B737NG Alternate flap duty cycle

[ANAJASJAL008]

Hi all,

FCOM says about alternate duty cycle as fllows.
After a complete extend/retract cycle, i.e., 0 to 15 and back to 0, allow 5 minutes cooling before attempting another extension.

But if I stop the flaps 1 after go around, i.e., 0 to 15 and back to 1, I should wait 5 minutes cooling before attempting another extension?

What do you think about this?

Regards,

[Capt Quentin McHale]

ANAJASJAL008,

You must remember that by using alternate flap extension you are using the flap ELECTRIC motor not the flap hydraulic drive motor. I would think the FCOM by stating COMPLETE ext/ret cycle means 0-15-0 without stopping. So cooling period makes sense. On the other hand during a go around, I think you would have ample time for flap electric motor cooling by the time you do your circuit and are lined up on finals again. Also the flap motor is mounted in the main gear wheel well, so I'm assuming there would be plenty of cooling air swirling around with gear extended.

Rgds McHale.