SD3-60 AIRCRAFT MAINTENANCE MANUAL

Transcription

1 AMM FLIGHT DIRECTOR SYSTEM - DESCRIPTION & OPERATION 1. Description A. General Refer to Figure 1. Identical, left and right, systems are installed (one for each pilot); each provides information to "assist" in the manual flight of the aircraft or to monitor the operation of an autopilot, if fitted. Both systems comprise an air data sensor, a flight guidance computer, a flight control panel, an attitude director indicator, a vertical gyro and a horiontal situation indicator. In essence, the attitude director indicator provides indication of aircraft attitude in pitch and roll and the horiontal situation indicator provides indication of aircraft attitude in yaw. Warning flags are provided to monitor the inputs to both units. The flight control panel provides mode selection, annunciation, and self-test facilities. B. Detail (1) Flight director indicator, Collins type ADI-84A (Part number ). The flight director indicators, No. 1 and No. 2, and idented 'JT' and 'JU' respectively are mounted at their associated pilot's position on panel 1P. Each instrument displays aircraft attitude and flight director information by means of a symbolic 3-dimensional forward view display. Refer to Figure 2. Aircraft attitude is displayed by the relationship of a stationary delta-shaped aircraft symbol with respect to a moveable horion line. The horion line moves in roll and pitch axes, the presentation being marked to represent sky and ground, respectively, above and below the horion line. Bank angle is shown by a scale at the top of the indicator. Two axis flight director s are displayed by two pointers, flanking the aircraft symbol. These pointers forming an interrupted "V", referred to as V-bars, always move in unison; they are servo driven for combined pitch and roll s. Sensing provides a "fly to", directing the pilot to fly into the V-bars. The V-bars are aligned with the edges of the aircraft symbol when the has been satisfied. The V-bars are deflected out of view when not in use. Other displays include glideslope deviation, localier deviation, radar altitude deviation and an annunciator for decision height. An inclinometer provides slip/skid information. Warning flags monitor gyro computer, glideslope, and radar altitude. A localier shutter is also provided which opens when a localier frequency is selected. Page 1

2 Flight Director System Figure 1 Page 2

3 Flight Director Indicator Figure 2 Page 3

4 Horiontal Situation Indicator Figure 3 Page 4

5 (2) Horiontal situation indicator, Collins type HSI-70 (Part number ). The horiontal situation indicators, No. 1 and No. 2, are idented 'JN' and 'JP' respectively and are mounted at their associated pilots position on panel 1P. The horiontal situation indicator is an electromechanical instrument that provides the pilot with visual displays of aircraft heading, deviation relative to a selected VOR or LOC station, and to/from information for a VOR station, glideslope and compass slaving indication. Warning glags are incorporated with the glideslope deviation, deviation and compass heading displays to warn the pilot of invalid display operation. The slave indicator gives the pilot a visual indication of the slaving status of the directional gyro with respect to the flux detector. Gear driven outputs interface with other units in the flight director system to provide selected and selected heading information. (3) Flight control panel, Collins type FCP-65 (Part number ) The flight control panels, No. 1 and No. 2, are idented 'JR' and 'JS' respectively and are mounted above their associated flight director indicators on panel 1P. The panel provides mode selection and annunciation, and is the controller for the flight director system. In addition to the control of the normal operating modes the panel provides for selection of a test mode. Pushing the test button causes the system to check the status of the units supplying data to it. If a failure is detected the appropriate annunciator will light. The available mode selections on the panel are:- (a) HDG : Heading mode (b) NAV : VOR navigation mode APPR : LOC navigation mode (d) REV : Reverse mode (e) ALT : Altitude hold mode ALT SEL : Preselected al titude mode (only operational when the altitude preselect option is used). (g) VS : Vertical speed hold mode (h) IAS : Indicated airspeed hold mode The indicators which will shows at one time or another, on the panel are, reading from left to right and top to bottom (a) HDG (green) : Heading mode (b) NAV (green) : VOR navigation mode Page 5

