Narrative:

We announced our taxi intentions for runway 18 and started to position ourselves at the hold short line at this uncontrolled airport in excellent VFR conditions. We had landed 15 minutes earlier after being advised by unicom the active runway was 18. The wind remained out of the south 200 @ 6 knots. After all before take off checklists were complete I scanned the downwind base and final approach positions and found them to be clear of traffic. The first officer stated clear right. As I started to position our aircraft onto runway 18 we observed a [light plane]; high and just past us on the upwind leg to runway 18. The first officer and I assumed this [light aircraft] was maybe missing a practice approach to runway 36 but after making a call in the blind to the aircraft they stated that they had departed runway 36. There was never any collision threat but I certainly would have paused a moment longer before starting to position our aircraft onto runway 18 for departure. Neither I nor the first officer heard the [other aircraft] announce his departure. In a post flight discussion our crew discussed the events of earlier in the day and noted the potential hazards of operating at uncontrolled airports and the importance of remaining vigilant at all times.

Related reports:

Google
 

Original NASA ASRS Text

Title: Corporate jet Captain reports an opposite direction takeoff by a light plane at an uncontrolled airport as he taxis onto Runway 18 for takeoff. Both aircraft were on the correct Unicom frequency but the Captain did not hear any announcements from the light plane pilot.

Narrative: We announced our taxi intentions for Runway 18 and started to position ourselves at the hold short line at this uncontrolled airport in excellent VFR conditions. We had landed 15 minutes earlier after being advised by Unicom the active runway was 18. The wind remained out of the south 200 @ 6 knots. After all before take off checklists were complete I scanned the downwind base and final approach positions and found them to be clear of traffic. The First Officer stated clear right. As I started to position our aircraft onto Runway 18 we observed a [light plane]; high and just past us on the upwind leg to Runway 18. The First Officer and I assumed this [light aircraft] was maybe missing a practice approach to Runway 36 but after making a call in the blind to the aircraft they stated that they had departed Runway 36. There was never any collision threat but I certainly would have paused a moment longer before starting to position our aircraft onto Runway 18 for departure. Neither I nor the First Officer heard the [other aircraft] announce his departure. In a post flight discussion our crew discussed the events of earlier in the day and noted the potential hazards of operating at uncontrolled airports and the importance of remaining vigilant at all times.

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.