Single Source Study Sheet - Systems

Question 1

Fuel Flow in the Engine

Answer 1

1. Pump (engine driven)
2. Fuel filter
3. HMU
4. Liquid to liquid cooler
5. ODV

Question 2

Mechanical Mixing (MMU functions)

Answer 2

Collective to Pitch - Compensates for rotor downwash

_Collective to Roll _- Compensates for Translating Tendency

Collective to Yaw - Torques Effect

Yaw to Pitch - Lift component of Tail Rotor

Question 3

Electronic Coupling (explain to collective to airspeed to yaw)

Answer 3

Collective to Airspeed to Yaw - Compensates for torque effect in addition to Collective to Yaw mixing based on collective position and airspeed. FCC#2 commands yaw trim actuator 100% below 40 knots decreases until 100 knots, none above 100 knots.

Question 4

AFCS five subsystems

Answer 4

1. Trim
2. FPS
3. Coupled Flight Director
4. SAS
5. Stabilator

Question 5

FPS purpose

Answer 5

Basic autopilot – Enhances static stability through long term rate dampening in pitch, roll, and yaw. When coupled with Trim, FPS has 100% control authority (10% per second).

Question 6

FPS Below 50 knots and above 50 knots

Answer 6

_Below 50 Kts _ _Above 50 Kts _

Att. Hold ** Pitch ** Att. Hold
Att. Hold ** Roll ** Att. Hold
Hdg Hold **Yaw ** Head Hold/Turn coord

Question 7

These systems must be on and operational for FPS to function at 100%

Answer 7

1. SAS 1 and/or SAS 2
2. SAS/Boost
3. Trim
4. Stabilator (helps, but not req.)

Question 8

Trim purpose

Answer 8

Provides a gradient and detent holding force for pitch, roll, collective, and yaw.

Question 9

**Trim consist of **

Answer 9

• 3 electromechanical actuators (collective, roll and yaw),
• 1 electrohydromechanical actuator. (pitch) (SAS/Boost required for operation.)

Question 10

Trim slip clutches require ___ lbs of force during an actuator jam.

Yaw ___

Roll ___

Coll ___

Answer 10

80 lbs max in yaw,

13 lbs max roll,

22 lbs max collective

FCC monitors continuously, will turn off driving trim actuator.

Question 11

AVCS purpose

Answer 11

Reduces cockpit and cabin vibrations by mechanically generating additional vibrations that are out-of-phase with the main rotor (90-105 NR).

Uses 3 Force Generators

Question 12

SAS 1&2 purpose

Answer 12

Provides short term rate dampening in pitch, roll, and yaw axis.

Question 13

SAS 1&2 enhances (1)_________ & (2)___________

(3)___________ Control authority ((4)_____________).

Controled by (5) ______________

Answer 13

1. ) turn coordination >50 kts.
2. ) Hover augment <50 kts.
3. ) 5% control authority each.
4. ) (total 10% control authority)
5. ) respective FCC computer.

Question 14

SAS Input:

Answer 14

1. Pitch,Roll, and Yaw signals from respective EGIs (Nose)
2. Airspeed – Air Data Computers

Malfunction indicated by erratic movement, Reset CPTR1/ 2, or turn off that SAS

Question 15

Stabilator purpose

Answer 15

Variable angle of incidence airfoil that enhances the handling qualities in the pitch axis in forward flight.

Question 16

Stabilator functions

Answer 16

1. Streamlines w/ rotor downwash at low speed (below 30 kts) to min. nose up attitude from downwash. (ADC, FCC)
2. Collective Coupling to min. pitch attitude excursions due to collective inputs. (Collective Pos. Transducers) begins@30kts
3. Angle of Incidence decreases above 30 kts. to improve static stability. (ADC, FCC)
4. Lateral Sideslip to pitch coupling to reduce susceptibility to gusts. Stab up for right pedal, stab down for left pedal. (Lat. accelerometers)
5. Pitch Rate Feedback to improve dynamic stability. Dampen pitch excursions due to turbulence or “G” forces. (EGI, FCC)

Question 17

ODV functions

Answer 17

1. Hot Start Prevention shuts fuel flow at 900°C.
2. Over-speed protection (NP) from DEC at 120+1%
3. Purges main fuel manifold and allows back flow of high-pressure air for purging.
4. Sends fuel through manifold to injectors for starting & eng

Question 18

HMU purpose

Answer 18

Basic fuel control; high press. fuel pump & variable geometry servo-actuator.

