Demonstration Advanced Avionics System (DAAS) functional description

45 Cruise Performance Fuel/Distance/Time IDCC Controls and Displays 134 Vitt ir List of Illustrations (Concluded) 46 DAAS Panel 137 47, DABi IDCC Display Pages 139 48 DABS Information Flow 141 49 BIT IDCC Display Pages 146 50 DAAS BITE Hardware Logic 150 51 IDCC Check List 151 52 1DCC Emergency Procedures 153 5:3 DAAS Control Panel 157 ix w1w.-I - ^ , --- -.,- - MhWILA. List of Tables Table Page 1 IDCC Data Entry Operation Error Messages 38 2 Navigation Kalman Filter Gains 101 3 Flight Warning System 113 4 Aircraft Configuration Monitoring 117 I Weight and Balance Function Algorithms 131 6 Takeoff Performance Algorithms 133 7 Cruise Performance, Level/Distance/Time Function Algorithms 135 8 DAAS BIT Mechanization 142 9 DAAS BIT Tests 143 10 Analog Inputs 160 11 Analog Outputs 162 12 Discrete Inputs and Outputs 163 1 3 Bus Data Buffer Definition 164 x __. .,iii ►, .^ ^-,a..,__ -.,^_ ,,..._^_^ .^_-t 1^., a,:- ..^-._^.:,--. Section 1.0 Introduction The Demonstration Advanced Avionics System (DAAS) integrates a comprehensive set of general aviation avionics functions into an advanced hardware mechanization for demonstration in a Cessna 4028 aircraft. This document presents a functional definition of DAAS. The emphasis is on description of function rather than implement- `ion. Major Sections of the document are: • DAAS System Description — This section contains block diagrams, descriptiot.s of system and computer architecture and describes significant hardware elements. • Multifunction Controls and Displays — The DAAS multifunction Integrated Data Control Center (IDCC) and Electronic Horizontal Situation Indicator (EHSI) are described. • DAAS System Functions — This section describes the functions that the DAAS will perform. It is organized by function. This functional definition is the basis for the DAAS hardware and software design. F_ Section 2.0 DAAS System Concept Several years ago the NASA Ames Research Center initiated a program to imprc avionics for general aviation by applying, whenever possible, new developments computing and sensing devices. The overall objective was to improve the safety a dependability ( schedule adherence) .1 general aviation IFR operations without increi ing the required pilot training/ei^,erience by exploiting advanced technology computers, displays and system design. Earlier studies in the program provided a do base in computer technology potential, air traffic control environment, and systi coN'iguration possibilities. These studies also indicated that to bring advanced avion ►LO benefits to general aviation at an affordable price, changes should not merely be those of improving existing devices and adding a few new "aids" to an already crowded cockpit; but should take the form of a rather sweeping change in the approach to combining sensors, computers and displays into systems which will meet the overall objective. The current Demonstration Advance Avionics System ( DAAS) is the cul- mination of this effort and is intended to demonstrate the feasability of the approach by designing, building and flying a set of demonstration equipment. 2 Section 3.0 DAAS System Description The DAAS is an integrated system. It performs a broad range of general aviation avionics functions using one computer system, and shared controls and displays. This section introduces the DAAS function set, and describes the system architecture and its components to provide background for the d' tailed function definition of subsequent sections. 3.1 DAAS FUNCTIONS DAAS Functions include: • Autopilot • Yaw Damper HDG SEL (Heading Select) ALT, ALT ARM (Altitude Hold, Altitude Arm) NAV, VNAV Couplt4: " ;ontrol Approach Coupled Control • Navigation/Flight Planning VOR, VOR/DME Radio Navigation • 10 Waypoints, 10 NAVAID Storage • Kalman Filter Blending Moving Map Display • VNAV (Vertical Navigation) Flight Warning/Advisory System Engine Parameter Monitoring Warning Aircraft Configuration Monitoring, Warning Airspeed and Stall Monitoring, Warning Altitude Advisory Function Marker Beacon Advisory Function NAV A 1D Identification Monitoring Autopilot/Flight Director BIT Fault Warning t.• 3 • • GMT Clock Function • Fuel Totalizer i inction • Weight and Balance Computations • Performance Computations Takeoff Performanc. • Cruise Performance Fuel/Distance/Time Computation • DABS (Discrete Address Beacon System) ATC Communication, Weather Report- ing • BIT (Built in Test) • Normal, Emergency Checklists The autopilot is a digital version of the King KFC 200 modified for compatibility with DAAS. The navigation/flight planning function computes aircraft position with respect to an entered flight plan, and blends dead-reckoning position (as determined frorn airspeed and heading) with position extracted from automatically tuned VOR/DME receivers. DAAS include, extensive monitoring, with warning capability. For example, the DAAS system monitors engine performance (MAP, RPM), aircraft configuration Q;ear position, flap position, etc.) with respect to flight condition, and ground proximity and informs the pilot of undesirable situations. The DAAS computer serves as a GMT clock. Fuel flow is integrated to totalize fuel used. Wei , t and balance, and takeoff cruise performance calculations can be quickly and conveniently performed using D XAS controls and displays. 