Chapter 1–6 Key Terms: Aerodynamics, Stability, Load Factor, and Maneuvering Speeds (Vocabulary)

Vocabulary flashcards covering p factor, slipstream effects, stability concepts, load factor, maneuvering speeds (VA, VNO, VNE), stall concepts (Vs, alpha critical), and common references (POH, V–N diagram) as discussed in the lecture notes.

P factor (propeller factor)

Asymmetric thrust from a spinning propeller at high angles of attack that causes the airplane to yaw to the left; the descending blade on the right has a higher angle of attack and produces more thrust and drag, requiring rudder input (usually to the right) to compensate.

Asymmetric propeller thrust

Unequal thrust between the propeller blades during rotation, leading to yaw and uneven drag, especially at high angles of attack.

Descending blade

The blade moving downward in the propeller arc; at high angles of attack it has a higher angle of attack and tends to produce more thrust (and drag) than the ascending blade.

Ascending blade

The blade moving upward in the propeller arc; at high angles of attack, it has a comparatively lower angle of attack than the descending blade.

Spiral slipstream

The corkscrew flow produced by a spinning propeller; this spiraling air can strike the tail and rudder, creating a left turning tendency that may require right rudder.

Rudder correction

Using the rudder to counteract yawing tendencies from p factor and spiral slipstream to maintain coordinated flight.

Static stability

The initial tendency of an aircraft to return to its original attitude after a disturbance.

Dynamic stability

The tendency of an aircraft to return to, or diverge from, its equilibrium attitude over time after a disturbance.

Center of gravity (CG)

The point where the aircraft’s weight is considered to act; CG location significantly affects stability and controllability.

Forward CG

CG toward the nose; generally increases stability and stall recovery ease but may reduce overall performance.

Aft CG

CG toward the tail; reduces stability and makes stall recovery harder.

Load factor

The total lift on the aircraft’s structure relative to its weight, expressed as a multiple of weight (in g’s).

Maneuvering speed (VA)

The speed at which full, abrupt control inputs can be made without overstressing the airframe; VA decreases with lighter weight and increases with heavier weight; not shown directly on the ASI.

VA at different weights (max maneuver airspeed)

The aircraft’s VA changes with weight; for example, a Cessna 172 might show different VA values at 2300 lb, 1950 lb, and 1600 lb (e.g., 97, 89, 80 knots respectively).

Stall speed (Vs)

The minimum speed at which the aircraft can produce enough lift to support its weight in a given configuration.

Critical angle of attack (alpha critical)

The angle of attack at which the wing stalls; beyond this angle, lift rapidly decreases unless recovered.

Stall

Condition where lift is insufficient to support weight due to reaching/exceeding the critical angle of attack; a well-designed aircraft will pitch down to recover.

VNO (maximum structural cruising speed)

The speed limit for normal operation; above this speed, structural damage could occur; typically shown as a yellow/upper limit on the V–N diagram.

VNE (never exceed speed)

The maximum speed that must not be exceeded; exceeding it can lead to structural failure.

POH (Pilot’s Operating Handbook)

The official manual listing aircraft limitations, performance, weight limits, and operating procedures.

G-l diagram (load factor diagram)

A velocity–load factor diagram showing how load factor changes with airspeed and bank angle; includes regions for normal (green), caution (yellow), damage (orange), and VNE limits.

Normal operating range (green arc)

The speed range on the V–N diagram where normal flight is expected and structural limits are not exceeded.

Structural damage range (orange)**

Part of the V–N diagram where speeds can cause structural damage if exceeded.

Extended structural limit (VNO to VNE boundaries)

The transition from safe, normal operation to speeds where structural concerns increase; staying within green and caution ranges is advised.

Forward CG vs. aft CG (stability/recovery)

Forward CG improves stability and stall recovery; aft CG reduces stability and makes recovery harder.