An MD88's nose gear door failed to close when the gear were raised after takeoff. An emergency was declared and the aircraft returned to land at the departure airport.

Narrative

After takeoff and retracting the landing gear; the nose gear indicated unsafe and the noise level in the cockpit confirmed that the nose gear did not retract normally. Departure had us level off at 5;000 feet; with a vector east of the airport to deal with the situation. An emergency was declared. A decision was made to conduct a flyby of the Tower to get an external assessment before an attempt was made to extend the landing gear. The observation from the Tower during the flyby was that the nose gear was up; but the nose gear doors were open. Tower directed us to a downwind to land. The landing gear was extended on downwind with all normal indications. The ILS was flown to an uneventful landing with a full stop on the runway at the far end. We were met on the runway by airport rescue personnel who informed us that our nose tires looked normal. There was some concern that our problem could have been the result of a blown tire. Company Maintenance personnel also inspected the nose gear and determined that the nose landing gear strut was completely compressed and was likely the cause of the problem. We were cleared to taxi back to the terminal and deplaned the passengers.