Magnetic compass. A device for determining direction
measured from magnetic north.
Magneto. A self-contained engine-driven unit that supplies
electrical current to the spark plugs, completely independent
of the airplane’s electrical system. Normally there are two
magnetos per engine.
Make/model. Refers to the manufacturer and model of a
specific aircraft.
Maneuvering altitude. An altitude above the ground
that allows a sufficient margin of height to permit safe
maneuvering.
Maneuvering speed (VA). The maximum speed at which full,
abrupt control movement can be used without overstressing
the airframe.
Maneuverability. Ability of an aircraft to change directions
along a flightpath and withstand the stresses imposed upon
it.
Mast. The carriage structural component that is attached to
the rear of the carriage keel and the top of the front tube. The
top is the carriage attachment the wing.
Maximum gross weight. The maximum authorized weight
of the aircraft and all of its equipment as specified in the
POH/AFM/AOI for the aircraft.
Maximum structure cruising speed (VNO). The speed not
to exceed except in smooth air; the upper limit of the green
arc.
Mean aerodynamic chord (MAC). The average distance
from the leading edge to the trailing edge of the wing.
Mean sea level (MSL). The average height of the surface
of the sea for all stages of tide. A number preceding MSL
indicates altitude in feet above mean sea level.
Mechanical Turbulence. Type of turbulence caused by
obstructions on the ground interfering with smooth flow
of the wind. Trees, buildings and terrain can all cause
mechanical turbulence.
Medical certificate. Acceptable evidence of physical fitness
on a form prescribed by the Administrator.
Medium-banked turn. Turn resulting from a degree of bank
(approximately 20 to 45 degrees) at which the WSC remains
at a constant bank.
METAR. See Aviation Routine Weather Report.
Microburts. A strong downdraft which normally occurs over
horizontal distances of 1 NM or less and vertical distances of
less than 1,000 feet. In spite of its small horizontal scale, an
intense microburst could induce windspeeds greater than 100
knots and downdrafts as strong as 6,000 feet per minute.
Military Operations Area (MOA). Airspace of defined
vertical and lateral limits established for the purpose of
separating certain military training activity from IFR
traffic.
Military Training Routes (MTR). Special routes developed
to allow the military to conduct low-altitude, high-speed
training.
Minimum controllable airspeed. An airspeed at which any
further increase in angle of attack, increase in load factor, or
reduction in power, would result in an immediate stall.
Minimum drag speed (L/D MAX). The point on the total
drag curve where the lift-to-drag ratio is the greatest. At this
speed, total drag is minimized.
Mindset. A factor in aeronautical decision making where
decision making is influenced by preconceived ideas about
the outcome of events. For example, an expectation of
improving weather conditions can lead to increased risk
during a flight.
Mixture. The ratio of fuel to air entering the engine’s
cylinders.
MOA. See Military operations Area.
Mode C transponder. A receiver/transmitter which will
generate a radar reply signal upon proper interrogation; the
interrogation and reply being on different frequencies. Mode
C means the reply signal includes altitude information.
Moment. A force that causes or tries to cause an object to
rotate. The product of the weight of an item multiplied by its
arm. Moments are expressed in pound-inches (lb-in). Total
moment is the weight of the PPC multiplied by the distance
between the datum and the CG.
Moment arm. The distance from a datum to the applied
force.
MSL. See mean sea level.
National Airspace System (NAS). The common network of
United States airspace. air navigation facilities, equipment
and services, airports or landing areas; sectional charts,
information and services; rules, regulations and procedures,
technical information; and manpower and material.
National Security Area (NSA). Area consisting of airspace
of defined vertical and lateral dimensions established at
locations where there is a requirement for increased security
and safety of ground facilities. Pilots are requested to
voluntarily avoid flying through the depicted NSA. When it
is necessary to provide a greater level of security and safety,
flight in NSAs may be temporarily prohibited. Regulatory
prohibitions are disseminated via NOTAMs.
National Transportation Safety Board (NTSB). A United
States Government independent organization responsible for
investigations of accidents involving aviation, highways,
waterways, pipelines, and railroads in the United States.
NTSB is charged by congress to investigate every civil
aviation accident in the United States.
