Speedbrakes & Wheelbrakes:
FYI, may I provide some figures for a typical mid-size two-engine transport (RTO at 135KTAS):
Figures are lbs.
===================SpeedBrakes========
====================Dn=====Up=====Diff
Drag..............8.500...14.700..+73%
Lift.............52.000...-1.200.-102%
Load on Wheels..141.600..194.800..+38%
Braking Force....75.900...98.000..+29%
--------------------------------------
Max.Stop.Force...84.400..112.700..+34%
(brakes & drag)
Happy landings
dolly