What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
On may 23, 2016, at 2130 central daylight time, a Cessna citation 501, N804ST, registered to eagle ii aero, LLC, experienced a rapid decompression at 43,000 feet. The flight which was bound for san antonio, Texas (ksat) made an emergency landing at the Texarkana, Arkansas (ktxk). The 14 CFR part 91 flight was operating on an IFR flight plan. The airplane was substantially damaged. The airman was not wearing his oxygen mask at the time of the rapid decompression. Upon recognition of the rapid decompression, the airman configured the aircraft for emergency descent.
The airman stated within 20 seconds the aircraft lost all cabin pressurization and the cabin altitude climbed from 8,000 feet and 8.5 psid to ambient altitude and 0 psid. After commanding a rapid descent, the airman and all occupants lost consciousness before donning their oxygen mask. The aircraft went into uncontrolled flight for approximately 36,000 feet when the pilot and passengers regained consciousness at 7,000 feet. The airman became fully cognizant regaining control of the aircraft approximately 7,000 feet, subsequently making an uneventful landing. The flight originated from perryville, Missouri (KKO2). There were three passengers on board the aircraft, one of whom was sitting in the other cockpit flight control station.
Post-accident examination of the airplane revealed the root cause was the primary pressurization duct into the cabin being separated from its connection to the water separator (coalescer). The duct?s metal retaining clamp was present with its retaining screw in place. The clamp was not fractured and was resting on the metal flange attached to the separator.
As the FAA filed it
ON MAY 23, 2016, AT 2130 CENTRAL DAYLIGHT TIME, A CESSNA CITATION 501, N804ST, REGISTERED TO EAGLE II AERO, LLC, EXPERIENCED A RAPID DECOMPRESSION AT 43,000 FEET. THE FLIGHT WHICH WAS BOUND FOR SAN ANTONIO, TEXAS (KSAT) MADE AN EMERGENCY LANDING AT THE TEXARKANA, ARKANSAS (KTXK). THE 14 CFR PART 91 FLIGHT WAS OPERATING ON AN IFR FLIGHT PLAN. THE AIRPLANE WAS SUBSTANTIALLY DAMAGED. THE AIRMAN WAS NOT WEARING HIS OXYGEN MASK AT THE TIME OF THE RAPID DECOMPRESSION. UPON RECOGNITION OF THE RAPID DECOMPRESSION, THE AIRMAN CONFIGURED THE AIRCRAFT FOR EMERGENCY DESCENT.
THE AIRMAN STATED WITHIN 20 SECONDS THE AIRCRAFT LOST ALL CABIN PRESSURIZATION AND THE CABIN ALTITUDE CLIMBED FROM 8,000 FEET AND 8.5 PSID TO AMBIENT ALTITUDE AND 0 PSID. AFTER COMMANDING A RAPID DESCENT, THE AIRMAN AND ALL OCCUPANTS LOST CONSCIOUSNESS BEFORE DONNING THEIR OXYGEN MASK. THE AIRCRAFT WENT INTO UNCONTROLLED FLIGHT FOR APPROXIMATELY 36,000 FEET WHEN THE PILOT AND PASSENGERS REGAINED CONSCIOUSNESS AT 7,000 FEET. THE AIRMAN BECAME FULLY COGNIZANT REGAINING CONTROL OF THE AIRCRAFT APPROXIMATELY 7,000 FEET, SUBSEQUENTLY MAKING AN UNEVENTFUL LANDING. THE FLIGHT ORIGINATED FROM PERRYVILLE, MISSOURI (KKO2). THERE WERE THREE PASSENGERS ON BOARD THE AIRCRAFT, ONE OF WHOM WAS SITTING IN THE OTHER COCKPIT FLIGHT CONTROL STATION.
POST-ACCIDENT EXAMINATION OF THE AIRPLANE REVEALED THE ROOT CAUSE WAS THE PRIMARY PRESSURIZATION DUCT INTO THE CABIN BEING SEPARATED FROM ITS CONNECTION TO THE WATER SEPARATOR (COALESCER). THE DUCT?S METAL RETAINING CLAMP WAS PRESENT WITH ITS RETAINING SCREW IN PLACE. THE CLAMP WAS NOT FRACTURED AND WAS RESTING ON THE METAL FLANGE ATTACHED TO THE SEPARATOR.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.