4 ^^ a Th ,^ DAAS system will determine fuel and time required to fly specific segment distances given altitude, temperature, wind data, end engine power setting. ATC text messages (e.g., CLIMB AND MAINTAIN 12000 FT) or weather information at destination can ba communicated to the DAAS pilot via DADS cibta link and displayed on the DAAS electronic display, The DAAS s ystem will detect and localize its own faults via BIT. Provisions are also included for troubleshooting the DAAS hardware through DAAS controls and electronic displays. Normal and emergency checklists are stored in the DAAS computer, and are available for display at the push of a button. These functions are managed via shared controls and displays, and perfermed in the common DAAS computer system. Following is an introduction to the DAAS contro l s and displays, computer system architecture, and a description of DAAS major subsystems. 3.2 DAAS CONTROLS AND DISPLAYS — GENERAL The DAAS Cessna 402B aircraft contains: * Controls and displays necessary to manage DAAS functions. • Additional instruments necessary for IFR flig'..'. operations. • Independent safety pilot instrument installation. These controls and displays are laved out in the 402B control panel as indice.ed in Figure 1., Cessna 402B Panel Layout. DAAS pilot is in the left seat, and the safety pilot is the right seat. Electronic d;-plays — the Electronic Horizontal Situation Indicator (EHSI) and Integrated Data Control Center (IDCC) — are key elements of the panel. 5 IDC ENCODING ALTIMETER KAP 719 AUTOPILO T ANNUNCIATOR PANEL , II At r c o a 0^)0 OVERHEAD CONTROL PANEL - —^ (See Figure 7) KCI 3I0 fDI \ WARNING CAUTION LIGHTS DABS MESSAGE PENDING LIGHT\ FOI ILS SOURCE SELECT S IAITCH\ IAS INDICATOR TELEDYNE ANGLE Of ATTACK INDICATOR Oki 229 AM, FUEL QUANTITY INDICATOR RMI SOURCE SELEC T SWITCH KA 9 1 A COMPASS SLAVING CONTROL RC ALLEN TURN ♦ SLIP INDICATOR EHSI EHSI CONTROLS -^' ILMIL ' IDCC PAGE SELECT CONTROLS ALPHA NUMERIC KEYBOARD iOVqq^^^^Y^^`^^ 3 V tIt.7t>UV 4 ooh 00 - -- k • 0 0000 80(500 0 6'66 66 Dd T oc oo bo ao o_ LEFT CIRCUIT BRE'AKER PANEL (See F pure 7) DAAS PILOT PANEL E'OU)OUT FRAME I F r`` A (• '^ r xr.^ vtRtlCAI SPEED INDICATOR MANIFOLD 111 11E33URE INDICATOR RPM IN DICATOR FUEL FLOW INDICATOR EOT INDICATOR Oil PRESS TEMP 'NDIC A T OR/ / ANNUNCIATOR PANEL /0,11IIIISPEFE INOICATOR 0XYGIN CYt INDER PRESSURE INDICATOR PROP DEICE INDICATOR KG 251 ARTIFICAL HORIZON ii I ^_ ALTIMETER I ! I I 1 ^' - - SUC T ION GAGE VER T ICAL SPEED INDICATOR _ O \ KA SIA COMPASS SLAVING CONTROL r 1^ KG S25 PNI _ -- TURN E BANK INDICATOR `^ •/ j^-^ - '^'y ` \ '.' KMA 24 AUDIO PANEL ^ NAV RADIO COMM RADIO NAV I CON T ROL SELECT LS IARO NAV 2 CONIRC • - !ELECT DME CONTROL SELECT KMA 24 AUDIO PANEL fl \^^ \ KY tK COMM TRANSCEIVER KY 1N COMM TRANSCEIVER ^A KN S3 NAV RECEIVER 0000000 KN 53 NAv RECEIVER 0000 O SAFETY PILOT PANEL I 0000 O KN 62A DME Kh '6A TRANSPONDER KMC MO AUTOPILOT MODE CONTROLLER \ DA.AS CIRCUIT BREAKER PANEL Figure 1 Cessna 4028 Control Panel Layout The EHSI presents a moving map display showing aircraft position with respect to desired course. The display is a 4.5-inch by 4.5-inch monochromatic Ball Brothers 103C CRT raster display unit. The display unit has 256- by 256-dot matrix display capability. P43 phosphor is used together with an appropriate narrow band optical filter to allow operation in bright sunlight. The EHSI is controlled by functional control buttons and a map slew controller. The Integrated Data Control Center (IDCC) is the pilot's primary means of interacting with DAAS. Included are a keyboard at the bottom of the unit and a set of function buttons along the top. The function buttons include a set of page select buttons which determine the information that is displayed on the IDCC display. The IDCC display CRT is identical to the EHSI, i.e., 4.5-inch by 4.5-inch Ball Brothers monochromatic unit. The IDCC can display 16 lines of 32 characters each. Line spacing is 0.25 inch, character height is 0.162 inch, and character width is 0.125 inch. The IDCC is implemented with menu select buttons along each side of the CRT, or with a pressure sensitive plastic screen overlay for touch point menu selection. The alternate approaches can be implemented to allow comparison during flight test. The DAAS EHSI is surrounded by the conventional "T" pattern of flight control instruments. The ADI used in DAAS is the 4-inch King KCI 310 Flight Command Indicator. The altimeter is an IDC Encoding Altimeter type 519-28702-571. An Altitute Alert light is mounted en the altimeter. The rate-of-climb indicator provides vertical speed information to the pilot. The display presents rates of climb, or descent, in feet per minute. The face is 2-1/4 inches wide. The King KI 226 RMI displays heading and bearing to a selected VOR station. The DAAS Autopilot Mode Controller is located on the pedestal, and the Autopilot Mode Annunciator is located above the altimeter. DAAS engine instruments and radio stack are centrally located and are accessible to the DAAS pilot and the safety pilot. 