KLM MD-11 - Speed-On-Pitch AP;FD Speed Protection

MD-11 Flight Crew Operations Manual
k
Automatic Flight -
Description and Operation
Auto.10.26
• The FMA flashes THRUST and V/S or FPA five times before becoming
steady.
• The FMA flashes HI SPEED PROTECTION or LO SPEED
PROTECTION.
At 10 knots over or underspeed:
• The AP/FD pitch mode reverts to pitch speed protection with a Vmin or
Vmax speed target.
• The throttles are clamped at their existing positions.
• The FMA flashes PITCH five times before becoming steady.
• The FMA flashes HI SPEED PROTECTION or LO SPEED
PROTECTION.
If the V/S FPA mode is engaged, the ATS is on, and a Vmax or FMS Vmin speed
limit violation occurs, the following will happen at 5 knots over or underspeed:
• The AP/FD will revert to pitch speed protection with a Vmin or Vmax
speed target.
• The ATS mode will change to climb thrust or idle clamp to provide
compatible mode control. Since the ATS was previously in a speed mode,
the throttles will already be at the maximum or minimum position to
control speed.
• The FMA flashes PITCH five times before becoming steady.
• The FMA flashes HI SPEED PROTECTION or LO SPEED
PROTECTION.
Terminating a speed protection mode requires pilot manual disengagement or
selection of another mode.
Speed-On-Pitch AP/FD Speed Protection
ATS speed limiting and ATS speed protection are the primary means used by the
FCC to limit speed excursions outside the normal speed envelope.Whenever the
altitude FMA window displays HOLD, ATS speed protection is the only speed
protection mode that is available. However, whenever the altitude FMA displays
a mode other than HOLD, AP/FD Speed-on-Pitch (SOP) speed protection is also
available to prevent overspeed or underspeed.
The typical sequencing and scheduling of both ATS and SOP speed protection is
as follows:
1. Aircraft begins to violate Vmin or Vmax.
2. Aircraft reverts to Speed-on-Thrust (if engaged in a Speed-on-Pitch mode),
and autothrottles engage (if off) no later than Vmin-5 (low speed) or
Vmax+5 (high speed). The FMA displays speed protection indications.
3. If the speed violation continues, SOP speed protection comes on no later
than Vmin-10 (low Speed) or Vmax+10 (high speed)
October 02, 2006