A Southwest Airlines flight that mistakenly landed at a regional airport in Missouri on Sunday night – seven miles from its original destination and on a runway half as short as the intended airport – was certainly a surprise, but not as uncommon as you might think.

This is the second time in two months a wrong airport landing has taken place, and at least the third time in the last 17 months.

“Oh, it’s happened many times and it’s not complicated as to why. The single most-common reason is complacency,” retired pilot and aviation consultant Capt. Barry Schiff told TravelPulse.com today. “Pilots sometimes just don’t double-check their positions, or don’t use their navigational aids. That’s pretty much all there is to it. It’s one of those dumb mistakes.”

Southwest Airlines Flight 4013 took from Chicago’s Midway International Airport on Sunday and was headed to the entertainment mecca of Branson, Mo., carrying 124 passengers and five crew. Instead of landing at Branson Airport, however, the Boeing 737 landed at Taney County Airport seven miles away. According to the respective websites, the longest runway at Taney County’s M. Graham Clark Downtown Airport is 3,738 feet; Branson’s is more than a mile long at 7,140 feet.

All passengers and crew were safe, although the pilot needed to slam on the brakes on the short runway and narrowly missed going over an embankment.

The incident naturally brought out criticism – both pointed and humorous – from the Twitter crowd.

@SouthwestAir lets you pick your own seats, and apparently your own airport as well #wannagetaway

— Francisco Ramos (@FRamosComedy) January 13, 2014

New slogan for SWA Southwest Airlines, we may not get you to the right airport but we will get you close. #Southwest #SWA

— Mark Whitesell (@mwhitesell) January 13, 2014

But Southwest today grounded the pilots until the National Transportation Safety Board and Federal Aviation Administration conducts an investigation, and Missouri resident Capt. Dan Stratman, a retired pilot with more than 13,000 hours logged and now a consultant for Kansas City, Mo.-based Aviation Litigation Consulting, Inc., said it’s no laughing matter.

“I’m flabbergasted,” Stratman said. “I live in Missouri and have been to both of those airports. I cannot believe anybody that does this for a living could land at Taney County (Airport) and not realize it wasn’t the Branson Airport. They are two completely different airports. One is a commericial airport, one is for general aviation. The instrumentation alone we use in airplanes should have pointed out the difference.”

Schiff indicated the pilot probably wasn’t paying attention, especially since air traffic controllers at Branson Airport actually cleared the Southwest flight for landing.

But, Schiff said, the responsibility still lies in the cockpit more than with air traffic controllers.

“Once they clear them for visiual approach, it’s up to the pilots to put it where it belong,” Schiff said. “They have radio aids, navigational aids that tell them where they are, quite accurately I might add, and sometimes you just have to look out the window.”

Schiff said he is convinced the pilot didn’t know.

“If he suspected he was landing at the wrong airport, he’d pull up and go around,” he said. “He likely didn’t know until after he landed. Then you suddently get a sense the end of the runway is approaching quicker than it should. It isn’t much different than driving down a highway and suddenly seeing for one reason or another that you don’t have a lot of space left, and you slam on the brakes.”

A similar incident happened in November when a 747 Boeing Dreamlifter cargo jet landed at Jabara Airport in Wichita, Kan., nine miles from its intended destination at McConnell Air Force Base. No one was hurt.

In August, 2012, a commuter jet scheduled to land in Clarksburg, West Va., instead landed 10 miles away at Fairmont Municipal Airport. None of the 11 passengers or three crew were injured on United Express Flight 4049, which was operated by Silver Airways.

Stratman said in the case of the Southwest flight landing at the wrong airport in Missouri Sunday night, there were a “handful of clues” that should have told the pilot he or she was at the wrong airport.

“For one,” Stratman said, “the distances between the airports should have been a clue. Two, the two runways are different magnetic heading. If one is running north-south, and you come up on an airport whose runway runs east-west, that’s a big clue.”

Follow me on Twitter @RichTravelPulse.