PLT OF GA ACFT EXPERIENCES TWO CLOSE ENCOUNTERS IN THE CIRCUIT AT BOI.

Narrative

I WAS THE SOLE OCCUPANT OF A LOW WING ACFT (X). I HAD RETURNED TO BOI; MY HOME BASE AFTER A SHORT XCOUNTRY FLT. WHEN I WAS HANDED OFF TO THE TWR; I REQUESTED MULTIPLE TOUCH AND GOES; WHICH WAS APPROVED. ON MY SECOND APCH; I WAS ADVISED THAT I WOULD BE #2; FOLLOWING AN ARROW (Y). AS I WAS APPROX ABEAM THE APCH END OF RWY 10R ON A R DOWNWIND; I OBSERVED A LOW WING ACFT ON WHAT APPEARED TO BE AN APCH. I EXTENDED MY DOWNWIND AND CONTINUED TO WATCH THAT ACFT AS IT DSNDED ON THE APCH. I HAD ALSO HEARD OTHER TFC BEING CLRED TO LAND ON RWY 10L AND WANTED TO BE CERTAIN THAT THE ACFT I WAS WATCHING WAS HEADED FOR RWY 10R. AS I CONTINUED DOWNWIND; IT APPEARED THAT THE ACFT I WAS WATCHING LANDED ON RWY 10R; AT WHICH TIME I ADVISED THE TWR THAT I HAD THE LNDG ACFT IN SIGHT. I WAS CLRED TO TURN BASE AT MY DISCRETION; WHICH I DID ALMOST IMMEDIATELY. I WAS ALSO CLRED TO LAND ON RWY 10R. SHORTLY AFTER I TURNED ON FINAL; THE TWR ADVISED ME TO HOLD MY ALT; WHICH WAS APPROX 3800 FT MSL AT THE TIME. I ACKNOWLEDGED AND MAINTAINED ALT. THE TWR THEN ADVISED ANOTHER ACFT TO TURN 20 DEGS L FOR FINAL TO RWY 10L. I LOOKED OUT AND DOWN FROM MY L WINDOW AND OBSERVED A T-TAILED LOW WING ACFT (Z) BANKING TO THE L BELOW AND SLIGHTLY BEHIND ME. I ESTIMATED THE ACFT WAS ABOUT 300 FT BELOW ME AND ONLY SLIGHTLY BEHIND. I WAS THEN CLRED TO DSND FOR LNDG. AS I WAS DSNDING; THE TWR CALLED A CHEROKEE (Y); WHICH HAD PERFORMED A TOUCH AND GO BEHIND ME ON MY FIRST LNDG. I HAD PREVIOUSLY HEARD THE TWR TELL THAT ACFT TO EXTEND HIS DOWNWIND. THE TWR CALLED THE CHEROKEE AND ASKED IF HE HAD TURNED BASE; WHICH HE ACKNOWLEDGED. THE TWR THEN TOLD THE CHEROKEE TO TURN TO A S HEADING AND CONTINUE DOWNWIND. I LOOKED TO MY R AND SAW THE CHEROKEE TURNING AWAY FROM ME AT A DISTANCE WHICH I ESTIMATED TO BE 700-800 FT AND AT APPROX THE SAME ALT. I THEN CONTINUED TO A TOUCH AND GO LNDG. AFTER COMPLETING A THIRD LNDG; I PARKED MY AIRPLANE. ALTHOUGH I HAD NOT BEEN ASKED TO CALL THE TWR; AFTER THINKING ABOUT THE SIT; I DECIDED TO CALL TO FIND OUT WHAT HAD HAPPENED. THE TWR SUPVR ADVISED ME THAT HE WAS ONLY AWARE OF THE SECOND SIT. APPARENTLY; THE CHEROKEE HAD NOT ACKNOWLEDGED THE FIRST INSTRUCTION TO CONTINUE DOWNWIND; AND HAD INSTEAD TURNED BASE. THE SUPVR EXPLAINED THAT THE CTLR ON DUTY WAS RELATIVELY NEW; AND WAS NOT USED TO WORKING HVY TFC. HE APOLOGIZED FOR THE INCIDENT AND STATED THAT THEY (THE TWR) SHOULD HAVE BEEN PROVIDING BETTER SVC. I TOLD HIM MY INTENT WAS JUST TO FIND OUT WHAT HAD HAPPENED AND TO MAKE SURE I HAD NOT DONE SOMETHING WRONG. HE TOLD ME THAT IT DID NOT APPEAR THAT I HAD DONE ANYTHING WRONG; BUT RATHER IT WAS AN ERROR IN THE TWR. HE STATED THAT HE WOULD LOOK INTO THE FIRST INCIDENT; WHICH HE WAS NOT FAMILIAR WITH; AND CALL ME BACK WITHIN 10 MINS IF HE NEEDED ANY MORE INFO FROM ME OR HAD ANY CONCERNS. HE ALSO STATED THAT HE WOULD NOT CALL UNLESS THERE WAS A NEED TO DO SO. I NEVER HEARD BACK FROM HIM. MY PERCEPTION WAS THAT THE FIRST INCIDENT MAY HAVE BEEN CAUSED BY A PLT WHO OVERSHOT THE APCH PATH TO RWY 10L. THAT PERCEPTION IS BASED ON RADIO TFC WHICH INDICATED TO THAT PLT TO TURN BACK TO THE APCH FOR RWY 10L; RATHER THAN HAVING ONE OF US BREAK OFF THE APCH TO RWY 10R.