Question 19

HMU functions acronym

Answer 19

PM CAN VDTO

Question 20

HMU functions “PM”

Answer 20

Pumps fuel at high pressure

Meters fuel to ODV in response to PAS, LDS, torque motor from DEC, & engine variables.

Question 21

HMU functions “CAN”

Answer 21

Collective Pitch Compensation through the LDS. When the collective is moved, NG is reset for immediate NP response.

Accel/Decel fuel flow limiting preventing compressor stalls, engine damage, or flame out.

NG limiting - limits max torque available under low temperature conditions.

Question 22

HMU functions “VDTO”

Answer 22

Variable Geometry Positioning of the inlet guide vanes for optimum performance.

DEC lockout PAS Overide & Control with DEC inoperative. Allows pilot to mechanically bypass torque motor inputs.

Torque Motor to Trim NG Output. to fine tune engine output. Can be over ridden in DEC lockout.

Opens Vapor Vent for manual HMU priming, to remove air from HMU.

Question 23

DEC purpose

Answer 23

Controls electrical functions of engines and transmits operation info to the cockpit.

Question 24

DEC functions acronym

Answer 24

IN FLT HHOT

Question 25

## Footnote **DEC functions “IN"**

Answer 25

## Footnote 1. **_I_**sochronous NP Governing. DEC will maintain Np reference 2. **_N_**P Reference from the cockpit, (INCR/DECR from 96-100%)

Question 26

## Footnote **DEC functions “FLT"**

Answer 26

* **_F_**ault Indication. DEC code sent to corresponding ENG Q indicator and the FMS DEC status page. * **_L_**oad Sharing/Torque Matching. Increase Q of low side to match up to 3% NP above reference. * **_T_**ransient Droop Compensation. 4-1 improvement to compensate for transient rotor droop. Uses coll. Pos. transducer signal.

Question 27

## Footnote **DEC functions “HHOT"**

Answer 27

## Footnote 6. **_H_**istory Counter. Sends signals to History Counter. 7. **_H_**ot Start Preventer. Tells ODV to shut off fuel when 900°C is reached, Ng\<60, Np\<50. 8. **_O_**verspeed Protection. Triggered when Np reaches 120±1%. 9. **_T_**GT Limiting. Limits fuel flow when reaching appx. 879 Dual Eng, 903 (21⁄2 min) when opp Q is \< 50%.

Question 28

## Footnote **Engine Alternator functions**

Answer 28

Three windings for three functions: 1. **_N_**g signal to cockpit tachometer. (green) 2. **_I_**gnition power to the exciters during start. (yellow) 3. **_D_**EC power. (yellow) Loss of alt. does not result in high side failure

Question 29

## Footnote **Weight-On Wheels Switch functions acronym**

Answer 29

CHAFF AIM TUBE

Question 30

## Footnote **Weight-On Wheels Switch functions “CHAFF"**

Answer 30

* **_C_**VR/FDR: IBIT, erase on gnd * **_H_**ydraulic leak test disabled in fight. * **_A_**udio for low NR disabled on the ground. * **_F_**light Dir. Modes enabled in-flight * **_F_**MS-Model acft, EGI GC or GPS alignment IBIT on ground/ EGI air alignment in flight

Question 31

## Footnote **Weight-On Wheels Switch functions “AIM"**

Answer 31

## Footnote 6. **_A_**FCS Pitch, Roll Att hold/ Hdg hold/ Maneuvering Stab/ Rad Alt hold/ Airspeed hold – Enabled in-flight. 7. **_I_**FF Mode 4-Auto Zeroize enabled in flight. 8. **_M_**FD status page activation on ground

