Brightness Control
Rotate – controls display brightness.

Message (MSG) Light
Illuminated (white) – scratchpad message is shown.

Offset (OFST) Light (U7 and on)
Illuminated (white) – LNAV gives guidance for lateral route offset.

CALL Light (CDU with MENU Key)
Illuminated (white) – A subsystem other than the FMC is requesting control of the CDU.
Function and Execute Keys

CDU
Copyright . The Boeing Company. See title page for details.
11.10.2  December 7, 2001

Flight Management, Navigation -Controls and Indicators 737 Operations Manual

CDU Function Keys
Push –
.
INIT REF – shows page for data initialization or for reference data

.
RTE – shows page to input or change origin, destination, or route

.
CLB – shows page to view or change climb data

.
CRZ – shows page to view or change cruise data

.
DES – shows page to view or change descent data

.  
DIR INTC – shows page to modify route to fly directly from present
position to any waypoint or to intercept any course to any waypoint

.
MENU – shows page to choose subsystems controlled by CDU

.
LEGS –

.
shows page to evaluate or modify lateral and vertical data

.
shows page to control PLAN mode display

.  
DEP ARR – shows page to input or change departure and arrival
procedures

.  
HOLD – shows page to create holding patterns and show holding pattern data

.  
PROG – shows page to view dynamic flight and navigation data,
including waypoint and destination ETAs, fuel remaining, and arrival
estimates

.
N1 LIMIT – shows page to view or change N1 thrust limits

.
FIX – shows page to create reference points on map display

.  
PREV PAGE – shows previous page of related pages (for example, LEGS pages)

.
NEXT PAGE – shows next page of related pages.

Execute (EXEC) Key
Push –
.
makes data modification(s) active

.
extinguishes execute light.

Execute Light
Illuminated (white) – active data is modified but not executed.
Flight Management, Navigation -Controls and Indicators 737 Operations Manual

Alpha/Numeric and Miscellaneous Keys

Alpha/Numeric Keys
Push –
.
puts selected character in scratchpad

.
Slash (/) key – puts “/” in scratchpad

.  
Plus Minus (+/–) key – first push puts “–” in scratchpad. Subsequent pushes alternate between “+” and “–”.

Delete (DEL) Key
Push – puts DELETE in scratchpad.

Clear (CLR) Key
Push –
.
clears the last scratchpad character

.
clears scratchpad message. Push and hold – clears all scratchpad data.

Space (SP) Key
Push – puts space in scratchpad.
Copyright . The Boeing Company. See title page for details.
11.10.4   December 1, 2000

Flight Management, Navigation -Controls and Indicators 737 Operations Manual
CDU Page Components

Page Title
Subject or name of data shown on page.
ACT (active) or MOD (modified) shows whether page contains active or modified
data.

Line Title
Title of data on line below.

Line
Shows –
.
prompts

.
selections
. options

.
data.

Scratchpad
Shows messages, alpha–numeric entries or line selected data.

Page Number
Left number is page number. Right number is total number of related pages.

Boxes
Data input is mandatory.
Flight Management, Navigation -Controls and Indicators 737 Operations Manual

Dashes
Data input is optional. The data is not mandatory.

Prompts
Show pages, select modes, and control displays. Caret “<” or “>” is before or after prompt.
FMC Source Select Switch

FMC Source Select Switch
BOTH ON L –
.
selects left FMC for all FMC operations

.
right map will annunciate “FMC L.” NORMAL –

.
left FMC controls CDUs and provides input to the autothrottle system

.
right FMC operates in synchronization with left FMC

.
maps display composite information from both FMCs BOTH ON R –