PA46 pilot reports pressurization loss at FL270 and rapid descent to 12000 feet. Oxygen mask causes ...

Attributes
ACN	785706
Time
Date	200805
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : zdv.artcc
State Reference	CO
Altitude	msl single value : 27000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdv.artcc
Operator	general aviation : personal
Make Model Name	PA-46 Malibu
Operating Under FAR Part	Part 91
Flight Phase	cruise : level ground : parked
Flight Plan	IFR
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : multi engine pilot : commercial
Experience	flight time last 90 days : 50 flight time total : 6500 flight time type : 600
ASRS Report	785706
Events
Anomaly	aircraft equipment problem : critical altitude deviation : excursion from assigned altitude
Independent Detector	other flight crewa
Resolutory Action	controller : issued new clearance
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

I was cruising at FL270 and had a rapid total depressurization. I immediately notified ATC and told them I was making a rapid descent. While putting on the emergency oxygen; my headset was knocked off and it was several moments until I re-established contact with ATC. I checked my TCAS; making sure there were no other aircraft in my path. When I re-established contact; ATC told me to turn to 90 degrees and descend to 12000 ft as requested; and asked if I wanted to declare an emergency. I told ATC things were under control and I didn't need to declare an emergency. Descended to a non oxygen altitude and continued the flight to my destination. ATC was very helpful and did not take issue with my descent; and may have authority/authorized it; but I'm not sure because my headset was off for a few moments while putting on the oxygen; so I'm not sure if I descended with or without clearance. The pressure loss was the result of the microswitch on the gear that depressurizes when the gear is lowered failing in-flight with the gear up. I may not have descended without permission; but am not sure; even though ATC did not say I did anything wrong and was very helpful.

Original NASA ASRS Text

Title: PA46 PILOT REPORTS PRESSURIZATION LOSS AT FL270 AND RAPID DESCENT TO 12000 FEET. OXYGEN MASK CAUSES HEADSET TO FALL OFF AND NO COM UNTIL IT IS RETRIEVED.

Narrative: I WAS CRUISING AT FL270 AND HAD A RAPID TOTAL DEPRESSURIZATION. I IMMEDIATELY NOTIFIED ATC AND TOLD THEM I WAS MAKING A RAPID DSCNT. WHILE PUTTING ON THE EMER OXYGEN; MY HEADSET WAS KNOCKED OFF AND IT WAS SEVERAL MOMENTS UNTIL I RE-ESTABLISHED CONTACT WITH ATC. I CHKED MY TCAS; MAKING SURE THERE WERE NO OTHER ACFT IN MY PATH. WHEN I RE-ESTABLISHED CONTACT; ATC TOLD ME TO TURN TO 90 DEGS AND DSND TO 12000 FT AS REQUESTED; AND ASKED IF I WANTED TO DECLARE AN EMER. I TOLD ATC THINGS WERE UNDER CTL AND I DIDN'T NEED TO DECLARE AN EMER. DSNDED TO A NON OXYGEN ALT AND CONTINUED THE FLT TO MY DEST. ATC WAS VERY HELPFUL AND DID NOT TAKE ISSUE WITH MY DSCNT; AND MAY HAVE AUTH IT; BUT I'M NOT SURE BECAUSE MY HEADSET WAS OFF FOR A FEW MOMENTS WHILE PUTTING ON THE OXYGEN; SO I'M NOT SURE IF I DSNDED WITH OR WITHOUT CLRNC. THE PRESSURE LOSS WAS THE RESULT OF THE MICROSWITCH ON THE GEAR THAT DEPRESSURIZES WHEN THE GEAR IS LOWERED FAILING INFLT WITH THE GEAR UP. I MAY NOT HAVE DSNDED WITHOUT PERMISSION; BUT AM NOT SURE; EVEN THOUGH ATC DID NOT SAY I DID ANYTHING WRONG AND WAS VERY HELPFUL.

Data retrieved from NASA's ASRS site as of May 2009 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.

PA46 pilot reports pressurization loss at FL270 and rapid descent to 12000 feet. Oxygen mask causes headset to fall off and no communication until it is retrieved.