9 Unique DAAS switch controls located on the panel include: • NAV 1-DAAS/MANUAL Tune (located to the right of the NAV 1 radio) • NAV 2-DAAS/MANUAL Tune (located to the right of the NAV 2 radio) • DME TRANSFER (located to the right of the DME) • VOR source switch (located to the lower left of the R.MI) • ILS source switch (located to the lower left of the ADI) NAV Receivers can be tuned manually (MANUAL) or automatically (DAAS). The DME transfer switch allows the DME receiver to be tuned by either NAV receiver 1 or 2. The DAAS position slaves the DME to the NAV receiver being controlled by DAAS. The safety pilot instrument set is independent from the DAAS instruments, and adequate for safe flight with DAAS inoperative. The safety pilot's Pictorial Navigation Indicator displays aircraft magnetic heading (gyro-stabilized), selected heading and selected course. Also, VOR and localizer course deviation, glideslope deviation and a TO -FROM indication are presented. The safety pilot's KG-258 artificial horizon is an air driven unit. It is the safety pilot's basiv attitude/horizon reference indicator. Aircraft master power controls (see Figure 7) are centrally 1 :)cated overhead. Circuit breakers (see Figure 7) are located on the pedestal. 3.3 DAAS SYSTEM ARCHITECTURE DAAS system architecture is presented in Figure 2. The architecture is characterized by a modular computer system structure; i.e., multimicroprocessors interconnected by an IEEE 488 data bus. Each processor block in Figure 1, except for the radio system, represents an Intel 8086 16-bit microprocessor, 2k by 16 PROM memory, and 4k by 16 to 16k by 16 RAM memory. The radio System uses the Intel 8048 microprocessor. Each processor performs a function, and interfaces directly with the subsystems associated with that function. At power-on, the bits controller Central Computer (CC) CPU-1 takes functional programs from the nonvolatile bubble memor y , and sequentially 10 Fe e ^- t -; III: -- - - - - - - - - - - - - -- .^ ^ i I i i I F i n o e ^- - -----------'11 -- - - - - - - - -- - - - ---, V e el f ^ I 'y ^ a asT ID Q m c^ 0 N m rm a 11 loads each processor at the rate of approximately 2 seconds per processor. When all processors are loaded, the bus controller activates the system. The bus controller then manages bus communications during normal operations. A portable TI Silent 700 cassette unit can interface with the bus controller to allow load or modifications of the functional software. CC-CPU 5 is a spare processor. If processor CC-CPU 3 or CC-CPU 4 fails and the bus controller detects the failure, the bus controller will load CC-CPU 5 with appropriate software from bubble memory, and CC-CPU 5 will take over the function of the failed processor. (Note: This reconfiguration capability is especially important when an EHSI and an EADI are included in the system.With a failure in one display, the spare processor can be loaded to allow time sharing of the remaining good display as both EADI and EHSI.) Such reconfiguration could be extended to other processors such as CC-CPU 2, the autopilot. However, for such reconfiguration the spare processor must interface with autopilot subsystems, which requires additional multiplexing of hard- ware. Reconfiguration was thus applied only to a limited degree in this demonstrator system. The DAAS architecture is modular. Functions can be added by adding necessary standard processor modules onto the 488 data bus, and interfacing these processor modules with the devices associated with the new function. Six processors are contained in the DAAS Central Computer Unit. One processor is contained in the IDCC, and one processor is contained in the radio adapter unit. 3.4 DAAS MAJOR SUBSYSTEMS DAAS system components, and their interconnections are depicted in Figure 3, DAAS System Diagram. Interconnection between the DAAS panel instruments, sensors, and the DAAS computer system is shown. The DAAS Central Computer obtains data from the radio system (radio adapter unit, radio stack), flight control sensors, engine instruments, .;onfiguration status sensors, and IDCC. Functional computations are performed on the input data and the results applied to EHSI, FDI, warning/caution lights, and autopilot servos. 12 13 F- E cc 0 E m v ri m a Following is a description of the DAAS major subsystems including: • Central Computer Unit • Radio System • Flight Control Sensors, Servo Actuators • Engine Sensors • Configuration Monitor Sensors • Miscellaneous Sensors • DABS Selected devices are depicted in Figure 4. 3.4.1 Central Computer knit The computer unit performs the functions of navigation, engine monitoring, flight control, weight and balance computations, performance computations and maintenance test. The computer unit contains six 16-bit, Intel 6086 Microprocessors interconnected through an IEEE 488 Data Bus System. Following is description of Central Computer elements including: • Processor • Input/Output • Bubble Memory Syster i • EHSI Display Controll ►r • Power Supplies 3.4.1.1 Central Computer Processor — The Central Computer processor, Figure 4, is designed to fit on a single subassembly. The 8086 Microprocessor, 4k RAM, 2k UV-EPROM, interrupt controller, clock, memory chip-select logic, bus-buffer logic, and 488 bus interface are included on this subassembly. The Intel 8096 was selected for the computer unit microprocessor based on: • Availability of the microprocessor • Availability and cost of software development hardware and support software • Microprocessor throughput capability • Availability of High Order Language (HOL) 14 15 I— ZM ir Li a Q D Q _O O Q ix UV 3 ^v E a^ N V) Q Q V w a 0U J Q F- Z w U v a^ LL w J 00 O N NW VO CL 8086 Processor hardware and software development support equipment were available when needed in mid-1979. The processor has adequate throughput, and a PLM higher order language compiler is available. The 8086 is a 16-bit integer microcomputer. It contains four 16-bit index registers. The processor chip can address 1 megabyte of memory. The H-MOS device is contained in a 40-pin dual in-line package. Each processor module has a 2k x 16 PROM and 4k x 16 to 16k x 16 RAM memory. Software required to load each processor RAM is located in PROM. Ultraviolet eraseable PROM is implemented using the 2k x 8 2716 device, and RAM is implemented using the 4k x 1 2141 part. Analog and discrete I/O conversions, and IEEE 488 data bus transactions are controlled directly by the 8086 processor. The Bus Interface Unit (BIM) between the Intel 8086 Microcomputers and the IEEE 488 Data Bus is implemented using a TMS 9914 Talker/Listener interface chip and two 75160 bus drivers. The TMS 9914 is designed to perform the interface function between an IEEE 488 bus and a microprocessor. IEEE 188 standard protocol is handled automatically in Taiker, Listener, or Controller ope. ational modes. 3.4.1.2 Central Computer Input/Output -- The central computer unit contains input/output (I/O) and control circuitry which is summarized as fellows: 64 Discrete Input Channels 48 Discrete Output Channels 64 Analog A/D Liput Channels 16 Analog Output Channels 1 Video Output to EHSI-CRT 12 (approx) Special input conversions (frequency to digital, frequency to voltage, miscellaneous discrete interfaces, etc.). 6 (aprox) -Gain of 100 buffered Irw level input conversions 4 Servo interfaces with associated logic. i 16 6 AC input signal conversions including a demodulator controller, 1 Scott-T transformer, and 5 detriodulators. 2 DABS serial digital interfaces (SM and ELM) 1 Hardware Real-time-clock counter 1 1/0 control logic, including BIT logic circuitry. 1 Master clear detection and timing circuit and other special power handling circuitry. 3.4.1.3 Bubble Memory System — DAAS 1.024 mega-bit nonvolatile program storage is implemented using the Rockwell RLM 658 Bubble Memory Module, and the RCM 650 Bubble Memory Control Module. The memory system contains four 256k magnetic bubble devices using a block access design and organized as a 256k x 4-bit memory. All of the electronics necessary to operate the devices; i.e., sense amplifier, coil drivers, generator, and logic circuits are included. The four devices operate in parallel providing 4-bit-wide data which is routed to four of eight data interface lines, determined by a switch setting. The block length as seen at the output is 260 valid bits long. Four are designated as address bits and 256 as data bits. 3.4.1.4 EHSI Display Controller — The EHSI display is controlled by A?,T-512 display controller located in the central computer unit. The ALT-512 is a complete graphics display controller on a single S-100 bus plug in board. it contains its own refresh memory, TV sync and video generator, and all 1/0 for the S-100 bus. Each display dot (pixel) is addressable via X-Y registers and can either be written into or read out. The board has six output and two input ports built-in. The display field consists of two 256 x 256 x 1 planes. Either or both planes can be displayed in various combinations. 3.4.1.5 Central Computer Power Supplies — The Central Computer Unit contains system power supplies. Power supplies convert 28 Vdc input ;. ewer to 5 Vdc (Abbott BN100d-5A), and to 15 Vdc (Abbott BBN50D . 15A). A 115 volt, 400 Hz power conversion is included for ±21 Vdc (unregulated) and 26 Vac power needs. A master clear generation circuit is also included in the central computer unit. 3.4.2 DAAS Radio System The DAAS Radio System provides the communication and navigation radios for DAAS as well as the necessary data processing and information exchange between the DAAS computer and the system radios. The radio system is composed of the following units: Radio Adapter Unit KH 196 Comm 1 VHF KY ! 96 Comm 2 VHF KMA 24 Audio Panel (with KA 35A) DME channeling switch and the ILS source switch KN 53 Nav 1 VOR/LOC/GS KN 53 Nav 2 VOR/LOC/GS KN 62A DME Following is a description of these radio system elements. 3.4.2.1 Radio Adapter Unit — The functions performed by the radio adapter unit (RAU) are: • Tune the radios as commanded by the DAAS computer • Process VOR/LOC/GS data from Nav 1 and Nav 2 • Process station identifiers • Process DME distance • Generate a radio system status word • Format th&a data for block transfer • Exchange information with the DAAS computer via the IEEE 488 bus In addition to interfacing with the radio units, the 'QLA U also interfaces with: • 28-Vdc aircraft power • KMA 24 audio panel (with KA 35A) • KCI 310 FDI (through ILS source switch) • KI 226 RMI (through the VOR source switch) • DME channeling switch and ILS source switch • DAAS/Manual status switch for each Nav receiver The switches used by the pilot for radio system mode selection are: Nav 1 ManuaVDAAS Nav 2 Manual/DAAS DME Nav 1/DAAS/Nav 2 ILS Source Nav 1/DAAS/Nav 2 VOR Source Nav 1/Nav 2 Complete pilot backup in a manual mode of operation is assured by the Manual position of the switches. 