A MD80 Captain refused a single pack aircraft during a high outside air temperature cycle because the aircraft's interior temperature would reach an unsafe level for the passengers and crew. The aircraft was removed from service.

Narrative

Logbook indicates single pack placarded. Cabin temperature with conditioned air indicated 92 degrees Fahrenheit; OAT 36 degrees Celsius (97 F); cockpit temperature measured by thermometer 95F. Conditioned airflow weak - clearly; as soon as ground air was disconnected for pushback; with one air conditioning pack operational the aircraft temperature would soar quickly during our takeoff. Also; the altitude limitation plus short flight time would ensure that the interior would never sufficiently cool and the destination temperature was also 36 degrees Celsius. This clearly is a danger to crew and passengers; particularly the very young; very old and those with underlying medical concerns. Flight Operations are aware of the aging MD80 fleet and single-pack ops risks and predictable results. It is unsafe to plan and dispatch aircraft this way. I put an entry into the logbook: 'Unable to cool cabin and cockpit below 92 degrees with single pack and ground air - unsafe for crew or passengers.' Maintenance evaluated the situation and took the aircraft out of service. Clearly; it should have never been IN SERVICE; according to maintenance; which confirms my experience and my assessment as well. Why are the Operations Managers and Fleet Staff still allowing this single-pack risk under these conditions? Do not dispatch MD80's with a single-pack when the OAT is over 80. We know the risk created when we so; so why do the Operations and Fleet Staff continue this dangerous practice?