Chapter 2; Section C (Flight Instruments)

Question 1

Define “V” speed of V₁

Answer 1

The speed beyond which the takeoff should no longer be aborted.

Question 2

Define “V” speed of V₂

Answer 2

Takeoff safety speed. The speed at which the aircraft may safely be climbed with one engine inoperative.

Question 3

Define “V” speed of V_{2 MIN}

Answer 3

Minimum takeoff safety speed.

Question 4

Define “V” speed of V₃

Answer 4

Flap retraction speed.

Question 5

Define “V” speed of V₄

Answer 5

Steady initial climb speed. The all engines operating take-off climb speed used to the point where acceleration to flap retraction speed is initiated. Should be attained by a gross height of 400 feet.

Question 6

Define “V” speed of VA

Answer 6

Design maneuvering speed. This is the speed above which it is unwise to make full application of any single flight control (or “pull to the stops”) as it may generate a force greater than the aircraft’s structural limitations.

Question 7

Define “V” speed of V_at

Answer 7

Indicated airspeed at threshold, which is usually equal to the stall speed V_S0 multiplied by 1.3 or stall speed V_S1g multiplied by 1.23 in the landing configuration at the maximum certificated landing mass, though some manufacturers apply different criteria. If both V_S0 and V_S1g are available, the higher resulting V_at shall be applied.[12] Also called “approach speed”.

Question 8

Define “V” speed of V_B

Answer 8

Design speed for maximum gust intensity.

Question 9

Define “V” speed of V_C

Answer 9

Design cruise speed, used to show compliance with gust intensity loading.

Question 10

Define “V” speed of V_cef

Answer 10

generally used in documentation of military aircraft performance.

(Ref to V₁)

Question 11

Define “V” speed of V_D

Answer 11

Design diving speed, the highest speed planned to be achieved in testing.

Question 12

Define “V” speed of V_DF

Answer 12

Demonstrated flight diving speed, the highest actual speed achieved in testing.

Question 13

Define “V” speed of V_EF

Answer 13

The speed at which the critical engine is assumed to fail during takeoff.

Question 14

Define “V” speed of V_F

Answer 14

Designed flap speed.

Question 15

Define “V” speed of V_FC

Answer 15

Maximum speed for stability characteristics

Question 16

Define “V” speed of V_FE

Answer 16

Maximum flap extended speed.

Question 17

Define “V” speed of V_FTO

Answer 17

Final takeoff speed.

Question 18

Define “V” speed of V_H

Answer 18

Maximum speed in level flight at maximum continuous power

Question 19

Define “V” speed of V_LE

Answer 19

Maximum landing gear extended speed. This is the maximum speed at which a retractable gear aircraft should be flown with the landing gear extended.

Question 20

Define “V” speed of V_LO

Answer 20

Maximum landing gear operating speed. This is the maximum speed at which the landing gear on a retractable gear aircraft should be extended or retracted.

Question 21

Define “V” speed of V_LOF

Answer 21

Lift-off speed.

Question 22

Define “V” speed of V_MC

Answer 22

Minimum control speed. Mostly used as the minimum control speed for the takeoff configuration (takeoff flaps). Several VMCs exist for different flight phases and airplane configurations: VMCG, VMCA, VMCA1, VMCA2, VMCL, VMCL1, VMCL2. Refer to the minimum control speed article for a thorough explanation.

Question 23

Define “V” speed of V_MCA

Answer 23

Minimum control speed in the air (or airborne). The minimum speed at which steady straight flight can be maintained when an engine fails or is inoperative and with the corresponding opposite engine set to provide maximum thrust, provided a small (3° - 5°) bank angle is being maintained away from the inoperative engine and the rudder is used up to maximum to maintain straight flight. The exact required bank angle for VMCA to be valid should be provided by the manufacturer with VMC(A) data; any other bank angle results in a higher actual VMC(A). Refer to the minimum control speed article for a description of (pilot-induced) factors that have influence on VMCA. VMCA is also presented as VMC in many manuals

Question 24

Define “V” speed of V_MCG

Answer 24

Minimum control speed on the ground is the lowest speed at which the takeoff may be safely continued following an engine failure during the takeoff run. Below VMCG, the throttles need to be closed at once when an engine fails, to avoid veering off the runway.

