AIRPLANES WITH SPEED TAPE DISPLAY AIRPLANES WITH EURO FORMAT FAST/SLOW DISPLAY
Autothrottle - FL CH Mode
Figure 15

EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 22-32-00
 ALL  ú ú 01 Page 31 ú Sep 28/01
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
M21387
A
757
MAINTENANCE MANUAL

AIRPLANES WITH SPEED TAPE DISPLAY AIRPLANES WITH EURO FORMAT FAST/SLOW DISPLAY
Autothrottle - Go-Around Mode
Figure 16

EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 22-32-00
 ALL  ú ú 09 Page 32 ú Sep 28/01
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
M21521
A
757
MAINTENANCE MANUAL

EPR OR THR AS INSTALLED

MODE CONTROL PANEL
ATTITUDE DIRECTOR INDICATION
. A/T ARM
. IDLE MODE SHOWN
. IN SPEED MODE FLARE
. FAST/SLOW DISPLAY UNTIL
IS COMMANDED BY FCC
TOUCH DOWN

UPPER EICAS DISPLAY
. GA MODE AUTOMATICALLY SELECTED BY LANDING

AIRPLANES WITH STANDARD FORMAT FAST/SLOW DISPLAY AIRPLANES WITH SPEED TAPE DISPLAY AIRPLANES WITH EURO FORMAT FAST/SLOW DISPLAY
Autothrottle - Flare Retard
Figure 17

EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 22-32-00
 ALL  ú ú 08 Page 33 ú Sep 28/01
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
M21558
A
757
MAINTENANCE MANUAL

 (b)  When flare retard is requested, the thrust levers retard to the flare idle limit at a controlled rate. For the autoland flare retard mode, the PLA is commanded to 2 degrees below the computed aft limit.
 (17)
 Autothrottle - Idle Mode (Fig. 18)

 (a)  
Autothrottle idle occurs when requested by the flight management computer. The autothrottle must be armed and engaged in the VNAV mode to accept this request.

 (b)  
When the idle mode is engaged, the thrust levers retard to ground or flight idle limits at a controlled rate. While the thrust levers are moving to the idle positon, IDLE is annunicated on the EADI. When the thrust levers reach the idle position, throttle hold is engaged. This removes autothrottle servomotor generator excitation, and THR-HLD is annunicated on the EADI.

 (18)
 Thrust Management System - EPR, FLCH Mode Signals and Servo Drive

 (a)  
Thrust lever position is determined in three steps: 1) The TMC generates a desired throttle rate command signal in order to reach the EPR target. 2) The TMC internal automatic limits override the rate command signal to prevent exceeding EPR or PLA limits.

 3)  The rate command signal drives the A/T servomotor generator at a desired rate. The signal is limited by a scheduled rate limit which does not allow the command to exceed the performance of the engine.

 (b)  
EPR Control in TO or VNAV Mode

 1)  An ENABLE signal (SERVO CONTROL FROM THRUST) from the mode select logic allows selection of EPR error when the TO or VNAV mode is engaged. In the TO mode, the difference between the engine actual EPR and the EPR reference is used for the EPR error. When the VNAV mode is engaged and a valid SELECT FMC EPR TARGET CMD signal is received, actual EPR and FMC target EPR determine EPR error.

 (c)  
EPR Control when not in TO or VNAV Mode

 1)  When in an EPR (or THR) mode other than TO or VNAV, the SPEED CONTROL THROTTLE RATE CMD signal provides initial rate. The rate is computed to increase airplane speed to the upper limit. With the flaps retracted, maximum operating airspeed (VMO) or maximum operating Mach (MMO) is taken as the limit. With the flaps extended, flap placard speed is taken as the limit. The airplane speed is at the upper speed limit unless actual EPR reaches the EPR REF limit. In this case, automatic override occurs and the airplane speed is limited to EPR REF.

 (d)  
Minimum and Maximum EPR Protection and Power Lever Angle limits. 1) The approach idle power provides the minimum thrust setting
　
中國航空網 www.k6050.com
航空翻譯 www.aviation.cn
本文鏈接地址：757 AMM 飛機維護手冊 自動飛行 AUTOFLIGHT 2(124)