NTSB.  See National Transportation Safety Board. 

Optical illusion.  A misleading visual image. For the purpose of this handbook, the term refers to the brain’s misinterpretation of features on the ground associated with landing, which causes a pilot to misread the spatial relationships between the aircraft and the runway. 

Orientation.  Awareness of the position of the aircraft and of oneself in relation to a specific reference point. 

Personality.  The embodiment of personal traits and characteristics of an individual that are set at a very early age and extremely resistant to change. 

PFD.  See primary flight display. 

PIC.  See pilot in command. 

Pilotage.  Navigation by visual reference to landmarks. 

Pilot error.  An accident in which an action or decision made by the pilot was the cause or a contributing factor that led to the accident. 

Pilot in command (PIC).  The pilot responsible for the operation and safety of an aircraft. 

Pilot report (PIREP).  Report of meteorological phenomena encountered by aircraft. 

Pilot’s Operating Handbook/Airplane Flight Manual (POH/AFM).  Published by the airframe manufacturer, FAA- approved documents that list the operating conditions for a particular model of aircraft. 

PIREP. See pilot report. 

POH/AFM.  See Pilot’s Operating Handbook/Airplane Flight Manual. 

Poor judgment chain. A series of mistakes that may lead to an accident or incident. Two basic principles generally associated with the creation of a poor judgment chain are: (1) one bad decision often leads to another; and (2) as a string of bad decisions grows, it reduces the number of subsequent alternatives for continued safe flight. ADM is intended to break the poor judgment chain before it can cause an accident or incident. 

Primary flight display (PFD).  A display that provides increased situational awareness to the pilot by replacing the traditional six instruments used for instrument flight with an easy-to-scan display that provides the horizon, airspeed, altitude, vertical speed, trend, trim, and rate of turn among other key relevant indications. 

Residual risk.  Risk left over after system safety efforts have been fully employed. It is not necessarily the same as acceptable risk. Residual risk is the sum of acceptable risk and unidentified risk. This is the total risk passed on to the user. 

Risk.  The future impact of a hazard that is not eliminated or controlled. 

Risk assessment.  An approach to managing uncertainty. Risk assessment is a quantitative value assigned to a task, action, or event. 

Risk elements.  There are four fundamental risk elements in aviation: the pilot, the aircraft, the environment, and the external pressures 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. 

Single-pilot resource management (SRM).  The ability for a pilot to manage all resources effectively to ensure the outcome of the flight is successful. 

Situational awareness.  Pilot knowledge of where the aircraft is in regard to location, air traffic control, weather, regulations, aircraft status, and other factors that may affect flight. 

Spatial disorientation.  The state of confusion due to misleading information being sent to the brain from various sensory organs, resulting in a lack of awareness of the aircraft position in relation to a specific reference point. 

SRM.  See single-pilot resource management. 

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. 

Stress.  The body’s response to demands placed upon it. 