NAVAID. Naviagtional aid.
NAV/COM. Navigation and communication radio.
Newton’s Third Law of Motion. Whenever one body exerts
a force on another, the second body always exerts on the first,
a force that is equal in magnitude but opposite in direction.
Nontowered Airport. An airport that does not have an
operating control tower. Two-way radio communications
are not required at uncontrolled airports, although it is good
operating practice for pilots to transmit their intentions on
the specified frequency.
NOTAM. See Notice to Airmen.
Notice to Airmen. A notice containing information
concerning facilities, services, or procedures, the timely
knowledge of which is essential to personnel concerned with
flight operations.
Notice To Airman (NOTAM). Notice to Airman that is
regulatory in nature.
Octane. The rating system of gasoline with regard to its
antidetonating qualities.
Operating limitations. Limitations published by aircraft
manufacturers to define limitations on maneuvers, flight load
factors, speeds and other limits. Presented in the aircraft in
the form of placards and printed in the limitations section of
the aircraft flight manual.
Overcontrolling. Using more movement in the control
column than is necessary to achieve the desired pitch-and-
bank condition.
Overshooting. The act of over flying an intended spot for
landing or flying through a course intended for intercept.
Overspeed. A condition in which an engine has produced
more rpm than the manufacturer recommends, or a condition
in which the actual engine speed is higher than the desired
engine speed as set on the propeller control.
Overtemp. A condition in which a device has reached a
temperature above that approved by the manufacturer or any
exhaust temperature that exceeds the maximum allowable for
a given operating condition or time limit. Can cause internal
damage to an engine.
Parallel runways. Two or more runways at the same airport
whose centerlines are parallel. In addition to runway number,
parallel runways are designated as L(left) and R(right)
or if three parallel runways exist, L(left), C (center) and
R(right).
Parasite drag. That part of total drag created by the design or
shape of PPC parts. Parasite drag increases with an increase
in airspeed.
Pattern altitude. The common altitude used for aircraft
maneuvering in the traffic pattern. Usually 1,000 above the
airport surface.
Personality tendencies. Personal traits and characteristics of
an individual that are set at a very early age and extremely
resistant to change.
P-factor. A tendency for an aircraft to yaw to the left due
to the descending propeller blade on the right producing
more thrust than the ascending blade on the left. This
occurs when the aircraft’s longitudinal axis is in a climbing
attitude in relation to the relative wind. The P-factor would
be to the right if the aircraft had a counterclockwise rotating
propeller.
PIC. See pilot in command.
Pilotage. Navigational technique based on flight by reference
to ground landmarks.
Pilot in command. The pilot responsible for the operation
and safety of an aircraft.
Pilot’s Operating Handbook (POH). A document
developed by the aircraft manufacturer and contains the
Aircraft Flight Manual (AFM) information or Aircraft
Operating Instructions (AOI) information.
Pitch. The rotation of a WSC about its lateral axis.
Pitch angle. The angle between the wing and the horizontal
plane of the earth.
Pitch attitude. The angle of the longitudinal axis relative
to the horizon. Pitch attitude serves as a visual reference for
the pilot to maintain orchange airspeed.
Placards. Small statements or pictorial signs permanently
fixed in the cockpit and visible to the pilot. Placards are used
for operating limitations (e.g., weight or speeds) or to indicate
the position of an operating lever (e.g., landing gear retracted
or down and locked).
Planform. The shape or form of a wing as viewed from
above. It may be long and tapered, short and rectangular, or
various other shapes.
POH. See Pilot's Operating Handbook.
Positive Dynamic Stability. The tendency over time for an
aircraft to return to a predisturbed
state.
Position lights. Lights on an aircraft consisting of a red
light on the left wing, a green light on the right wing, and
a white light on the tail. The Code of Federal Regulations
requires that these lights be displayed in flight from sunset
to sunrise.
Positive static stability. The initial tendency to return to a
state of equilibrium when disturbed from that state.
Porpoising. Oscillating around the lateral axis of the aircraft
during landing.
