(9)
Flight Management Computer
(10)
Takeoff/Go-Around Switches at Thrust Levers
(11)
STALL WARNING TEST NO. 2 Switch on P5-18 module
E.
Various flight conditions are monitored by the SMC to determine when to activate the control column shaker. The shaker will be activated by whichever condition gives the earliest warning of an approaching stall.
(1)
Normal Stall Warning
(a)
The control column shaker is activated when airplane angle of attack becomes too great. The specific angle of attack at which the shaker is activated depends on flap position.
(2)
Asymmetry Stall Warning
(a)
If there is asymmetry in the flap system, the angle of attack required to activate the shaker will be lowered. The amount by which it is lowered depends on flap position.
(3)
High Thrust Stall Warning
(a)
The high thrust stall warning is enabled when N2 for the opposite engine is greater than 75%. In this condition, the angle of attack required to activate the shaker will be lowered. The amount by which it is lowered depends on flap position and the coefficient of thrust gradient (CTG). The SMC uses airspeed and the N1 tachometer for the near engine to calculate the CTG.
(4)
Speed Floor Stall Warning
(a)
The stall warning computer will activate the shaker if airspeed falls below a reference speed for a given flap position (Table I).
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27-32-00
COMPUTER P/N 65-52822 ú CONFIG 2 ú 02 Page 5 ú Nov 15/98
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
737-300/400/500MAINTENANCE MANUAL
FLAP SETTING MINIMUM AIRSPEED (KNOTS)
40 90 30 90 25 95 15 100 10 100 5 105 2 105 1 110
TABLE I
F. Stall Management Computer Output Bus
(1)
The SMC has an ARINC 429 output bus which supplies data to several airplane systems.
(2)
EFIS Pitch Limit
(a)
The SMC calculates a value of airplane pitch limit. This value is used by the EFIS symbol generator for the pitch limit display on the pilots' electronic attitude director indicators (EADI) (Ref 34-22-00).
(3)
Ground Proximity Warning
(a)
The ground proximity warning computer uses values of flap position, stick shaker activation angle of attack, and minimum operating airspeed to compute a windshear warning (Ref 34-42-01).
(4)
Digital Flight Data Acquisition Unit
(a)
Data from the SMC is transmitted to the digital flight data acquisition unit for storage (Ref 31-24-00).
G.
BITE and SMC Input Monitoring
(1)
The SMC has internal built-in test equipment (BITE) for maintenance and testing purposes. There is an SMC maintenance control panel on the front of the SMC. This panel has controls for selecting test and input monitoring functions and an alphanumeric display for showing the status of the functions selected.
(2)
When the BITE ON OFF button is pushed, the SMC runs a BITE test. The display will read TEST IN PROGRESS during the test and then SYSTEM OK when the test passes. After the test passes, several test and monitoring functions can be selected with the MENU button. When the ON/OFF button is pushed again, the SMC returns to normal operation.
5. Self-Test Switch________________
A. A self-test pushbutton switch for each SMC is located on the STALL WARNING TEST module on the P5 overhead panel. Pressing the No. 1 or No. 2 test button will activate the corresponding control column shaker. If the SMC has detected any fault, the test button will not activate the shaker. Once the fault is corrected, the self-test will again activate the shaker. The SMC will turn off the shaker motor if the test switch is held on for more than 20 seconds.
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. AIRPLANES WITH STALL MANAGEMENT ú
27-32-00
COMPUTER P/N 65-52822 ú CONFIG 2 ú 04 Page 6 ú Nov 15/98
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
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本文链接地址：737-300 400 500 AMM 飞机维护手册 飞行操纵 FLIGHT CONTROLS 3(29)
