Fam 4 Flashcards
Collective to yaw
Cause: main rotor torque
Compensation requirement: nose yaws right when collective is increased
Compensation: tail rotor thrust is increased
Collective to lateral
Cause: lateral lead (tail rotor propeller effect)
Compensation requirement: helicopter drifts right when collective is increased
Compensation: rotor disc is tilted left
Collective to longitudinal
Cause: rotor downwash on stabilator
Compensation requirement: nose pitches up and helicopter drifts aft when collective is increased
Compensation: rotor disc is tilted forward
Yaw to longitudinal
Cause: tail rotor lift vector
Compensation requirement: nose pitches down and helicopter drifts forward when left pedal is applied
Compensation: rotor disc is tilted aft
Collective/airspeed to yaw (electronic compensation)
Cause: camber of tail rotor pylon varies side load with airspeed
Compensation requirement: nose yaws left as airspeed increases
Compensation: a portion of the main rotor torque compensation is provide by a trim input that is proportional to collective position and airspeed. The trim input is then progressively washed out as pylon side loads increase with airspeed
Where are the flight controls inputs combined? And what does this mean?
In the mixing unit to produce uncoupled airframe response characteristics.
Meaning the mixing unit applies corrective flight control inputs to counter unwanted responses from the aircraft.
Boost servo hardover vs PAS malfunction
PAS malfunction = 3 cautions (BOOST SERVO OFF + SAS + AFCS DEGRADED)
Boost servo hardover = no cautions
They feel similar though
Boost servo hardover
- “Boost boost boost”
- Sas/boost - off
C: up to 75# of left pedal force will be required when hovering with boost servos off with starboard crosswinds (from right). This value is significantly lowered with port crosswinds (from left)
C: landings with BOOST SERVO OFF on all single spot air-capable ships should only be attempted if there is no large landing platform (LPD or larger) or shore base available
1 AND #2 hyd pump fail
1 hyd pump & #2 hyd pump & #1+#2 hyd pump fail & backup pump on
- Reateict flight control movement
- Land as soon as possible
1 OR #2 hyd pump fail (single)
Non memory
(#1/#2) hyd pump and backup pump on
Note: momentary loss of pressure to the T/R servo with the #1 HYD PUMP failure can cause LDI logic to automatically switch from the #1 T/R servo to the #2 T/R servo resulting in the illumination of the #1 TAIL RTR SERVO caution and #2 TAIL RTR SERVO ON advisory
Warning: failure to ensure BACKUP PUMP switch is ON or in AUTO position prior to landing with a #1 HYD PUMP caution present will result in the loss of tail rotor control when the WOW is activated
#1 RSVR LOW #1 TAIL RTR SERVO #2 TAIL RTR SERVO ON BACKUP PUMP ON
1 tail rotor servo leak
Land as soon as practicable
#1 RSVR LOW #1 HYD PUMP BACKUP PUMP ON
1 primary servo OR #1 transfer module leak
- Servo -1st off
- Land as soon as possible
If the BACKUP RSVR LOW caution also appears or thr backup pump fails:
3. Land as soon as possible
(Note: be prepared for loss of tail rotor control)
If the #2 PRI SERVO PRESS caution and/or HYD warning appears:
4. Land immediately
(Warning: failure to ensure BACKUP HYD PMP switch is in AUTO or ON position prior to landing with a #1 RSVR LOW or #1 HYD PUMP caution present will result in loss of tail rotor directional conteolnwhen the weight on wheels switch is activated)
#1 TAIL RTR SERVO #2 TAIL RTR SERVO ON BACKUP PUMP ON
1 tail rotor servo malfunction
2 RSVR LOW
BOOST SERVO OFF
SAS
AFCS DEGRADED
Pilot assist servo leak
Non memory
W: consider securing sas/boost prior to reaching landing environment
C: try to land on LPD+ or shore
C: 75# of left pedal w/right crosswind (starboard), significantly reduced with left crosswind (port)
#2 RSVR LOW #2 HYD PUMP BACKUP PUMP ON
2 primary servo OR #2 transfer module leak
- Servo - 2nd off
- Land as soon as practicable
(Note: failure to ensure BACKUP PUMP switch is in AUTO or ON position prior to landing with a #2 HYD PUMP caution present will result in loss of pilot asset servos when the WOW switch is activated)
if the BACKUP RSVR LOW caution also appears or backup pump fails:
3. Land as soon as possible
(Note: be prepared for loss of the PAS)
If the #1 PRI SERVO PRESS caution and/or HYD warning appears:
4. Land immediately
BOOST SERVO OFF
SAS
AFCS DEGRADED
non memory
**shallow approach to a hover
C: 75# of left pedal with starboard XW (from right). Significantly reduced with port XW (from left)
C: try to land on LPD or larger or land
BACKUP RSVR LOW
non memory
UTILITY HYD PUMP or UTILITY HYD PUMP HOT or UTILITY HYD RSVR LOW
- stop dome
AFCS DEGRADED
- safe altitude and airspeed - establish (wave off, ITO, as req.)
Note: if the AFCS DEGRADED caution appears during a night/IMC coupled hover or automatic approach, consideration may be given to continuing hover/approach if not disoriented or unstable
AFCC I/O FAIL
and
AFCS DEGRADED
non memory
cause is AFCC power loss…just reset CBs
SAS (caution)
W: failure of either SAS 1 or SAS 2 are usually, but not necessarily, following by a fail advisory indication. This can include loss of altitude hold function
The cause is loss of hydraulic pressure to SAS actuator(s) or loss of electrical power to both SAS 1 and SAS 2
What is the main purpose of the hydraulic system?
to provide pressure for the flight control system, APU, and rescue hoist system
Utility hydraulic system provides hydraulics for what?
sonar reeling machine only
Hydraulic cautions…. what does each one mean?
- # 1/#2 RSVR LOW
- BACKUP RSVR LOW
- # 1 HYD PUMP
- # 2 HYD PUMP
- # 1 TAIL RTR SERVO
- # 1/#2 RSVR LOW = low level switch in rsvr activated
- BACKUP RSVR LOW = LL switch in bkup rsvr activated
- # 1 HYD PUMP = loss of #1 hyd px
- # 2 HYD PUMP = loss of #2 hyd px
- # 1 TAIL RTR SERVO = loss of 1st stage tail rotor px
How does collective inputs get to rotors?
Coll -> PAS via boost servos and trim actuators -> mixing unit -> ALL 1st stage primary servo and 1st stage T/R servos -> rotors
How does pitch inputs get to the rotors?
PITCH via cyclic -> PAS via boost servo (SAS and Trim actuators) -> mixing unit -> fore and aft primary servos -> rotors
What does the mixing unit do?
combines the 3 flight control inputs to produce uncoupled airframe response characteristics…..meaning the mixing unit applies corrective flight control inputs to counter unwanted response
PAS Malfunction Approach and Landing
- normal or shallower approach to 20’AGL hover. Turn on HVR mode
- turn into wind, lower collective. Pause at 10’AGL to verify stability
- USE SMALL CONTROL INPUTS
- keep collective full down until SAS/BOOST turned on