18 The DAAS system radio adapter unit ( RAI') uses a m ►croprocesavr system for a flexible interface for control and data processing. The interface exchanges data with the DAAS Central Computer on the 488 bus using standard talker /listener functions and hand- shaking protocol, The processor receives tuning commands from t!he DAAS Central Computer. The processor then sends the tuning commands to the navigation and communication radios, processes the received navigation data, and transfers this data in block format to the DAAS Central Computer. The data block transfers occur at a fixed rate of approximately 20 updates per second as required by the bus controller. A dedicated general purpose interface buffer IGPIBI handles the standard talker/listener protocol for transferring data. Data is stored in a buffer to eliminate slowing down the R.AI' processor. Bus setup time is 5 45 μs and data transfer rate is 5 15 us per byte. Na y I and Nav 2 provide a video composite with either VOR or LOC information modulated onto the 9960 • Hz subcarrier. The interface circuit identifies what type of information is present, demodulates the composite, and d igitizes the result. The VOR/LOC data fron, Nav 1 and Nav 2 can also be displayed on the KI 226 and the KCI 310 indicators. The specific display mode is a function of the status switch. a. Glider lope information is also available from the KN 53 Navigation Receivers. The signal will be conditioned in the interface for digital conversion. The digitized data will then be processed and maintained in the data block for transfer to DAAS. As with VOR/LOC, glideslope information can also be displayed on the KCI 310 Indicator. The program will select the Nav unit to be displayed when in the DAAS mode. To validate active channels of the navigation radios, the Morse Code identifiers will be read electronically, converted to the ASCII equivalent of the received Morse Code and transmitted to the central computer as part of the data block. The RAI' has capability to tune the KN 53 NAV Receivers, and the KY 196 COM Transceivers. The si milarity in tuning procedure for the KN 53 and KY 196 allows a common method of t,ming these radios. The interface will .^ • imulate the actions of the front panel rotary knobs by closing increment/decrement switches electronically to change frequency. The standby frequency onl y is affected by the tuning switches. To c• ha ript. the active channel, standby is tuned to the selected frequency, and an a c• ti%e st andby exchange is executed. The approximate worst case tuning time for a KY 196 or KS 5:3 to sweep full band is 250 milliseconds. To execute an active/standby exchange, approximately 50 milliseconds is required. The hardware for tuning the KY 196 transceivers is included in the RAU. but not the necessary software. 19 The KN 62A DME can be tuned by command from the DAAS Central Computer, or by Nav 1 direct or Nav 2 direct through a common bus. The KN 62A tuning format is the 2 x 5 code. Approximately three seconds are required to tune the KN 62A and acquire valid range data. To verify the auto tuning function, or to read the DME channel, data is read from the internal tune bus. This data is serial BCD information. A sync and clock are available to strobe this data into the interface. Range information from the KN 62A is 18 bits of serial BCD data. A synchronous clock is provided to shift the data into the RAU inte,,'ace for processing. The RAC' microprocessor will convert this data to a 15-bit binary word (LSB - 0.02 NM) and maintain the current distance code in the data blocx for transmittal to the central computer. 3.4.2.2 Communication Radios -- The DAAS communication radios consist of two VHF transceivers (KY 196 modified). These are located at the top of the radio stack as shown in Figure 1. They each have a standby and active frequency storage capability. Interchanging standby and active frequencies is accomplished by pressing a button on the front panel. They tune a frequency range from 118.0 M11z to 135.975 MHz. They have a minimum transmitter output of 16 watts and a receiver sensitivity of 2μV for 6 dB s +n!n. They have automatic squelch with manual override on the front panel. 3.4.2.3 Navigation Radios -- The navigation radios consist of two VORJLOCIGS receivers (KN 53 modified) plus one DME receiver (KN 62A modified). These are located just Lelow the communication radios. Active and standby frequencies are stored and displayed the same as in the communication transceivers discussed above. The VORIL.00 receivers tune t..: frequency range from 108.0 MHz to 114.95 MHz. As with the communication transceivers, these rt eive rs can be locally or remotely tuned. The GS receiver is channeled from the LOC frequent y selected. Forty channels of GS are available in the range of 329.15 MHz through 335.0 .'