The Lear 45 is not like the the classic Learjets of old , which are all variations of the same theme . The 45 is a clean sheet design , quite a sophisticated little jet for its size with steering , braking and spoileron by wire , though primary controls are still conventional cable . Spoilers can deploy to a maximum of 60 degrees depending on amongst other things , control wheel position , airspeed and flap position . They can act as speed brakes , lift dumps on landing and give roll control augmentation, they also provide the left hand seat with primary roll control during an aileron jam/disconnect situation . The spoilers are hydraulically powered(3000psi) and electronically controlled by RVDT's and a dedicated spoileron computer . In speed brake mode , the spoilers can be deployed to any position desired within the spoiler speed schedule , not just either up or down , as to how effective they are you will have to ask a pilot !
As for asymmetric deployment.....never say never but I think it is highly unlikely . The spoileron computer constantly monitors the whole system , any failure will cause hydraulic power to be removed via a SOV and the hydraulic return to be opened allowing the spoilers to 'blow down' . If the monitor system itself fails to do this , crew can use the control wheel Master Switch to achieve the same effect . In the event of a jam , the computer will command the jammed spoiler to retract for 5 to 7 seconds , the unjammed spoiler remains fully effective . If the jam will not clear
, the AFM procedure is to match the unjammed panel to the jammed panel using the spoiler lever and the EICAS display of panel deployment angle . The AFM also gives a procedure for landing with one or both spoilers deployed , so it would seem that the aircraft is controllable with a jammed panel
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Ok I have to rest now , hope this is of some help