Powered parachute (PPC). A powered aircraft comprised
of a flexible or semi-rigid wing connected to a fuselage (cart)
so that the wing is not in position for flight until the aircraft
is in motion. The fuselage of a powered parachute contains
the aircraft engine, a seat for each occupant and is attached
to the aircraft’s landing gear.
Power-off descent. Aircraft configuration where a descent
occurs with power at idle.
Powerplant. A complete engine and propeller combination
with accessories.
PPC. See powered parachute.
PPCL. Powered parachute land.
PPCS. Powered parachute sea.
Practical test. Flight test administered by an FAA examiner
or designated examiner as a prerequisite for pilot certification.
Successful completion of the practical test is required to
earn a pilot certificate or rating. Commonly known as a
checkride.
Practical Test Standards (PTS). An FAA published
document of standards that must be met for the issuance
of a particular pilot certificate or rating. FAA inspectors
and designated pilot examiners use these standards when
conducting pilot practical tests, and flight instructors use the
PTS while preparing applicants for practical tests.
Preflight inspection. Aircraft inspection conducted
to determine if an aircraft is mechanically and legally
airworthy.
Preignition. Ignition occurring in the cylinder before the
time of normal ignition. Preignition is often caused by a
local hot spot in the combustion chamber igniting the fuel/air
mixture.
Pressure altitude. The altitude indicated when the altimeter
setting window (barometric scale) is adjusted to 29.92. This
is the altitude above the standard datum plane, which is a
theoretical plane where air pressure (corrected to 15 ºC)
equals 29.92 "Hg. Pressure altitude is used to compute density
altitude, true altitude, true airspeed, and other performance
data.
Private airport. Airport that is privately owned and not
available to the public without prior permission. They are
depicted on sectional charts for emergency and landmark
purposes.
Private Pilot Certificate. An FAA-issued pilot certificate
permitting carriage of passengers on a not-for-hire basis.
Reference 14 CFR part 61.
Prohibited area. Designated airspace within which flight
of aircraft is prohibited.
Propeller. A device for propelling an aircraft that,
when rotated, produces by its action on the air, a thrust
approximately perpendicular to its plane of rotation. It
includes the control components normally supplied by its
manufacturer.
Propeller blade angle. The angle between the propeller
chord and the propeller plane of rotation.
Propeller blast. The volume of air accelerated behind a
propeller producing thrust.
Propeller slipstream. The volume of air accelerated behind
a propeller producing thrust.
PTS. See Practical Test Standards.
Public airport. Airport that is available to the aviation
public.
Pusher configuration. Propeller configuration where the
propeller shaft faces the rear of the aircraft. Thrust produced
by the propeller pushes the aircraft, rather than pulling it.
Reciprocating engine. An engine that converts the heat
energy from burning fuel into the reciprocating movement of
the pistons. This movement is converted into a rotary motion
by the connecting rods and crankshaft.
Reduction gear. The gear arrangement in an aircraft engine
that allows the engine to turn at a faster speed than the
propeller.
Reflex. The opposite curvature of the airfoil at the trailing
edge which produces a positive pitching moment of the
WSC airfoil.
Reflex lines. Wires attached to the top of the king post and
the trailing edge of the airfoil to maintain the reflex of the
airfoil, used on some wings for trim by raising and lowering
the trailing edge of the wing.
Region of reverse command. Flight regime in which flight
at a higher airspeed requires a lower power setting and a
lower airspeed requires a higher power setting in order to
maintain altitude.
Registration certificate. A federal certificate that documents
aircraft ownership.
Relative humidity. The ratio of the existing amount of
water vapor in the air at a given temperature to the maximum
amount that could exist at that temperature; usually expressed
in percent.
Relative wind. The direction the wind strikes an airfoil. If a
wing moves forward horizontally, the relative wind moves
backward horizontally. Relative wind is parallel to and
opposite the flightpath of the airplane.
Restricted area. Airspace designated under 14 CFR part
73 within which the flight of aircraft, while not wholly
prohibited, is subject to restriction.
Ribs. The parts of an aircraft wing structure that give the
wing its aerodynamic cross section. WSC has battens that
are inserted in to the sail that act as ribs.
Risk. The future impact of a hazard that is not eliminated
or controlled.
