Another 300ft, and the Boeing 737-700 N272WN would have rolled 60ft down the embankment, resulting in an accident
A Southwest Boeing 737-700 registered N272WN, operating as Southwest Airlines flight 1403 scheduled to land at Branson Airport (KBBG) from Chicago Midway (KMDW), landed instead at M. Graham Clark Downtown Airport (KPLK), about 5NM to the north of the intended destination airport.
The incident happened on 13th Jan 2014 at ~00:11 UTC (12th Jan 2014 18:11 CST).
The 737 landed on Runway 12 at KPLK (3738ft long x 100 ft wide), and stopped right on the piano keys of runway 30, leaving just 300ft to the edge of the 60 ft embankment on which the ends of the runway sit. The tires were reportedly “smoking" with the intensity with which they were applied.
The runway at KBBG is oriented 14-32 (7140ft long x 150 ft wide). It is difficult to understand how the pilot may have landed at KPLK instead of KBBG. Pilot error seems unlikely, as the pilot may have initiated a go-around seeing runway “12" instead of “14" or “32" that may have been expected at KBBG. KBBG has an ILS approach for runway 32 and two RNAV GPS Approaches for 14 and 32, either of which may have been strung into the FMS.
Sunset in the area was 17:18 local time, and civil twilight till 17:46 local. The aircraft landed in the absence of natural light. KBBG and KPLK both have runway edge lights, but Runway 14 and 32 at KBBG have PAPIs (Precision Approach Path Indicator), while KPLK has no visual approach aids for runway 12. Further, the hangars and terminal building for KBBG are on the left (when approaching runway 14), while those at KPLK are on the right (when approaching runway 12).
Based on Flightaware’s track of Southwest 4013, the aircraft deviated from its intended flight path 111 NM away: possibly indicating an intentional deviation from the flight path at or close to the top of descent. The airplane’s track seems to have drifted to the north-northwest, while winds generally blew from south-southeast. This track shift can occur if the airplane’s flying on the heading mode, but may easily get noticed as a deviation from the active flight plan route on the navigation display in the cockpit.
SW1403 started deviating from its track close to its TOD, 111NM away from KBBG
So, we have 2 pilots in a 737-700 that has an INS (Inertial Navigation System) with periodic VOR-DME / DME-DME position updates, augmented by a GPS, that together can compute the aircraft’s position with great accuracy, and displays the planned route from Chicago Midway (KMDW) to Branson Airport (KBBG). This combination of man-machine seems unlikely to land at the wrong airport. Or did the crew enter the wrong destination? Highly unlikely, considering that pilots usually select the company route rather than punching in the route manually. Further, the route is usually cross checked with the filed flight plan. And yes, Southwest does not fly its Boeings into KPLK: the runway is, evidently, too short; choosing a wrong route seems unlikely.
Did the pilots get the automation mode wrong, and fly a heading rather than LNAV? Even if they did, the aircraft’s position would have clearly shown a deviation from the active flight plan. Did the pilots miss the building and hangar lights that somehow was on the right instead of the left? possible. Did the pilots notice the absence of the PAPI? unlikely. It was dark, and they would have very much noticed the PAPIs absence, or relied on the GPS approach to KBBG, which would have shown them that they were far off the field.
In short, everything about this approach somehow does not seem to point solely towards pilot error.