Question 32

## Footnote **Weight-On Wheels Switch functions “TUBE"**

Answer 32

* **_T_**hermal protection for B/U pump enabled on the ground. * **_U_**nderfreq. protection disabled in flt. (right switch) * **_B_**/U Pump Auto ON regardless of switch position enabled in flight. Disabled on gnd unless Acc Low * **_E_**SSS jettison disabled on ground. (right switch)

Question 33

## Footnote **_Lights, Switches, & MISC_** #1 and #2 FUEL LOW ``` #1 and #2 FUEL PRESS Fuel filter bypass pop ``` Fuel Boost pump

Answer 33

#1 and #2 FUEL LOW≤ 172 pounds #1 and #2 FUEL PRESS≤ 9 psi Fuel filter bypass pop = 8-10 psid Fuel Boost pump = 25 psi

Question 34

``` **_Lights, Switches, & MISC _** #1 and #2 PRI SVO PRESS ``` BOOST SERVO OFF #1 and #2 RSVR LOW

Answer 34

## Footnote ``` #1 and #2 PRI SVO PRESS ≤ 2000 psi BOOST SERVO OFF ≤ 2000 psi ``` #1 and #2 RSVR LOW ≤ 60% cap.

Question 35

## Footnote ``` **_Lights, Switches, & MISC _** #1/ #2 Hyd return bypass = ``` #1/ #2 Hyd Impd byp. = Hyd. System pres. = Pilot Assist pres reducer btn pops = Utility mod. velocity fuse \>

Answer 35

#1/ #2 Hyd return bypass = 100±10 psid #1/ #2 Hyd Impd byp. = 70±10 psid Hyd. System pres. = 3000 psi Pilot Assist pres reducer btn pops = 1375 psi Utility mod. velocity fuse \> 1.5 gpm

Question 36

## Footnote **_Lights, Switches, & MISC _** XMSN OIL PRESS #1 and #2 ENG INLET ANTI-ICE Hyd pump temp labels

Answer 36

## Footnote XMSN OIL PRESS \< 14±2 psi #1 and #2 ENG INLET ANTI-ICE 93°C Hyd pump temp labels \> 132°C (270F)

Question 37

## Footnote ``` **_Lights, Switches, & MISC_** #1/#2 ENG OUT light/audio ``` NG LOW ROTOR RPM light/audio NR Lose Main GENs on gnd NR Lose Main GENs in air

Answer 37

#1/#2 ENG OUT light/audio \<55% NG LOW ROTOR RPM audio/lt \<96% NR NR Lose Main GENs on gnd 93-95% NR NR Lose Main GENs in air 85-89% NR

Question 38

## Footnote **_Lights, Switches, & MISC _** Gravity Refuel: Pressure Refuel: Closed Circuit:

Answer 38

Gravity Refuel: 360gal Pressure Refuel: 359gal, 300gpm, 55psi Closed Circuit: 356gal, 110gpm, 15psi

Question 39

_**Lights, Switches, & MISC (wrong \*\*edit with -10\*\*)**_ Eng Anti-ice on: #% Tq +## lbs/hr Cockpit Heater on: #% Tq +## lbs/hr Engine Idle fuel @ sea lvl ## lbs/hr Engine Idle fuel @ 5000ft ## lbs/hr Engine Fly fuel @ sea lvl ## lbs/hr Engine Fly fuel @ 5000ft ## lbs/hr

Answer 39

Eng Anti-ice on: 20% Tq +100 lbs/hr Cockpit Heater on: 5% Tq +20 lbs/hr Engine Idle fuel @ sea lvl 322 lbs/hr Engine Idle fuel @ 5000ft 277 lbs/hr Engine Fly fuel @ sea lvl 552 lbs/hr Engine Fly fuel @ 5000ft 479 lbs/hr