FAA ATP Aerodynamics & Aircraft Performance Questions

During a turn with constant power

• the aircraft nose will pitch down.
• the aircraft will decelerate.
• the rate of descent will increase.

Explanation: While in a turn part of the vertical component of lift has been diverted to horizontal lift. If total lift is not increased (increase in angle of attack) the aircraft nose will pitch down.

FAA Airplane Flying Handbook - Turns

What is load factor?

• Lift multiplied by the total weight.
• Lift subtracted from the total weight.
• Lift divided by the total weight.

Explanation: Load factor is the ratio of the total load supported by the airplane's wings to the actual weight of the airplane and its contents, or actual load supported by the wings' lift divided by the total weight of the airplane.

FAA Airplane Flying Handbook - Load Factor

Under what condition should stalls never be practiced in a twin-engine airplane?

• With one engine inoperative.
• With climb power on.
• With full flaps and gear extended.

Explanation: With full power applied to the operative engine, as the airspeed drops below V(MC), the airplane tends to roll as well as yaw into the inoperative engine. This tendency becomes greater as the airspeed is further reduced. Since this tendency must be counteracted by aileron control, the yaw condition is aggravated by aileron roll (the 'down' aileron creates more drag than the 'up' aileron). If a stall occurs in this condition, a violent roll into the dead engine may be experienced.

FAA Airplane Flying Handbook - Engine-Out Stalls

If the boundary layer separates

• drag is decreased.
• the wing is about to stall and stop producing lift.
• ice will sublimate and not freeze.

Explanation: The boundary layer gives any object an 'effective' shape that is usually slightly different from the physical shape. The boundary layer may also separate from the body, thus creating an effective shape much different from the physical shape of the object. This change in the physical shape of the boundary layer causes a dramatic decrease in lift and an increase in drag. When this happens, the airfoil has stalled.

FAA Airplane Flying Handbook - Boundary Layer

What is the effect on total drag of an aircraft if the airspeed decreases in level flight below that speed for maximum L/D?

• Drag increases because of increased induced drag.
• Drag increases because of increased parasite drag.
• Drag decreases because of lower induced drag.

Explanation: The airspeed at which minimum drag occurs is the same airspeed at which the maximum lift/drag ratio (L/D) takes place. At speeds below maximum L/D, any decrease in airspeed will result in an increase in total drag due to the increase in induced drag. Answer (B) is incorrect because parasite drag varies directly (not inversely) with airspeed. Answer (C) is incorrect because drag increases (not decreases) from any speed other than that for maximum L/D.

FAA Airplane Flying Handbook - Region of Reversed Command

Maximum range performance of a turbojet aircraft is obtained by which procedure as aircraft weight reduces?

• Increasing speed or altitude.
• Increasing altitude or decreasing speed.
• Increasing speed or decreasing altitude.

Explanation: As a turbojet-powered airplane burns fuel, its maximum range profile can be maintained by increasing the cruise altitude to improve the specific fuel consumption of the engines and by decreasing airspeed to maintain the optimum L/D ratio. Answer (A) is incorrect because, as weight decreases, the optimum speed decreases, or altitude increases. Answer (C) is incorrect because, as weight decreases, speed decreases, or altitude increases.

FAA Airplane Flying Handbook - Turbojet Range Performance

At what speed, with reference to L/D(MAX), does maximum range for a jet airplane occur?

• A speed less than that for L/D(MAX).
• A speed equal to that for L/D(MAX).
• A speed greater than that for L/D(MAX).

Explanation: Maximum range is obtained at the aerodynamic condition which produces a maximum proportion between the square root of the lift coefficient and the drag coefficient. It occurs where the proportion between velocity and thrust required is greatest. This point is located by a straight line from the origin tangent to the curve, and is consequently at a higher airspeed than L/D(MAX). Answer (A) is incorrect because a speed greater than L/D(MAX) will obtain maximum range for a jet airplane. Answer (B) is incorrect because a speed equal to that of L/D(MAX) is a jet airplane's maximum endurance, not range.

FAA Airplane Flying Handbook - Range Performance

To avoid the wingtip vortices of a departing jet airplane during takeoff, the pilot should

• lift off at a point well past the jet airplane's flightpath.
• climb above and stay upwind of the jet airplane's flightpath.
• remain below the flightpath of the jet airplane.

Explanation: When departing behind a large aircraft, note its rotation point and rotate prior to that point. During the climb, stay above and upwind of the large aircraft's climb path until turning clear of its wake. Answer (A) is incorrect because, if you rotate beyond the jet's rotation point, you will have to fly up into the jet's vortices. Answer (C) is incorrect because the jet's vortices will sink. If you stay below the jet's flight path, you will fly in the area of the vortices.

AIM 7-3-4 - Vortex Avoidance Procedures