Narrative:

En route from pbi to clt at FL370. 'Engine heat on' noticed cabin vertical speed climbing 1000 FPM with flow light on. Terminated engine heat, no effect on cabin vertical speed. At approximately 9500 ft cabin altitude initiated emergency descent. Captain called for checklist after immediate memory actions were completed. Descended to 11000 ft. Oxygen mask emergency drop in cabin did not occur (cabin 11000 ft). After leveloff 'C' flight attendant said loud air noise around L-2 door. Suspected door seal. Landed, etc, with no further event. Incident noted in aircraft maintenance log. Supplemental information from acn 305536: approximately 50 NM south of flo VOR, deviating for line of thunderstorms, speed equal to .75 mach in tops, night conditions, engine heat on. Cabin flow light illuminated, rate 500 FPM. Exited cloud deck and secured engine heat. Cabin stabilized. Approximately 5 mins later, flow light on again. Cabin rate 1000 FPM. Outflow valve fully closed. Initiated emergency descent, secured 11000 ft from the center. Declared emergency. Momentarily recovered pressurization FL250. Requested FL240. Cumulus clouds still prevalent. Numerous showers. Lost cabin again rate of 1500 FPM. Continued to 11000 ft, depressurized cabin. Cabin crew was briefed shortly after emergency descent was initiated to again brief passenger on the possibility of oxygen mask extension from the overhead. Passenger reassured of the aircraft's structural integrity. Callback conversation with reporter revealed the following information: the first officer (PNF) declared an emergency and the captain began a high speed emergency descent. (The power levers idle, and the speed brakes utilized). Trouble- shooting consisted of anti-ice 'on/off' (which, first officer states, did not affect the cabin altitude climb rate), and the outflow valve's manual closure. The lead flight attendant was in the cockpit when the problem was detected, and during descent initiation. Other crew members were briefed, and passenger were informed of possible oxygen mask deployment. Masks are scheduled to deploy between 13500 ft and 14000 ft. The problem was isolated to the door seal, and a report describing the nature of the emergency was submitted to the chief pilot.

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Original NASA ASRS Text

Title: AN MD-80 DEVELOPED PRESSURIZATION PROBS AT FL370 WITH ENG ANTI-ICE ON. ENG HEAT WAS SUSPECT, BUT DOOR SEAL FAILURE WAS ROOT CAUSE. EMER DSCNT AND DECLARATION ACCOMPLISHED.

Narrative: ENRTE FROM PBI TO CLT AT FL370. 'ENG HEAT ON' NOTICED CABIN VERT SPD CLBING 1000 FPM WITH FLOW LIGHT ON. TERMINATED ENG HEAT, NO EFFECT ON CABIN VERT SPD. AT APPROX 9500 FT CABIN ALT INITIATED EMER DSCNT. CAPT CALLED FOR CHKLIST AFTER IMMEDIATE MEMORY ACTIONS WERE COMPLETED. DSNDED TO 11000 FT. OXYGEN MASK EMER DROP IN CABIN DID NOT OCCUR (CABIN 11000 FT). AFTER LEVELOFF 'C' FLT ATTENDANT SAID LOUD AIR NOISE AROUND L-2 DOOR. SUSPECTED DOOR SEAL. LANDED, ETC, WITH NO FURTHER EVENT. INCIDENT NOTED IN ACFT MAINT LOG. SUPPLEMENTAL INFO FROM ACN 305536: APPROX 50 NM S OF FLO VOR, DEVIATING FOR LINE OF TSTMS, SPD EQUAL TO .75 MACH IN TOPS, NIGHT CONDITIONS, ENG HEAT ON. CABIN FLOW LIGHT ILLUMINATED, RATE 500 FPM. EXITED CLOUD DECK AND SECURED ENG HEAT. CABIN STABILIZED. APPROX 5 MINS LATER, FLOW LIGHT ON AGAIN. CABIN RATE 1000 FPM. OUTFLOW VALVE FULLY CLOSED. INITIATED EMER DSCNT, SECURED 11000 FT FROM THE CTR. DECLARED EMER. MOMENTARILY RECOVERED PRESSURIZATION FL250. REQUESTED FL240. CUMULUS CLOUDS STILL PREVALENT. NUMEROUS SHOWERS. LOST CABIN AGAIN RATE OF 1500 FPM. CONTINUED TO 11000 FT, DEPRESSURIZED CABIN. CABIN CREW WAS BRIEFED SHORTLY AFTER EMER DSCNT WAS INITIATED TO AGAIN BRIEF PAX ON THE POSSIBILITY OF OXYGEN MASK EXTENSION FROM THE OVERHEAD. PAX REASSURED OF THE ACFT'S STRUCTURAL INTEGRITY. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE FO (PNF) DECLARED AN EMER AND THE CAPT BEGAN A HIGH SPD EMER DSCNT. (THE PWR LEVERS IDLE, AND THE SPD BRAKES UTILIZED). TROUBLE- SHOOTING CONSISTED OF ANTI-ICE 'ON/OFF' (WHICH, FO STATES, DID NOT AFFECT THE CABIN ALT CLB RATE), AND THE OUTFLOW VALVE'S MANUAL CLOSURE. THE LEAD FLT ATTENDANT WAS IN THE COCKPIT WHEN THE PROB WAS DETECTED, AND DURING DSCNT INITIATION. OTHER CREW MEMBERS WERE BRIEFED, AND PAX WERE INFORMED OF POSSIBLE OXYGEN MASK DEPLOYMENT. MASKS ARE SCHEDULED TO DEPLOY BTWN 13500 FT AND 14000 FT. THE PROB WAS ISOLATED TO THE DOOR SEAL, AND A RPT DESCRIBING THE NATURE OF THE EMER WAS SUBMITTED TO THE CHIEF PLT.

Data retrieved from NASA's ASRS site as of July 2007 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.