Narrative:

After takeoff noticed that the nose gear took a little bit longer to retract than the main gear (nose gear door stayed open a couple of seconds longer than usual) but it ended up retracting and fully closing the door showing a normal gear up and locked position on the gear indicator. Prior to reaching level flight the nose gear door advisory light then illuminated around 3 seconds before extinguishing again. The captain ran the checklist even though the door closed again. The captain contacted dispatch and maintenance and advised them of the abnormality; and at this point being unable to ascertain the true extent of the malfunction/erroneous illumination the captain decided to declare an emergency and continue to destination as the gear indicated normal (up and locked position/landing gear indicator = dark) during cruise. The flight attendant was also advised of the situation and the cabin was secured for a normal landing. On the approach the captain still requested a fly by and get a confirmation from the trucks standing by the runway and tower of the exterior conditions of the landing gear even though the indication in the cockpit showed a normal fully down and locked position after the gear was extended. After this we initiated a go around while leaving the gear down and locked for vectors back to landing for reasons of safety; the flight crew requested to fly a runway heading and also requested an altitude of 2;500 feet or so; 3;000 feet was assigned by tower and the flight was switched to approach for vectors back to the runway; the captain decided an emergency brace position for the passengers [was appropriate] as a precautionary action. The flight attendant was instructed to prepare for a normal landing. The captain landed the aircraft.

Google
 

Original NASA ASRS Text

Title: DHC8-200 flight crew notes that the nose gear retracts slowly after takeoff and informs the Captain. All is normal until cruise when the nose gear door advisory light illuminated for a couple of seconds before extinguishing. Flight continues to destination after declaring an emergency and a fly by to let the Tower view the nose landing gear. An uneventful landing ensues. The Flight Attendant's report is also included.

Narrative: After takeoff noticed that the nose gear took a little bit longer to retract than the main gear (nose gear door stayed open a couple of seconds longer than usual) but it ended up retracting and fully closing the door showing a normal gear up and locked position on the gear indicator. Prior to reaching level flight the nose gear door advisory light then illuminated around 3 seconds before extinguishing again. The Captain ran the checklist even though the door closed again. The captain contacted Dispatch and Maintenance and advised them of the abnormality; and at this point being unable to ascertain the true extent of the malfunction/erroneous illumination the Captain decided to declare an emergency and continue to destination as the gear indicated normal (up and locked position/landing gear indicator = dark) during cruise. The Flight Attendant was also advised of the situation and the cabin was secured for a normal landing. On the approach the Captain still requested a fly by and get a confirmation from the trucks standing by the runway and Tower of the exterior conditions of the landing gear even though the indication in the cockpit showed a normal fully down and locked position after the gear was extended. After this we initiated a go around while leaving the gear down and locked for vectors back to landing for reasons of safety; the flight crew requested to fly a runway heading and also requested an altitude of 2;500 feet or so; 3;000 feet was assigned by Tower and the flight was switched to approach for vectors back to the runway; the Captain decided an emergency brace position for the passengers [was appropriate] as a precautionary action. The Flight Attendant was instructed to prepare for a normal landing. The Captain landed the aircraft.

Data retrieved from NASA's ASRS site as of July 2013 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.