of lift and an increase in drag. This can happen when the angle of attack, which is the angle between the wing and the oncoming airflow, becomes too large, causing the air to separate from the surface of the wing and form turbulence. In a stall, the aircraft will typically start to descend, even if the pilot is still applying upward elevator pressure. Stalls can occur during takeoff, landing, or in flight and can be dangerous if not recognized and corrected in a timely manner. It is important for pilots to understand and be trained in stall recognition and recovery procedures.
The standard lapse rate refers to the average rate of decrease in temperature with increasing altitude in the Earth's lower atmosphere. This temperature decrease is considered "standard" because it is based on the average atmospheric conditions that are typically encountered at mid-latitudes. The standard lapse rate is approximately 2°C per 1,000 feet of altitude gain, or 6.5°C per kilometer. This means that, on average, the temperature decreases by 2°C for every 1,000 feet (300 meters) of altitude gain. This standard lapse rate is used as a reference for various calculations in aviation, including flight planning and performance calculations.
A standard rate turn in aviation is a type of turn performed by an aircraft in which the rate of turn is considered "standard." A standard rate turn is typically used as a reference for pilots and aircraft performance, and is defined as a turn in which the aircraft rotates 360 degrees in 2 minutes (a rate of 3 degrees per second).

In a standard rate turn, the pilot will bank the aircraft to initiate the turn and then maintain a constant bank angle until the desired direction is reached. The bank angle is typically set to approximately 15 degrees, which will result in a standard rate of turn.

Standard rate turns are important for pilots because they allow for standardized performance measurements and make it easier to perform turns accurately and consistently. They are also used in air traffic control procedures and during navigation to maintain a consistent rate of turn.
Straight-and-level flight is a flight condition in which an aircraft flies at a constant altitude and airspeed, with wings level and not climbing or descending. In this condition, the aircraft's attitude, altitude, and airspeed remain constant, providing a smooth and steady flight for passengers. This is a basic flight maneuver that all pilots must master, and is often used for cruise flight during long-distance flights or for conducting aerial photography or surveillance. Flying straight-and-level requires precise control of the aircraft's thrust, pitch, and roll, and is an essential component of safe and efficient air travel.
Stratus clouds are a type of low-level clouds characterized by a uniform, featureless base and a dull, gray appearance. They typically form at low altitudes, often below 6,500 feet (2,000 meters), and can cover large areas of the sky. Stratus clouds are typically associated with overcast and cloudy weather conditions, and can bring light precipitation, such as drizzle or light rain. In aviation, pilots use the appearance of stratus clouds to assess the weather conditions and to make decisions about flight routes, altitudes, and approaches. Stratus clouds can also have an impact on aircraft performance, as they can reduce visibility and cause turbulence, which can affect the comfort of passengers and crew members.
A super-midsize jet is a type of aircraft that falls between a midsize jet and a large-cabin jet in terms of size, range, and capabilities. It typically has a range of around 4,000 to 5,000 nautical miles, and can carry between 8 to 14 passengers, with a cabin space that is typically more spacious and comfortable than a midsize jet but smaller than a large-cabin jet. These jets are typically used for long-haul flights and offer a balance of performance, cost-effectiveness, and comfort.

|  A  |  B  |  C  |  D  |  E  |  F  |  G  |  H  |  I  |  J  |  K  |  L  |  M  |  N  |  O  |  P  |  Q  |   R   |  S  |  T  |  U  |  V  |  W  |  X  |  Y  |  Z  |