CORP ACFT UNABLE TO ACTIVATE THRUST REVERSERS RUNS OFF END OF RWY.

Narrative

LNDG WAS FROM AN ILS 20; EGHI; CEILING 700 FT; VISIBILITY 3 MI; RAIN. WINDSHEAR AT 400 FT AGL; 10 KTS. APCH FLOWN NEAR VREF DUE TO RELATIVELY SHORT (5600 FT) RWY. PWR REDUCED TO IDLE THRUST; AT VREF; APPROX 1000 FT SHORT OF THRESHOLD. LNDG FIRM TO AVOID HYDROPLANING. ATTEMPTED TO ACTUATE REVERSE THRUST. ANNUNCIATOR LIGHTS SHOWED NO 'DEPLOY' LIGHTS. BEGAN MAX BRAKING EFFORT THAT CONTINUED TO END OF RWY. RESTOWED AND REATTEMPTED REVERSE THRUST. #1 AND #4 'ARM' ONLY #2 AND #3 'UNLOCK' ONLY. ACFT COMMANDER (IN R SEAT) PULLED FULL REVERSE THRUST ON #2 AND #3 IN CONTRAVENTION OF ESTABLISHED PROCS. THIS ACTION (WITHOUT DEPLOY LIGHTS) WILL GENERATE FORWARD THRUST. I RESTOWED REVERSERS AND REATTEMPTED. AGAIN; PIC (R SEAT) OVERRODE AND ATTEMPTED REVERSE WITHOUT DEPLOY LIGHTS. I AGAIN REASSUMED CTL AND STOWED LEVERS; SECURED ALL 4 ENGS TO MINIMIZE FOD AND PREPARED FOR OVERSHOOT. ACFT DEPARTED BY 200 FT. FACTORS: WX -- RAIN 'HVY' ACCORDING TO WITNESSES; RPTED BY TWR AS 'LIGHT.' WINDSHEAR -- POSSIBLE TAILWIND ON TOUCHDOWN IF MICROBURST PRESENT; WITNESSES RPTED APPARENT ACFT ACCELERATION AFTER TOUCHDOWN. MECHANICAL -- IMPROPER/INCOMPLETE SEQUENCING OF THRUST REVERSERS. HUMAN -- PIC; NOT FLYING; ATTEMPTED; TWICE; TO ASSUME CTL OF REVERSE LEVERS IN CONTRAVENTION OF ACCEPTED PRACTICES/PROCS. ATTEMPTED FULL REVERSE (TWICE); ALSO IMPROPER. OPERATOR -- PIC; NOT FLYING; FAILED TO INFORM SIC (PF) OF MAINT STATUS OF ACFT. IT WAS FOUND TO BE OUT OF COMPLIANCE WITH APPROVED ACFT INSPECTION PROGRAM (AAIP) AND HAD NO MAINT IN PAST YR. PIC HAD BEEN AWARE OF THIS FOR ENTIRE TRIP. SIC WAS A 'STANDBY' PLT; UNAWARE OF STATUS OF ACFT.