Aviation Termionology

Question 1

MDA or MDH

Answer 1

Minimum Descent Altitude or Height. For non precision approaches, this is the altitude in MSL below which you may not descend (on final approach, or when circling to land) if the runway environment is not visible. This altitude guarantees obstacle clearance from the FAF to the MAP. The MAP on a non-precision approach is the point (detemined by DME distance, or by time) at which you decide to land or execute the missed approach. At the VDP you may descend below the MDA, MDH, if you have the runway environment in sight.

Question 2

TCH

Answer 2

Threshold Crossing Height. If you follow the ILS down properly, this is the height at which you will cross the runway threshold.

Question 3

IAF

Answer 3

This is where the instrument approach begins.

Question 4

DA or DH

Answer 4

On a precision approach, this is the altitude in MSL at which you must make the decision: I see the runway environment and will land, or I do not see it and I will execute the missed approach.

Question 5

VDP

Answer 5

Visual Descent Point. On a non precision approach, this is the defined point at which you may go below the MDA, if and only if you have the runway environment in sight.

Question 6

Metar Translation: R31/2700FT

Answer 6

Runway three one RVR two thousand seven hundred

Question 7

RVR is low, high, variable, changing, rising, falling - METAR examples

Answer 7

M Minus: RVR is less than lowest reportable sensor value (e.g. M0600FT)

P Plus: RVR greater than highest reportable sensor value (e.g. P6000FT)

V Variable If the RVR is variable between 2000 and 4000 feet for runway 6L: (R06L/2000V4000FT)

N Indicates observation is Not changing significantly (e.g. R22/P1500N)

U indicates an improvement or that the visibility is going Up (e.g. R22/P1000U)

D indicates the visibility is decreasing or going Down (e.g. R04/P1500D)

Question 8

RVR: How to tell if it is expressed in feet or meters on an approach plate

Answer 8

On instrument approach plates, if the ceiling is followed by a dash (-) the visibility required is statue miles, where as if the ceiling is followed by a slash (/) the visibility required is in feet.

Question 9

THRE replaces TDZE

Answer 9

THRE = Threshold, and TDZE = Touch Down Zone Elevation. Airport Elevation is measured at some “central point” on the airport, the THRE references the runway threshold. For example, the elevation of KAPC is 35, the THRE for 06 and 36L is 14.

Question 10

Black Triangle with a white capital “T”

Answer 10

Something non-standard exists for this airport, for example, departure or arrival procedures.

Question 11

MALSR

Answer 11

MALSR designates a Medium intensity Approach Lighting System with Runway alignment indicator lights. The dot on the A5 symbol denotes the presence of sequenced flashing lights … a “Rabbit.”

Question 12

MSA

Answer 12

The minimum safe altitude—MSA—within 25 nm is shown inside a circle on the plan view of the approach plate. MSA provides 1000 ft. of clearance from all terrain and known obstructions. The 25 nm radius circle is centered on the Navaid used for the approach. For KAPC that is SGD. The center symbol in the MSA diagram corresponds to the type Navaid used for the approach, or it is a waypoint symbol if flying a GPS approach. In KAPC there are three MSA’s, 4300 if you approach from the North, 5100 if you approach from the southeast, and 3800 if you approach from the southwest.

Question 13

Which way to turn in a procedure turn?

Answer 13

The procedure turn begins with a 45° turn away from the outbound track. Fly that heading for a minute or so, nothing hard and fast about that time, then execute a 180° turn away from the airport to return to the desired bearing to the beacon. So on the VOR 6 into KAPC, you turn left first, hdg 185, and then right, hdg 005, to intercept the SGD 203 radial, 050 inbound, this right turn (the second turn in the PT) is away from KAPC.

Question 14

Maneuvering speed

Answer 14

Maneuvering speed is defined as 1.3 times the stall speed at maximum gross weight in the landing configuration. For a C152 a this is 46 knots, with a stall speed of 40 without flaps, and 35 with flaps.

Question 15

Vx versus Vy

Answer 15

Climbing at Vx allows pilots to maximize the altitude gain per unit ground distance. That is, Vx allows pilots to maximize their climb while sacrificing the least amount of ground distance. This occurs at the speed for which the difference between thrust and drag is the greatest (maximum excess thrust). For a C152 Vx is 55 kts.

Climbing at Vy allows pilots to maximize the altitude gain per unit time. That is, Vy, allows pilots to maximize their climb while sacrificing the least amount of time. This occurs at the speed for which the difference between engine power and the power required to overcome the aircraft’s drag is the greatest (maximum excess power). Climb rate is proportional to excess power. For C152 Vy is 67

Vx increases with altitude and Vy decreases with altitude.

Vx = Vy at the airplane’s absolute ceiling, the altitude above which it cannot climb using just its own lift.

Question 16

Landing Mins for VOR 6 KAPC

Answer 16

S-6 460-1, MDA is 460 Ft and 1 mile RVR, for circling it is 600-1 which means 600 Ft and 1 mile RVR. The small number in the table, below the 600, is 565, this is the height above the airport when you reach the MDA. The airport is 35 Ft at KAPC, 600 minus 35 is 565. The numbers in parentheses are for military folks.