6 ARM (amber) : VOR navigation mode armed (d) DR (green) : Dead reconing mode (e) APPR (green) : LOC navigation mode ARM (amber) : LOC navigation mode armed (g) REV (green) : Reverse mode (h) ALT (green) : Altitude hold mode (i) VS (green) : Vertical speed hold mode (j) GS (green) : Glideslope mode (k) ARM (amber) : Glideslope mode armed (l) IAS (green) : Indicated airspeed mode (m) GA (green) : Go around mode Other indicators are possible, but only when an altitude preselector, yaw damper or autopilot are fitted. The integral lighting of each panel is controlled by an appropriate GENERAL dimmer control on panel 1P. Refer to , pb1. Annunciator brilliance is controlled by a photo sensor and associated circuitry. (4) Vertical gyro, Collins type 332D-11T (Part number ) This unit is the source of pitch and roll attitude reference for the flight director. Three wire 400 H synchro outputs, conforming to ARINC are provided in both pitch and roll axes. The unit has a built-in start cycle and monitoring circuits, and fast erection is automatic during starting. The left and right gyros are mounted in the fuselage roof between Stns. 146 and 159 and are idented 1FD5 and 2FD5 respectively. Two additional outputs are available, one roll and one pitch. The No. 1 vertical gyro outputs are used for stabiliation of the Weather Radar antenna and the No. 2 vertical gyro outputs are used as inputs to the Flight Data Recorder. A complete detailed description of a 332D-11T vertical gyro is available in the relevant Collins manual. (5) Flight guide computer, Collins type FGC-65 (Part Number ) The flight guidance computers, left and right, are idented 1FD2 and 2FD2 are respectively located in the No. 1 and No. 2 radio bays. The computer processes all the information from various sources to provide outputs to drive the V-bars and the warning flags. Page 6

7 2. Operation A complete detailed description of the computer is available in the relevant Collins manual. (6) Air data sensor, Collins type ADS-65 (Part number ) The air data sensors, left and right, are idented 1FD1 and 2FD2 and are respectively located on the flight compartment left and right sidewalls at Stn.32. The sensor is an electrically powered air pressure sensor hose. Outputs are indicated speed, barometric altitude, and vertical speed. The unit operates in the range of ft. to + 45,000 ft. and in IAS range of 75 to 300 knots. The operating range for vertical speed is 0 to ± 10,000 ft./min. A complete detailed description of the air data sensor is available in the relevant Collins manual. In addition to the equipment detailed in paragraphs (1) to (6) there is also a go around (G/A) and SYNC switch on each handwheel. A gyro fast erect switch is also provided at each pilots position on panel 1P. The left flight director system is powered via the following circuit breakers and systems:- C/B No. Panel System 58 1D left 28V DC essential services busbar 300 1D left 26V AC busbar 304 1D left 26V AC busbar 324 1D left 115V AC busbar 404 5D No. 1 VOR/ILS/Marker beacon 28V DC The right flight director system is powered via the following circuit breakers and systems:- C/B No. Panel System 178 2D right 28V DC essential services busbar 350 2D right 26V AC busbar 354 2D right 26V AC busbar 369 2D right 115V AC busbar 434 6D No. 2 VOR/ILS/Marker beacon 28V DC Data for the various operational modes is derived from - the associated Gyro Compass. Refer to , pb1. - VOR/ILS/Marker beacon. Refer to , pb1. Page 7

8 Both flight director systems are identical but operationally independant of each other. Refer to Table 1. Refer to Table 2. Mode selection is made by pressing one of the momentary switches on the flight control panel. If all the necessary signals and power bias are not available for that mode then the associated indication on the flight control panel will flash. Table 1 shows the result of selecting a lateral mode under different conditions and table 2 shows the result, under different conditions, of selecting a vertical mode. Table 2 also incorporates the two switch functions on the handwheel; go around and pitch sync. When no mode has been selected the V-bars are biased out of view. other functions, except the computer flag, are independant of the computer. These functions are:- A. Pitch and roll attitude information displayed on the ADI-84A by the relationship between the delta-shaped aircraft symbol and the artificial horion line. A pitch scale is marked on the attitude and the artificial horion line. A pitch scale is marked on the attitude tape and indication of roll is given by a moving pointer against a fixed scale at the top of the instrument. If this data is invalid the GYRO flag will come into view. B. Slip/skid information is provided by means of an inclinometer on the ADI-84A. C. Your attitude information is provided in the form of a compass card on the HSI-70. This is driven from the Gyro Compass system and indication of the slaving status is provided by a slaving meter in the top right hand corner of the instrument. This centres when the compass card has synchronised with the Gyro Compass. If this data is invalid the HEADING flag will come into view. D. VOR deviation is provided by the bar of the pointer moving against a scale on the background. A TO/FROM pointer is also provided. If this data is invalid the TO/FROM indication will be replaced by the VOR/LOC flag. E. LOC deviation is provided also by the bar of the pointer. There is also a runway symbol on the ADI-84A which provides LOC deviation. On selection of a LOC frequency a localiser shutter opens to allow viewing of the runway symbol. The TO/FROM indication is blank but will be replaced by the VOR/LOC flag if the LOC information is invalid. F. Glideslope deviation is provided on both the ADI-84A and the HSI-70 and is in the form of a pointer against a scale. If this data is invalid, both GS flags will come into view and obscure the pointers. NOTE: In the case of pitch, roll, VOR/ILS deviation and glideslope deviation the aircraft should be controlled in such a way as to move the delta-shaped aircraft symbol to the pitch, roll or deviation, not the reverse. Page 8

