Flight Characteristics - NATOPS Ch. 11

Question 1

Normal Hover Attitude

Answer 1

4 to 5 degrees nose up

2 to 3 degrees left wing down

Question 2

Blade Tip Speed

Answer 2

725 fps (0.65 Mach)

Question 3

When are you considered in ground effect?

Answer 3

RADALT less than 45 feet

Question 4

What rate of climb will maintaining hover power give you once at 80 KIAS?

Answer 4

500 fpm rate of climb

Question 5

When does NATOPS define translational lift occurring?

Answer 5

At 17 KIAS, when the ground vortex is felt rolling up under the aircraft as speed increased through 30 KIAS.

Question 6

Method to Recover from Blade Stall

Answer 6

Decrease collective.
Decrease severity of maneuver.
Decrease airspeed.
Increase rotor rpm.
Decrease altitude.
Decrease gross weight.

Question 7

What type of tail rotor do we have?

Answer 7

Tractor tail rotor canted 20 degrees that provides 2.5 percent of the overall lift.

Question 8

LTE Effects

Answer 8

AOA Reduction - 060-120
Weather vaning - 120-240 degrees
TR VRS - 210-330 degrees
Main Rotor Disc interaction - 280-330
Or 30-80

Question 9

Left roll rates in excess of ____ degrees per second in forward flight above _____ KIAS may cause damage to the tail rotor spar.

Answer 9

30 degrees per second

75 KIAS

Question 10

What vibrations are felt through the main rotor?

Answer 10

4 per

Question 11

Inducement of less than 1g flight by rapid application of forward cyclic may result in exceeding main rotor flapping margin limits and _______ __________ _____________.

Answer 11

Droop stop pounding

Question 12

The effects of humidity become apparent above _____ percent relative humidity.

Answer 12

40%

Question 13

A good rule of thumb is to add _____ feet to DA for every 10 percent of relative humidity above ____.

Answer 13

100 feet

40%

Question 14

Vortex Ring State

Answer 14

Descent rates greater than 700 fpm, speeds 0-20 KIAS

Exaggerated at descent rates greater than 1500 and speeds 5-10 KIAS

Question 15

What is the descent rate in fully developed VRS?

Answer 15

6000 fpm

Question 16

How do you recover from VRS?

Answer 16

Decrease collective.

Increase forward airspeed.

Enter auto if altitude permits.

Question 17

Minimum rate of descent airspeed in an auto

Answer 17

75 KIAS

Question 18

Maximum glide airspeed in an auto

Answer 18

95 KIAS

Question 19

Static Rollover Angle

Answer 19

28 degrees

Question 20

Critical Rollover Angle

Answer 20

12 degrees

Question 21

When operating in a salt spray environment for any period of time, a TGT rise of _____ or more for constant torque is an indication of engine performance degradation and possible ______ ________. A TGT rise of greater than ______ for a constant torque is an indication of engine performance degradation, which may result in ________ ________.

Answer 21

20 degrees C

Salt encrustation

40 degrees C

Compressor stalls

Question 22

The best indication of performance loss due to salt spray ingestion is the relationship between ______ and _____.

Answer 22

TGT and torque

Question 23

The probability of salt ingestion is greatest in winds of ___ to ____ knots.

At ___ to ___ knots, salt spray is generated but is blown aft underneath the engines so that the rate of salt ingestion is small.

Answer 23

8 to 12 knots

15 to 20 knots

Question 24

What does a one per vibration indicate?

Answer 24

Comes from main rotor system. Generally caused by blade out of track, worn or loose control rod end bearings, or malfunctioning blade damper.

Question 25

What does a 4 per vibration indicate?

Answer 25

Loose or worn vibration absorbers, swashplate, damper servicing, asymmetrical blade loading, etc.

Question 26

What does a 5 cycle per second vibration indicate in the tail?

Answer 26

Tail shake. Lateral bending mode of the tail pylon in certain flight regimes.

Question 27

What do high frequency vibrations indicate?

Answer 27

Tail rotor drive shaft unbalanced, bad bearings, or a failing IGB/TGB gearbox.

Question 28

What does a one times tail rotor speed indicate?

Answer 28

Feels close to a 4 per and hard to isolate by the pilot. May be tail rotor imbalance, damage, loose hardware, pitch change link bearing wear, or loose IGB/TGB.

Question 29

What is Ground Resonance?

Answer 29

A self excited mechanical vibration that involves :
a coupling lead-lag motion of the main rotor blades with
the in-plane motion or the rotor hub
and the rolling motion of the aircraft on its landing gear.