Dual flight.  Flight time that is received and logged as training time. Dual flight time must be endorsed by a Certificated Flight Instructor. 

Dynamic hydroplaning.  A condition that exists when landing on a surface with standing water deeper than the tread depth of the tires. When the brakes are applied, there is a possibility that the brake will lock up and the tire will ride on the surface of the water, much like a water ski. When tires are hydroplaning, directional control and braking action are virtually impossible. An effective anti-skid system can minimize the effects of hydroplaning. 

Dynamic pressure.  The pressure a moving fluid would have if it were stopped. Reference 14 CFR section 61.51(h). 

Dynamic stability. The property of an aircraft that causes it, when disturbed from straight-and level flight, to develop forces or moments that restore the original condition of straight and level. 

EFAS.  See En Route Flight Advisory Service. 

EGT. See exhaust gas temperature. 

E-LSA (Experimental Light-Sport Aircraft). An aircraft issued an experimental certificate under 14 CFR part 21. 

ELT. See emergency locator transmitter. 

Emergency frequency. Frequency that is used by aircraft in distress to gain ATC assistance.121.5 MHz is an international emergency frequency guarded by Flight Service Stations and some military and civil aircraft. Reference AIM paragraph 6-3-1. 

Emergency locator transmitter (ELT).  A small, self- contained radio transmitter that will automatically, upon the impact of a crash, transmit an emergency signal on 121.5, 243.0, or 406.0 MHz. 

Energy management.  The ability for a pilot to maintain high kinetic energy levels in turbulent air and while near the ground is energy management for WSC. Higher speed and higher power is higher energy. Lower speed and lower power is lower energy. 

En Route Flight Advisory Service (EFAS).  An en route weather-only AFSS service. 

Encoding altimeter. A special type of pressure altimeter used to send a signal to the air traffic controller on the ground, showing the pressure altitude the aircraft is flying. 

Error chain.  A series of mistakes that may lead to an accident or incident. Two basic principles generally associated with the creation of an error 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. Aeronautical decision making is intended to break the error chain before it can cause an accident or incident. 

Evaporation. The transformation of a liquid to a gaseous state, such as the change of water to water vapor. 

Exhaust.  The rear opening of a turbine engine exhaust duct. The nozzle acts as an orifice, the size of which determines the density and velocity of the gases as they emerge from the engine. 

Exhaust gas temperature (EGT). The temperature of the exhaust gases as they leave the cylinders of a reciprocating engine. 

Exhaust manifold. The part of the engine that collects exhaust gases leaving the cylinders. 

FAA.  See Federal Aviation Administration. 

FAA inspector. FAA personnel who can administer practical and proficiency tests and can issue pilot certificates. 

FAA knowledge exam.  Written exam administered by the FAA as a prerequisite for pilot certification. Passing the knowledge and practical exams is required for pilot applicants to be issued FAA certificates or ratings. 

Federal airways. Class E airspace areas that extend upward from 1,200 feet to, but not including, 18,000 feet MSL, unless otherwise specified. 

Federal Aviation Administration (FAA).  The federal agency within the Department of Transportation that has the responsibility of promoting safety in the air, by both regulation and education. 

Federal Aviation Regulations (FARs) . The former name of the part of 14 CFR comprised of rules prescribed by the FAA governing all aviation activities in the United States. 

Field elevation. The highest point of an airport’s usable runways measured in feet from mean sea level. 

Final.  Leg of the traffic pattern that is a descending flightpath starting from the completion of the base-to-final turn and extending to the point of touchdown. 

