(a)
minimum idle
(b)
approach idle
(c)
N1 at 1.25 EPR
C.
The table contains data at outer air temperatures (OAT) from -40 to 120°F (-40 to 48°C) in increments of 4°F (2.2°C). The table also contains data at barometric pressures of 22.0-31.0 inches of mercury.
D.
Use the targets under a no air bleed or electrical load condition. The limits for each target are shown at the bottom of each page.
TASK 71-00-01-972-001-N00
2. Find Engine Checkout Target___________________________
A. Standard Tools and Equipment
(1)
Thermometer - Alcohol, MIL-T-11399, Type ML-5, -40 to 120°F (-40 to 49°C) range, accurate to |0.5°F (|0.25°C).
(2)
Thermometer - Mercury, -40 to 120 °F (-40 to 49°C) range, accurate to |0.5°F (|0.25°C) (optional to an alcohol thermometer if the thermometer is not taken on the airplane)
B.
Procedure
S 972-002-N00
(1) To find the engine checkout target, do these steps.
(a)
Get the local barometric pressure (not corrected to sea level) from the control tower.
CAUTION:_______DO NOT PUT A MERCURY THERMOMETER ON THE AIRPLANE. IF THE THERMOMETER BREAKS, MERCURY CAN TOUCH AIRPLANE COMPONENTS AND CAUSE DAMAGE TO THE COMPONENT.
(b)
Measure the outer air temperature (OAT) from a point in the shade near the airplane.
(c)
Find the OAT on the table of engine checkout targets.
(d)
Find the correct target for the test to be done.
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
71-00-01
ALL ú ú N01 Page 201 ú Jun 18/01
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
////////////////////////A / PW4000 SERIES /747-400 / ENGINES /MAINTENANCE MANUAL ////////////////////////
IF:
OUTSIDE AIR TEMPERATURE (OAT) = 60`F (15`C)BAROMETRIC PRESSURE = 30.0 INCHES OF MERCURY
FIND TEST VALUES:
MINIMUM IDLE SPEED = 63.7 |1.5% N2 BURNER PRESSURE AT MINIMUM IDLE = 41.1 |3.0 PSIA APPROACH IDLE SPEED = 73.0 |1.5% N2 %N1 @ 1.40 EPR = 90.4 |1.5% N2
OAT`F CHECKOUT B AROMET RIC PR ESSURE , INCH ES OF MERCUR Y
(`C) TARGETS 31.0 30.0 29.0 28.0 27.0 26.0 25.0 24.0 23.0 22.0
60 (16) MIN IDLE, %N2 APP IDLE, %N2 %N1 @ 1.40 EPR MIN PB, PSIA 63.7 70.5 90.4 49.0 63.7 90.4 70.5 48.1 63.7 90.4 70.7 47.2 63.7 90.4 71.1 46.3 63.7 90.4 71.4 45.3 90.4 73.0 41.163.7 90.4 73.6 39.963.7
64 (18) MIN IDLE, %N2 APP IDLE, %N2 %N1 @ 1.40 EPR MIN PB, PSIA 63.9 90.7 70.7 49.0 63.9 90.7 70.7 48.1 63.9 90.7 71.0 47.2 63.9 90.7 71.3 46.3 63.9 90.7 71.6 45.3 63.9 90.7 72.0 44.4 63.9 90.7 72.3 43.3 63.9 90.7 72.8 42.2 63.9 90.7 73.3 41.1 90.7 73.8 39.963.9
TARGET VALUE TOLERANCES
TOLS: +/-1.5 %N2 (MIN IDLE) +/-1.5 %N2 (APP IDLE) +/-3.0 PSIA (MIN PB) +/-1.5 %N2 (N1 @ 1.40 EPR)
____THE EEC CONTROLS MINIMUM IDLE SPEED ON THE GROUND BY ONE OF TWO SCHEDULES:
NOTE: A MINIMUM N2 SCHEDULE OR A MINIMUM PB SCHEDULE. THE EEC SELECTS THE SCHED-ULE THAT GIVES THE HIGHER FUEL FLOW. AMBIENT CONDITIONS AND SERVICE BLEED AFFECT %N2, FUEL FLOW, AND PB. THUS, THE EEC MAY CONTROL FUEL FLOW BASED ON %N2 ON SOME CONDITIONS AND PB ON OTHERS. ENGINE IDLE OPERATION IS SATIS-FACTORY IF THE %N2 IS WITHIN THE LIMITS OR THE PB IS WITHIN THE LIMITS. IT IS NOT NECESSARY FOR BOTH %N2 AND PB TO BE WITHIN THE LIMITS AT THE SAME TIME (ALTHOUGH THEY USUALLY ARE).
Trim Table Usage Example
Figure 201
G07139
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
71-00-01
ALL ú ú N01 Page 202 ú Oct 10/97
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
(e) Read across the table to find the target value for the OAT and barometric pressure which you found.
NOTE: If the OAT or the barometric pressure is not on the
____ table, you can interpolate to find the correct target value.
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：747-400 AMM 飞机维护手册 动力装置 POWER PLANT 1(105)
