Aircraft Dispatcher flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Standard IFR vertical separation

Below FL290, IFR aircraft receive 1,000 ft vertical separation; non-RVSM airspace requires 2,000 ft above FL290, while RVSM airspace uses 1,000 ft between FL290 and FL410.

VOR radial

A magnetic bearing measured clockwise from magnetic north, originating at the VOR station and extending outward; the OBS displays the selected radial relative to the aircraft's position.

Transponder emergency codes

Squawk 7500 for unlawful interference (hijack), 7600 for radio communication failure, and 7700 for any other emergency requiring immediate ATC attention.

ILS Category I minimums

A precision approach with a decision height not lower than 200 ft and RVR not less than 1,800 ft (550 m), requiring no special crew qualification beyond the instrument rating.

ISA sea-level conditions

15 °C, 1013.25 hPa (29.92 inHg), and zero density altitude; standard lapse rate is about 2 °C per 1,000 ft up to the tropopause.

Ceiling definition

The height above ground of the lowest broken or overcast layer, or the vertical visibility into an obscuration; scattered layers do not constitute a ceiling.

Standard holding pattern

Right turns, 1-minute inbound legs at or below 14,000 ft MSL and 1.5-minute legs above; timing begins abeam the fix or on inbound passage.

Freezing rain icing hazard

Supercooled drops freeze on impact, producing clear ice; freezing rain is classified as severe icing because accumulation can be rapid and exceed the aircraft's deicing capability.

Balanced field length

The runway length at which accelerate-stop distance equals accelerate-go distance to 35 ft, defining the V1 that minimizes the required field length.

Density altitude formula

Density altitude equals pressure altitude plus 120 times (OAT minus ISA temperature for that altitude); higher density altitude reduces engine thrust, lift, and climb performance.

VREF definition

The landing reference speed, equal to 1.3 times the stall speed in the landing configuration (VSO), allowing a 30 percent margin above the stall.

Climb gradient formula

Percent gradient equals (altitude gained divided by horizontal distance travelled) times 100; a 3.3 percent gradient corresponds to about 200 ft per nautical mile.

Weight shift formula

Distance the CG moves equals (weight shifted times distance between stations) divided by total weight; used to move the CG to a target by shifting or adding load.

Maximum zero fuel weight

The maximum weight of the aircraft including payload but excluding usable fuel; it limits wing bending moments and is a structural, not performance, limit.

Percent MAC formula

Percent MAC equals (CG arm minus LEMAC arm) divided by MAC length times 100; it expresses CG position as a percentage of the mean aerodynamic chord from the leading edge.

Aft CG effects

An aft CG reduces longitudinal stability and elevator effectiveness for rotation but lowers trim drag; excessive aft loading can make the aircraft uncontrollable in pitch.

1-2-3 alternate rule

An IFR alternate is required when the destination forecast at ETA plus or minus 1 hour has a ceiling below 2,000 ft or visibility less than 3 statute miles.

Equal time point formula

ETP distance equals (total route distance times return groundspeed) divided by (outbound groundspeed plus return groundspeed); the point from which time to either airport is equal.

Wind correction angle

WCA is approximately arcsin of [(wind speed divided by TAS) times sin of the wind angle]; apply it to true course for true heading, then correct for magnetic variation.

Great circle route

The shortest distance between two points on a sphere; it appears curved on a Mercator chart and requires continuously changing true headings unless approximated by a rhumb line.

Final reserve fuel

For turbine aircraft, 30 minutes of holding fuel at 1,500 ft above the alternate at holding speed; for piston aircraft, 45 minutes of holding fuel.

Contingency fuel

Normally 5 percent of trip fuel, or 3 percent when an enroute alternate is available, intended to cover forecast, routing, and altitude deviations.

Minimum fuel advisory

Declared to ATC when committed to land at a specific airport and any change to the clearance would result in landing below final reserve; it is not an emergency.

Dispatcher duty limit

A certificated dispatcher may not remain on duty more than 10 hours in any 24-hour period and must have 8 consecutive hours of rest in the preceding 24 hours.

Dispatcher certificate minimum age

Applicants must be at least 23 years old, read, speak and understand English, and pass the FAA knowledge, oral, and practical tests under Part 65.

Joint flight release

The aircraft dispatcher and the pilot in command must both sign the dispatch release, and each shares operational control responsibility for the flight under Part 121.

PIC emergency authority

In an emergency the PIC may deviate from any rule to the extent required by the emergency and must notify ATC when able; the dispatcher may not override this authority.

Alcohol limits for crew

Crew members may not act within 8 hours of consuming alcohol, while under its influence, or with a blood alcohol concentration of 0.04 percent or greater.

Useful consciousness at FL350

At FL350, useful consciousness after rapid decompression is typically 30 to 60 seconds, requiring immediate donning of oxygen and an emergency descent.

Emergency descent target altitude

After a decompression, descend at maximum rate (often 6,000-8,000 fpm) to FL100 or the minimum safe altitude, whichever is higher, while establishing crew oxygen.

MAYDAY versus PAN PAN

MAYDAY signals distress (grave and imminent danger requiring immediate assistance); PAN PAN signals urgency (a serious condition that does not yet require immediate assistance).

Circadian low performance window

The body's lowest alertness period is roughly 0300-0500 local time, when fatigue-related errors peak; controlled rest and careful task allocation reduce the risk.