LEAR LR36 FLT CREW HAS SELF INDUCED UNUSUAL ATTITUDE DURING MANEUVERS.

Narrative

WHILE ATTEMPTING TO JOIN THE OTHER ACFT IN THE FLT; THE PF (THE CAPT) LOST SIGHT OF THE OTHER ACFT IN THE SUN AND ROLLED THE ACFT INTO AN EXTREME ANGLE OF BANK. THE PF DID NOT IMMEDIATELY CORRECT AND THEN THE NOSE PITCHED DOWN. AIRSPD BUILT RAPIDLY. I ASKED THE CAPT WHAT HE WAS DOING AND HE IMMEDIATELY BEGAN THE UNUSUAL ATTITUDE RECOVERY. A SMOOTH; LOW G RECOVERY WAS ACCOMPLISHED AND THE ACFT BROUGHT BACK TO LEVEL FLT. I ASKED THE CAPT IF THE ACFT WAS CONTROLLABLE AND THE CAPT WENT THROUGH CONTROLLABILITY CHKS TO INCLUDE SLOW FLT AND LOWERING THE GEAR. AFTER DETERMINING IT WAS CONTROLLABLE; THE FLT WAS CONTINUED. A NORMAL APCH AND FULL FLAP LNDG WERE MADE. DURING POSTFLT INSPECTION; IT WAS DISCOVERED THAT THE R ELEVATOR HAD SEPARATED FROM THE ACFT. BETTER COM BTWN THE CREW MEMBERS WOULD HAVE HELPED TO MORE RAPIDLY IDENT THAT THE PF WAS SPATIALLY DISORIENTED AND POSSIBLY CAUSED ME TO TAKE ACTION SOONER BEFORE A DANGEROUS SITUATION DEVELOPED. GREATER ASSERTIVENESS ON MY PART WOULD ALSO HAVE HELPED PREVENT THE UPSET FROM OCCURRING. THE ACFT SHOULD HAVE BEEN IMMEDIATELY LANDED AT THE NEAREST ARPT; REGARDLESS OF THE CREW'S OPINION OF THE AIRWORTHINESS OF THE ACFT AFTER THE UPSET.