B737NG limitations vs. same for classic

[jesperzac]

Hi all,

I am fairly new on B737NG and have a question concerning the limitations for speed brake use with flaps extended.

On classic I am told that you are not allowed to use speed brakes with flap settings of more than 15.

However, I cannot find any such or similar limitation in the NG manual. I can only find that during flight, speed brakes should only be extended to the flight detent and that speed brakes should not be extended below 1,000' RH.

Is anyone able to confirm that there is no max speeds and no flaps restrictions when using speed brakes on the B737NG?

Thanks in advance.

[BOAC]

I believe there may still be a speed restriction on some un-modified NGs(800's?) but on 'normal' NGs, no restriction. On any 737 it is not a good idea to use speedbrake with flap, and especially with more than F5 as the buffet on the tailplane can be high and does not do the structure any good. My very first Fleet Manger on 737s used to threaten to saw your arm off if you used s/brake and flap.

There is no technical 'limit' though on flap settings and it COULD be used up to F40 although there is a warning about increased stall speeds with s/brake extended.

[jesperzac]

Thanks a lot for the prompt answer!

It was badly needed... I am Captain on B737NG with JetX and due for the first OPC on this type...

Best regards,
Jesper

[Stan Woolley]

From the 737NG FCTM......

" The use of speedbrakes with flap extended should be avoided,if possible.With flaps 15 or greater, the speedbrakes should be retracted. "

[polzin]

kp

I had a Boeing instructor tell me one time that if you needed speed brake and flaps then things were so screwed up that you needed to do something else.
Not very scientific but just common sense.