Risk elements. The four fundamental areas of exposure to
risk: the pilot, the aircraft, the environment, and the type of
operation that comprise any given aviation situation.
Risk management. The part of the decision making process
which relies on situational awareness, problem recognition,
and good judgment to reduce risks associated with each
flight.
Roll. The rotation of an aircraft about its longitudinal axis. It
is controlled by moving the control bar side to side.
Roundout (flare). The slow, smooth transition from a normal
approach attitude to a landing attitude. This maneuver is
accomplished in a WSC by easing forward on the control
bar from approach speed as the WSC gets near the ground
for landing to reduce the descent rate to zero as the back
whels are inches above the ground, continuing to move the
control bar forward reducing speed as the back wheels are
inches above the landing surface, and continuing to push the
control bar full forward until the back wheels settle to the
surface for touchdown.
RPM. Revolutions per minute for the engine crankshaft. A
measure of rotational speed. One rpm is one revolution made
in one minute.
Runway. A defined rectangular area on a land airport
prepared for the landing and takeoff run of aircraft along its
length. Runways are normally numbered in relation to their
magnetic direction rounded off to the nearest 10 degrees (e.g.,
Runway 1, Runway 25).
Runway incursion. Any occurrence at an airport involving
an aircraft, vehicle, person, or object on the ground that
creates a collision hazard or results in loss of separation
with an aircraft taking off, intending to takeoff, landing, or
intending to land.
Runway threshold markings. Runway threshold markings
come in two configurations. They either consist of eight
longitudinal stripes of uniform dimensions disposed
symmetrically about the runway centerline, or the number of
stripes is related to the runway width. A threshold marking
helps identify the beginning of the runway that is available
for landing. In some instances, the landing threshold may
be displaced.
Safety directive. A manufacturer issued change to a S-LSA
that must be complied with. This is similar to an airworthiness
directive which is a regulatory notice sent out by the FAA to
the registered owner of an aircraft informing the owner of a
condition that prevents the aircraft from continuing to meet
its conditions for airworthiness. Airworthiness Directives
(AD notes) must be complied with within the required time
limit, and the fact of compliance, the date of compliance, and
the method of compliance must be recorded in the aircraft’s
maintenance records.
SAR. See search and rescue.
Scan. A procedure used by the pilot to visually identify all
resources of information in flight.
Scanning. Systematic means of searching for other aircraft.
Scanning is most effective when successive areas of the
sky are brought into focus using a series of short, regularly
spaced eye movements.
Scenario-based training. The instructor provides pilot,
aircraft, environment, and operational risk elements to train
the student to utilize ADM in making the best decision for
the given set of circumstances.
SD. See safety directave.
Sea level. A reference height used to determine standard
atmospheric conditions and altitude measurements.
Search and rescue (SAR). A lifesaving service provided
through the combined efforts of the federal agencies signatory
to the National SAR plan along with state agencies.
Sectional charts. Designed for visual navigation of slow
or medium speed aircraft. Topographic information on
these charts features the portrayal of relief, and a judicious
selection of visual check points for VFR flight. Aeronautical
information includes visual and radio aids to navigation,
airports, controlled airspace, restricted areas, obstructions
and related data.
See and avoid. When weather conditions permit, pilots
operating IFR or VFR are required to observe and maneuver
to avoid other aircraft. Right-of-way rules are contained in
14 CFR part 91.
Segmented circle. A visual indicator around a windsock
or tetrahedron designed to show the traffic pattern for each
runway.
Shallow-banked turn. Turns in which the bank is less than
approximately 20 degrees.
Single Pilot Resource Management (SRM). Area of human
factors study that addresses application of management skills
in the cockpit. Single pilots of small aircraft must make
effective use of all available resources; human resources,
hardware, and information.
Single surface wing. one piece of fabric for most of the
airfoil on a WSC with the cross bar exposed to the airflow.
Typically used for slower wings.
Situational awareness. The accurate perception and
understanding of all the factors and conditions within the four
fundamental risk elements that affect safety before, during,
and after the flight.
Skills and procedures. The procedural, psychomotor, and
perceptual skills used to control a specific aircraft or its
systems. They are the airmanship abilities that are gained
through conventional training, are perfected, and become
almost automatic through experience.
