Smiths Aerospace
Electronic Systems – Malvern
DOC NO.0134ED
MAINTENANCE MANUAL SUPPLEMENT
BOEING B737-100/200/300/400/500
28-41-04
DIGITAL CALIBRATION TRIM UNIT COVER AND LABEL– REMOVAL/INSTALLATION
1. General
A. This procedure has two tasks:
(1) A task to remove the digital calibration trim unit (DCTU) cover and label
(2) A task to install the DCTU cover and label
2. Digital Calibration Trim Unit (DCTU) Cover Removal
A. Access
(1) Location Zone
(a) 101
Control Cabin Left
(b) 102
Control Cabin Right
B. Procedure
(1) Open these circuit breakers and attach DO-NOT-CLOSE tags:
(a) P6 Main Power Distribution Panel
1) EP GND FUELING
2) FUEL
QTY
(2) Loosen the clamp screw of the applicable fuel quantity indicator.
(3) Move the fuel quantity indicator and the DCTU away from the panel.
(4) Loosen the screw on the cover of the DCTU.
(5) Move the cover back to the airplane wire bundle.
(6) Disengage the DCTU from the rear of the fuel quantity indicator.
(7) Keep the fuel quantity indicator for the subsequent installation.
(8) At the rear of the DCTU, disconnect the electrical connector that goes to the airplane wire bundle.
(a) Retain the data as listed on the DCTU label and save for installation on new DCTU cover.
(b) Remove the DCTU cover from the airplane wire bundle and discard
3.
Page 408
Apr 19/02
Airplanes with Smiths 2307 Model Fuel Quantity
Indicators with TSU
EFFECTIVITY
