Chapter 11 NATOPS

Question 1

The MH-60R is considered to be hovering in ground effect at radar altimeter altitudes _________.

Answer 1

At or below 45 feet

Question 2

Blowback

Answer 2

If the aircraft is exposed to a headwind gust, the retreating blade sees less relative wind velocity and the advancing blade sees more relative wind velocity. This causes the rotor disk to be tilted back…causing the nose of the helicopter to pitch up.

Question 3

Stabilator position during slow speed flight

Answer 3

Below 30 knots, the stabilator is 42 degrees trailing edge down

Question 4

Speed at which ground vortex is encountered and then rolled up under the aircraft

Answer 4

17 knots, dissipates until 30 knots

Question 5

Blade stall cause

Answer 5

Retreating blade tip is traveling at the rotational velocity minus the forward speed of the helicopter. As the in-air velocity of the retreating blade decreases, the blade angle of attack must be increased to equalize lift to provide stabilized flight.

Question 6

Blade stall characteristics

Answer 6

4 vibrations per revolutions
Pitch up and left
Little to no cyclic authority

Question 7

Methods of eliminating roughness caused by blade stall

Answer 7

1. Decrease collective pitch
2. Decrease severity of maneuver
3. Gradually decrease airspeed
4. Increase rotor RPM
5. Decrease altitude
6. Decrease gross weight

Question 8

Tail rotor lift

Answer 8

2.5 percent

Question 9

Tail rotor canted

Answer 9

20 degrees left

Question 10

Loss of tail rotor authority

Answer 10

Is a power issue. Nr droops, torque increases while power available to the main and tail rotor decreases rapidly. Eventually the tail rotor can no longer produce enough thrust to act against the high torque

Question 11

loss of tail rotor effectiveness

Wind considerations

Answer 11

Weather vaning
Tail rotor Vortex ring state
Main rotor disk vortex

Question 12

Weather vaning

Answer 12

120-240 degrees relative wind tends to weather vane the nose of the aircraft into the wind. If yaw has been established, weather vaning will accelerate the yaw rate

Question 13

Loss of translational lift (tail rotor)

Answer 13

Increased power demand and additional anti-torque requirements. If loss of translational lift occurs when the aircraft is in a right turn, the right turn will be accelerated.

Question 14

Hover/air taxi

Answer 14

Right sideward flight or a right crosswind, increases flow across the tail, resulting in a reduction in AOA for a set pedal position and a reduction in tail rotor trust.

Main rotor tip vortex can interact

Question 15

Blade tip speed

Answer 15

725 feet per second

Mach .65