Aircraft Components and Controls Flashcards
7 cards from real SIFT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Aircraft Components and Controls flashcards as text
What happens to the tail rotor's anti-torque requirement when main rotor pitch (collective) is increased?
Answer: It increases because more engine torque is needed to drive the rotor at higher pitch
Increasing collective requires more engine torque to maintain rotor RPM, which increases the torque reaction the tail rotor must counteract.
The 'T-tail' configuration on a fixed-wing aircraft places the horizontal stabilizer:
Answer: At the top of the vertical stabilizer
A T-tail mounts the horizontal stabilizer at the top of the vertical fin, keeping it out of the wing's disturbed wake but creating risk of deep stall.
What is the primary purpose of a 'mixing unit' (or mixing lever) in a helicopter flight control system?
Answer: Prevents a cyclic input from also changing overall (collective) blade pitch
The mixing unit mechanically separates cyclic and collective inputs so that moving the cyclic doesn't inadvertently change the average (collective) pitch of all blades.
What is 'adverse yaw' in a fixed-wing aircraft?
Answer: The tendency of the aircraft to yaw toward the lowered (rising) aileron during a roll input
Adverse yaw occurs because the down-going aileron (on the rising wing) generates more drag than the up-going aileron, pulling the nose toward the rising wing instead of the direction of roll.
In a tandem-rotor helicopter (e.g., CH-47 Chinook), how is torque typically counteracted?
Answer: By the two rotors spinning in opposite directions, canceling each other's torque
Tandem-rotor helicopters use two counter-rotating rotors whose torques cancel each other out, eliminating the need for a tail rotor.
What is the function of 'ground spoilers' (also called lift dumpers) that deploy automatically on touchdown?
Answer: Reduce bounce by limiting residual lift so wheel brakes are more effective
Ground spoilers destroy remaining wing lift upon touchdown, transferring the aircraft's full weight to the wheels immediately so that brakes and tires can decelerate the aircraft most effectively.
Which primary control input would a helicopter pilot use to initiate a left pedal turn while in a hover?
Answer: Left anti-torque pedal
Pushing the left anti-torque pedal increases tail rotor thrust, which yaws the nose of the helicopter to the left while in a hover.