.:Hz. 20 A. t 3.4.2.4 DME — The DME receiver can be either remotely or locally tuned. In remote operation, it is channeled from the radio adapter box so that it can operate in conjunction with either of the VOR/LOC/GS receivers ;Nav 1 or Nav 2). In the nonscanning mode the receiver can display distance to station. The DME tunes 200 channels, has a minimum output of 50 watts and a sensitivity of —82 dB minimum. The nominal search time is 3 seconds for range information. 3.4.2.5 Transponder KT 7 16"A — The KT 76A is a radar beacon transponder that transmits on a frequency of 1090 MHz f 3 MHz. Output power is 200 watts peak. The receiver frequency is 1030 MHz. An identify code number is selected at the front panel. The KT 76A is capable of locating the user through the air traffic controller. Range and azimuth are established by the return from the transponder's pulsed transmitter, in reply to a routine interrogation from the ground radar site. When used in conjunction with an encoding altimeter, the KT 76A can be used to convey altitude information. 3.4.3 Flight Control Sensors, Servoectuatore The following flight control sensors, servoactuators are described below: VG 208 Main System Vertical Gyro KMT 112 Magnetic Azimuth Transmitter KA 51A Slaving Accessory KSG 105 Directional Gyro GG 2472 Yaw Rate Gyro KDC 380 Air Data Computer (used for altitude error and IAS outputs only) IDC 28702 Altimeter (corrected altitude) Autopilot Servoactuators 3.4.3.1 VG 208 Vertical Gyro — The Jet VG 208 Vertical Gyro is a remotely mounted electrically driven gyro which supplies attitude reference information to the KCI 310 Attitude Director Indicator. Additionally, pitch and roll attitude signals are supplied to the DAAS computer for use within the autopilot/flight die^tor and navigation portions ofthe system. Required excitation input consists of 26 VRMS, 400 Hz. The output scale factors are 206 mV/deg commencing with zero (0) millivolts at zero (0) degrees. 21 3.4.3.2 KMT l l2 Magnetic Azimuth Transmitter — The KMT 112 Magnetic Azimuth Transmitter, senses the earth's magnetic field and furnishes this information to the KSG 105 Slaved Directional Gyro as an 800-Hz synchro control transmitter type output. Input power of 4.75 VRMS, 400 Hz, is required and is furnished from the KSG 105. 3.4.3.3 KA 51A Slaving Accessory — The KA 51A is a slaving accessory used in conjunction with the KSG 105 D irectional Gyro and KMT 112 Magnetic Azimuth Transmitter to comprise the KCS 305 Slaved Gyrocompass System. The KA 51A is a panel mounted unit that displays the slaving error between the KSG 105 and the KMT 112. Required power inputs consists of +12 Vdc and 13 VRMS, 400 Hz (both voltages from the KSG 105). The slaving meter drive signal is furnished by the KSG 105. Manual slave signals are pilot initiated through the activation of the push button switches which are part of the KA 51A. 3.4.3.4 KSG 105 Slaved Directional Gyro — The KSG 105 Slaved Directional Gyro provides gyro-stabilized aircraft heading information to DAAS. It requires 115-Vac, 400-Hz sinewave, input power. Additionally, it requires a signal input from the KMT 112 Magnetic Azimuth Transmitter and a synchro excitation voltage of 26 Vac, 400 Hz. 3.4.3.5 GG 2472 Yaw Rate Gyro — The GG 2472 Rate Gyro is used to detect yaw rate and input this ii-formation to the DAAS computer. The unit is a spring restrained, fluid damped, gyroscope with a synchronous hysteresis spinmotor and a variable reluctance signal generator. The self-contained demodulator outputs the do rate signal for use by the computer. Input requirements consist of single phase, 26-VRMS, 400-Hz excitation and input power (26 V; 7 VA). Sync time is typically less than 60 seconds, and the rate scale factor (volts do/deg/sec) is 0.200 f 10%. Threshold is less than 0.01 deg/sec and the rated output load is 10 k. 3.4.3.6 KDC 380 Air Data Computer — The KDC 380 Air Data Computer is an electromechanical unit that senses pressure inputs (total and static), and provides signals of altitude for altitude hold and indicated airspeed for configuration monitoring. 22 3.4.3.7 IDC 28702 Altimeter — The encoding altimeter provides a pressure altitude signal to the KT 76A Transponder and also a corrected altitude signal to the DAAS computer. The corrected altitude signal is the primary DAAS VNAV altitude reference. When pressure altitude is required it is computed from this signal and the pilot entered altimeter setting. 3.4.3.8 Autopilot Servoactuators — The DAAS Autopilot servoactuator mecha- nization is illustrated in Figure b. Shown are the pitch servoactuator, roll and yaw servoactuator and the pitch trim servoactuator mechanization. The electric servos are clutch activated for autopilot engagement. All servos except the trim servo include tachometer rate sensing for servo loop stabilization. The pitch servoactuator includes torque switches for auto trim engagement. Clockwise and counterclockwise torque limit sensors are located on the engage plate. As the motor turns in either diection, the load causes the motor assembly to move laterally, actuating the small microswitches on the engage plate. Screws on the front of the engage plate enable the switches to be positioned to detect factory specified torques. The normally open contacts of each switch are routed to the DAAS computer as an indication that auto trim signals should be activated. The pitch trim servo includes a transfer relay to switch from manual to automatic trim. 3.4.1 Engine Sensors The following engine sensors are used to supply inputs to the DAAS computer: RPM Sensor (2) Manifold Pressure (2) Fuel Flow Sensor (2) 23 CW LIMIT .o M ---- T CLUTCH e^ e CC; LIMIT KS 270 PITCH AUTOPILOT SERVO ACTUATOR -t=a -0 III CLUTCH KS 271 ROLL, YAW AUTOPILOT SERVO ACTUATOR AUTOPILOT DRIVE +28V M MANUAL DRIVE CLUTCH M - MOTOR TRANSFER T -TACK ELECTRIC TRIM ENABLE RELAY KS 272 PITCH TRIM SERVO ACTUATOR Figure 5. DAAS Autopilot Servo Actuator Mechanization 3.4.4.1 RPM Sensor — Tach generators mounted on each engine provide RPM data to the DAAS computer. The Tachometer outputs a varying frequency signal with 1 Hz corresponding to 60 rpm. The variable frequency signal is converted to do in a NASA signal conversion box, resulting in a 1 .67 m y/rpm signal scale factor. 