AVIONICS TRAINING MANUAL FOR
BELL 212/412/412EP HELICOPTERS
GLOBAL POTITION SYSTEM
TRIMBLE- 2100/2101
INTRODUCTION
A satellite based navigation system using a constellation of 24 satellite in six orbits inclined at
an angle of 55 degree to the equator or biting in 12 hours at a height of 20200 km.
PRINCIPLE OF OPERATION- GPS
COMPOSTION AND LOCATION
1
RECEIVER AND DISPLAY UNIT .
BETWEEN BOTH INSTRUMENT PANEL.
2
ANTENNA
TOP OF THE TAIL BOOM
TECHNICAL SPECIFICATIONS
1
RECEIVER FREQUENCY
1575.42MHz
2
GPS CODE
C/A (COARSE ACQUISITION)
3
NUMBER OF CHANNELS
6 ( PARALLEL)
4
SUPPLY VOLTAGE
10-30V DC MAXIMUM
5
UPDATE RATE
ONCE PER SECOND
6
ANT. I/P IMPEDENCE
95 OHM
DGPS
FRONT PANEL OF RXR & DISPLAY UNIT-GPS
INDICATORS
The indicators show which Rxr is being usd for navigation.
The indicaors are IFR
This indicator is lit when the system has sufficient navigation accuracy and integrity to meet
the applicable TSO requirement for the current phase of light
GPS
This indicator is lit when the GPS Rxr is being used
LORAN This indicator is lit when the LORAN Rxr is being used for navigation.
PUSH BUTTON KEYS ON “R&D UNIT -GPS
NINE ILLUMINATED PUSH-BUTTON KEYS ARE USED FOR MODE SELECTION AND DATA
ENTRY.THE KEYS ARE DESCRIBED AS FOLLOWS:NAV
THE NAVIGATION MODE IS USED TO ACCESS NAVIGATION
INFORMATION.THIS INCLUDES THE AIRCRAFT `SCURRENT GROUND
SPEED,DIRECTION,DESTINATION, ESTIMATED TIME ENROUTE AND MORE.
WPT
THE WAYPOINT MODE PROVIDES ACCESS TO DATABASE INFORMATION.
COMPLETE INFORMATION IS AVAILABLE ON AIRPORTS ,VORs, NDBs,
INTERSECTIONS AND USERS WAYPOINTS. DESTINATION SELECTION IS ALSO A
FUNCTION OF THIS MODE.
FPL
THE FLIGHT PLAN MODE IS USED TO PLAN THE ROU TE OF A FLIGHT
..FLIGHT PLAN MAY BE CREATED, EDITED, REVERSED OR ERASED. THE
NAVIGATOR CAN STORE UP TO 20 DIFFERENT FLIGHT PLANS.
CALC
THE CALCULATOR MODE PERFORMS MANY COMMON E6B COMPUTER
FUNCTION. THIS MODE IS USED TO SAVE PRESENT POSITION AND CALCULATE
VNAV PROFILES, WIND SPEED AND DIRECTION, FUEL RANGES, FLIGHT PLAN
SUMMARIESS AND MORE.
AUX
THE AUXILIARY MODE PROVIDES ACCESS TO LESS COMMONLY USED
FUNCTIONS. THE MODE IS DIVIDED INTO FIVE CATEGORIES: CHECKLIST, SYSTEM
STATUS INFORMATION, SENSOR STATUS INFORMATION, SYSTEM SETUP AND
INSTALLATION.
APT/ VOR
THE AIRPORT/VOR MODE PROVIDES INFORMATION ON THE 20 NEAREST
AIRPORTS, VORs,NDBs , INTER SECTIONS AND USER WAYPOINTS, AND ALSO THE
NEAREST AGENCY OR AGENCIES.
D
THE FUNCTION OF DIRECT KEY IS TO SELECT A DESTINATON. IT MAY
ALSO BE USED TO SELECT A DIRECT TRACK, RE-CENTRE THE CDI AND ACTIVATE
A FLIGHT PLAN.
