SMT JET LNDG ON 4000 FT STRIP AT NIGHT HAD NON PROPORTIONAL BRAKING. R MAIN GEAR WENT OFF RWY. ACFT WAS STOPPED ON RWY; BARELY.

Narrative

AS A FAIRLY HIGH TIME PLT OPERATING ADVANCED TURBOPROP AND JET ACFT AS PIC; IT MUST NOT BE FORGOTTEN THE NEED FOR PROPER ACFT FAMILIARIZATION AND HANDLING CHARACTERISTICS. A NORMAL LNDG WAS MADE INTO A 4000 FT PAVED DRY STRIP. THE ACFT BRAKED UNEVENLY AND STEERING WAS DIFFICULT. THE ACFT WAS IN FULL REVERSE AND MAX BRAKING WAS INITIATED; WHEEL LOCK-UP OCCURRED AND THE ACFT WAS STOPPED ON THE REMAINING RWY SURFACE. HOWEVER; DURING THE ROLLOUT; THE MAIN GEAR 'R SIDE AND NOSE GEAR' LEFT THE PAVED LNDG SURFACE. NO DAMAGE TO ACFT; NO INJURY; NO PROPERTY DAMAGE. A THOROUGH PREFLT SHOWED NO EVIDENCE OF ACFT MALFUNCTION. FURTHER INVESTIGATION SUGGESTED A LEAKY SEAL. R MAIN GEAR CAUSED FLUID TO LEAK ON ACFT BRAKE AND CAUSE DIRECTION PROBLEMS DUE TO NONPROPORTIONAL BRAKING. LESSON LEARNED: TRAIN WITH ALL NEW EQUIP NO MATTER WHAT THE PLT QUALIFICATIONS ARE. INITIATE ALL BRAKING IMMEDIATELY AFTER TOUCHDOWN (CORPORATE PLTS OFTEN FLY FOR THE PAX COMFORT). WEAR SHOES THAT PROPERLY INTERACT WITH THE ACFT PEDAL DESIGN. THE FIRST TIME YOU ACCEPT AVIATION AS REDUNDANT YOU WILL SEE SOMETHING VERY NEW.