Narrative:

Initially we were going to be dispatched with forward cargo heat inoperative due to an overheat warning on the previous flight. Dangerous goods 'explosives' were loaded in the forward cargo anyway. Later the mechanic was surprised that occurred because he did not tell the loaders it was going to be signed off; but he subsequently did sign the system off assuming the 100 degree plus day was the cause. Taxiing out we received an 'overheat condition' in the forward cargo pit on the taxi to the runway. Since it is impossible to discern what the 'explosives' actually are with current procedures and determine if it could be ignited by excessive temperatures; we taxied back to the gate to offload the hazmat.

Google
 

Original NASA ASRS Text

Title: B767 Captain reports being dispatched with hazmat; explosives; in the forward cargo compartment which had a recent history of overheat warnings. The warning repeats and the flight returns to the gate to offload the hazmat.

Narrative: Initially we were going to be dispatched with forward cargo heat inoperative due to an overheat warning on the previous flight. Dangerous Goods 'Explosives' were loaded in the forward cargo anyway. Later the mechanic was surprised that occurred because he did not tell the loaders it was going to be signed off; but he subsequently did sign the system off assuming the 100 degree plus day was the cause. Taxiing out we received an 'Overheat Condition' in the forward cargo pit on the taxi to the runway. Since it is impossible to discern what the 'Explosives' actually are with current procedures and determine if it could be ignited by excessive temperatures; we taxied back to the gate to offload the hazmat.

Data retrieved from NASA's ASRS site as of April 2012 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.