Skin. The outside covering of an aircraft airframe.
Skin friction drag. The type of parasite drag resulting from
a rough surface which deflects the streamlines of air on the
surface, causing resistance to smooth airflow.
S-LSA (Special Light-Sport Aircraft). An aircraft issued a
special airworthiness certificate in accordance with 14 CFR
section 21.290 in the light-sport category. These aircraft meet
the ASTM industry-developed consensus standards.
Solo flight. Flight that is conducted and logged when a pilot
is the sole occupant of an aircraft.
Spatial disorientation. Specifically refers to the lack of
orientation with regard to the position, attitude, or movement
of the WSC in space.
Special flight permit. A flight permit issued to an aircraft
that does not meet airworthiness requirements but is capable
of safe flight. A special flight permit can be issued to move
an aircraft for the purposes of maintenance or repair, buyer
delivery, manufacturer flight tests, evacuation from danger,
or customer demonstration. Also referred to as a ferry
permit.
Special Use Airspace (SUA). Airspace that exists where
activities must be confined because of their nature. Consists
of prohibited, restricted, warning, military operations, and
alert areas.
Speed. The distance traveled in a given time.
Sport Pilot Certificate. An FAA-issued pilot certificate,
allowing the holder to operate a light-sport aircraft in the
category, class, make and model for which they are endorsed
to do so.
SRM. See Single Pilot Resource Management.
Stabilized Approach. A landing approach in which the pilot
establishes and maintains a constant angle glidepath towards
a predetermined point on the landing runway. It is based on
the pilot’s judgment of certain visual cues, and depends on
the maintenance of a constant final descent airspeed and
configuration.
Stall. A rapid decrease in lift caused by the separation of
airflow from the wing’s surface brought on by exceeding
the critical angle of attack. A stall can occur at any pitch
attitude or airspeed.
Stalling speed. For WSC, the power-off stall speed at the
maximum takeoff weight (the lower limit of the green arc).
Standard airport traffic pattern. The left-hand turn traffic
flow that is prescribed for aircraft landing at, taxiing on, or
taking off from an airport. Reference 14 CFR section 91.126
(a)(1) and AIM chapter 4, section 3.
Standard Atmosphere. Consisting of those atmospheric
conditions at sea level that include a barometric pressure
of 29.92 inches of mercury ("Hg) or 1013.2 millibars, and
a temperature of 15 °C (59 °F). Pressure and temperature
normally decrease as altitude increases. The standard lapse
rate in the lower atmosphere for each 1,000 feet of altitude
is approximately 1 "Hg and 2 °C (3.5 °F). For example, the
standard pressure and temperature at 3,000 feet mean sea
level (MSL) is 26.92 "Hg (29.92 – 3) and 9 °C (15 – 6).
Static pressure. The pressure of air that is still, or not
moving, measured perpendicular to the surface exposed to
the air.
Static stability. The initial tendency an aircraft displays
when disturbed from a state of equilibrium.
Stationary front. A front that is moving at a speed of less
than 5 knots.
Steep turn. Turn resulting from a degree of bank of 45
degrees or more.
Straight-in approach. Entry into the traffic pattern by
interception of the extended runway centerline (final
approach course) without executing any other portion of the
traffic pattern.
Stress management. The personal analysis of the kinds of
stress experienced while flying, the application of appropriate
stress assessment tools, and other coping mechanisms.
Strobe. A high-intensity white flashing light. Strobe lights
are located on aircraft wingtips to increase aircraft visibility
in low light conditions.
Strut. Wing structural member used to hold the wings in
place instead of the flying and ground wires for some designs.
The “strutted wing” does not use a kingpost.
Student Pilot Certificate. An FAA issued certificate that
permits student pilots to exercise solo pilot privileges with
limitations. This can be a student’s FAA third class medical
or a student pilot certificate issued for flying an LSA using
a driver’s license as medical eligibility.
SUA. See special use airspace.
Surface analysis chart. A report that depicts an analysis of
the current surface weather. Shows the areas of high and low
pressure, fronts, temperatures, dewpoints, wind directions
and speeds, local weather, and visual obstructions.
