ARMY SIFT EXAM QUESTIONS WITH
VERIFIED SOLUTIONS
A helicopter is: - ANS-A type of rotorcraft
Helicopter turbine engines produce _________ thrust per pound than piston engines: -
ANS-more
The main forces acting on a helicopter are: - ANS-Lift, weight, thrust, and drag
Helicopters typically have between __ and __ main rotor blade(s): - ANS-2, 6
Depending on the type of helicopter, main rotor system components can include: - ANS-
A stabilizer bar, upper and lower swashplates, and counterweights.
Pitch horns, teeter or coning hinges, and blade grips.
Pitch and scissor links, and control rods.
The function of the flybar is: - ANS-To decrease crosswind thrust on the blades and
enhance flight stability by keeping the bar stable as the rotor spins
Thrust acts ________ to the aircraft's ________________________: - ANS-parallel,
longitudinal axis
Profile drag consists of __________ created by __________ and __________: - ANS-
induced drag, angular momentum, aircraft components that do not contribute to lift.
skin friction, surface imperfections, form drag.
an inclined main rotor disk, increasing angle of attack, high blade rpm.
None of the above
Vortices produced by spinning rotor blades create: - ANS-Induced drag
When plotted on a graph, L/DMAX is the point where the helicopter's _____________. -
ANS-Total lift-to-drag ratio is the greatest
A helicopter's potential energy is affected by: - ANS-The aircraft's height above the
ground
Which of the following factors affect the lift produced by spinning rotor blades: - ANS-
Airfoil coefficient of lift.
Air density.
