Report of illegal oxygen bottle being replaced after a one time flight.

Attributes
ACN	297852
Time
Date	199503
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : sjd
State Reference	FO
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : ord
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	climbout : takeoff ground : preflight
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 100 flight time total : 4800 flight time type : 2800
ASRS Report	297852
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe non adherence : published procedure other anomaly other
Independent Detector	other other : unspecified
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

We reported to sjo for our first flight of the day. During my cockpit preflight inspection, I found the crew oxygen bottle to be empty. We notified los cabos operations and subsequently another air carrier. Maintenance crew installed a full bottle. We checked that the bottle was secure and our oxygen system functioned properly. The maintenance log was signed off by the other air carrier mechanic, our passenger were hoarded and we flew to mzt. On arrival in mzt, we were notified by company maintenance control that the replacement oxygen bottle was not legal. We waited in mzt until a proper bottle was delivered from lax and installed. At mzt another air carrier mechanic signed the maintenance log and we departed for sfo. I guess the way to avoid such a situation is to not assume that a maintenance log sign-off is legal unless the mechanic is a company employee or you have direct contact with company maintenance control.

Original NASA ASRS Text

Title: RPT OF ILLEGAL OXYGEN BOTTLE BEING REPLACED AFTER A ONE TIME FLT.

Narrative: WE RPTED TO SJO FOR OUR FIRST FLT OF THE DAY. DURING MY COCKPIT PREFLT INSPECTION, I FOUND THE CREW OXYGEN BOTTLE TO BE EMPTY. WE NOTIFIED LOS CABOS OPS AND SUBSEQUENTLY ANOTHER ACR. MAINT CREW INSTALLED A FULL BOTTLE. WE CHKED THAT THE BOTTLE WAS SECURE AND OUR OXYGEN SYS FUNCTIONED PROPERLY. THE MAINT LOG WAS SIGNED OFF BY THE OTHER ACR MECH, OUR PAX WERE HOARDED AND WE FLEW TO MZT. ON ARR IN MZT, WE WERE NOTIFIED BY COMPANY MAINT CTL THAT THE REPLACEMENT OXYGEN BOTTLE WAS NOT LEGAL. WE WAITED IN MZT UNTIL A PROPER BOTTLE WAS DELIVERED FROM LAX AND INSTALLED. AT MZT ANOTHER ACR MECH SIGNED THE MAINT LOG AND WE DEPARTED FOR SFO. I GUESS THE WAY TO AVOID SUCH A SIT IS TO NOT ASSUME THAT A MAINT LOG SIGN-OFF IS LEGAL UNLESS THE MECH IS A COMPANY EMPLOYEE OR YOU HAVE DIRECT CONTACT WITH COMPANY MAINT CTL.

Data retrieved from NASA's ASRS site as of July 2007 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.