Narrative:

The CL65 has 2 air conditioning packs, 1 primarily for the cockpit, and 1 primarily for the cabin. Each pack can be controled either manually or automatically to set the desired outflow temperature. If one pack is inoperative, the remaining pack can adequately pressurize and ventilate the entire aircraft, up to a maximum altitude of FL250. My crew and I were on a 'continuous duty' assignment to tul and back that reported at XA45 and was scheduled to release at XN17, the next morning, without a legal rest period in between. That was legal because our total duty time was scheduled to be 13 hours 32 mins. Contractually, the company can only expect us to put in 14 hours with a pilot option of 15 hours. So, the scheduling pressure could quickly mount if a paperwork or mechanical problem occurred. When we landed at tul, the cabin pack outlet temperature became unctlably hot. Neither automatic, nor manual, modes were effective. The pack was turned off and deferred by maintenance control. The next morning, we started the APU and turned on the cockpit pack. Automatic mode had no effect and the corresponding circuit breaker was pulled. I wrote the problem in the maintenance log and called maintenance control. The mechanic directed me to reset the circuit breaker and void my write-up. I refused because this was contrary to our company policy. The mechanic said contract maintenance would be called to check it out. Meanwhile, our dispatcher had mistakenly filed our return flight above FL250. So, the dispatch release had to be amended and the fuel numbers recalculated. Then maintenance informed me that no mechanic was available. So, the automatic mode on the cabin pack was deferred on the phone with maintenance control. The controller assured me and dispatch that this deferral would not interact negatively with the previous cabin pack deferral. So, with the deferrals and amendments addressed, we eventually departed tul. Only after we had departed did I have the spare time to look up the MEL under which the automatic control on the cockpit pack was deferred. I studied its interaction with the MEL under which the cabin pack was deferred. The 2 do not appear to mesh well. The company contends that the 2 deferrals are compatible, but the union feels otherwise and intends to pursue the issue at a somewhat later date. The union and the company are also pursuing the issue of maintenance control pushing pilots to reset circuit breakers and void write-ups. In the future, I will examine the MEL verbiage at the time of the deferral to ensure its legality, instead of relying on maintenance control, regardless of scheduling pressures.

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Original NASA ASRS Text

Title: CL65 CREW RPTED THE ACR MAINT CTLR APPROVED FLT WITH 1 PACK MEL'ED INOP AND TEMP CTL PROBS WITH THE OTHER PACK.

Narrative: THE CL65 HAS 2 AIR CONDITIONING PACKS, 1 PRIMARILY FOR THE COCKPIT, AND 1 PRIMARILY FOR THE CABIN. EACH PACK CAN BE CTLED EITHER MANUALLY OR AUTOMATICALLY TO SET THE DESIRED OUTFLOW TEMP. IF ONE PACK IS INOP, THE REMAINING PACK CAN ADEQUATELY PRESSURIZE AND VENTILATE THE ENTIRE ACFT, UP TO A MAX ALT OF FL250. MY CREW AND I WERE ON A 'CONTINUOUS DUTY' ASSIGNMENT TO TUL AND BACK THAT RPTED AT XA45 AND WAS SCHEDULED TO RELEASE AT XN17, THE NEXT MORNING, WITHOUT A LEGAL REST PERIOD IN BTWN. THAT WAS LEGAL BECAUSE OUR TOTAL DUTY TIME WAS SCHEDULED TO BE 13 HRS 32 MINS. CONTRACTUALLY, THE COMPANY CAN ONLY EXPECT US TO PUT IN 14 HRS WITH A PLT OPTION OF 15 HRS. SO, THE SCHEDULING PRESSURE COULD QUICKLY MOUNT IF A PAPERWORK OR MECHANICAL PROB OCCURRED. WHEN WE LANDED AT TUL, THE CABIN PACK OUTLET TEMP BECAME UNCTLABLY HOT. NEITHER AUTO, NOR MANUAL, MODES WERE EFFECTIVE. THE PACK WAS TURNED OFF AND DEFERRED BY MAINT CTL. THE NEXT MORNING, WE STARTED THE APU AND TURNED ON THE COCKPIT PACK. AUTO MODE HAD NO EFFECT AND THE CORRESPONDING CIRCUIT BREAKER WAS PULLED. I WROTE THE PROB IN THE MAINT LOG AND CALLED MAINT CTL. THE MECH DIRECTED ME TO RESET THE CIRCUIT BREAKER AND VOID MY WRITE-UP. I REFUSED BECAUSE THIS WAS CONTRARY TO OUR COMPANY POLICY. THE MECH SAID CONTRACT MAINT WOULD BE CALLED TO CHK IT OUT. MEANWHILE, OUR DISPATCHER HAD MISTAKENLY FILED OUR RETURN FLT ABOVE FL250. SO, THE DISPATCH RELEASE HAD TO BE AMENDED AND THE FUEL NUMBERS RECALCULATED. THEN MAINT INFORMED ME THAT NO MECH WAS AVAILABLE. SO, THE AUTO MODE ON THE CABIN PACK WAS DEFERRED ON THE PHONE WITH MAINT CTL. THE CTLR ASSURED ME AND DISPATCH THAT THIS DEFERRAL WOULD NOT INTERACT NEGATIVELY WITH THE PREVIOUS CABIN PACK DEFERRAL. SO, WITH THE DEFERRALS AND AMENDMENTS ADDRESSED, WE EVENTUALLY DEPARTED TUL. ONLY AFTER WE HAD DEPARTED DID I HAVE THE SPARE TIME TO LOOK UP THE MEL UNDER WHICH THE AUTO CTL ON THE COCKPIT PACK WAS DEFERRED. I STUDIED ITS INTERACTION WITH THE MEL UNDER WHICH THE CABIN PACK WAS DEFERRED. THE 2 DO NOT APPEAR TO MESH WELL. THE COMPANY CONTENDS THAT THE 2 DEFERRALS ARE COMPATIBLE, BUT THE UNION FEELS OTHERWISE AND INTENDS TO PURSUE THE ISSUE AT A SOMEWHAT LATER DATE. THE UNION AND THE COMPANY ARE ALSO PURSUING THE ISSUE OF MAINT CTL PUSHING PLTS TO RESET CIRCUIT BREAKERS AND VOID WRITE-UPS. IN THE FUTURE, I WILL EXAMINE THE MEL VERBIAGE AT THE TIME OF THE DEFERRAL TO ENSURE ITS LEGALITY, INSTEAD OF RELYING ON MAINT CTL, REGARDLESS OF SCHEDULING PRESSURES.

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.