What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
On 11/05/12, a/c N990GC a lear 31 departed ksua, while climbing to 43,000FT MSL (mean sea level), and upon passing through 36,000FT MSL, it experienced an abrupt loss of cabin pressure, the cabin VSI (vertical speed indicator) immediately showed over 6,000FT/MIN cabin altitude rise, emergency decent procedures were initiated, the emergency pressurization system stabilized around 20,000FT MSL, and the aircraft returned to ksua. The aircraft had just completed a 12 year inspection at precision jet (P0ZR) in Stuart, FL. A lear qualified test pilot performed the first post inspection flight, there were no issues. The second flight (with the owner and co-pilot) encountered the issues described above. Upon inspection, it was noticed that the leak originated from the air conditioning low pressure line as it passes through the aft pressure bulkhead. The sealant was fully removed, the line was cleaned, then fully resealed. Ground test and subsequent flight test found to be normal. No others issues have surfaced since. The air conditioning low pressure line is not removed during the removal and installation of the air conditioning pack assembly (required for the 12 year inspection), but it is repositioned to facilitate the task, this would allow any old sealant which may have lost its pliability to crack. Recommendation: replace the sealant on the air conditioner low pressure line as it runs through the aft pressure bulkhead after reinstallation of the air conditioning pack during the 12 year inspection. Precision jet submitted an SDR on subject low pressure line sealant issue.
As the FAA filed it
ON 11/05/12, A/C N990GC A LEAR 31 DEPARTED KSUA, WHILE CLIMBING TO 43,000FT MSL (MEAN SEA LEVEL), AND UPON PASSING THROUGH 36,000FT MSL, IT EXPERIENCED AN ABRUPT LOSS OF CABIN PRESSURE, THE CABIN VSI (VERTICAL SPEED INDICATOR) IMMEDIATELY SHOWED OVER 6,000FT/MIN CABIN ALTITUDE RISE, EMERGENCY DECENT PROCEDURES WERE INITIATED, THE EMERGENCY PRESSURIZATION SYSTEM STABILIZED AROUND 20,000FT MSL, AND THE AIRCRAFT RETURNED TO KSUA.THE AIRCRAFT HAD JUST COMPLETED A 12 YEAR INSPECTION AT PRECISION JET (P0ZR) IN STUART, FL. A LEAR QUALIFIED TEST PILOT PERFORMED THE FIRST POST INSPECTION FLIGHT, THERE WERE NO ISSUES. THE SECOND FLIGHT (WITH THE OWNER AND CO-PILOT) ENCOUNTERED THE ISSUES DESCRIBED ABOVE. UPON INSPECTION, IT WAS NOTICED THAT THE LEAK ORIGINATED FROM THE AIR CONDITIONING LOW PRESSURE LINE AS IT PASSES THROUGH THE AFT PRESSURE BULKHEAD. THE SEALANT WAS FULLY REMOVED, THE LINE WAS CLEANED, THEN FULLY RESEALED. GROUND TEST AND SUBSEQUENT FLIGHT TEST FOUND TO BE NORMAL. NO OTHERS ISSUES HAVE SURFACED SINCE.THE AIR CONDITIONING LOW PRESSURE LINE IS NOT REMOVED DURING THE REMOVAL AND INSTALLATION OF THE AIR CONDITIONING PACK ASSEMBLY (REQUIRED FOR THE 12 YEAR INSPECTION), BUT IT IS REPOSITIONED TO FACILITATE THE TASK, THIS WOULD ALLOW ANY OLD SEALANT WHICH MAY HAVE LOST ITS PLIABILITY TO CRACK. RECOMMENDATION: REPLACE THE SEALANT ON THE AIR CONDITIONER LOW PRESSURE LINE AS IT RUNS THROUGH THE AFT PRESSURE BULKHEAD AFTER REINSTALLATION OF THE AIR CONDITIONING PACK DURING THE 12 YEAR INSPECTION.PRECISION JET SUBMITTED AN SDR ON SUBJECT LOW PRESSURE LINE SEALANT ISSUE.