9 G. Radar altitude of 0 to 200 ft. is provided on the ADI-84A. This is just a repeater from the Radar Altitude system. Refer to , pb1. A decision height indicator is also provided and this lights when the radar altitude is below the height set on the radar altimeter indicator by the decision height warning index. If this data is invalid the RAD ALT flag will come into view and obscure the radar altimeter scale and pointer. The two additional controls on the HSI-70 are the COURSE knob, which positions the pointer to the desired radial for VOR navigation or to the runway heading for localier appraoch, and the heading (HDG) knob which positions the heading bug to the desired heading. Displacement of the bug from the lubber line represents the direction and magnitude of deviation of selected heading from existing heading. Both of these controls can be used as inputs to the computer. 3. Self Test When the TEST button on the FCP-65 is pushed and held the system goes through a self test procedure. Indication of a successful test is when all the indications on the FCP-65 flash repeatedly. Page 9

10 Active mode No mode GO AROUND HDG NAV APPR (receiver tuned to LOC frequency) REV MODE VOR LOC VOR FRONT COURSE APPR (receiver tuned to VOR freq.) GLIDESLOPE OPERATION INHIBITED Submode condition System condition Roll steer display (ADI) Annunciator display Off mode for flight director Off Maintains wings level Captures and holds a selected heading Before capture Heading select intercept out of view Roll error Computed heading GA HDG HDG NAV ARM After capture Tracks selected radial or Computed Over the cone Uncouples radio. Accepts changes Memoried Before capture Heading select intercept to inbound Computed heading NAV NAV DR HDG APPR ARM Lateral Mode Chart Table 1 After capture Tracks inbound Computed LOC APPR GS ARM Before capture Heading select intercept to back LOC Computed heading HDG APPR ARM REV After capture Before capture Tracks back Heading LOC select intercept Computed LOC APPR REV Computed heading HDG APPR ARM After capture Tracks selected radial Computed A PPR Over the cone Uncouples radio. Accepts changes Memoried APPR DR Page 10

11 Page 11 ACTIVE LATERAL MODE HDG.NAV APPR. APPR MODE (AFTER GS CAPTURE) HDG. NAV. APPR (BEFORE GS CAPTURE) ACTIVE VERTICAL MODE GO AROUND GLIDESLOPE NO MODE ALT IAS V/S SUBMODE CONDITION GO AROUND SYSTEM CONDITION MAINTAINS A FIXED PITCH UP REFERENCE PITCH STEER DISPLAY (ADI) ANNUNCIATOR DISPLAY BEFORE MIDDLE MARKER INOPERATIVE RADIO ALTIMETER NORMAL GLIDESLOPE APPROACH GAINS AFTER MIDDLE MARKER REDUCED GLIDESLOPE APPROACH GAINS OPERATING RADIO ALTIMETER GLIDESLOPE APPROACH GAINS PROGRAMMED WITH RADIO ALTITUDE Vertical Mode Chart Table 2 PITCH HOLD MAINTAINS PITCH ATTITUDE MAINTAINS ALTITUDE PITCH ERROR COMPUTED GLIDESLOPE COMMAND PITCH ERROR COMPUTED ALTITUDE COMMAND MAINTAINS INDICATED AIRSPEED COMPUTED IAS COMMAND GA GS ALT IAS V/S SYNC SWITCH NOT ACTIVE SYNCS TO PITCH ATTITUDE MAINTAINS VERTICAL SPEED COMPUTED V/ S COMMAND GS ARM (WHEN IN APPR MODE ON LOC) DISCONNECTS MODE, RETURNS TO PITCH HOLD

