B727 IS FLOWN WITH 2 MEL'S IN CONFLICT WITH EACH OTHER OUT OF CLE; OH.

Narrative

SIT: COMPOUNDING MEL'S (POSSIBLY CONTRADICTING EACH OTHER) AND CREW; MAINT; DISPATCH MISINTERP. #1 MEL: UPPER AND LOWER YAW DAMPER ENGAGE LIGHTS INOP. 1) CHK RUDDER POS INDICATOR NORMAL. 2) CHK YAW DAMPER OPS NORMAL DURING TAXI. 3) MAINTAIN ALT/AIRSPD FOR ONE OR BOTH YAW DAMPER INOP. DURING TAXI OUT; YAW DAMPERS APPEARED NORMAL; BUT UPPER RUDDER POS INDICATOR DID NOT RETURN TO EXACT CTR (CLOSE BUT UNACCEPTABLE). ADVISED DISPATCH AND MAINT CTL AND RETURNED TO GATE FOR LCL MECH TO MEL RUDDER POS INDICATOR. THIS WAS AGREED UPON BY CAPT (ME); DISPATCH; MAINT CTL; MECH AND CREW. #2 MEL: RUDDER INDICATOR INOP. 1) VERIFY RUDDER DEFLECTION VISUALLY PRIOR TO FLT. 2) MAINTAIN ALT AND AIRSPD FOR YAW DAMPER INOP. CREW COMPLIED WITH MEL AND FLEW TO DEST. PROB: MEL'S DO NOT COORDINATE AND #1 MEL SAYS VERIFY RUDDER POS INDICATOR FOR NORMAL RUDDER OPS. WE MISSED THIS POSSIBLE CONFLICT IN THE HEAT OF HANDLING THE SECOND MEL. DURING #2 MEL WE VERIFIED RUDDER OPS VISUALLY. THE SUBSEQUENT FLC REFUSED AIRPLANE AND BROUGHT IT TO OUR ATTN. THEY MAY BE RIGHT. MANY PEOPLE INCLUDING THE LCL CHIEF PLT AND POSSIBLY THE TRAINING DEPT HAD THE SAME MISINTERP AS WE DID. I AM TOLD THE TRAINING DEPT CHANGED THEIR MIND AFTER 24 HRS AND AGREED WITH ACFT REFUSAL. NOTE: HAD BOTH YAW DAMPERS BEEN INOP WE WOULD HAVE OPERATED UNDER YAW DAMPER INOP AND INDICATOR INOP WITH NO CONFUSION.