COUNTD-
MSG
THE MESSAGE KEY IS USED TO VIEW SYSTEM WARNINGS AND
ADVISORIES. ANNUNCIATOR LIGHTS INDICATE THAT A MESSAGE IS PRESENT.
WHEN THE WARNING
(WRN) OR ADVISORY (ADV) ANNUNCIATOR
LIGHTS
ARE ON, SIMPLY PRESS THE MESSAGE KEY TO DISPL THE
MESSAGE.
ENT
THE ENTER KEY IS USED TO ENTER ,SELECT OR CHANGE THE
INFORMATION CURRENTLY DISPLAYED ON THE LED SCREEN. THIS KEY IS
GENERALLY USED IN CONJUNCTION WITH THE SELECTOR KNOB.
POWER SW:- A POWER SWITCH TURN THE RDU ON AND OFF
SELECTOR KNOBS:THE LARGE OUTER SELECTOR KNOB (SHADED), DURING DATA ENTRY IS
USED TO SELECT THE FIELD TO EDIT. THIS KNOB HAS OTHER FUNCTIONS SPECIFIC
TO EACH MODE OF OPERATION.
COUNTD--------
THE SMALL INNER SELECTOR KNOB (SHADED),DURING DATA ENTRY IS USED TO
CHANGE THE CONTENTS OF THE SELECTED FIELD. THIS KNOB HAS OTHER FUNCTIONS
SPECIFIC TO EACH MODE OF OPERATION.
NAV DATA CARD SLOT:--THE NAV DATA CARD SLOT ALLOWS THE PILOT TO INSERT
EITHER THE NORTH AMERICAN OR INTERNATIONAL DATABASE CARDS PROVIDED BY
JEPPESSEN. THESE CONTAIN INFORMATION ABOUT AIRPORTS,VORS, NDBSAND
INTERSECTIONS.
CAUTION:-DO NOT REMOVE SATA CARD WHEN POWER IS ON
ANNUNICATOR LIGHTS
The annunicator light alerts the pilot of warning and advisory message. The annunicator lights are WRN
ALERTS THE PILOT THAT A WARNING
MESSAGE SHOULD BE READ.PRESS THE
MSG KEY TO VIEW THE MESSAGE.
ADV
ALERTS THE PILOT THAT AN ADVISORY
MESSAGE SHOULD BE READ. PRESS THE
MSG KEY TO VIEW THE MESSAGE.
PTK
INDICATE PILOT HAS SELECTED
PARALLEL TRACK
APR
NOT IN USE
ERRORS IN GPS
1 SATELLITE CLOCK ERROR
2 SATELLITE EPHEMERIS ERROR
3 ATMOSPHERIC PROPAGATION ERROR
4 INSTRUMENT /RECEIVER ERROR
5 SATELLITE GEOMETRY ERROR
ADVANTAGE OF GPS
(A): CAPABLE OF USING WORLDWIDE AT ALL OPERATING SPEEDS AND ALTITUDES.
(B): HIGHLY ACCURATE.
(C): AVAILABLE THROUGHOUT THE 24 HOURS WITH NO
DIMINUTION OF ACCURACY
(D) PROVIDE S 3D POSTIONING ON A CONTINUOUS BASIS
(E) UNRESTRICTED RANGE
(F) ENTRILY SPACE RANGE
(G) COUPLED WITH INERTIAL NAV. SYSTEM
(H) SEPERATION OF A/C CAN BE REDUCED WITH FULLY
DEVELOPED GPS.
(J) IT CAN BE USED AS PRECISION APPROACH AID
DISADVANTAGE OF GPS
1 IT IS AVAILABLE UP TO 2002 AD
2 IT IS LIABLE TO BE INTERRUPTED
3 IT IS STILL TECHNICALLY UNDER DEVELOPMENT
4 NOT ACCURATE IN CIVIL MODE AS COMPARED
TO MILITARY MODE.
5 CAN NOT INDICATE SATELLITE MALFUNCTIONING
TO PILOT PRESENTLY.