AIRPLANE
OPERATIONS
MANUAL
NAVIGATION AND
COMMUNICATION
MARCH 30, 2001
2-18-30
Page
11
Code
02
ATTITUDE MODE SELECTION
The following procedure applies to the selection of the ATT mode after
the FAULT annunciator has illuminated (and an IRS 1 (2) FAIL caution
message is presented on the EICAS, on airplanes equipped with
EICAS 17 onwards):
− Set the MSU switch to ATT.
− If the FAULT annunciator extinguishes itself, the ALIGN annunciator
will illuminate for 20 seconds (and an IRS 1 (2) ALN advisory
message is presented on the EICAS, on airplanes equipped with
EICAS 17 onwards).
− Hold the airplane steady, straight and level until the ALIGN
annunciator extinguishes itself (and an IRS 1 (2) ALN advisory
message disappears from the EICAS, on airplanes equipped with
EICAS 17 onwards).
− Initialize the IRU with magnetic heading through the FMS CDU.
− Update heading periodically through the FMS CDU.
− When operating in the attitude mode the IRS 1 (2) ATT MODE
caution message (only for airplanes equipped with EICAS 17
onwards) is presented on the EICAS.
CAUTION: WHEN OPERATING IN THE ATTITUDE MODE,
ATTITUDE OUTPUTS ARE NOT AS ACCURATE AS
WHEN OPERATING IN THE NAV MODE, AND
MAGNETIC HEADING MUST BE ENTERED
PERIODICALLY, THROUGH THE FMS CDU.
POWER DOWN
− Set the MSU switch to OFF. The ALIGN annunciator illuminates (and
an IRS 1 (2) ALN advisory message is presented on the EICAS, on
airplanes equipped with EICAS 17 onwards).
− After the ALIGN annunciator extinguishes itself (and an IRS 1 (2)
ALN advisory message is removed from the EICAS, on airplanes
equipped with EICAS 17 onwards), de-energize the airplane.
To Next Page
