Southwest Air Lines Flight 611

Southwest Air Lines Flight 611 was a scheduled flight from Naha to Ishigaki. On 26 August 1982, the Boeing 737-200 overran the runway while attempting to land. The aircraft caught fire and was destroyed, but none of the 133 passengers and 5 crew died in the accident although two crew and one passenger were seriously injured.

Aircraft and crew
The aircraft was a Boeing 737-2Q3 (JA8444) that had its maiden flight in December 1978 and was powered by two Pratt & Whitney JT8D-17 turbofan engines. It had logged 5,056 flight hours at the time of the accident. On the day of the accident, the aircraft had flown from Naha to Miyako and then back, without any problems.

The captain, aged 40, had been with the airline since 1973 and became a Boeing 737 captain in 1980. He had 1,666 flight hours, all of which were on the Boeing 737. The first officer, aged 29, had been with the airline since 1974 and became a 737 first officer in 1981. The first officer had 878 flight hours, all on the Boeing 737.

Flight
Southwest Air Lines Flight 611 took off on runway 36 from Naha Airport on the island of Okinawa at 13:09 for a regular flight to Ishigaki Airport, Japan. The aircraft climbed to the cruising altitude of Flight level 240 (approximately 24000 ft). On approach to Ishigaki, the crew was given weather information for Ishigaki — wind 300 degrees at 12 kn; temperature 32 C; active runway: Runway 22. At 13:33 Flight 611 descended to 8,000 ft. The crew of Flight 611 made a crosswind landing at a speed of 131 kn, slightly higher than the reference airspeed. The aircraft bounced and on touching down again the spoilers and thrust reversers did not seem to operate. The flight crew shut down both engines but this action disabled the anti-skid braking system, and during the landing rolls the inner tires on both main gear legs burst almost simultaneously. Flight 611 overran the runway and came to rest 145 m beyond the threshold at 13:49. Everyone on board was evacuated. At 14:01 the Boeing 737 caught fire and was destroyed.

None of the 138 passengers and crew were killed in the accident, but 67 were injured. Serious injuries were prevented by a quick evacuation although a stewardess and an elderly woman passenger were detained in hospital.

Investigation
The Aircraft Accident Investigation Commission (AAIC) investigated the accident. The investigators initially suspected that a mechanical failure had caused the accident, but five days later, the AAIC stated that the flight crew's actions was more likely because of the high-speed landing.

The AAIC determined that the cause of the accident was the flight crew's inappropriate decision to shut down the engines and the captain's delay in applying the brakes. The lack of anti-skid reduced braking action to half of what it would have been if the anti-skid was on. Even with the high-speed landing, the accident could have been prevented by applying maximum braking and not shutting down the engines, which would have resulted in the aircraft stopping in the runway safety area instead of overshooting the runway altogether.

Aftermath
The Japanese branch of the Air Line Pilots Association (ALPA) questioned the AAIC's findings on the accident. A criminal prosecution of the captain, citing negligence, was opened by the Naha District Prosecutor's Office, but the case was later dismissed due to lack of evidence. Aviation official determined that Ishigaki Airport's runway length of 4900 ft, was insufficient for the Boeing 737 to land on safely. This led to Ishigaki Airport being closed in 2013 and it was replaced by the New Ishigaki Airport.

In 2008, before Ishigaki Airport was closed, a training for a runway overrun was held at the airport, with 250 people participating.