On 5 March 2000, a Boeing 737-300 being operated by Southwest Airlines on a scheduled passenger flight from Las Vegas to Burbank overran the landing destination runway in normal day visibility after a steep visual approach had been flown at an abnormally high speed. The aircraft exited the airport perimeter and came to a stop on a city street near a gas station. An emergency evacuation of the 142 occupants led to 2 serious injuries and 42 minor injuries and the aircraft was extensively damaged.
An Investigation was carried out by the National Transportation Safety Board (USA) (NTSB). It found that the visual approach which preceded the overrun landing had been initially flown not below 230 KIAS at the request of ATC. Just over 2.5 minutes before eventual touchdown, the flight was cleared for a visual approach which had the effect of cancelling the minimum speed restriction which was still in force at that time. The final approach was found to have been flown at an average flight path angle of 7° and at an average rate of descent of 2200 fpm in the airspeed range 182-200 kts. GPWS/TAWS Alerts and Warnings had begun to sound continuously from 34 seconds before touchdown until just before touchdown, beginning with the Alert ‘Sink Rate’ and then changing to the Warning “Whoop, Whoop, Pull Up” twenty seconds later. Although land flap 40 was selected during the approach, it did not deploy until the limiting speed for extension was reached during the landing roll when brakes were applied and thrust reversers deployed. It was noted that the target airspeed for final approach was 138 KIAS and that both the continued approach at excessive speed and the failure to appropriately respond to GPWS hard warnings had been in complete contravention of Southwest Airlines SOPs.
The Investigation noted the role of ATC in positioning the accident aircraft in such a way that it was “too fast, too high, and too close to the runway threshold to leave any safe options other than a go-around manoeuvre”.
During the course of the investigation, money was awarded to the Airport to install a 50m long Engineered Materials Arresting System (Engineered Materials Arresting System) at the end of the runway where the overrun had occurred and this work was completed in January 2002.
In respect of survival issues evidenced by this accident, the NTSB on 26 April 2001 issued two Safety Recommendations to the FAA to:
- “issue an Airworthiness Directive to require all operators of Boeing 737-300 through -500 series airplanes to replace the slide cover latch brackets on forward slide compartments with the type of slide cover latch brackets installed on the forward slide compartments of Boeing 737-600 through -900 series airplanes." (A-01-12)
- “issue an Airworthiness Directive to require initial and periodic inspections (at appropriate intervals) of the pivot bracket assemblies on all Trans Aero Industries Model 90835 jumpseats installed on Boeing 737-300 through -500 series airplanes (A-01-13)
The NTSB finding of probable cause was that “the flight crews excessive airspeed and flight path angle during the approach and landing and its failure to abort the approach when stabilized approach criteria were not met” and that “contributing to the accident was the controller’s positioning of the airplane in such a manner as to leave no safe options for the flight crew other than a go-around manoeuvre”.
The Final Report of the Investigation was adopted on 26 June 2002 and may be seen in full at SKYbrary bookshelf: NTSB Report DCA00MA030 Southwest Airlines flight 1455, Southwest Airlines flight 1455, Boeing 737-300, N668SW, Burbank, California, March 5, 2000
No further Safety Recommendations were made.