AN SJ30 PROTOTYPE JET ACFT EXPERIENCES LOSS OF ACFT CTL DURING TEST FLT ACTIVITY.

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PROTOTYPE JET ACFT ON TEST FLT TO EVALUATE AIR FLOW ON AND AROUND SLATS/WING. LEVEL FLT; 125-130 KIAS. FLAPS WERE SELECTED TO APCH SETTING. SHORTLY THEREAFTER UNCOMMANDED L ROLL COMMENCED. THE 30 DEGS/SECOND ROLL RATE WAS COUNTERED WITH FULL LATERAL CTL (AILERONS); FULL RUDDER; AND FULL ASYMMETRIC THRUST. ROLLING THROUGH 120 DEG OF BANK ANGLE FLAPS WERE RESELECTED TO A TKOF SETTING (LESS FLAP) FOLLOWED SHORTLY BY A LOUD SNAPPING SOUND AND ACCOMPANYING ROLL RATE DECREASE. ACFT WAS RECOVERED IN LEVEL AND STRAIGHT FLT AT APPROX 6000 FT MSL (A 3000 FT LOSS); HEADING ROUGHLY NE. PWR WAS REESTABLISHED SYMMETRICALLY AND EMER WAS DECLARED. A LOW/NO FLAP LNDG WAS PLANNED AT A RELATIVELY HIGH VREF (APCH SPD) (160 KIAS). THE DECISION TO RETURN TO SAT WAS BASED ON SEVERAL FACTORS: 1) THE ACFT WAS CONTROLLABLE AT THE SELECTED VREF. 2) 'SAT' ARPT WAS THE CLOSEST ARPT WITH SUFFICIENT RWY TO ALLOW A SAFE LNDG AND IN FACT ALMOST THE CLOSEST ARPT OF ANY SORT. 3) CRASH AND RESCUE PERSONNEL WERE IMMEDIATELY AVAILABLE FOR HOT BRAKES/BRAKE FIRE WHICH I ASSUMED WERE ALMOST DEFINITE POSSIBILITIES. 4) A NEARLY STRAIGHT IN APCH (ALBEIT TO A DOWNWIND RWY) WAS AVAILABLE WITH MINIMUM MANEUVERING. SUBSEQUENT LNDG WAS UNEVENTFUL WITH THE EXCEPTION OF HOT BRAKES. CRASH CREW COOLED BRAKES WITH FANS; AND ACFT WAS TOWED TO THE HANGAR. I THINK IT IS IMPORTANT TO POINT OUT THE DECISION MAKING PROCESS VIS A VIS THE DECISION TO RETURN TO SAT VERSUS SOME OTHER LESS CAPABLE ARPT. THE DECISION MUST BE THOUGHT ABOUT PRIOR TO ANY EMER OCCURRENCE AS 'IN THE HEAT OF BATTLE' DECISION PROCESS MAY BE LESS THAN OPTIMUM BECAUSE OF A MULTITUDE OF SENSORY DISTRACTIONS. THE PROCESS MUST INCLUDE THE DANGER PRESENTED TO THE GENERAL PUBLIC AS WELL AS THE CREW. ALL THINGS CONSIDERED THE RETURN TO SAT APPEARED SAFE AS THE ACFT EXHIBITED CONTROLLABILITY WITHIN THE LIMITS FLOWN; AND ONLY THE CHANCE OF HOT BRAKES MAKE THE LNDG OTHER THAN NORMAL. BOTTOM LINE: IN AS MUCH AS POSSIBLE; THINK THROUGH POSSIBLE SCENARIOS BEFORE THEY BECOME REALITY.