B767-300ER flight crew enroute to an atlantic crossing reported they diverted to an enroute airport ...

Narrative:

Eastbound the first officer's oxygen mask failed. The mask was continuously leaking oxygen. This condition would have depleted the cockpit oxygen bottle at a rapid rate making it unsafe for an atlantic crossing. After discussion with dispatch and [maintenance]; a decision to land at [a suitable airport] was made. An emergency was declared. An overweight landing was executed. This aircraft also had a compromised braking system due to a placard on inoperable brake. We decided to dump fuel to increase performance margins. Maintenance replaced mask; completed overweight landing and ETOPS inspections. We completed flight to [destination]. About 8;000 pounds of fuel was dumped at fl 340; about 30 minutes prior to landing.

Original NASA ASRS Text

Title: B767-300ER flight crew enroute to an Atlantic crossing reported they diverted to an enroute airport because of the First Officer's oxygen mask was leaking.

Narrative: Eastbound the First Officer's oxygen mask failed. The mask was continuously leaking oxygen. This condition would have depleted the cockpit oxygen bottle at a rapid rate making it unsafe for an Atlantic crossing. After discussion with Dispatch and [Maintenance]; a decision to land at [a suitable airport] was made. An emergency was declared. An overweight landing was executed. This aircraft also had a compromised braking system due to a placard on inoperable brake. We decided to dump fuel to increase performance margins. Maintenance replaced mask; completed overweight landing and ETOPS inspections. We completed flight to [destination]. About 8;000 pounds of fuel was dumped at FL 340; about 30 minutes prior to landing.

Data retrieved from NASA's ASRS site as of July 2013 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.

Attributes
ACN	1048922
Time
Date	201211
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	B767-300 and 300 ER
Operating Under FAR Part	Part 121
Flight Plan	IFR
Component
Aircraft Component	Oxygen System/Crew
Person 1
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	First Officer
Events
Anomaly	Aircraft Equipment Problem Less Severe

B767-300ER flight crew enroute to an atlantic crossing reported they diverted to an enroute airport because of the first officer's oxygen mask was leaking.