AILERON CTL HAS MUSHY FEEL.

Narrative

WE STARTED THE TRIP WITH AN ACFT BEING BROUGHT TO US FROM THE MAINT HANGAR. AFTER SEVERAL DELAYS DUE TO VARIOUS MECHANICAL PROBS; WE WERE FINALLY UNDERWAY. THE CAPT HAD JUST COME BACK FROM A 3 WK VACATION SO WE DECIDED I WOULD TAKE THE FIRST LEG. SHORTLY AFTER ROTATION OFF RWY 1R; WHILE IN THE TURN TO A 030 DEG HDG; I NOTICED A 'MUSHINESS' IN THE ROLL CTLS. I TOLD THE CAPT THAT THE CTLS FELT WEIRD; AND HE ASKED ME TO ELABORATE. IT WAS VERY DIFFICULT FOR ME TO DESCRIBE; BUT I THREW OUT A FEW WORDS LIKE 'FEELS LIKE I'M FLYING A C152; THERE'S A LOT OF PLAY IN THE TURNING MOTION; IT DOESN'T RESPOND IMMEDIATELY TO INPUTS.' ONCE WE GOT UP TO A HIGHER ALT; APPROX 4000 FT THE CAPT TOOK THE CTL WHEEL AN ROLLED IT BACK AND FORTH A FEW TIMES. HE GAVE IT BACK SAYING 'WELL; I'VE BEEN ON VACATION FOR A WHILE.' I TOOK THIS TO MEAN HE WAS DIPLOMATICALLY TRYING TO TELL ME HE COULDN'T FEEL ANY PROBS. I THEN THOUGHT THAT PERHAPS THERE WAS SOME MINOR PROB IN JUST MY CTL COLUMN; AND THE FLT CONTINUED NORMALLY TO OUR DEST. THE CAPT TOOK THE NEXT LEG AND DURING CLBOUT HE; TOO; MENTIONED THAT THE CTLS DID INDEED FEEL STRANGE. UP AT CRUISE ALT HE STUDIED THE ACFT'S MAINT HISTORY AND DISCOVERED AN AILERON PCU HAD BEEN RECENTLY REPLACED. WE SPECULATED THAT EITHER THE NEW PCU WAS FAULTY OR THE FEEL COMPUTER HAD A MALFUNCTION. THE CAPT THEN CALLED MAINT AND WE WERE GIVEN ANOTHER ACFT IN SFO. THE FOLLOWING DAY; BEFORE WE STARTED THE DAY'S FLYING; THE CAPT LOOKED UP WHAT MAINT HAD BEEN DONE ON THE MUSHY-FLT-CTLS ACFT. WE WERE DISMAYED TO READ THAT ENGINEERING TOOK THE PLANE ON A TEST FLT AND FOUND THE AILERONS TO BE PRIMARILY INOP. THIS PUZZLED ME SINCE I HAD VERIFIED AILERON MOVEMENT DURING THE CTL CHKS ON THE GND BEFORE EACH LEG. THE CAPT SUGGESTED THAT MOVEMENT WAS DECREASED UNDER AERODYNAMIC LOADS. AFTER FINISHING THE TRIP AND RETURNING HOME; THE CAPT CALLED ENGINEERING FOR SOME FOLLOW-UP ON THE ACFT. THE AILERON PCU WAS EVENTUALLY REPLACED AFTER OTHER REPAIRS HAD BEEN INEFFECTIVE; AND THE ACFT RETURNED TO THE LINE UNDER A 1 WK MAINT WATCH. BESIDES MY CONCERN OVER THE 'WHAT IFS' OF THE WHOLE AFFAIR -- WHAT IF WE HAD LOST AN ENG DURING TKOF ROLL WITH A STRONG XWIND; WHAT IF WE HAD ENCOUNTERED WAKE TURB ON SHORT FINAL -- I ALSO CAN'T HELP WONDERING IF FAULTY AILERON PCU'S WERE CONTRIBUTING FACTOR IN THE COS AND PIT ACCIDENTS.