Flight crew experienced failure of the captain's emergency oxygen mask during cruise.

Attributes
ACN	1677527
Time
Date	201908
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	A320
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Component
Aircraft Component	Oxygen System/Crew
Person 1
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine Flight Crew Instrument
Experience	Flight Crew Last 90 Days 187
Events
Anomaly	Aircraft Equipment Problem Critical

Narrative:

After quick donning the captain's O2 (oxygen) mask a malfunction occurred whereby the hose that is attached to the bib/nipple on the mask portion became detached. O2 escaped uncontained for approximately 15 sec. The crew O2 system lost 250 psi. I stopped the runaway O2 by using the 'reset' switches inside the O2 mask compartment. This could have been a more serious event if this mask failed during a rapid descent.

Original NASA ASRS Text

Title: Flight Crew experienced failure of the Captain's Emergency Oxygen Mask during cruise.

Narrative: After quick donning the Captain's O2 (Oxygen) mask a malfunction occurred whereby the hose that is attached to the bib/nipple on the mask portion became detached. O2 escaped uncontained for approximately 15 sec. The crew O2 system lost 250 psi. I stopped the runaway O2 by using the 'reset' switches inside the O2 mask compartment. This could have been a more serious event if this mask failed during a Rapid Descent.

Data retrieved from NASA's ASRS site 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.