Narrative:

During the descent to 9000 ft the #1 engine oil pressure gauge began to fluctuate. I had the first officer advise the flight attendants that we may need to perform a precautionary shutdown of the #1 engine. (Note oil press was still above 40psi.) shortly thereafter (within maybe 2 min) the #1 oil pressure warning light illuminated and we proceeded to shut down the #1 engine per the checklist.we advised ATC of the shutdown and declared the emergency. I then had the first officer call dispatch and tell them we would like to divert to ZZZ. The first officer also made a PA to the passengers and called the flight attendant to tell her that it would be a normal landing with no need to brace and we would be on the ground in approx 15 minutes. We then completed the single engine preliminary landing checklist. ZZZ weather was VFR and we were told to expect a visual approach from approach. We advised approach that we would like the equipment on standby. Once we were talking to ZZZ tower we completed the single engine landing checklist and briefed a possible go-around. I then entered the pattern and performed a normal landing. Once clear of the runway I had the trucks circle us to verify that it was safe to taxi. We completed the single engine after landing checklist and taxied to the gate. We then swapped into the awaiting aircraft and continued on. All in all it was as uneventful as an emergency situation could be.I think it would be wise in the future to have the crew stand down at this point and not continue with their day. We realized later in the day when we finally had a break and time to talk about what happened after our round trip. That we had forgot to report that we had a communication issue during our flight. The #1 and #2 comms would step on each other if both were active at the same time.

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Original NASA ASRS Text

Title: DHC-8 Captain reports low oil pressure while in descent from 17000 FT. Engine was shut down; emergency declared with a divert to nearest suitable airport.

Narrative: During the descent to 9000 FT the #1 engine oil pressure gauge began to fluctuate. I had the First Officer advise the flight attendants that we may need to perform a precautionary shutdown of the #1 engine. (Note oil press was still above 40psi.) Shortly thereafter (within maybe 2 min) the #1 Oil Pressure Warning Light illuminated and we proceeded to shut down the #1 engine per the checklist.We advised ATC of the shutdown and declared the emergency. I then had the First Officer call Dispatch and tell them we would like to divert to ZZZ. The First Officer also made a PA to the passengers and called the Flight Attendant to tell her that it would be a normal landing with no need to brace and we would be on the ground in approx 15 minutes. We then completed the Single Engine Preliminary Landing Checklist. ZZZ weather was VFR and we were told to expect a visual approach from approach. We advised approach that we would like the equipment on standby. Once we were talking to ZZZ tower we completed the Single Engine Landing Checklist and briefed a possible go-around. I then entered the pattern and performed a normal landing. Once clear of the runway I had the trucks circle us to verify that it was safe to taxi. We completed the Single Engine After Landing Checklist and taxied to the gate. We then swapped into the awaiting aircraft and continued on. All in all it was as uneventful as an emergency situation could be.I think it would be wise in the future to have the crew stand down at this point and not continue with their day. We realized later in the day when we finally had a break and time to talk about what happened after our round trip. That we had forgot to report that we had a communication issue during our flight. The #1 and #2 COMMS would step on each other if both were active at the same time.

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.