Flight Characteristics - NATOPS Ch. 11 Flashcards
Normal Hover Attitude
4 to 5 degrees nose up
2 to 3 degrees left wing down
Blade Tip Speed
725 fps (0.65 Mach)
When are you considered in ground effect?
RADALT less than 45 feet
What rate of climb will maintaining hover power give you once at 80 KIAS?
500 fpm rate of climb
When does NATOPS define translational lift occurring?
At 17 KIAS, when the ground vortex is felt rolling up under the aircraft as speed increased through 30 KIAS.
Method to Recover from Blade Stall
Decrease collective.
Decrease severity of maneuver.
Decrease airspeed.
Increase rotor rpm.
Decrease altitude.
Decrease gross weight.
What type of tail rotor do we have?
Tractor tail rotor canted 20 degrees that provides 2.5 percent of the overall lift.
LTE Effects
AOA Reduction - 060-120
Weather vaning - 120-240 degrees
TR VRS - 210-330 degrees
Main Rotor Disc interaction - 280-330
Or 30-80
Left roll rates in excess of ____ degrees per second in forward flight above _____ KIAS may cause damage to the tail rotor spar.
30 degrees per second
75 KIAS
What vibrations are felt through the main rotor?
4 per
Inducement of less than 1g flight by rapid application of forward cyclic may result in exceeding main rotor flapping margin limits and _______ __________ _____________.
Droop stop pounding
The effects of humidity become apparent above _____ percent relative humidity.
40%
A good rule of thumb is to add _____ feet to DA for every 10 percent of relative humidity above ____.
100 feet
40%
Vortex Ring State
Descent rates greater than 700 fpm, speeds 0-20 KIAS
Exaggerated at descent rates greater than 1500 and speeds 5-10 KIAS
What is the descent rate in fully developed VRS?
6000 fpm
How do you recover from VRS?
Decrease collective.
Increase forward airspeed.
Enter auto if altitude permits.
Minimum rate of descent airspeed in an auto
75 KIAS
Maximum glide airspeed in an auto
95 KIAS
Static Rollover Angle
28 degrees
Critical Rollover Angle
12 degrees
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 ________ ________.
20 degrees C
Salt encrustation
40 degrees C
Compressor stalls
The best indication of performance loss due to salt spray ingestion is the relationship between ______ and _____.
TGT and torque
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.
8 to 12 knots
15 to 20 knots
What does a one per vibration indicate?
Comes from main rotor system. Generally caused by blade out of track, worn or loose control rod end bearings, or malfunctioning blade damper.
What does a 4 per vibration indicate?
Loose or worn vibration absorbers, swashplate, damper servicing, asymmetrical blade loading, etc.
What does a 5 cycle per second vibration indicate in the tail?
Tail shake. Lateral bending mode of the tail pylon in certain flight regimes.
What do high frequency vibrations indicate?
Tail rotor drive shaft unbalanced, bad bearings, or a failing IGB/TGB gearbox.
What does a one times tail rotor speed indicate?
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.
What is Ground Resonance?
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.
