Narrative:

Immediately after takeoff; the captain asked for 'gear up.' when I pulled the gear handle up; only the nose gear and the right main showed up and locked on the panel. The left main gear did show that it was not up and locked. We ran the appropriate checklists; and decided to return to the departure airport. Emergency was filed with departure; we requested vectors for the ILS and we confirmed with approach and tower that we were able to extend the gear; and to get three green lights; and that everything seem to work fine for us at that point. The landing was smooth and normal; we exited the runway and contacted ground. We told ground that we did not need any assistance from that point on; but the fire trucks decided to follow us in to our hangar to make sure we were fine.

Google
 

Original NASA ASRS Text

Title: A Beechjet 4000 left main gear failed to retract after takeoff. All gear were successfully extended and the flight returned to departure airport.

Narrative: Immediately after takeoff; the Captain asked for 'Gear Up.' When I pulled the gear handle up; only the nose gear and the right main showed up and locked on the panel. The left main gear did show that it was not up and locked. We ran the appropriate checklists; and decided to return to the departure airport. Emergency was filed with Departure; we requested vectors for the ILS and we confirmed with Approach and Tower that we were able to extend the gear; and to get three green lights; and that everything seem to work fine for us at that point. The landing was smooth and normal; we exited the runway and contacted Ground. We told Ground that we did not need any assistance from that point on; but the fire trucks decided to follow us in to our hangar to make sure we were fine.

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.