12 AMM FLIGHT DIRECTOR SYSTEM - MAINTENANCE PRACTICES 1. Removal/Installation A. Remove an air data sensor (ADS-65). When an ADS-65 is disconnected from the pitot and static systems during removal both the aircraft pitot and static pipes and the ADS-65 pitot and static inlet ports should be blanked off. B. Install an air data sensor (ADS-65) Once an ADS-65 has been installed and connected up to the aircraft pitot and static systems both pitot and static pressure system tests should be performed on the relevant system. Refer to , pb Adjustment/Test A. Bench tests The flight director system should be tested in accordance with the procedure in the relevant manufacturers Maintenance Manual. B. Pre-installation tests Check that the units are free from signs of mechanical damage, corrosion or other defects. C. Post-installation tests Test equipment required:- Altitude and airspeed simulator Portable VOR and ILS flight line test sets with a facility for selecting different strengths of output signal. (1) Preparation (a) Refer to , pb301. Provide electrical power. (b) Apply AC and DC power to the flight director and associated gyro compass and navigation receiver. Check that the HEADING, GYRO and COMPUTER flags are out of view within five minutes of switch on. (d) Connect the altitude and airspeed simulator to the appropriate pitot/static system. (e) Ensure that the RAD ALT flag is in view by opening C/B No.409 on distribution panel 5D. Page 201

13 (2) Lighting (a) Press and hold test button on the FCP-65 and check that all annunciations come up on the FCP-65 annunciation panel. (The annunciations will flash at approximately 1 H). (b) Alternatively cover and uncover the light sensor on the FCP-65 and check that the annunciations are dim when the sensor is covered and bright when uncovered. Release the FCP-65 test button. (d) Check that the FCP-65 selector buttons are lit when the associated GENERAL dimmer is rotated clockwise. (e) On FCP-65 press each mode button in turn and check that each button will latch and the respective mode annunciator is lit. NOTE: 1. HDG, NAV and APPR functions are interlocked and only one can be selected at any one time. The only exceptions to this are when the NAV or APPR modes only arm, then when NAV or APPR are selected they will annunciate on ARM and HDG will either come on also or stay on if previously selected. 2. ALT, VS and IAS functions are also interlocked, only one can be s selected at any one time and when HDG, NAV or APPR has been previously selected, and when the conditions for glideslope capture have not been met. 3. REV function can only be selected if NAV or APPR has been previously selected. Check that the ADI-84A and HSI-70 are illuminated when the associated FLT SYSTEM dimmer is rotated clockwise. (3) Gyro and compass inputs (a) Remove the mounting screws securing the vertical gyro to the airframe and mount the gyro on a tilt table. (b) Tilt the vertical reference gyro to simulate a right bank and check that horion rotates CCW. Repeat for left bank. (d) Tilt the vertical reference gyro to simulate a pitch down attitude and check that horion moves up. (e) Repeat for pitch up. Page 202

14 Rotate the directional gyro to simulate a right turn and check that the compass card rotates CCW (alternatively complete aircraft may be rotated). (g) Repeat for left turn. (4) Radio deviation signals (a) Tune to VOR frequency on the test set. (b) Adjust pointer for ero deflection on deviation bar. Set the TO/FROM pointer on HSI-70 to FROM by means of test set selection. (d) Increase pointer heading by 10 and check that the deviation bar deflects to the right 2 dots approximately. (e) Tune to LOC frequency and check that localier shutter opens at base of ADI-84A display. Set glideslope deviation input at ero and check that both glideslope deviation pointers are at ero. (g) Set glideslope deviation input at 150µA and check that both glideslope deviation pointers are at 2 dots up approximately. (h) Repeat for -150µA input (5) Flag logic checks (a) On FCP-65 press HDG button. (b) Check HEADING flag is out of view. Trip compass system breaker and check that HEADING flag comes into view, and that HDG annunciator flashes. (d) Reset the compass system breaker. (e) Check that HDG annunciator is steady and HEADING, GYRO and COMPUTER flags are out of view. Trip the vertical reference gyro breaker and check that the GYRO and COMPUTER flags are in view, and that HDG annunciator flashes. (g) Reset vertical reference gyro breaker and check that GYRO and COMPUTER flags are out of view and HDG annunciator is steady. (6) HDG mode (a) Set heading bug 10 right of the lubber line and check V-bars right bank. Page 203

