AN INSTRUCTOR AND STUDENT PILOT APCHING MER WERE GIVEN CONFUSING TFC AND SEQUENCE INFO BY A TRAINEE CONTROLLER CAUSING AN NMAC IN THE TFC PATTERN.

Narrative

MY STUDENT AND I DEPARTED AFTER SOME LNDG PRACTICE TO RETURN TO OUR HOME BASE (MER). UPON CHKING IN WITH TWR; WE WERE TOLD TO ENTER A L DOWNWIND FOR RWY 31. NORMALLY A R DOWNWIND IS USED FOR RWY 31 AT CASTLE; BUT SOMETIMES WE USE THE L DOWNWIND WHEN IT IS CONVENIENT. ONCE WE STARTED TO GET ABEAM THE DEP END; A SENECA (OR SEMINOLE; BUT I BELIEVE SENECA) CHKED IN '3.5 MI TO THE W.' I LOOKED DOWN AT MY COMPASS AND SAW W WAS BEHIND US; SLIGHTLY TO THE R OF OUR TAIL. I THOUGHT 'HE WILL BE SEQUENCED BEHIND US.' KEY PHRASE HERE IS 'I THOUGHT.' WE THEN PROCEEDED ON THE L DOWNWIND; AND CONTINUED TO MONITOR THE RADIO CALLS. AT ONE POINT; TWR CALLED US AND TOLD US WE WERE #2 (AS MY STUDENT LATER REITERATED) TFC WAS 1 O'CLOCK POS; A CESSNA. NOW INTERESTINGLY ENOUGH; THE TWR MEANT TO SAY WE WERE FOLLOWING THE SENECA; AND IN REALITY WE WERE NOW #3; BECAUSE THERE ACTUALLY WAS A CESSNA TURNING A R BASE. IN HINDSIGHT; I REALIZE I TRANSPOSED THE TWR GIVEN DIRECTION OF 1 O'CLOCK POS WITH THE CESSNA WHICH WAS IN OUR 11 O'CLOCK POS. BUT WE WERE TOLD WE WERE #2 BEHIND A CESSNA; AND WHEN I LOOKED OUT AND SAW A CESSNA; THAT'S ALL I NEEDED. AT THE 45 DEG POINT; MY STUDENT TURNED BASE. AT THAT POINT; MASSIVE CONFUSION REIGNED. THE TWR TOLD US TO MAKE A R 360 DEG TURN. I TOOK CTL FROM MY STUDENT; CONFIRMED THE R 360 DEG TURN WITH TWR; AT WHICH POINT HE SAID NO. WE RE-ENTERED THE L BASE; AT WHICH POINT I HEARD ANOTHER CTLR COME ON FREQ. HE ADMONISHED US TO 'FOLLOW DIRECTIONS;' AND TOLD US THE SENECA'S REAL POS. I IMMEDIATELY REALIZED WE WERE TO FOLLOW THE SENECA; WHICH WAS NOW OFF TO OUR R. I ROLLED R; SAW THE SENECA; WHICH WAS ABOVE US; TO OUR R; DSNDING; AND ROLLING INTO US. THERE WAS A FEW SECONDS WHERE I WAS NOT SURE THAT I HAD MANY OPTIONS AS ALL OF THEM SEEMED TO PUT US ON A COLLISION COURSE. I FINALLY ROLLED HARD R (STALL WARNING BLARING) AND WE MADE IT; ALBEIT VERY CLOSE; MAYBE 200-300 FT SEPARATION. I DON'T KNOW IF THE SENECA SAW US. WE THEN FOLLOWED BEHIND HIM. I CALLED THE TWR AFTERWARDS (THEY DID NOT ASK ME; I CALLED ON MY OWN) AND WAS TOLD IT WAS A TRAINEE CTLR; SO WE WERE TOLD WE WERE #2 WHEN WE WERE #3 AND TOLD TO FOLLOW A CESSNA WHEN IT WAS A SENECA. ALL IN ALL; I HAVE NO HARD FEELINGS TOWARD THE CTLRS ABOUT THIS SITUATION; BUT FELT I NEEDED TO WRITE IN ABOUT THIS FOR ONE SPECIFIC REASON -- THIS PLACE NEEDS RADAR! THIS TWR WAS JUST PUT INTO OP A COUPLE OF MONTHS AGO AND THESE CTLRS SO FAR HAVE BEEN DOING A GREAT JOB. BUT THEY HAVE A TOUGH ONE; WITH 7-8 ACFT IN THE PATTERN AT ANY ONE TIME. ANYTHING FROM A TAIL DRAGGER TO A C130 AND DC8. AND I HEAR THAT IT'S POSSIBLE THAT MER MAY LOSE FUNDING FOR THE TWR (WE WERE TOLD THIS BY THE ARPT MGMNT AND OTHERS). NO! THIS TWR NEEDS TO BE HERE AND IT NEEDS RADAR! KEEP IN MIND THAT MCE IS JUST A FEW MI AWAY (HVY STUDENT TFC ALONG WITH B1900 AND CPR JET TFC) AND SO IS TURLOCK (O15); ALTHOUGH TURLOCK IS FAIRLY QUIET. IT IS MIND BOGGLING TO THINK THAT THIS PIECE OF AIRSPACE IS BEING MANAGED WITH BINOCULARS.