Tailwind. Wind blowing in the same direction the aircraft is
moving. When an aircraft is flying with a tailwind, its speed
over the ground is equal to its speed through the air, plus the
speed the air is moving over the ground.
Takeoff clearance. ATC authorization for an aircraft to
depart a runway. It is predicated on known traffic and known
physical airport conditions.
Taxi. The movement of an aircraft under its own power
while on the ground.
Taxiway. Airport area designated for aircraft surface
movement.
Temporary flight restriction (TFR). Designated airspace
of specified dimension where flight is temporarily restricted
or prohibited. NOTAMs are issued to advise airmen of local
TFR restrictions.
Terminal aerodrome forecast (TAF). A report established
for the 5 statute mile radius around an airport. Utilizes the
same descriptors and abbreviations as the METAR report.
Terminal Radar Service Area (TRSA). Area where
participating pilots can receive additional radar services, the
purpose of which is to provide separation between all IFR
operations and participating VFR aircraft.
TFR. See temporary flight restriction.
Thermal. A buoyant plume or bubble of rising air.
Throttle. The control in an aircraft that regulates the power
or thrust the pilot wants the engine to develop from the valve
in a carburetor or fuel control unit that determines the amount
of fuel-air mixture that is fed to the engine.
Thrust. The force which imparts a change in the velocity
of a mass. A forward force which propels the WSC through
the air.
Thrust line. An imaginary line passing through the center of
the propeller hub, perpendicular to the plane of the propeller
rotation.
Title 14 of the Code of Federal Regulations (14 CFR).
That portion of the code formerly called the Federal Aviation
Regulations (FAR) governing the operation of aircraft,
airways, and airmen.
Torque. (1) A resistance to turning or twisting. (2) Forces
that produce a twisting or rotating motion. (3) In a WSC, the
tendency of the aircraft to turn (roll) in the opposite direction
of rotation of the engine and propeller.
Total drag. The sum of the parasite and induced drag.
Touch and go. An operation by an aircraft that lands and
takes off without stopping.
Touchdown point. The point or intended point at which an
aircraft first makes contact with the landing surface.
Touchdown zone. The portion of a runway, beyond the
threshold, where it is intended landing aircraft first contact
the runway.
Towered airport. An airport that has an operating control
tower.
Track. The actual path made over the ground in flight.
Traffic pattern. The traffic flow that is prescribed for aircraft
landing at or taking off from an airport.
Traffic pattern indicators. Ground based visual indicators
that identify traffic pattern direction at certain airports.
Trailing edge. The aft edge of the airfoil. In normal flight,
it is the portion of the airfoil where airflow over the upper
surface rejoins the lower surface airflow.
Training bars. An attachment to the control frame which
allows the instructor in the rear seat to move the control bar
and control the pitch and bank with a solid attachment.
Transponder. The airborne portion of the secondary
surveillance radar system. The transponder emits a reply
when queried by a radar facility.
Tricycle gear configuration. Landing gear configuration
employing a third wheel located on the nose of the aircraft.
True airspeed. Actual airspeed, determined by applying a
correction for pressure altitude and temperature to the CAS.
Because air density decreases with an increase in altitude, an
airplane has to be flown faster at higher altitudes to cause the
same pressure difference between pitot impact pressure and
static pressure. Therefore, for a given calibrated airspeed,
true airspeed increases as altitude increases; or for a given
true airspeed, calibrated airspeed decreases as altitude
increases.
True altitude. The vertical distance of the airplane above
sea level. the actual altitude. It is often expressed as feet
above mean sea level (MSL). Airport, terrain, and obstacle
elevations on sectional charts are true altitudes.
TRSA. See Terminal Radar Service Area.
Tuck. A nose down situation in a WSC where the pitch
angle is over 90 degrees down resulting from a whip stall or
severe turbulence.
Tumble. The WSC rotating uncontrollably around its
lateral axis from a whip stall or severe turbulence. Results
of a tumble would probably cause a structural failure with
catastrophic consequences.
Turbulence. An occurrence in which a flow of fluid is
unsteady.
Twist. The design of the WSC wing in which a wing is
twisted so its angle of attack is less at the tip than at the root.