A DC9-30 on start of descent at FL260 declared an emergency due to loss of cabin pressure, cause unk...

Attributes
ACN	449327
Time
Date	199909
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : dtw.airport
State Reference	MI
Altitude	msl single value : 26000
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zob.artcc
Operator	common carrier : air carrier
Make Model Name	DC-9 30
Operating Under FAR Part	Part 121
Flight Phase	descent : vacating altitude
Route In Use	enroute airway : j16.airway
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : commercial pilot : instrument pilot : multi engine
Experience	flight time last 90 days : 165 flight time total : 12000 flight time type : 8000
ASRS Report	449327
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	aircraft equipment : altitude alert other flight crewa other flight crewb
Resolutory Action	flight crew : declared emergency flight crew : landed in emergency condition
Consequence	other other other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

At start of descent from FL260 to 12000 ft (air carrier flight abc from buf-dtw) the electronic pressurization system on DC9-30 (xyz) dumped the cabin. Cabin pressure went from 5000 ft to 16000 ft before control was restored. We started a rapid descent and completed all communication and emergency procedures and checklists. All passenger oxygen mask deployed, we declared an emergency with ATC (ZOB). Also contacted dtw operations and maintenance control. We were handed to dtw approach control. Approach and landing were uneventful. Once cabin was below 5000 ft we canceled the emergency with ATC. Air carrier technicians met the aircraft at the gate in dtw and 4 or 5 passenger were treated. No serious injuries noted. Callback conversation with reporter revealed the following information: the reporter stated the cause of the pressurization failure is unknown as maintenance did not advise the crew. The reporter said on arrival the aircraft was towed to the hangar for repair.

Original NASA ASRS Text

Title: A DC9-30 ON START OF DSCNT AT FL260 DECLARED AN EMER DUE TO LOSS OF CABIN PRESSURE, CAUSE UNKNOWN.

Narrative: AT START OF DSCNT FROM FL260 TO 12000 FT (ACR FLT ABC FROM BUF-DTW) THE ELECTRONIC PRESSURIZATION SYS ON DC9-30 (XYZ) DUMPED THE CABIN. CABIN PRESSURE WENT FROM 5000 FT TO 16000 FT BEFORE CTL WAS RESTORED. WE STARTED A RAPID DSCNT AND COMPLETED ALL COM AND EMER PROCS AND CHKLISTS. ALL PAX OXYGEN MASK DEPLOYED, WE DECLARED AN EMER WITH ATC (ZOB). ALSO CONTACTED DTW OPS AND MAINT CTL. WE WERE HANDED TO DTW APCH CTL. APCH AND LNDG WERE UNEVENTFUL. ONCE CABIN WAS BELOW 5000 FT WE CANCELED THE EMER WITH ATC. ACR TECHNICIANS MET THE ACFT AT THE GATE IN DTW AND 4 OR 5 PAX WERE TREATED. NO SERIOUS INJURIES NOTED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE CAUSE OF THE PRESSURIZATION FAILURE IS UNKNOWN AS MAINT DID NOT ADVISE THE CREW. THE RPTR SAID ON ARR THE ACFT WAS TOWED TO THE HANGAR FOR REPAIR.

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.

A DC9-30 on start of descent at FL260 declared an emergency due to loss of cabin pressure, cause unknown.