Date: 201402
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: 10
Light: Night
Aircraft: Small Transport; Low Wing; 2 Turboprop Eng
Operator: Air Taxi
Operating under: Part 135
Flight plan: IFR
Mission: Passenger
Flight phase: Landing
Airspace: Class E ZZZ
ATC / advisory: Center ZZZ
Reporter organization: Air Taxi
Reporter function: Pilot Not Flying
Reporter qualification: Flight Crew Flight Instructor; Flight Crew Instrument; Flight Crew Multiengine
Human factors: Communication Breakdown; Confusion; Distraction; Situational Awareness
Anomaly: Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Landing Without Clearance; Deviation / Discrepancy - Procedural Clearance; Ground Incursion Runway
Detector: Person Flight Crew
When detected: Taxi
Result: General None Reported / Taken
Contributing factors: Airport; Human Factors; Environment - Non Weather Related
Primary problem: Human Factors

Narrative: The crew: Two pilot crew- on demand Part 135 charter IFR night flight drop off 1 passenger then onto another to drop off 1 passenger and return to our home base. Weather 9 OVC at the departure airport and 24 OVC at the destination. Pilot flying has approximately 8;000 plus hours; civilian trained and holds a CFI; CFII; MEI; ATP; check airman; Class I medical. Has flown into this airport for 'over 10 years....' Pilot not flying holds same ratings and medical; but was trained civilian prior to entering the military: retired military pilot; 8;000 plus hours; Evaluator and Instructor Pilot- T-37B and C-130 E/H/J. Had flown into this airport before both solo and with another crewmember in the past; including the same pilot earlier in the day.The situation: Decent out of cruise with Center after getting local weather. Crew decided to proceed direct initial approach fix for the ILS-5 since weather was questionable as to being able to proceed for the visual. Center lost radar contact (only) with us below 3;000 FT (normal...). Crew decided on the procedure turn followed by the approach but if we picked up the field visually; we would proceed visually but back up the approach with the ILS-5. Prior planning by the pilot not flying using the A/FD indicated pilot controlled lighting on CTAF frequency would illuminate the runway and taxiway lights. During decent; the pilot not flying obtained local weather using ASOS frequency (winds 130/8-18; 10 miles visibility 24 OVC 29.81') leading to the decision to use the ILS-5. Center subsequently cleared us for the approach; asked us if we wanted to cancel in the air or on the ground with FSS- we chose on the ground as Part 135 rules require remaining on an IFR clearance until touchdown. Meanwhile the pilot not flying communicated position and intentions on CTAF frequency (123.00) and clicked the mic numerous times to illuminate the field in the hopes of obtaining visual contact while proceeding to the initial approach fix. Shortly there after; we broke out of IMC conditions. The pilot not flying observed the illuminated runway at the 1 O'clock position and notified the pilot flying. We canceled our approach request with Center in favor of the visual; but agreed within the cockpit to continue to back up our SA with the ILS-5 approach during final. All checklist items were accomplished in accordance with directives for the particular phase of flight we were in- no one felt rushed for the approach at any time. Pilot not flying made another CTAF position call on final. The approach seemed steep but was quickly corrected by observing PAPI indicators showing on glide path. Upon landing and rollout; we noticed the FBO was not where we expected it to be; but all taxiways and hangars were. The pilot not flying used his Foreflight software to determine where on the field the aircraft was now that it was traveling at less than 40 KTS and would indicate position (vs. enabling own-ship to the ALWAYS setting....) a requirement mandated by the FAA. A closer look at the approach plate indicated we were at the wrong airport only 5 miles to the southwest.Causal factors: 1. Strength of an idea: Pilot not flying saw what he thought was the runway and told the pilot flying he had the field in sight. Pilot flying agreed as it looked close enough to the current position. A closer look at online resources would have shown otherwise. 2. Not maintaining SA during the approach: had we referenced the glideslope indications on the approach we had dialed up; it would have led us to question the closeness of the airports and hopefully trained our eyes to look farther down final to see the correct destination- which too was illuminated. 3. Abandoning the ILS-5 approach in favor of a visual in very dark overcast conditions. Little to no cultural lighting was available. 4. Duplicate airfield information: both airports have the SAME Unicom and CTAF frequencies. Both require activation of runway lighting on the SAMECTAF frequency. Both runways are on ILS-5 approach plate (profile and plan view) and NO word of caution to not mistaken one airport for the other is noted. Runway dimensions are EXACTLY the SAME. The only difference is a 10 degree heading change for the runways (Runway 4 vs. Runway 5.....)Recommendations: 1. FAA should allow pilots to use the 'own-ship ON- always' setting for positional SA. 2. Note on all approaches to both airports stating to use caution to ensure correct airfield / closeness of the two fields can be mistaken for the other. This can happen both in daytime and at night. 3. Change the Unicom and CTAF frequencies for one of the airfields to prevent the illumination of both airfields lighting systems at the same time. Note: When we discussed this situation with one of the passengers; he replied; 'No big deal; it happens all the time here. This isn't the first time for me....' He smiled and walked away into the darkness.




Synopsis: After a night approach; a Part 135 crew landed at the wrong airport five miles short their destination after activating both airport's lights on the common CTAF frequency.