B757 Captain reports being dispatched with the cockpit auto temperature controller inoperative and instructions on how to regulate cockpit temperature should it become too warm. The temperature did become too warm on climbout and attempts to regulate it were unsuccessful. Flight diverted for maintenance.
Synopsis
B757 Captain reports being dispatched with the cockpit auto temperature controller inoperative and instructions on how to regulate cockpit temperature should it become too warm. The temperature did become too warm on climbout and attempts to regulate it were unsuccessful. Flight diverted for maintenance.
Narrative
Upon reviewing the Log History and Maintenance Write-ups of aircraft the First Officer and I noted a write up concerning the cockpit auto temperature controller. There was an MEL card stating that AUTO was inoperative; and the system was to be run in the OFF position. Also there was a statement that the inbound crew at one point were unable to control the temperature of the cockpit and it had reached 98F. The MEL Placard stated that if the cockpit got too warm that we were to turn off the trim air; and the entire aircraft would regulate to a median temperature of about 70F. Our takeoff and departure was normal. Climbing out of FL230 the cockpit temperature rose to about 98 - 99F. The trim air was turned off; but the temperature continued to rise. The Right Recirc fan was also turned off. With the temperature in the cockpit around 100 I decided to divert the flight. An ATC Clearance was attained; and we turned toward our divert airport. Descending we experienced the RIGHT PACK OFF EICAS; followed in quick order R PACK TEMP; R RECIRC FAN; TRIM AIR; AFT CABIN TEMP; FWD CABIN TEMP and FLT DECK TEMP EICAS messages. With the Left Cockpit Auto controller malfunctioning; and the Right Pack OFF; I suggested that the APU be started; and a timely descent down to 10;000 MSL Which was accomplished by First Officer. Landed at a gross weight of 211;100 LBS. First Officer made an extremely soft touch down. We rolled to the end; without event. We logged the overweight landing. Upon taxi in a Line Maintenance Technician expressed that we could have just selected AUTO for the Cockpit temperature control; which he did. Upon so doing; the cockpit and entire aircraft system worked excellently. We explained to him that it would have been in violation of FAR's to reactivate a system which was MEL'ed INOP.
Second reporter narrative
During climbout we could not control the flight deck temperature. It reached 98 degrees and stayed there most of the time. The RT Pack controller was to be run in STANDBY; as the auto controller was MEL'ed inop. The prior crew had written up the system on the way in. I followed the MEL guidelines and ran the pack in STANDBY and also tried turning off the trim air; all to no avail. We even turned off the RT Recirc Fan to attempt to get cool ambient air from the atmosphere through the system. The other 2 zones; first class and the economy cabin were controllable and were comfortable for the most part. The Captain and I decided to turn around and have Maintenance further evaluate the system. We then had the RT Pack trip and subsequently descended on down to 10000 FT. Our gross weight was about 211.2 lbs. We taxied up to the gate and off loaded our passengers and waited for another aircraft to become available. When the three mechanics arrived in the cockpit one of them took the RT Pack selector switch to AUTO and the system seemed to work normally. He then made a comment to me as to why I did not run the pack in AUTO. I told him that I complied with the MEL card and ran the pack in standby as was called for. I told him pilots were not allowed to deviate from prescribed MEL guidelines. He seemed to understand my reasoning. Upon later talking with the Flight Office I learned this aircraft went out several hours later with a new cockpit crew and developed the same problem we had; only to a much worse degree. My concern is with the maintenance being done on these airplanes. I had a similar encounter this year taking an extended delay of over 6 hours due to maintenance issues. It took all night to resolve a maintenance issue. These 2 incidents are leaving me with questions involving how completely we are conducting our maintenance at this company.
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Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.