Narrative:

While climbing through FL270; a muffled thump was heard from the aft cabin. We then noticed a loss of cabin pressure with a cabin climb rate of approximately 2700 FPM. Cockpit masks were donned and cabin masks were manually deployed. Center was notified of the cabin depressurization and the need for an immediate descent to 10;000 feet. We descended to 10;000 feet. Qrc and QRH procedures were completed. The passengers were observed with masks on and were informed of the situation and that we would provide more information soon. At 10;000 feet we elected to divert to an airport approximately eighty miles ahead. I notified the passengers that their masks could be removed and of our divert. They seemed calm and ok with our decision.the flight was then completed uneventfully and upon inspection in the rear bay; a significant bleed air leak was detected with the APU running. An almost identical event happened a few years ago in another hawker. I do not recall the tail number. The 'thump' was also heard just prior the depressurization.

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Original NASA ASRS Text

Title: HS-125 series Captain reported experiencing a loss of pressurization. The crew initiated an immediate descent and diverted to a nearby airport.

Narrative: While climbing through FL270; a muffled thump was heard from the aft cabin. We then noticed a loss of cabin pressure with a cabin climb rate of approximately 2700 FPM. Cockpit masks were donned and cabin masks were manually deployed. Center was notified of the cabin depressurization and the need for an immediate descent to 10;000 feet. We descended to 10;000 feet. QRC and QRH procedures were completed. The passengers were observed with masks on and were informed of the situation and that we would provide more information soon. At 10;000 feet we elected to divert to an airport approximately eighty miles ahead. I notified the passengers that their masks could be removed and of our divert. They seemed calm and ok with our decision.The flight was then completed uneventfully and upon inspection in the rear bay; a significant bleed air leak was detected with the APU running. An almost identical event happened a few years ago in another Hawker. I do not recall the tail number. The 'thump' was also heard just prior the depressurization.

Data retrieved from NASA's ASRS site 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.