"Ron Parsons" wrote in message
...
In article ,
(WaltBJ) wrote:

However, some, like the 727, say
'no speed brake use with flaps extended' since loss of lift because of
turbulence behind the s/b results in aero center shifting aft
resulting in a marked nose-down reaction and loss of altitude. Not
good on approach.

Actually that is because a loss of hydraulics with both s/b and flaps
out leaves the s/b floating, still causing drag whereas if they were
down, they would stay down for the most part.

There is very little pitch change with 727 speedbrakes even if you only
deploy one set, ie the inboards only, or the outboards. So little that
you can't use them to offset unwanted pitch like you can on a 707 or 135.

Which are, like any airliner, completely different from a fighter speed
brake.