NCAA Instrument Rating Theory flashcards

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

Semicircular rule

IFR cruising levels: track 000-179 degrees uses odd thousands; track 180-359 degrees uses even thousands. Ensures opposite-direction traffic is separated by at least 1,000 ft.

Transition altitude

Altitude at or below which the altimeter is set to local QNH. Above the transition level, standard pressure 1013.25 hPa (29.92 inHg) is used.

Lost communication procedure

Squawk 7600, continue under last acknowledged clearance, and follow published lost-communication procedures. If no clearance, follow the route and altitude in the flight plan.

Alternate aerodrome requirement

An IFR flight plan must name an alternate unless weather permits visual approach and landing or the destination has an approved approach and meets published alternate minima.

Fuel planning components

Taxi fuel, trip fuel, contingency fuel (typically 5% of trip), alternate fuel, final reserve (30 minutes holding at 1,500 ft), and extra fuel.

Standard departure climb gradient

Default SID gradient is 3.3% (200 ft/NM). If a higher gradient is published, the aircraft must be capable of achieving it in the expected conditions.

Holding pattern entry

Direct entry when within 180 degrees of inbound; parallel when 180-270 degrees; teardrop when 270-360 degrees. Standard turns are right-hand unless published otherwise.

Descent planning rule

A 3-degree path requires approximately 300 ft/NM. To lose 10,000 ft, plan about 33 NM. Adjust for wind and speed.

VOR radial

A magnetic bearing from the station. The CDI shows course deviation; the TO/FROM flag depends on the aircraft's position relative to the selected radial.

ILS localizer

Provides lateral guidance within approximately +/- 2.5 degrees of the runway centreline. The glideslope provides vertical guidance at typically 3.0 degrees.

Marker beacons

Outer marker at approximately 4-7 NM from threshold; middle marker at approximately 3,500 ft; inner marker at approximately 1,000-1,500 ft.

DME slant range

DME measures slant-range distance. At high altitude or close to the station, slant-range error becomes significant; at 30,000 ft over the station, DME reads approximately 3 NM.

Transponder codes

7700 emergency, 7600 radio failure, 7500 unlawful interference. Mode C provides pressure altitude to ATC.

Standard atmosphere

Sea level pressure 1013.25 hPa (29.92 inHg), temperature 15 degrees C, lapse rate 1.98 degrees C per 1,000 ft up to the tropopause at approximately 36,090 ft.

Clear ice

Forms in large supercooled droplets, typically 0 to -10 degrees C. It is dense and heavy and can significantly degrade aircraft performance.

Freezing rain

Implies a warm layer aloft above a subfreezing layer near the surface. It is a severe icing hazard and warrants avoidance.

Low-level wind shear

Reported as microburst or gust front. Go-around is recommended if airspeed changes by 15 kt or vertical speed changes by 500 ft/min on approach.

Mountain wave

Strong winds over ridges produce lenticular and rotor clouds with severe turbulence. Expect downdrafts on the lee side; plan terrain clearance accordingly.

Hypoxia

Symptoms include euphoria, impaired judgement, and cyanosis. Time of useful consciousness at FL 250 is approximately 3-5 minutes; at FL 350, approximately 30-60 seconds.

Somatogravic illusion

A false sensation of pitch during acceleration. During acceleration, the pilot may perceive a climb and push forward; during deceleration, a descent.

Sterile cockpit

Below 10,000 ft, non-essential conversation is prohibited. Focus on taxi, takeoff, approach, and landing phases to reduce distraction and error.

DECIDE model

Detect, Estimate, Choose, Identify, Do, Evaluate. A structured decision-making model that supports in-flight decisions under stress.

Density altitude

Increases with altitude, temperature, and humidity. High density altitude reduces engine power, propeller thrust, and lift; use flight manual charts.

Climb gradient formula

Gradient (%) = (rate of climb in ft/min / groundspeed in kt) x 60 / 6076 x 100, or approximately rate/groundspeed x 100.

Landing distance required

Must not exceed landing distance available. Apply 1.15 factor for dry runway and additional factors for wet or contaminated runways.

Final reserve fuel

For turbine aircraft, typically 30 minutes holding at 1,500 ft above the alternate. For piston aircraft, 45 minutes is common.

Initial IFR call

Aircraft identification, position, altitude, and request. Example: "Cessna 12345, 20 miles south of ABC, 5,000 ft, request IFR clearance to XYZ."

Readback requirement

Mandatory for clearances, runway assignments, hold short instructions, altitude assignments, and frequency changes. Use standard phraseology.

MAYDAY and PAN PAN

MAYDAY, MAYDAY, MAYDAY for distress; PAN PAN, PAN PAN, PAN PAN for urgency. Follow with call sign, nature, position, altitude, and intentions.

Precision versus non-precision approach

Precision approach (ILS, GLS, PAR) has vertical guidance. Non-precision (VOR, NDB, LOC, RNAV LNAV) has no vertical guidance.

Decision altitude versus MDA

DA is used on precision approaches; MDA is used on non-precision approaches. The missed approach point must be identified.

Stabilised approach criteria

By 1,000 ft AGL in IMC, be on the correct track, at the correct speed, and in the landing configuration; otherwise go around.