Narrative:

During the climb out from tys to rdu a red low oil pressure annunciator illuminated. We cancelled the warning and I, being the PNF, read the quick reference handbook (QRH) to determine the best course of action. Based on the QRH, we determined that it was not necessary to declare an emergency or do a precautionary engine shutdown, but that we should return to tys. At that time, we were only about 20 mi to the east of tys and I am pretty sure we were right around 10000 ft. I think the order of handoffs went from tys departure to ZME and then ZTL. I think we were talking to ZTL when we decided to return to tys. He asked if he could provide any assistance and we declined. At this time, I thought he assigned us 11000 ft and a heading back to the airport and I set the altitude alerter for 11000 ft. The other pilot was flying and he began the turn toward the assigned heading while I occupied myself with setting up the radios and talking to the flight attendant, etc. The next time I looked up, we were just below 10000 ft and the altitude alerter had not gone off. The PF stated that he thought we were assigned 10000 ft.. The altitude alerter never went off, which makes me think we were not yet at 11000 when assigned that altitude and that maintaining 11000 ft would have involved a climb. The PF said he had in mind that we were given a descent so that is what he did. At that point I think we were switched back to either ZME or tys approach and they must have seen our altitude and told us to just maintain 10000. Nothing was ever said by approach or center about the possible altitude deviation and, to the best of my knowledge, there was no conflict with any other aircraft. Looking back, it appears that declaring an emergency even for this small of a problem may have been the best course of action. It would have allowed for more flexibility with ATC instructions, in this case, altitude assignments.

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Original NASA ASRS Text

Title: LTT HAS OIL PRESSURE ANNUNCIATOR LIGHT ILLUMINATE. REQUEST RETURN TO DEP ARPT. CONFUSION REF ASSIGNED ALT. ALTDEV.

Narrative: DURING THE CLBOUT FROM TYS TO RDU A RED LOW OIL PRESSURE ANNUNCIATOR ILLUMINATED. WE CANCELLED THE WARNING AND I, BEING THE PNF, READ THE QUICK REF HANDBOOK (QRH) TO DETERMINE THE BEST COURSE OF ACTION. BASED ON THE QRH, WE DETERMINED THAT IT WAS NOT NECESSARY TO DECLARE AN EMER OR DO A PRECAUTIONARY ENG SHUTDOWN, BUT THAT WE SHOULD RETURN TO TYS. AT THAT TIME, WE WERE ONLY ABOUT 20 MI TO THE E OF TYS AND I AM PRETTY SURE WE WERE RIGHT AROUND 10000 FT. I THINK THE ORDER OF HDOFS WENT FROM TYS DEP TO ZME AND THEN ZTL. I THINK WE WERE TALKING TO ZTL WHEN WE DECIDED TO RETURN TO TYS. HE ASKED IF HE COULD PROVIDE ANY ASSISTANCE AND WE DECLINED. AT THIS TIME, I THOUGHT HE ASSIGNED US 11000 FT AND A HDG BACK TO THE ARPT AND I SET THE ALT ALERTER FOR 11000 FT. THE OTHER PLT WAS FLYING AND HE BEGAN THE TURN TOWARD THE ASSIGNED HDG WHILE I OCCUPIED MYSELF WITH SETTING UP THE RADIOS AND TALKING TO THE FLT ATTENDANT, ETC. THE NEXT TIME I LOOKED UP, WE WERE JUST BELOW 10000 FT AND THE ALT ALERTER HAD NOT GONE OFF. THE PF STATED THAT HE THOUGHT WE WERE ASSIGNED 10000 FT.. THE ALT ALERTER NEVER WENT OFF, WHICH MAKES ME THINK WE WERE NOT YET AT 11000 WHEN ASSIGNED THAT ALT AND THAT MAINTAINING 11000 FT WOULD HAVE INVOLVED A CLB. THE PF SAID HE HAD IN MIND THAT WE WERE GIVEN A DSCNT SO THAT IS WHAT HE DID. AT THAT POINT I THINK WE WERE SWITCHED BACK TO EITHER ZME OR TYS APCH AND THEY MUST HAVE SEEN OUR ALT AND TOLD US TO JUST MAINTAIN 10000. NOTHING WAS EVER SAID BY APCH OR CTR ABOUT THE POSSIBLE ALTDEV AND, TO THE BEST OF MY KNOWLEDGE, THERE WAS NO CONFLICT WITH ANY OTHER ACFT. LOOKING BACK, IT APPEARS THAT DECLARING AN EMER EVEN FOR THIS SMALL OF A PROBLEM MAY HAVE BEEN THE BEST COURSE OF ACTION. IT WOULD HAVE ALLOWED FOR MORE FLEXIBILITY WITH ATC INSTRUCTIONS, IN THIS CASE, ALT ASSIGNMENTS.

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.