Date: 201906
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Aircraft: Cessna 402/402C/B379 Businessliner/Utiliner
Operator: Air Taxi
Operating under: Part 135
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class D ZZZ
ATC / advisory: Tower ZZZ
Aircraft component: Landing Gear Indicating System
Component problem: Malfunctioning
Reporter organization: Air Taxi
Reporter function: Pilot Not Flying; Captain
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness; Troubleshooting; Communication Breakdown
Second reporter function: Pilot Flying; First Officer
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Landed in Emergency Condition; General Maintenance Action
Contributing factors: Aircraft; Human Factors; Procedure
Primary problem: Aircraft

Narrative: On approach into ZZZ runway XX the right main gear light did not illuminate after gear down was selected. A go around was initiated and I recycled the gear. Second time the gear came down the right main light still did not illuminate. I pressed the push to test button and no light was noticed. We informed tower we were sorting things out and would circle to the north of the airport and let them know when we were ready to come in. We followed the QRH to change the light bulb for the right main; however when testing it after; we noticed the left main was not illuminating. We decided to change the left light bulb however the First Officer pulled the gear cube out before I could pull the circuit breaker again. Reset the gear cube and only the right main would illuminate. We tried pulling the gear cube out again to replace the lights however the gear cube would not come out. We tried multiple times to get the gear cube out to no success. At this point we contacted [Operations Control] to discuss the next steps. It was decided to blow the gear down and follow the appropriate checklists for unconfirmed gear down (left main and nose). [Coordinated] with Tower and emergency equipment was rolled as a precaution. We landed safely with no further incident on runway XY. The passengers were shuttled from the aircraft to the terminal with their baggage while the aircraft was towed to our hangar. Not following QRH when a checklist had to be repeated i.e. second time changing light bulb did not pull CB (Circuit Breaker) before pulling gear cube out.


Second narrative: We were on approach into ZZZ. I pulled the gear switch down and we had positive indications for the nose and left main but negative indication for the right main. We initiated a go-around and the Captain began troubleshooting with the QRH. After determining that the bulb to the right main indicator needed to be changed; we pulled the circuit breaker and pulled the bulb quadrant for the landing gear indicators. After changing the bulb for the right main indicator; we put the bulb quadrant back in the panel. We did a push to test after resetting the circuit breaker and we got a positive indication for the nose and right main; but a negative indication for the left main. I pulled the bulb quadrant out to replace the bulb on the left main indicator. I think I must have thought that the circuit breaker was pulled again; but it was not. Upon push to test; we now only had a positive indication for the right main only. After consulting with [Operations Control]; we initiated the emergency blow-down procedure and proceeded to land. The captain communicated everything with ATC. Upon a successful landing; we came to a complete stop on the runway and shutdown. We evacuated the airplane and gate and airport personnel came to collect the baggage and passengers. We then towed the airplane off the runway and parked it in front of the hanger.


Synopsis: C402 flight crew reported failure to follow QRH with unsafe landing gear indications.