3.4.4.2 MAP Sensor — The MAP sensor is a small, high accuracy semiconductor strain/gage, a Celesco PLC-20-A2 device. The temperature compensated sensor provides a pressure signal with 20 psi range. 3.4.4.3 Fuel Flow Sensor — The DAAS Fuel Flow Sensor is the Flo Scan 200 Turbine Flow Transducer. 24 Series 200 turbine flow transducers measure flows of hydrocarbon fuels such as gasoline, kerosene, and No. 2 diesel fuel and other light transmitting, non-corrosive liquids of similar viscosity. The transducers give linear E ignals on ga ;oline across a 100-to-1 flow range down to 0.3 GPH. The transducers produce a current pulse signal from an opto-electronic pickup. Liquid enters the flow chamber tangentially, follows a helical flow path, and exits vertically, thereby venting any entrained vapor bubbles. The rotational velocity of the liquid is directly proportional to flow rate. A neutrally buoyant rotor spins with the liquid between V-jewel bearings. Rotor movement is sensed when notches in the rotor interrupt an infrared light beam between an LED and photo-transistor. 3.4.5 Configuration Status Sensors The following conditions are sensed and input to the DAAS computer to be used for status correlation and displaying warnings to the pilot as necessary. Wing Flaps - Position transmitter indicating flap positions of 0°, 15°, 30°, and 45° will be monitored. Cowl Flaps - Cowl flap position is determined using a pot transducer. Aux. Fuel Pumps - The 3-position auxiliary fuel pump switches are monitored to determine when the switches are in the "on" position. Cabin Doors - Switches are included to sense whether or not the doors are latched and secure. iTrim - Elevator trimpot is monitored to ensure that the trim is within take off limits. Landing Gear - Existing limit switches and gear-on-ground switch are monitored to give indications of gear down and locked, squat and gear up. Radar Altitude - Radar altitude is provided by an RT-221 Radar Altimeter. The ground proximity warning function uses radar altitude in conjunction witn barometric altitude rate. 25 A 3.4.6 Miscellaneous Sensors DAAS sensors also include True Airspeed (TAS) and Outside Air Temperature (OAT): 3.4.6.1 TAS Sensor — The DAAS TAS sensor is the J-TEC VA 210 Vortex Airspeed Sensor. The sensor provides a digital output signal at 45 Hz/kt to 200 kt airspeed. 3.4.6.2 OAT Sensor — The DAAS OAT sensor is a Rosemount 101F sensor. The temperature sensing element is a fast response, open wire, platinum resistance type element having 50 ohm resistance at 0° C. 3.4.7 DABS A demonstrat i on test bed for the Discrete Address Beacon System (DABS) is included in the DAAS system. This function, as described in paragraph 5.9, is mechanized in CC CPU-6 and interfaces with the DABS transponder and IDCC display. 3.5 DAAS POWER DISTRIBUTION Cessna 402B power distribution is illustrated in Figure 6, and power controls are shown in Figure 7, DAAS power comes from the aircraft alternator (battery) bus and is backed up by a dedicated DAAS battery, resulting in uninterrupted do power. When the avionics bus is off, the DAAS battery is disconnected from the aircraft alternator bus so power cart transients are avoided. When the avionics bus is turned on, the DAAS battery is connected to the aircraft alternator bus, and if the DAAS battery is low, it is charged rapidly. The DAAS system is diode coupled to the alternator bus, so it is not used for starting and low-voltage transients will not propagate to the DAAS. The DAAS battery can be disconnected from the alternator bus at any time by opening the DAAS bsttery charging circuit breaker. Aircraft power controls are located on the overhead control panel, and the DAAS power switch (locking switch) is located above the left circuit breaker panel, Figure 7. The control pedestal circuit breaker panel provides circuit breakers to protect .;irc.lits associated with the DAAS components. A guarded preflight/normal switch is also located on the circuit breaker panel. The purpose of this switch is to allow the use of DAAS for preflight flight planning with minimum battery drain (engines off). Tue DAAS battery supplies power for this function with the aircraft battery switch off. 26 V •2BV •28^ L ALT q AL1 100A {100A ALTERNATOR COATT) BUS — i AIRCRAFT p — BATTERY EMER C565 CO3S CDS6 BATTER SW. TO CO-PILu AVIONICS GYROKGIO2 DUS SW Ca DAAS BATT 26 VAC 400 NZ PC 17A CB44 INVERTER DAAS CBD1 COD16 CBO11 AVIONICS BUS f 115V TO C843 400 NZ KSG10S DDAAS DAAS BATT CDD COD10 POWER TO 13 (LOCKING) GG2472 TO PRE-FLT KC1310 TO VCZOB DAAS A BUS DAAS B BUS "—^ NORM CBD3 COD2 COD1 COD4-9, COD 11 ceoa IDCC ENS) R ADIO DAAS ADAPTER CENTRAL UNIT COMPUTER 2G VAC, 400 NZ COD 14 CBD20 F CBD18 CBD19 CBD22 CBD21 •21V -21V *15V -1SV N}V Figure 6. Cessna 402E Simplified Power Distribution With the DAAS power switch ON and the preflight/normal switch in the PREFLIGHT position, power is supplied only to the DAAS Computer, IDCC, and EHSI. In the NORMAL position, power is also supplied to the servo actuators, mode select panel, annunciator panel, attitude director indicator, and several sensors. 