Narrative:

Situation: compounding MEL's (possibly contradicting each other) and crew, maintenance, dispatch misinterp. #1 MEL: upper and lower yaw damper engage lights inoperative. 1) check rudder position indicator normal. 2) check yaw damper operations normal during taxi. 3) maintain altitude/airspeed for one or both yaw damper inoperative. During taxi out, yaw dampers appeared normal, but upper rudder position indicator did not return to exact center (close but unacceptable). Advised dispatch and maintenance control and returned to gate for local mechanic to MEL rudder position indicator. This was agreed upon by captain (me), dispatch, maintenance control, mechanic and crew. #2 MEL: rudder indicator inoperative. 1) verify rudder deflection visually prior to flight. 2) maintain altitude and airspeed for yaw damper inoperative. Crew complied with MEL and flew to destination. Problem: MEL's do not coordinate and #1 MEL says verify rudder position indicator for normal rudder operations. We missed this possible conflict in the heat of handling the second MEL. During #2 MEL we verified rudder operations visually. The subsequent flight crew refused airplane and brought it to our attention. They may be right. Many people including the local chief pilot and possibly the training department had the same misinterp as we did. I am told the training department changed their mind after 24 hours and agreed with aircraft refusal. Note: had both yaw dampers been inoperative we would have operated under yaw damper inoperative and indicator inoperative with no confusion.

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Original NASA ASRS Text

Title: 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.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.