Date: 201206
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Aircraft: Commercial Fixed Wing
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Ferry / Re-Positioning
Flight phase: Initial Approach
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ
Second aircraft: B737 Undifferentiated or Other Model
Aircraft component: Indicating and Warning - Landing Gear
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: Other / Unknown
Anomaly: ATC Issue All Types; Aircraft Equipment Problem Critical; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Fuel Issue
Detector: Person Air Traffic Control; Person Flight Crew
When detected: In-flight
Result: Flight Crew Landed in Emergency Condition; General Declared Emergency
Contributing factors: Aircraft; Procedure
Primary problem: Aircraft

Narrative: On a circling approach to the runway when the gear was selected down; the green nose gear safe indicator light failed to illuminate. We executed a go around and notified ATC who gave us runway heading and an altitude. We ran the gear unsafe checklist then contacted Dispatch and advised we were going to go below divert fuel but had determined our most suitable airport. We then declared an emergency and performed a low approach to verify gear down and locked by Tower; who did confirm the gear was down. ATC then re-circled us for an approach and normal landing.


Second narrative: Runway configuration: ILS Runway XXR circle to land Runway YY; Depart Runway XXR. Runway XXL closed. I was on Local Control working all arrival and departure traffic. Aircraft X had declared an emergency due to a bad gear indication. The Pilot requested a low approach so Tower and emergency personnel could conduct a visual inspection. Rather than clear the aircraft for the approach to Runway YY; the advertised arrival runway; the aircraft was cleared for an approach to Runway XXR; the advertised departure runway; in order to afford the Tower a better view of the landing gear. I cleared the emergency aircraft for a low approach on approximately a 6-8 mile final. A few moments later I cleared a B737 to LUAW on Runway XXR. Although I realized my error as the departure was taking the runway; I was unable to expedite the aircraft off the runway because all the taxiways to the east of Runway XXR were closed; and the taxiways to the right west were blocked by aircraft taxiing to the runway for departure. I was also unable to send Aircraft X around; deeming it more important to keep the aircraft at its present altitude of approximately 350 AGL for the purpose of conducting the landing gear inspection. As a result; the ASDE-X alarmed.I was too heavily focused on the arrivals; having aircraft landing on both Runway XXR and Runway YY at the same time and ensuring separation between the two. Better awareness and strip movement was in order.


Synopsis: A turboprop commuter aircraft was unable to get safe gear indications and requested a flyby of the Tower for a visual confirmation of the landing gear status. In attempting to manage the emergency request while maintaining traffic flow and separation the Local Controller cleared a B737 to LUAW on the runway about to be utilized for the flyby inspection. Due to taxiway closures and outbound traffic the Controller was unable to get the jet off the runway prior to the flyby and a facility ASDE-X alarm was triggered as the commuter aircraft passed overhead.