The flight crew of a md-83 reported a flight attendant had stressed concerns about an MEL'd observer...

Narrative:

We departed with an inoperative observer seat O2 mask. I do not think I briefed flight attendant at the gate on this item. (Was not sure we would even need a lav break on this fairly short leg). However; during the flight; the first officer needed to very briefly use the lav. I remember briefing the flight attendant at the time of transition about using the first officer's mask if necessary; due to MEL item. In hindsight; it would have been better to have accomplished this briefing before we departed. The MEL does not provide any guidance on inop observers O2 and lav breaks. I suppose using a portable O2 unit would have been possible; but this seemed like it would compromise the desired 3 second cockpit to cabin transition. O2 was always readily available to the flight attendant from the first officer's mask; which was positioned only a few inches from where the observers mask was located.

Original NASA ASRS Text

Title: The flight crew of a MD-83 reported a flight attendant had stressed concerns about an MEL'd Observer O2 mask required for their use when; per security requirements; they occupy that seat while a flight crewmember is absent from the cockpit.

Narrative: We departed with an inoperative observer seat O2 mask. I do not think I briefed Flight Attendant at the gate on this item. (was not sure we would even need a lav break on this fairly short leg). However; during the flight; the First Officer needed to very briefly use the lav. I remember briefing the Flight Attendant at the time of transition about using the First Officer's mask if necessary; due to MEL item. In hindsight; it would have been better to have accomplished this briefing before we departed. The MEL does not provide any guidance on inop observers O2 and lav breaks. I suppose using a portable O2 unit would have been possible; but this seemed like it would compromise the desired 3 second cockpit to cabin transition. O2 was always readily available to the Flight Attendant from the First Officer's mask; which was positioned only a few inches from where the observers mask was located.

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	1094199
Time
Date	201304
Local Time Of Day	0601-1200
Place
Locale Reference	DFW.Airport
State Reference	TX
Aircraft 1
Make Model Name	MD-83
Operating Under FAR Part	Part 121
Flight Plan	IFR
Component
Aircraft Component	Oxygen System/Crew
Person 1
Function	Pilot Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	Pilot Not Flying First Officer
Events
Anomaly	Aircraft Equipment Problem Critical

The flight crew of a md-83 reported a flight attendant had stressed concerns about an MEL'd observer O2 mask required for their use when; per security requirements; they occupy that seat while a flight crewmember is absent from the cockpit.