Narrative:

A dc-10-10 landed [and the] captain indicated with a logbook entry that all three of the aircraft's high pressure oxygen bottles indicated '0' psi on the cockpit gauge. After the aircraft blocked in; I opened the forward electronics bay door to look at two of the three O2 bottles. The bottles direct reading gauges read very low. I could not determine if the two O2 bottles in the electronics bay were completely empty. The remote gauge for the #3 bottle read very low as well. Using dc-10 aircraft maintenance manual (amm) 12-15-01-3 and general manual (gm) x-y-700 I serviced all three bottles to 500 psi. I waited a few minutes to determine if there was a leak. The gauges on both bottles held at 500 psi. The indirect reading gauge on [the] #3 bottle held its pressure as well. I went upstairs [to cockpit] and checked all of the crew and observers masks. I tested each mask with use. The captain of the flight told me he thought the first officer's mask was left 'on' after she used it during the flight. Also; one of the jumpseaters told me the right-hand observer's mask [oxygen] was free flowing then stopped; when I first started the O2 recharging procedure. I filled the three bottles to the required departure pressure and did the leak checks on the [supply] manifold and [servicing] fill areas.note: the dc-10 maintenance manual (MM) 12-15-01-3 refers you to gm x-y-700. In gm x-y-700; there is a section 6-D-3 that gives rules for charging high pressure oxygen cylinders. The high pressure recharging procedure does not have a requirement to change an empty bottle. In dc-10 MM 12-15-01; section 4-C states 'any cylinder that is determined to be completely empty cannot be recharged on the aircraft'. I'm not sure the O2 cylinders were completely empty. The gm had no requirement to change the bottles in the recharging high pressure bottles section. And the MM 12-15-01 section 4-C requires cylinder to be completely empty and it cannot be recharged on the aircraft.

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Original NASA ASRS Text

Title: A Line Mechanic reports he serviced all three Crew High Pressure Oxygen bottles on a DC-10 aircraft that indicated zero pressure; instead of removing the bottles. Reference in the DC-10 Maintenance Manual to refer to an incomplete General Manual; plus concerns about making scheduled departure time contributed to the incident.

Narrative: A DC-10-10 landed [and the] Captain indicated with a Logbook entry that all three of the aircraft's High Pressure Oxygen bottles indicated '0' psi on the cockpit gauge. After the aircraft blocked in; I opened the forward electronics bay door to look at two of the three O2 bottles. The bottles direct reading gauges read very low. I could not determine if the two O2 bottles in the electronics bay were completely empty. The remote gauge for the #3 bottle read very low as well. Using DC-10 Aircraft Maintenance Manual (AMM) 12-15-01-3 and General Manual (GM) X-Y-700 I serviced all three bottles to 500 PSI. I waited a few minutes to determine if there was a leak. The gauges on both bottles held at 500 PSI. The indirect reading gauge on [the] #3 bottle held its pressure as well. I went upstairs [to cockpit] and checked all of the Crew and Observers masks. I tested each mask with use. The Captain of the flight told me he thought the First Officer's mask was left 'On' after she used it during the flight. Also; one of the jumpseaters told me the right-hand Observer's mask [oxygen] was free flowing then stopped; when I first started the O2 recharging procedure. I filled the three bottles to the required departure pressure and did the leak checks on the [supply] manifold and [servicing] fill areas.Note: The DC-10 Maintenance Manual (MM) 12-15-01-3 refers you to GM X-Y-700. In GM X-Y-700; there is a Section 6-D-3 that gives rules for charging high pressure oxygen cylinders. The high pressure recharging procedure does not have a requirement to change an empty bottle. In DC-10 MM 12-15-01; Section 4-C states 'Any cylinder that is determined to be completely empty cannot be recharged on the aircraft'. I'm not sure the O2 cylinders were completely empty. The GM had no requirement to change the bottles in the Recharging High Pressure bottles section. And the MM 12-15-01 section 4-C requires cylinder to be completely empty and it cannot be recharged on the aircraft.

Data retrieved from NASA's ASRS site as of April 2012 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.