(4)
AMM 78-11-02/401, Turbine Exhaust Plug
E.
Access
(1)
Location Zone
412 Engine No. 1
422 Engine No. 2
432 Engine No. 3
442 Engine No. 4
F.
Prepare for the Trim Balance Procedure.
S 485-091-N00
(1)
Do the steps that follow to operate the AVM:
(a)
Look for the CDU found on the pedestal and get access to the CFDS initial menu.
(b)
Select EICAS CP.
(c)
Select 71 POWER PLANT from page 1/3 of the EICAS MAINTENANCE screen.
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
72-31-00
ALL ú ú N01 Page 516 ú Feb 15/99
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
G. As-Is Trim Balance Survey.
S 975-092-N00
(1)
Do the steps that follow to do the As-Is Trim Balance Survey:
(a)
Thermally stabilize the engine as follows:
NOTE: You must have a thermally stable engine before you
____
do the vibration survey.
WARNING:_______USE AMM 71-00-00/201 TO OPERATE THE POWER PLANT. IF YOU DO NOT USE THIS PROCEDURE, YOU CAN CAUSE DAMAGE TO EQUIPMENT OR INJURIES TO PERSONS.
1) Use the Power Plant Operation (Normal) procedure to start
the engine (AMM 71-00-00/201). 2) Operate the engine at minimum power for five minutes. 3) Do a slow acceleration to 1.3 EPR power, then stay at 1.3
EPR for three minutes. 4) Decrease the power to IDLE, then stay at IDLE for six minutes.
NOTE: You now have a thermally stable engine.
____
(b) To do the trim balance survey, stop at these N1 speeds and make a record of the stable trim balance data during the slow accel (90-120 seconds) to 90% N1 (3250 RPM) on Figure 506.
63% N1 (2250 RPM) speed
68% N1 (2450 RPM) speed
82% N1 (2950 RPM) speed
90% N1 (3250 RPM) speed
NOTE: The trim balance data points can be taken during the
____
vibration survey.
NOTE: The trim balance data is the PHASE (DEG>) and DISPL
____ (MILS) for the "A" flange pick-up. This data shows on the 71 POWER PLANT Screen of the selected CDU.
NOTE: Trim balance data is only taken during the accel
____
vibration survey.
(c) Do a slow decel (90-120 seconds) to IDLE.
NOTE: Trim balance data is only taken during the accel
____
vibration survey.
(d) Operate the engine at IDLE for five minutes to let the engine become cool.
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
72-31-00
ALL ú ú N01 Page 517 ú Oct 18/01
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
////////////////////////A / PW4000 SERIES /747-400 / ENGINES/MAINTENANCE MANUAL ////////////////////////
(e)
Use the Power Plant Operation (Normal) procedure to do the engine shutdown (AMM 71-00-00/201).
(f)
Remove the inlet cone (AMM 72-31-01/401).
(g)
Examine the hub flange for installed counterweights (See Figure 503).
(h)
If weights are installed, do these steps: 1) Examine the fan blades and fan hub for an N1 reference mark.
2) If there is no N1 Reference Mark on a fan blade or the fan hub, do the steps that follow to make an N1 Reference Mark (See Figure 504). a) Remove the retaining ring of the key washer and the key
washer.
NOTE: The key washer holds the turbine shaft plug
____
in position.
b) Use a PWA 85306 Puller to remove the plug.
c) Discard the packing.
d) Find the small recess on the end of the coupling
assembly of the turbine shaft.
NOTE: This recess gives the location of the short
____ tooth which makes the signal for the N1 speed transducer.
e) Make a mark with ink in a location which you can easily
see on the fan blade which is aligned with the recess. f) Lubricate a new packing with the petrolatum. g) Install the packing to the turbine shaft plug. h) Install the turbine shaft plug to the coupling ID. i) Install the key washer and the retainer ring. j) Make sure that the retainer ring is fully installed all
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 发动机 ENGINE 1(121)
