Flight Characteristics

Question 1

VRS limitations: when does the high sink rate warning system come on?

Answer 1

<60KCAS ; >800fpm sink

Question 2

What is pitch-up with side slip and what are factors that can cause it?

Answer 2

Pitch-up with side slip refers to the pitch-up tendency when the empennage and horizontal tail are directly downwind of a proprotor.

Factors that influence the onset and severity of this condition:
- Relative winds 30-60 deg off the nose that are greater than 20kts (downwash impingement on the tail causes the aircraft to pitch-up)
- Nacelle angle: higher nacelle angle reduce forward stick control margin, decreasing the ability to correct for inadvertent pitch up
- Longitudinal CG: Witch aft CG, any pitch-up tendency of the aircraft will be more difficult to arrest since control margins are already reduced in this axis

Question 3

Wind tolerance for rotor start-up and shutdown

Answer 3

Up to 45kts

Question 4

VTOL nacelle setting:

Answer 4

85-96 deg nacelles

Question 5

CONV nacelle setting:

Answer 5

1-84 deg nacelles

Question 6

APLN nacelle setting:

Answer 6

0 deg nacelle

Question 7

Describe the stages of VRS:

Answer 7

Stage I
- characterized by increased vibration levels, pitch bucking, or sluggishness of aircraft response to control inputs
- corrective action - increase TCL; trim nacelles forward to max rate for 2sec (~15deg forward); fly out with forward stick

Stage II
- aural cues (rumbling onset), markedly increased descent rate, or improper roll control response as VRS gets worse
- corrective actions - trim the nacelles forward at max rate for two seconds (~15 deg forward); simultaneous and immediate forward stick to fly out of condition
*Increasing TCL in late stages of VRS may aggravate the condition and cause a roll-off

Stage III
- characterized by rapid uncommanded roll and corresponding large pitch; each rotor operating at very different aerodynamic conditions (known as “roll-off”)
- correction: nacelles should be rotated forward at max rate for 2 secs (~15 deg forward) and unusual attitude recovery procedures should be performed

Question 8

75 STO

Answer 8

• Nacelle 75
• TCL full forward 6 seconds
• Liftoff at Vlof
• Approx 2 deg nose up
• 70-80 KCAS climb

Question 9

60 RTO

Answer 9

• Nacelle 60
• Release brakes ACFT begins to roll
• QM approx. 50% then pause 4-5sec
• Smoothly apply max TCL
• Nose level to slightly high
• Desired climb speed

Question 10

60 STO Level Attitude

Answer 10

• Nacelle 60
• TCL full fwd 6 sec
• Liftoff at Vlof
• Approx. 2 deg nose up
• 80-90 KCAS climb

Question 11

60 STO Attitude Capture

Answer 11

• Nacelle 60
• TCL full fwd 6 sec
• Rotate at Vrot
• 10deg nose high in 2 sec
• Accelerate to 80-90 KCAS

Question 12

Eighty (80) TTO

Answer 12

• Set hover nacelle
• depart vertically
• continue to climb at max power