2; DAAS POWTR ^.LOCKING SWITCH) ir P Vp (07 CD 40 4/ COCKPIT OVERHEAD PANEL LA- DAAS MODE SWITCH (GUARDED) LEFT SIDE CIRCUIT DAAS PEDESTAL PANEL (CBD) BREAKER (CB) PANEL Figure 7. DAAS Power Controls 28 Section 4.0 DAAS Multifunction Controls and Displays: IDCC and EHSI The DAAS system employs multifunction controls and displays including an Integrated Data Control Center (IDCC) and Electronic Horizontal Situation Indicator (EHSI). These multifunction controls and displays are involved in many of the DAAS functions and are thus introduced here preliminary to discussion of the individual functions in Section 5.0. 4.1 INTEGRATED DATA CONTROL CENTER (IDCC) DESCRIPTION The DAAS IDCC is shown in Figure 8. Two rows of push buttons located across the top of the device are 1) NAV function controls, and 2) display page select buttons. Data entry keyboard and special controls are located below the IDCC display. Following is a description of the IDCC controls and display. NAV function controls located above the IDCC display are described in Section 5.0. 4.1.1 Page Select Buttons Page select buttons above the IDCC display are used to call up various function display pages. 4.1.2 IDCC Display The 4.5 by 4.5-inch IDCC display is capable of displaying 16 lines of 32 characters. Available characters are presented in Figure 9. Line spacing is 0.25 inch, and character height is 0.162 inch. Character width is 0.125 inch. The center of the first line of characters is 0.45 inch from the top of the screen. The display general layout is shown in Figure 10. The display top line is reserved for the label or title of the page and the page number. The second line can be used for an y desired text. The lower left hand corner, 10 characters wide is reserved for data entry scratchpad. The remainder of the lower two lines are reserved for warning messages. 29 f' CONTIUlT 0 MIONTNp! 0 0 0 , - NAV PAO# !!LICT Wt ;lMO q OA'fA OVA A 'tll/ INIT OAN MOC W 5" al 1E IE lTAT !AL E 1LIBfl • BACK O FWD CID uc o.r r.. _.^ • .v OIM O Figure 8. Integrated Data Control Center 0 MBO ACK 0 a e 1, K i► μ v 0 r p v r v X W t E — 1 2 3 4 5 6 J 7 8 9 t < = > 1 @ A B C D E F G H I J K L M N 0 P 0 R S T U V W X Y Z_ o b c d e f g h i j k I m n o p q r s t u v w x y z { ; } Figure 9. IDCC Character Set Definition Standard page formats have been defined for the IDCC display. These are shown in Figure 10. A mixture of these formats is possible. 4.1.3 IDCC Touch Panel, Bezel Buttons The IDCC has a touch panel superimposed on the face of the display. It is implemented with a pressure sensitive CRT overlay. The touch positions are set up in a 2 (horizontal) by 4 (vertical) matrix. This allows the pilot to select one of 8 points on the IDCC display. Touch points are located at the asterisk symbols on the IDCC touchpoint display format of Figure 10. The pressure sensitive overlay can be replaced by a set of bezel mounted buttons which are used as an alternate to the touchpoint selection. The touchpoints (or alternate bezel buttons) are used in data entry , function switching, and toggle switching. Data entry is described in paragraph 4.1.6. For function switching, touchpoint (or bezel button) activates a function, e.g., selects a page or selects a function. Touching a toggle switch touchpoint will toggle to the other function. For example, a toggiv switch can be used to toggle between MDA or DH active or not active modes. See Figure 10 for examples. 31 e LAIEL ► AGE W T[ IT ^ r R TE IT 0 DATA ENTRY 0 TOUCN ► OINTS 0 M FU NC TI ON SW B N TOGGLE SW N WOW GS- 32 CHAN S CRATCH ►A IIII S TA TUM TS El a a k 14 k 1 a a 0 IDCC TOUCHPOINT DISPLAY — GENERAL LAYOUT DUAL PARAMETER DATA ENTRY ^+r DATA ENTRY ARROW SINGLE PARAMETER DATA ENTRY FUNCTION SWITCHING ^► DATA ENTRY ARROW ABIELt . 20 CHAIR ^— ' P' X' OF 'X X: TE XT I - 52JCHIAi Ml JTEA T - `12 1 C/IA^I t s c t i AT A EN,TR'^ t t t t !.. i- t- i z i t t t t t t t t Y s s : ^;10 CNAA t f ^ !_^ M tUNjCTi110sN. Sant r i s s 1 !_ 1+2 4M Aiit t i It tTEx T- 12 CHAR SE ,I ?("LEO' S! i t t i t t t t f CNAA s t t t s t-01 1TOi GG{LF = f = r t t C t t ^IO} CNAp-- S f i ^' t t J: t f 3 ^- t t + t--+ tr k=- ^ = t- - ^ -^ jMA RWIN G51 X32 1 11 4H Aj$5L t2 C JA J — j--1_ I t Xi OAF 1. j^T I .: t : r r_ r11 11 y. ;Q t _'t Y t t S-'- 3. t-: t tZ 2t0 K g t t:, i—s- r r C t^ 3;r g:^ t- f t OOCNt4 , t t t IFN lit I AT'E i1 IM CiAS 1 , /Oke 2t s , , r + ^ igE,` J?^a 4E 6 t t t t t t- .. t: t t t t N1 fat t 010 t0 nt t x' x : s t r s y M>^ t r r f1 •: t T,ES t t : t: t wf^i 1 i ^ f u tC+ R t t t t z IDCC TOUCHPOINT SWITCHING — EXAMPLES FUNCTION SWITCH TOGGLE SWITCH IDCC TOUCHPOINT DISPLAY — STANDARD FORMATS Figure 10. IDCC Display Page Formats 32