Question 25

Define "V" speed of **V_MCL**

Answer 25

Minimum control speed in the landing configuration with one engine inoperative.

Question 26

Define "V" speed of **V_MO**

Answer 26

Maximum operating limit speed.

Question 27

Define "V" speed of **V_MU**

Answer 27

Minimum unstick speed.

Question 28

Define "V" speed of **V_NE**

Answer 28

Never exceed speed

Question 29

Define "V" speed of **V_NO**

Answer 29

Maximum structural cruising speed or maximum speed for normal operations.

Question 30

Define "V" speed of **V_O**

Answer 30

Maximum operating maneuvering speed.

Question 31

Define "V" speed of **V_R**

Answer 31

Rotation speed. The speed at which the pilot begins to apply control inputs to cause the aircraft nose to pitch up, after which it will leave the ground.

Question 32

Define "V" speed of **V_rot**

Answer 32

Used instead of VR (*in discussions of the takeoff performance of military aircraft*) to denote rotation speed in conjunction with the term Vref (refusal speed).

Question 33

Define "V" speed of **V_Ref**

Answer 33

Landing reference speed or threshold crossing speed. ## Footnote (*In discussions of the takeoff performance of military aircraft, the term Vref stands for refusal speed. Refusal speed is the maximum speed during takeoff from which the air vehicle can stop within the available remaining runway length for a specified altitude, weight, and configuration.*) Incorrectly, or as an abbreviation, some documentation refers to V_ref and/or V_rot speeds as "Vr."

Question 34

Define "V" speed of **V_S**

Answer 34

Stall speed or minimum steady flight speed for which the aircraft is still controllable.

Question 35

Define "V" speed of **V_{S​ O}**

Answer 35

Stall speed or minimum flight speed in landing configuration.

Question 36

Define "V" speed of **V_{S ​1}**

Answer 36

Stall speed or minimum steady flight speed for which the aircraft is still controllable in a specific configuration.

Question 37

Define "V" speed of **V_{S R}**

Answer 37

Reference stall speed.

Question 38

Define "V" speed of **V_{S R 0}**

Answer 38

Reference stall speed in landing configuration.

Question 39

Define "V" speed of **V_{S R 1}**

Answer 39

Reference stall speed in a specific configuration.

Question 40

Define "V" speed of **V_SW**

Answer 40

Speed at which the stall warning will occur.

Question 41

Define "V" speed of **V_TOSS**

Answer 41

Category A rotorcraft takeoff safety speed.

Question 42

Define "V" speed of **V_X**

Answer 42

Speed that will allow for best angle of climb.

Question 43

Define "V" speed of **V_Y**

Answer 43

Speed that will allow for the best rate of climb.

Question 44

Define Hg.

Answer 44

Inches of mercury, (inHg and "Hg) is a unit of measurement for pressure. It is still used for barometric pressure in weather reports, refrigeration and aviation in the United States. It is the pressure exerted by a column of mercury of 1 inch (2.54 cm) in height at the standard acceleration of gravity.

Question 45

The altimeter elivation reference point for "**indicated altitude**" is

Question 46

The altimeter elivation reference point for "**pressure altitude**" is:

Answer 46

...the height above the standard datum plane when 29.92 is set i the altimeter scale. This is the vertical distance of above theoretical plane where atmospheric pressure is equal to 29.92 in. Hg

Question 47

The altimeter elivation reference point for "**density altitude**" is:

Answer 47

... the pressure altitude corrected for non-standard tempature. Density altitude increases as ambiant tempature increases

Question 48

The altimeter elivation reference point for "**calibrated altitude**" is:

Answer 48

... the indicated altitude corrected to compensate for instrument error.

Question 49

The altimeter elivation reference point for "**true altitude**" is:

Answer 49

...the actual height of an object above mean sea level (MSL).

Question 50

The altimeter elivation reference point for "**absolute altitude**" is:

Answer 50

... the actual height of the airplane above the earth's surface over which it is flying *Absolute altitude* is commonly referred to as heigh above ground level (AGL)