F. The selection of test type desired permits complete system, subsystem, mode or function testing, (Fig. 17) for example; GROUND FUNCT (2) provides a complete system test, FLIGHT DIR (5) provides tests applicable to that subsystem, HEADING (17) provides tests for that specific mode and VHF NAV (23) provides interface tests for that system. Selection of AUTOPILOT requires additional selection for function and mode to determine the specific tests. After a specific type of test is selected, the FCC automatically selects a group, (library) of tests (Fig. 18) which are applicable to the component or function involved. After test selection, instructions are provided for any flight deck actions required. At this point, a specific channel is selected (A or B) and cross channel checks are performed and instructions provided on the PDC CDU to prepare the airplane for the specific tests involved. When the operator performs the required action, the response is provided via the CDU and additional instructions are provided or testing can be initiated. After channel selection, several data lines between the MCP and FCC are switched to freeze existing data or provide O’s. At this point the tests are performed and any failures can be directed to the diagnostic routine which will identify failed LRU’s. When BITE is completed the PDC CDU is paged away from the autopilot test page which restores the AP/FD system to normal and extinguishes the warning light.
G. The BITE tests which are presently available are listed in Fig. 17. Approximate time for the BITE is also provided. These tests are identified by TEST group numbers which identify the test on the PDC CDU. The tests are defined by number on Fig. 18. The tests listed on this figure are the total number of library tests from which the automatically selected specific tests are derived. The numbers within the various test groups are identified on the PDC CDU (Fig. 14) left of the decimal point and sub tests identified following the decimal point and preceding the caret (<). Some library test contains subtests which are listed following SUB TEST on the second line of the PCD CDU display.
H. The first two digits represent the Test Group which are either channel ‘A’ tests if between 02-36, or channel ‘B’ tests if between 52 to 86. The digits after the decimal point represent the test sequence number of the test currently being performed. These test sequence numbers can be directly correlated to one of the engineering library tests via the test driver routines. In order to visualize the distribution of BITE library tests a matrix is provided in Fig. 18 showing these tests versus the displayed or selected test numbers. As seen these BITE library tests are spread throughout the selectable test groupings that are provided in the available menu.
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：737 AMM 飞机维护手册 AUTO FLIGHT 自动飞行 1(75)
