Southwest Airlines Flight 1455

NTSB narrative

The Board's full report is available at http://www.ntsb.gov/publictn/publictn.htm HISTORY OF FLIGHT

On March 5, 2000, about 1811 Pacific standard time (PST), Southwest Airlines, Inc., flight 1455, a Boeing 737-300 (737), N668SW, overran the departure end of runway 8 after landing at Burbank-Glendale-Pasadena Airport (BUR), Burbank, California. The airplane touched down at approximately 182 knots, and about 20 seconds later, at approximately 32 knots, collided with a metal blast fence and an airport perimeter wall. The airplane came to rest on a city street near a gas station off of the airport property. Of the 142 persons on board, 2 passengers sustained serious injuries; 41 passengers and the captain sustained minor injuries; and 94 passengers, 3 flight attendants, and the first officer sustained no injuries. The airplane sustained extensive exterior damage and some internal damage to the passenger cabin. During the accident sequence, the forward service door (1R) escape slide inflated inside the airplane; the nose gear collapsed; and the forward dual flight attendant jumpseat, which was occupied by two flight attendants, partially collapsed. The flight, which was operating on an instrument flight rules flight plan, was conducted under 14 Code of Federal Regulations (CFR) Part 121. Visual meteorological conditions (VMC) prevailed at the time of the accident, which occurred in twilight lighting conditions.

According to Southwest Airlines records, the accident flight was the flight crew's first flight of what was scheduled to be a 3-day flight sequence that consisted of five flights. The accident flight originated at McCarran International Airport (LAS), Las Vegas, Nevada, and was scheduled to depart about 1445 for BUR. The first officer of the accident flight stated to National Transportation Safety Board investigators that he arrived at LAS about 1245, and the captain indicated that he arrived about 1400. The first officer reported in a postaccident interview that he met the captain on the way to the gate. Southwest Airlines records indicate that the accident airplane arrived at LAS from Los Angeles International Airport, Los Angeles, California, about 1630, almost 2 hours behind schedule, because of rain and gusting winds in the LAS area. The accident flight crew indicated that the preflight inspection was normal and that no maintenance discrepancies were noted.

Flight 1455 departed the gate about 1650, more than 2 hours behind schedule. During postaccident interviews, the flight crew indicated to Safety Board investigators that the takeoff and en route portions of the flight to BUR were normal and uneventful. The first officer stated that after the flight crossed the PMD very high frequency omni-directional radio range (VOR) navigation transmitter at 8,000 feet, he obtained information Oscar from the BUR airport terminal information service (ATIS), which indicated that winds were from 260° at 18 knots, gusting to 26 knots, and that aircraft were landing on runways 33 and 26. At 1754:21, the captain stated, "plan on [runway] three three at the moment. [A]pproach descent checklist when you get the chance."

At 1802:52, the flight crew was advised by the Southern California terminal radar approach control (SCT) Woodland controller that the current ATIS was information Papa and that they should expect an instrument landing system (ILS) landing on runway 8. At 1803:29, when the airplane was about 20 nautical miles (nm) north of the BUDDE outer marker at an altitude of about 8,000 feet mean sea level (msl), the Woodland controller instructed flight 1455 to turn left to a heading of 190° and to descend to and maintain 6,000 feet msl. The first officer acknowledged the instructions.

At 1804:02, when the airplane was about 19 nm north of the BUDDE outer marker at an altitude of about 7,800 feet msl, the SCT Woodland controller stated, "Southwest fourteen fifty five, maintain two thirty or greater `til advised please." The captain acknowledged the airspeed adjustment assignment. The Woodland controller indicated in a postaccident interview that he imposed the speed restriction as part of sequencing Southwest flight 1455 between Southwest flight 1713 and Executive Jet flight 278.

After the first officer obtained information Papa, he switched back to the approach control frequency. At 1804:42, he informed the captain that the target airspeed for the approach would be 138 knots and, at 1804:49, that winds were "down to six knots." A few seconds later, he confirmed that aircraft were landing at BUR on runway 8. At 1805:08, when the airplane was about 16 nm north of the BUDDE outer marker at an altitude of about 6,000 feet msl, the SCT Woodland controller instructed flight 1455 to "turn left heading one six zero." At 1805:13, the captain indicated to the first officer that ATC "wants two hundred thirty knots or greater, for a while."

At 1805:54, the SCT Woodland controller cleared flight 1455 to descend to and maintain 5,000 feet and advised the pilots that they were following company traffic (Southwest Airlines flight 1713) that was at their "one o'clock and twelve miles [ahead of them] turning onto the final out of forty six hundred." The first officer acknowledged the clearance. At 1807:43, the Woodland controller cleared flight 1455 to descend to and maintain 3,000 feet. The first officer acknowledged the clearance. At 1808:18, the first officer notified ATC that he had the Southwest traffic in sight. At 1808:19, the Woodland controller issued an altitude restriction by stating, "cross Van Nuys at or above three thousand, cleared visual approach runway eight." The first officer acknowledged the clearance. At 1808:36, as the airplane was descending through about 3,800 feet msl, the captain began turning to the left for the final approach.

