A PA31-T cheyenne ii pilot leaves his assigned altitude when he suffers a loss of cabin pressure.

Attributes
ACN	538109
Time
Date	200201
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	navaid : bis.vor
State Reference	ND
Altitude	msl single value : 19000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zmp.artcc
Operator	other
Make Model Name	PA-31T Cheyenne II
Operating Under FAR Part	Part 91
Navigation In Use	other vortac
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	government other
Function	flight crew : single pilot
Qualification	pilot : atp pilot : commercial pilot : instrument pilot : multi engine
Experience	flight time last 90 days : 40 flight time total : 6000 flight time type : 10
ASRS Report	538109
Person 2
Function	observation : passenger
Events
Anomaly	aircraft equipment problem : critical altitude deviation : excursion from assigned altitude maintenance problem : improper maintenance non adherence : clearance non adherence : far non adherence : published procedure other anomaly other
Independent Detector	other flight crewa other other : 3 pax
Resolutory Action	other
Consequence	faa : reviewed incident with flight crew other other other
Supplementary
Problem Areas	Company Aircraft Flight Crew Human Performance Maintenance Human Performance
Primary Problem	Aircraft

Narrative:

Cheyenne ii in cruise at FL190. Sudden decompression due to the heater shroud hose clamp being insufficiently tightened. I immediately descended and turned off heading, then notified ATC. I didn't declare an emergency because by the time I was ready to communicate (oxygen masks on and descending) the situation was under control. The altitude deviation was my concern. The fix is to find a better way of attaching that hose to a cheyenne. This is a fairly common occurrence! 2 passenger are having ear injuries looked at.

Original NASA ASRS Text

Title: A PA31-T CHEYENNE II PLT LEAVES HIS ASSIGNED ALT WHEN HE SUFFERS A LOSS OF CABIN PRESSURE.

Narrative: CHEYENNE II IN CRUISE AT FL190. SUDDEN DECOMPRESSION DUE TO THE HEATER SHROUD HOSE CLAMP BEING INSUFFICIENTLY TIGHTENED. I IMMEDIATELY DSNDED AND TURNED OFF HDG, THEN NOTIFIED ATC. I DIDN'T DECLARE AN EMER BECAUSE BY THE TIME I WAS READY TO COMMUNICATE (OXYGEN MASKS ON AND DSNDING) THE SIT WAS UNDER CTL. THE ALTDEV WAS MY CONCERN. THE FIX IS TO FIND A BETTER WAY OF ATTACHING THAT HOSE TO A CHEYENNE. THIS IS A FAIRLY COMMON OCCURRENCE! 2 PAX ARE HAVING EAR INJURIES LOOKED AT.

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.