A EMBRAER 145 ON APCH AT 4000 SELECTED FLAPS 9 AND RECEIVED 'FLAPS FAIL' EICAS MSG. SELECTED FLAPS 22; RECEIVED FLAPS 22; BUT WARNINGS REMAINED.

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ON NORMAL DSCNT INTO ZZZ WE SELECTED FLAPS 9 (WE WERE IN A CLEAN CONFIGURATION) AT APPROX 210 KIAS. WE RECEIVED THE 'FLAP FAIL' EICAS MSG AND FLAP FEEDBACK INDICATOR INDICATED AN AMBER DASH. THE BACKUP INDICATOR ON THE RMU ENG PAGE ALSO INDICATED DASHES. WE CYCLED THE FLAP SELECTOR HANDLE TWICE; AND THOUGH NO EICAS MSG'S EXTINGUISHED; WE DID RECEIVE AN ADDITIONAL MSG 'FLAP LOW SPD' ON THE SECOND ATTEMPT. WE TOOK THIS AS A GOOD SIGN AND ASKED THE FA TO VERIFY FLAP MOVEMENT. SHE VERIFIED BOTH FLAPS INDICATING 9 VISUALLY. WE THEN SELECTED FLAPS 22. THE FA ONE AGAIN VERIFIED THE 22 SHOWING ON EACH FLAP OUTSIDE. WE ALSO FELT THE ASSOCIATED RUMBLE THAT IS SO FAMILIAR WITH FLAPS 22. AN UNEVENTFUL LANDING WAS MADE AT FLAPS 22 (NOT A NORMAL LNDG FLAP SETTING) AFTER ALL PERTINENT CHKLISTS WERE COMPLETED. THIS WAS MY FOURTH FLAP ABNORMALITY IN THE EMB 145; PRECEDED BY THREE COMPLETE FLAP FAILURES. ALL FOUR INCIDENTS HAVE OCCURRED WITHIN THE LAST NINE MONTHS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THIS WAS THE FOURTH FLAP PROB IN THE EMBRAER IN 9 MONTHS WITH THREE OF THE FAILURES BEING COMPLETE FLAP FAILURES. THE RPTR SAID IN ONE LOGBOOK; OF THE LAST FOURTEEN PAGES; ELEVEN PAGES HAD FLAP WRITE-UPS. THE RPTR STATED THE PROB SEEMS TO BE CAUSED BY THE VELOCITY SENSORS LOCATED ON THE JACKSCREWS WHICH SENSE FLAP DISPLACEMENT AND RATE OF MOVEMENT GIVING FALSE ASYMMETRIC INDICATIONS. THE RPTR SAID ANOTHER PROB SEEMS TO BE WHEN MAINT WORKS A WRITE UP; SUCH AS WE HAD; THEY POWER DOWN THE AIRPLANE WAIT A FEW MINS; REPOWER THE AIRPLANE AND MAKE A BITE TEST OF THE SYS. THE RPTR SAID IF THE SYS BITE TESTS OK IT IS SIGNED OFF PER THE MAINT MANUAL PROCS. THE RPTR STATED WITH ALL THE 'REBOOTING' OF THE COMPUTERS NOTHING GETS FIXED.