Narrative:

The flight was a medical charter from ZZZ, first officer, to san, us. The passenger had head injury, but medical equipment attached to him. Throughout the cruise portion of the flight, the cockpit doors were closed. The captain (who is a smoker) smoked several times during the 15 hour flight to san. I am a non smoker. On the part 91 flight from san to home base (ZZZ1) the nurse informed myself that oxygen had been in use the whole time, but did not want to upset the captain, who is also the owner of the company for fear of conflict. Up until this point, I was completely unaware of any oxygen in use.

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Original NASA ASRS Text

Title: WW24 CAPT REFUSED TO STOP SMOKING WHILE A PAX WAS ON MEDICAL OXYGEN.

Narrative: THE FLT WAS A MEDICAL CHARTER FROM ZZZ, FO, TO SAN, US. THE PAX HAD HEAD INJURY, BUT MEDICAL EQUIP ATTACHED TO HIM. THROUGHOUT THE CRUISE PORTION OF THE FLT, THE COCKPIT DOORS WERE CLOSED. THE CAPT (WHO IS A SMOKER) SMOKED SEVERAL TIMES DURING THE 15 HR FLT TO SAN. I AM A NON SMOKER. ON THE PART 91 FLT FROM SAN TO HOME BASE (ZZZ1) THE NURSE INFORMED MYSELF THAT OXYGEN HAD BEEN IN USE THE WHOLE TIME, BUT DID NOT WANT TO UPSET THE CAPT, WHO IS ALSO THE OWNER OF THE COMPANY FOR FEAR OF CONFLICT. UP UNTIL THIS POINT, I WAS COMPLETELY UNAWARE OF ANY OXYGEN IN USE.

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.