In postaccident interviews, the flight crew told investigators that, during the approach, the captain's navigation radio was tuned to the ILS frequency for runway 8, and the first officer's radio was tuned to the Van Nuys VOR. They indicated that the autopilot was engaged in the VOR/LOC mode and that the airplane captured the localizer course but then overshot the centerline before correcting back. The captain stated to investigators that as the flight passed about 2 miles west of Van Nuys at 3,000 feet at approximately 220 to 230 knots, he deployed the speed brakes.

According to the CVR, at 1809:28, when the airplane was at an indicated airspeed of about 220 knots, the captain called for "flaps five." At 1809:32, the flaps began to extend. At 1809:43, the captain called for "gear down." The captain indicated in a postaccident interview that at this point in the flight, he noted a 20-knot tailwind indication on the flight management system (FMS) screen. At 1809:53, the BUR tower controller stated, "Southwest fourteen fifty five, wind uh...two one zero at six [knots], runway eight, cleared to land." Simultaneously, the captain called for "flaps fifteen." At 1810:01, the captain again called for "flaps...fifteen" and "[flaps] twenty five."

From 1810:24 until 1810:59, the ground proximity warning system (GPWS) alerts were being continuously broadcast in the cockpit, first as "sink rate" and then, at 1810:44, switching to "whoop, whoop, pull up." At 1810:29, the captain stated, "flaps thirty, just put it down." At 1810:33, the captain stated, "put it to [flaps] forty. [I]t won't go, I know that. [I]t's all right. [F]inal descent checklist." After the GPWS "whoop, whoop, pull up" alert sounded at 1810:47, the captain stated, "that's all right," at 1810:53. A final "sink rate" warning was recorded at 1810:55. The first officer stated in a postaccident interview that instead of reading the final descent checklist, he visually confirmed the checklist items and remembered seeing the captain arm the ground spoilers. The first officer also stated that when the captain called for flaps 40°, the airspeed was about 180 knots and went as high as 190 knots during the approach. The first officer indicated that he pointed to his airspeed indicator to alert the captain of the flap limit speed of 158 knots at flaps 40°.

The captain told Safety Board investigators that he remembered hearing the "sink rate" warning from the GPWS but that he did not react to the warning because he did not feel that he had to take action. He stated that he did not remember any other GPWS warnings during the approach. The first officer indicated in a postaccident interview that he heard both the "sink rate" and the "pull up" GPWS warnings but that he believed that the captain was correcting.

The first officer also indicated to investigators that he selected the "Progress" page on the FMS cockpit display unit but that he could not recall what the wind values were during the approach. He stated to investigators that he was concerned thatthe ground speed was faster than normal but added that he did not verbalize his concern to the captain. The first officer further indicated to investigators that he felt that the approach was stabilized and that they were in a position to land.

The captain stated in a postaccident interview that he was aware that Southwest Airlines' standard procedure was for the captain and first officer to call "1,000 [feet above ground level (agl)], airspeed, and sink rate" when descending through 1,000 feet. However, no such callouts were recorded by the CVR. The captain also stated in a postaccident interview that he visually perceived that the airplane was "fast" as it crossed the approach end of runway 8. CVR and FDR data indicate that the airplane touched down at 1810:58 with flaps extended to 30° at about 182 knots; flaps then extended to 40° during the ground roll at about 145 knots.

The captain stated to Safety Board investigators that after touchdown, the end of the runway appeared to be closer than it should have been and that he thought they might hit the blast fence wall. The captain indicated that he braked "pretty good" while attempting to stop the airplane. FDR data indicate that the captain unlocked the thrust reversers 3.86 seconds after touchdown and that the thrust reversers deployed 4.91 seconds after touchdown. The first officer stated to investigators that the captain applied the wheel brakes before the airplane had decelerated to 80 knots and that, as the airplane passed the Southwest Airlines passenger boarding gates, he joined the captain in braking the airplane and applied the brakes as hard as he could. The captain indicated that as the airplane neared the end of the runway, he initiated a right turn using only the nosewheel steering tiller (not the rudder pedals).

At 1811:20, the cockpit area microphone (CAM) recorded impact sounds. The airplane departed the right side of the runway about 30° from the runway heading, penetrated a metal blast fence and an airport perimeter wall, and came to a stop on a city street off of the airport property. An emergency evacuation ensued, and all crewmembers and passengers successfully exited the airplane.

Verbatim NTSB analysis and probable cause from the NTSB dataset