KLM MD-11 - Engine out Driftdown

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MD-11 Flight Crew Operations Manual

FMS -

Controls and Displays

FMS.30.121

Engine Out Driftdown

When the aircraft is flying above the max EO altitude and an EO occurs, the

condition must be manually confirmed. When the FCP altitude is lowered and the

aircraft has slowed to the driftdown (DD) speed, the aircraft enters a DD.

If an EO occurs in climb above the 2 engine maximum altitude, the aircraft will

continue to climb with a speed target of DD and MCT power. When the aircraft

can no longer climb at the DD speed a level off will occur. The aircraft will remain

in level flight until the DD speed is reached and the FCP altitude is lowered. At

this time a DD to the FCP altitude will occur.

When an EO in cruise occurs and pilot has confirmed the engine out, the current

speed target will remain the active target. The thrust limit will transition to MCT,

however, the engaged mode will remain in altitude hold/speed. When the speed

target can no longer be maintained in altitude hold/speed, the mode will transition

to alt hold/max thrust and the speed target will become the DD speed. The aircraft

will remain in level flight until the DD speed is reached and the FCP altitude is

dialed down.

When the FCP altitude is lowered, the FMC transitions to DD EO descent (D/D

ENG OUT DES page on the MCDU). The cruise flight level is cleared on the INIT

page and the aircraft will descend to the FCP altitude. DD speed is displayed

adjacent to 1L on the D/D ENG OUT DES page as well as the speed targets on the

PFD speed tape and FMA. When the aircraft V/S is greater than -100 fpm for 60

seconds, the FMS enters a V/S mode and will descend at -100 fpm. The pilot can

edit this via the FCP and then reengage PROF mode.

If the FCP clearance altitude is below the 2 eng max altitude, the aircraft will

continue the descent to that altitude. To transition from descent to cruise, it will be

necessary to enter a cruise flight level on the INIT page. Once the cruise flight

level is entered, the FMC calculates a new EO econ cruise speed. Thrust limits

remain in manual MCT. Once below the 2 engine max altitude the V/S will

increase to -750 fpm. The FMS speed target will remain at the DD speed until one

of the following occurs:

LB1-3-0136

October 02, 2006