15 (b) Tilt the vertical reference gyro 10 right of the lubber line and check the V-bars read ero ±1. Return gyro to 000. (d) Set heading bug 10 left of the lubber line and check V-bars left bank. (e) Tilt the vertical reference gyro 10 left bank and check the V-bars read ero ±1. Set heading bug 90 right of the lubber line and check V-bars right bank. (g) Tilt the vertical reference gyro 25 right bank and check the V-bars read ero ±2. (h) Return heading bug to lubber line and vertical reference gyro to 000. (7) NAV mode (a) Tune to VOR frequency on the test set and check that localier shutter closes. (b) Adjust the pointer to give 2 dots deflection of the deviation bar. Rotate the directional gyro to bring the pointer to the lubber line. (d) On FCP-65 press NAV button and check: 1 HDG and NAV ARM annunciators are lit. 2 The V-bar s are a function of the heading bug deviation from the lubber line. (e) Set the pointer to ero the VOR deviation and check that only NAV annunciator is lit. Rotate the directional gyro to put the pointer under the lubber line and wait 20 seconds. (Alteratively complete aircraft may be rotated). (g) Adjust the pointer to give one dot deflection such that the aircraft symbol is to the left of the deviation bar abd check that the V-bars a right turn. (8) APPR mode (a) Set the pointer under the lubber line. (b) Tune to LOC frequency on the test set and check that localier shutter opens. Adjust inputs to give one dot up glideslope and one dot right localier. (d) On FCP-65 press HDG, APPR and ALT buttons in that order. Page 204

16 (e) Check that HDG, APPR ARM and ALT annunciators are lit. Adjust the localier input to ero the deviation bar (and runway symbol), and check that: 1 HDG and the ARM of APPR ARM annunciators goes out, and 2 after a pause GS ARM annunicator comes on (g) Adjust the glideslope input to ero the deviation pointers and check that only APPR and GS annunciators are lit. (h) Adjust inputs to give one dot up glideslope and one dot right localier. (i) (j) (k) (l) Check the V-bars read up for glidelope and right localier. Repeat paragraphs (8)(h) and (8)(i) for down/left deviations. Adjust inputs to ero deviations and wait 20 seconds. Adjust localier input to give 2 dots deviation of the deviation bar. (m) Tilt the vertical reference gyro 10 to offset the localier deviation and check the V- bars are ero ±1. (n) Return the vertical reference to ero and adjust localier input to ero deviation bar. (o) Adjust glideslope input to give 2 dots deviation of the glideslope pointer. (p) Check that switching on ILS middle marker reduces V-bars gain. (9) GA mode (a) Operate GA switch on handwheel and check that V-bars give wings level and pitch up of 8. (b) Check that only GA annunciation is lit. On FCP-65 press NAV button and check that GA annunciation is not lit. (d) Operate SYNC switch on test circuit and check that V-bars return to ero in pitch. (10) REV mode (a) Check that pointer is under the lubber line. (b) On FCP-65 press REV and APPR buttons and check that APPR ARM and REV annunciators are lit. Page 205

17 Adjust inputs to give one dot up glidelsope and one dot right localier. (d) Check that V-bars deviation is for back localier. (e) Adjust inputs to ero deviations and check that only APPR and REV annunciators are lit. (11) ALT mode (a) Adjust the altitude and airspeed simulator for 10,000 feet and 150 knots. (b) On FCP-65 press HDG and ALT buttons in that order and check that HDG and ALT annunciators are lit. Reduce altitude to 9,900 feet and check that V-bars pitch up. (d) Tilt the vertical reference gyro 5 pitch up and check that the V-bars are approximately ero. (e) Repeat paragraphs (11) and (11)(d) for 10,100 feet and pitch down. Return vertical reference gyro to ero. (g) Check that V-bars can be altered by varying the airspeed. (airspeed increased: V- bars reading decreased). (h) Operate the SYNC switch on the handwheel and check that the V-bars are at ero and only HDG annunciator is lit. (12) IAS mode (a) Adjust the altitude and airspeed simulator for 1000 feet and 150 knots. (b) On FCP-65 press IAS button and check that HDG and IAS annunciators are lit. Increase airspeed to 160 knots and check that V-bars give pitch up. (d) Reduce airspeed to 150 knots and check that V-bars are at ero. (e) Reduce airspeed to 140 knots and check that V-bars give pitch down. Increase altitude to 15,000 and check that the V-bars reading is decreasing as the altitude increases. (g) Operate the SYNC switch on the handwheel and check that the V-bars are at ero pitch and only HDG annunciator is lit. (13) VS mode (a) Reduce altitude at 1000 ft/min. Page 206

18 (b) On FCP-65 press VS button and check that HDG and VS annunciators are lit, and V-bars are at ero. Check that the V-bars can be altered by varying the vertical speed. (increase vertical speed : V-bars pitch up). (d) Operate the SYNC switch on handwheel and check that V-bars are at ero and only HDG annunciator is lit. (e) On FCP-65 press HDG button and check that there are no annunciations. Reduce altitude and airspeed to ero. (14) Second flight director system Repeat the functioning tests of paragraphs (1) to (13) for the second flight director system. Page 207