Narrative:

While enroute at FL250 my cabin rapidly depressurized. The cabin immediately filled with fog and visibility inside was minimal. Within a few seconds the fog dissipated and I initiated emergency action. I contacted center and I believe I said mayday; mayday; cheyenne nxxx; cabin depressurized. I am not sure if I also informed them of my intentions to initiate an emergency descent; I may have but I do not recall. I then initiated an emergency descent while turning right off the airway. While attempting to don my oxygen mask I removed my headset and instructed my wife and three children to put their oxygen masks on. I initially had difficulty getting my mask on and confirming there was oxygen flow while at the same time flying the airplane and dealing with my passengers. Once my mask was on and oxygen flow confirmed; I replace my headset. During this time I heard a few attempts by center to contact me; including an attempt made by another aircraft in the area acting on the request of center. I also believe that center was advised by the pilot of that aircraft that he believed I had my hands full and would most likely establish contact once my situation had stabilized. Upon reaching what I deemed a safe altitude of approximately 12;000 ft MSL and confirming that my passengers were safe and there were no injuries as a result of the severe pressure changes; I re-established contact with center and was granted clearance back to ZZZ. During that subsequent contact with center I informed them of what happened and that my situation was now under control and that I could be removed from emergency status. I was not instructed to call anyone nor was I requested to file any reports. To confirm that no additional action was required by I me contacted the ZZZ FSDO upon landing and was told that unless requested by the controller a report was not necessary. Inspection of the aircraft revealed that an air duct clamp at the heater forward of the firewall had not been properly tightened by maintenance personnel during an event inspection two weeks earlier.

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Original NASA ASRS Text

Title: PA31 pilot experiences loss of cabin pressurization at FL250 and descends to 12000 feet after declaring an emergency all while helping family members on board.

Narrative: While enroute at FL250 my cabin rapidly depressurized. The cabin immediately filled with fog and visibility inside was minimal. Within a few seconds the fog dissipated and I initiated emergency action. I contacted Center and I believe I said Mayday; Mayday; Cheyenne NXXX; cabin depressurized. I am not sure if I also informed them of my intentions to initiate an emergency descent; I may have but I do not recall. I then initiated an emergency descent while turning right off the airway. While attempting to don my oxygen mask I removed my headset and instructed my wife and three children to put their oxygen masks on. I initially had difficulty getting my mask on and confirming there was oxygen flow while at the same time flying the airplane and dealing with my passengers. Once my mask was on and oxygen flow confirmed; I replace my headset. During this time I heard a few attempts by Center to contact me; including an attempt made by another aircraft in the area acting on the request of Center. I also believe that Center was advised by the pilot of that aircraft that he believed I had my hands full and would most likely establish contact once my situation had stabilized. Upon reaching what I deemed a safe altitude of approximately 12;000 FT MSL and confirming that my passengers were safe and there were no injuries as a result of the severe pressure changes; I re-established contact with Center and was granted clearance back to ZZZ. During that subsequent contact with Center I informed them of what happened and that my situation was now under control and that I could be removed from emergency status. I was not instructed to call anyone nor was I requested to file any reports. To confirm that no additional action was required by I me contacted the ZZZ FSDO upon landing and was told that unless requested by the Controller a report was not necessary. Inspection of the aircraft revealed that an air duct clamp at the heater forward of the firewall had not been properly tightened by maintenance personnel during an event inspection two weeks earlier.

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.