B737-400 ACFT. RPTR CAPT PERCEIVES A PROB WHEN LNDG IN XWIND. JUST AFTER TOUCHDOWN WITH WING DOWN XWIND; RPTR BELIEVES THAT THE ACFT LURCHES AND SQUATS IN THE DIRECTION OF THE XWIND. THE AIRLINE MAINT WAS UNABLE TO FIND A PROB.

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THIS ASRS CONCERNS A SIT THAT INVOLVED AN ILL-DEFINED; AMBIGUOUS EQUIP MALFUNCTION THAT THE FLC GRADUALLY PERCEIVED OVER A SERIES OF FLTS. SPECIFICALLY; I RAISE THE DILEMMA OF WHAT IS THE PLT'S RESPONSIBILITY IN RELAYING TO THE MAINT DEPT A COGENT WRITE-UP OF A NEAR- INTANGIBLE MALFUNCTION THAT MAY WELL HAVE EXISTED; BUT WAS NOT RECOGNIZED; FOR SEVERAL LEGS; ESPECIALLY WHEN THE PLT'S PERCEPTION OF PRIOR LEGS MAY HAVE A DIRECT BEARING ON THE MAINT DEPT'S ABILITY TO TROUBLESHOOT. I EXPERIENCED THE SIT WHERE AN EVENT SUDDENLY CRYSTALLIZED MY PERCEPTION; AND I COULD SAY 'WE HAVE FELT THIS BEFORE;' BUT DID NOT RECOGNIZE IT AT THE TIME. I RECENTLY FLEW A B757-400 ON A SERIES OF 3 FLTS: ANCHORAGE-KODIAK- ANCHORAGE-SEATTLE. I FLEW THE FIRST LEG INTO KODIAK. THE APCH WAS MADE IN VMC WITH STRONG; GUSTING XWINDS AND CONTINUOUS LIGHT; AND OCCASIONALLY; MODERATE TURB. I FLEW THE PLANE TO A FIRM XCTLED TOUCHDOWN. DURING ROLLOUT THE COPLT ASKED IF IT HAD FELT AS THOUGH THE PLANE HAD SQUATTED TO THE R JUST AS IT TOUCHED DOWN. I HAD NOT PERCEIVED THAT; BUT I HAD BEEN FIGHTING TO KEEP THE R WING DOWN DURING THE TOUCHDOWN. WE DECIDED TO CAREFULLY INSPECT THE GEAR; STRUTS; ETC; BUT NO ABNORMALITY WAS FOUND DURING THE WALKAROUND. THE COPLT FLEW THE 2ND LEG BACK TO ANCHORAGE. AFTER AN UNEVENTFUL FLT AND A VISUAL APCH A SMOOTH TOUCHDOWN WAS MADE. WINDS WERE NEAR CALM. WE BOTH COMMENTED ON WHAT A SMOOTH LNDG IT WAS; ESPECIALLY CONSIDERING THE PREVIOUS LNDG AT KODIAK. I FLEW THE 3RD LEG TO SEATTLE. I SHOT AN ILS AND LANDED AT NIGHT; IN RAIN; WITH ANOTHER R HAND XWIND. THE SMOOTH TOUCHDOWN WAS IMMEDIATELY FOLLOWED BY A PRONOUNCED AND ABRUPT LURCH OR SQUAT TO THE R. THE EVENT WAS OVER IN LESS THAN A SECOND. IT BECAME INSTANTLY CLR TO BOTH OF US THAT WE HAD INDEED FELT SOMETHING SIMILAR IN KODIAK; BUT THAT IT HAD BEEN MASKED BY THE TURB AND GUSTS. IN RETROSPECT; WE MAY HAVE EXPERIENCED A VERY SUBTLE VERSION OF IT IN ANCHORAGE; BUT IT WAS SO SMOOTH THAT IT DID NOT AROUSE OUR SUSPICIONS. I WROTE A DETAILED DESCRIPTION OF THE SEATTLE LNDG IN THE MAINT LOGBOOK AND QUESTIONED WHETHER OR NOT THERE WAS AN ASYMMETRIC GND SPOILER DEPLOYMENT; OR A SQUAT SWITCH PROB. I SPECIFICALLY MENTIONED THAT WE HAD MADE 3 LNDGS WITH THE ACFT AND HAD FELT THIS PHENOMENON. I DID NOT ELABORATE; BUT I WANTED MAINT TO KNOW THAT THIS WAS NOT A RANDOM FLUKE ATTRIBUTABLE TO PLT TECHNIQUE ON A RAINY; WINDY; NIGHT LNDG. THERE WAS DEFINITELY SOMETHING WRONG WITH THE ACFT; AND IT HAD TAKEN 3 LNDGS FOR US TO EVEN REALIZE IT. AFTER OUR STARTLING EXPERIENCE IN SEATTLE; I WAS VERY MUCH CONCERNED ABOUT A 'CANNOT DUPLICATE; OPS CHK NORMAL' MAINT SIGN-OFF; WHICH WOULD PUT THE ACFT IN ANOTHER CREW'S UNSUSPECTING HANDS.