Date: 201405
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Aircraft: Dash 8-100
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Final Approach
Airspace: Class C ZZZ
ATC / advisory: Tower ZZZ
Aircraft component: Nose Gear
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Troubleshooting; Time Pressure; Distraction; Confusion; Workload; Communication Breakdown
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Flight Crew FLC complied w / Automation / Advisory; Flight Crew Landed in Emergency Condition; Flight Crew Took Evasive Action; General Declared Emergency; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: Upon landing gear extension on final approach the landing gear warning horn immediately sounded; the landing gear handle lights remained illuminated and the red nose gear unsafe warning light indicated an unsafe nose gear. The warning horn was exceptionally loud and could not be silenced. It was a major distraction. It was so loud that we were unable to communicate with each other and ATC. I made a PIC decision to retract the gear. The gear retracted normally and the horn silenced. We initiated a go-around; informed ATC; Operations; the Flight Attendant; and fully briefed the passengers. We referred to the Abnormal Procedure Checklist which directed us to the Alternate Landing Gear Extension Checklist. Before executing the checklist we discussed what happened while receiving delaying vectors from ATC. During the landing gear extension we heard and felt the nose gear go down and the door indications were normal of that of a gear extension. I decided that we were going to extend the gear again. The gear extended normally and indicated all were down and locked. We proceeded back to the airport for a second approach. A few minutes later the nose gear unsafe warning light illuminated without any other indications. We advised ATC that the unsafe nose gear indication returned and needed to continue receiving delaying vectors while we did an alternate gear extension. Once again I fully informed ATC; Operations; the Flight Attendant; and briefed the passengers. The alternate gear extension was performed and the gear verified down and locked with the alternate indication system. The flight landed without further incident.I installed the gear ins and nose gear down lock prior to deplaning the passengers. Flight Attendant advised me that the passengers were un-alarmed and calm. I contacted our Dispatcher so he could file his report; he then transferred me to Maintenance to make the required log book entry. Contract Maintenance was contacted and we eventually ferried the aircraft to ZZZ1.    It is reality that things break. What was really annoying was the fact that the landing gear horn was extremely loud and a real major distraction. The inability for us to hear the radios and each other even with headsets on initially made it difficult to deal with the issue until we retracted the gear and got the horn silenced. Granted; it needs to get the crews attention; but does not really need to be so loud with all the other visual indications we have.




Synopsis: A DHC-8-100 gear warning horn sounded at gear extension so an emergency was declared; a go-around executed; and the gear retracted because the warning horn volume interfered with checklist performance. The gear lowered normally the second time; but after a delayed alert again the emergency extension checklist was completed followed by a normal landing.