Flap Retraction - One Engine Inoperative

[double-alpha]

Hi,

I have tried with PSX 2 takeoffs with engine failure after V1.

According to the 787 FCTM :

1-VNAV is armed
At E/O acceleration height (400 ft), a near-level climb segment is commanded for acceleration.
I retract flaps on the takeoff flap retraction speed schedule.
With flaps up and airspeed at or above the flaps up maneuver speed, VNAV automatically sets the reference thrust limit to Max Continuous Thrust (CON).

PSX 747 behaves the same way


2-VNAV not armed
At engine out acceleration height, if VNAV is not engaged, leave the pitch mode in TO/GA and select flaps up maneuver speed on the MCP.
The flight director commands a near level flap retraction segment.
Accelerate and retract flaps on the takeoff flap retraction speed schedule.
After flap retraction and at or above flaps up maneuver speed, if VNAV is not engaged, select FLCH, verify maximum continuous thrust (CON) is set, select and execute ENG OUT prompt, and continue the climb to the obstacle clearance altitude.

The problem with PSX, the airplane keeps TOGA pitch mode with a constant speed (about V2+15), therefore I can't accelerate and retract flaps. At engine out acceleration height, I need to select FLCH and flaps up maneuver speed to accelerate !
Maybe I don't understand the procedure.
Or is it different with a 747-400 ? I don't have the FCTM for the 747 so I can't check.

Thank you for your comments

[Hardy Heinlin]

Hi,

on the 744 the FMC may change the command airspeed when the MCP SPD window is blank, and it can only be blank when VNAV is engaged. TOGA and FLCH will not blank the window.


Regards,

|-|ardy

[double-alpha]

Thank you.

I found an answer in a 747 FCTM I've just downloaded, and there is a difference between the 787 and the 747.

PSX behaves perfectly

Flap Retraction - One Engine Inoperative

747 :
At engine out acceleration height, if VNAV is not engaged, select FLCH and flaps up maneuvering speed + 20 knots on the MCP.
Engine-out acceleration and climb capability for flap retraction are functions of airplane thrust to weight ratio.
The flight director commands a near level flap retraction segment.
Accelerate and retract flaps on the flap-speed schedule

787 :
At engine out acceleration height, if VNAV is not engaged, leave the pitch mode in TO/GA and select flaps up maneuver speed on the MCP.
Engine-out acceleration and climb capability for flap retraction are functions of airplane thrust to weight ratio.
The flight director commands a near level flap retraction segment.
Accelerate and retract flaps on the takeoff flap retraction speed schedule

[DougSnow]

PSX behaves perfectly

You doubted it ?

[double-alpha]

Not at all!