KLM MD-11 - Indications; Guidance; Pop-Up FD and ATS

MD-11 Flight Crew Operations Manual
k
Automatic Flight -
Description and Operation
Auto.10.29
The WAGS is part of the AFS and gets data from the two central air data
computers (CADC), the inertial reference system (IRS), and other AFS
components. The CADC and the IRS can sense windshear conditions and will
send this data to the WAGS. The WAGS will then provide visual warnings on the
PFD and FMA and aural warnings through the CAWS. FD and AP are provided
through the AFS.
Indications
A red WINDSHEAR (decreasing performance) or an amber WINDSHEAR
(increasing performance) is displayed on the PFD top left corner when the WAGS
detects windshear.
The CAWS generates a tone and WINDSHEAR voice warning. Windshear modes
are also annunciated on the FMA.
The WAGS provides FD and AP pitch guidance for windshear during takeoff and
go-around.
The PLI (on PFD) shows the difference between aircraft AOA and stickshaker
AOA. The cyan PLI turns amber as the aircraft approaches stickshaker AOA. At
stickshaker AOA the PLI turns red. The PLI is for indication only and is not to be
used for guidance command.
The WAGS inhibits the EGPWS when windshear guidance is active and the
aircraft is responding properly. If WAGS commands are not being followed, the
EGPWS will be enabled.
Guidance
When an increasing or decreasing performance windshear is detected, guidance is
provided for best flight path angle through the windshear and a positive flight path
relative to the ground.
When windshear is detected and guidance is active, the system provides FD and/or
AP guidance during takeoff and go-around. The system commands a 1 degree
flight path angle until appropriate airspeed is achieved. The system then
commands pitch guidance to maintain this speed. For takeoff this speed is V2+30.
For go-around this speed is 1.3Vs+20.
Above 450 RA the system allows a zero (or slightly decreasing) flight path. Below
450 RA, if a positive flight path angle is not possible, the system will guide to
stickshaker AOA and altitude loss may occur as necessary in order to prevent a
stall.
Pop-Up FD and ATS
If the WAGS detects windshear and the FD is off, windshear guidance and
maximum power functions are still available. On takeoff, after liftoff, the FD pops
up on the PFD and the ATS goes to max available TO thrust.
November 16, 2009