Date: 201203
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: Dash 8-100
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Final Approach
Airspace: Class D ZZZ
ATC / advisory: Tower ZZZ
Aircraft component: Indicating and Warning - Landing Gear
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Troubleshooting
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Aircraft Equipment Problem Dissipated; Flight Crew Executed Go Around / Missed Approach
Contributing factors: Aircraft; Human Factors
Primary problem: Aircraft

Narrative: On approach at about 2;000 to 1;500 FT AGL; selected gear down. After selection First Officer noticed that the right main was not indicating down. We had no other signs that the gear was not down; no warning lights or horns. I then checked the alternate gear verification lights which indicated that all three gear where down and locked. We elected to go around and make sure that everything was okay. During the go around we casually asked the Tower to take a look at the right main to see if it appeared to be down. During the go around at about the time we were flying past the Tower the normal right main (Green) indication illuminated. On the downwind leg back to landing I reviewed the Non-Normal Gear Checklist in which it states that illumination of the three alternate indication lights is a positive indication that the gear is down and locked. Since we now had two indications that the gear was down; we felt there was no problem with landing. The Tower asked if we needed any assistance and we declined. For some reason the Tower had the CFR personnel pull the trucks out of the garage anyway about 50 FT. We never declared an emergency condition. We then landed without incident. After parking at the gate and securing the aircraft I contacted Maintenance and explained what happened; we spoke for about 9 minutes. They felt that since the normal indication came on without any input from us and that checking the past history on the plane that the normal indication module had been replaced within the last month that the module for the right main may have wiggled loose. They also felt that the alternate verification lights where an acceptable means of verification of normal gear extension and that it would be okay to continue without any additional maintenance or a write up in the aircraft log book. They also stated that since the aircraft was going into maintenance that night they would put in a follow-up item in their records to look into it. We then continued with the remainder of our trip with no further incident. [We were] notified by supervisor that FAA was looking into this incident. Make sure that event is documented in aircraft log.




Synopsis: DHC8-100 Captain experiences a landing gear indication malfunction during approach. During the ensuing go around the faulty indicator light begins to function normally and does so throughout the landing and the remaining flights on this aircraft during the day. A discussion with Maintenance indicates that no maintenance action is required nor is a logbook entry necessary. The FAA does not see it this way.