USAir Flight 1493

USAir Flight 1493 was a scheduled United States (US) domestic passenger flight from Syracuse Hancock International Airport, New York to San Francisco International Airport, California that collided with SkyWest Flight 5569 upon landing at a scheduled stopover at Los Angeles International Airport (LAX). The evening of Friday, February 1, 1991, saw slow to moderate air traffic at LAX, but as the USAir 737 was on final approach, a series of abnormalities distracted the local controller, including an aircraft that inadvertently switched off the tower frequency and a misplaced flight progress strip which resulted in the SkyWest Metroliner being told to taxi into takeoff position while the USAir flight was landing on the same runway without the Metroliner ever being given a takeoff clearance.

Upon landing, the 737 collided with the twin-engine turboprop, continued down the runway with the turboprop crushed beneath it, exited the runway, and caught fire. Twenty-two of 89 people aboard the landing 737 and all 12 aboard the turboprop died. Rescue workers were on the scene of the fire within minutes and began the evacuation of the plane. Because of the intense fire three of the 737's six exits could not be used. Neither of the front exits were usable, which caused the front passengers to try to use the overwing exits. However, only one of the overwing exits was usable, which caused a backlog to form. Most of those aboard the 737 who died in the accident did so from asphyxiation in the post-crash fire.

The National Transportation Safety Board (NTSB) found that the probable cause of the accident to be the procedures in use at the Los Angeles International Airport control tower provided inadequate redundancy that led to a loss of situational awareness by the local controller. The crash led directly to the use of the NTSB's recommendation of using different runways for takeoffs and landings at LAX.

Accident details


USAir flight 1493 was a scheduled service from Syracuse, making stops at Washington, D.C. and Columbus, Ohio, Los Angeles (LAX), before continuing to San Francisco. On February 1, 1991, after a crew change in Washington, it was under the command of Captain Colin Shaw, 48 and First Officer David Kelly, 32. On the second to last scheduled leg, the aircraft carried 83 passengers and a crew of six. Until impact with the smaller plane, this had been a routine flight.

The Los Angeles Airport consisted of four parallel runways. There were two runways north of the terminal and a set of runways south of the terminal. The runways and taxiways to the north of the terminal were called the North Complex and contained the northernmost runway 24R along with 24L which was closest runway to the terminal on the north side. There was no parallel taxiway between the runways, but there were several taxiways that let aircraft that landed on 24R to cross the inboard runway. Runways 25L and 25R were in the South Complex. To reduce taxi time, flights typically would try to depart from whichever complex was closest. Due to their northerly route of flight, Skywest 5569 was cleared to taxi to Runway 24L instead of the closer Runway 25R. The departure from the gate and taxi were normal and uneventful. They taxied from gate 32 to the runway via taxiways Kilo, 48, Tango, and 45 on a predetermined route called the north route. The taxiways have since been re-designated Charlie, Quebec, Delta, and Delta10 respectively. The flight was briefly not visible from the tower on taxiway 48 between Kilo and Tango in the area known as no mans land.

Immediately prior to SkyWest reaching runway 24L, a Wings West aircraft had landed on 24R and was holding short of 24L. The local controller attempted to cross the Wings West aircraft downfield but the crew had changed frequencies and did not answer, distracting the controller in her attempt to reestablish communications. Shortly after 6 PM local time, as USAir 1493 was making its final approach to LAX, SkyWest Airlines Flight 5569, a twin-engine Fairchild Metroliner (N683AV), a commuter flight bound for Palmdale with 10 passengers and two crew members on board, was cleared by LAX air traffic control (ATC) to taxi into its takeoff position at the intersection of taxiway 45, some 2,200 feet (670 m) from the runway threshold. After four attempts by the controller, the Wings West aircraft finally responded to the tower and apologized for switching frequencies. The local controller cleared them to cross runway 24L downfield. The same local controller cleared US1493 to land on the same runway with SkyWest still holding in position. Another Wings West aircraft called the tower reporting they were ready for takeoff. The tower controller queried this aircraft, another Metroliner, about their position, and they stated they were holding short of 24L behind a Southwest 737. The flight progress strip for this flight was still with the clearance delivery controller (another position in the control tower), and the local controller mistakenly thought this Metroliner was SkyWest 5569 and that the runway was clear of all aircraft. The first officer of USAir 1493 recalled hearing this conversation, but did not remember anyone being cleared to hold on the runway.

USAir 1493 touched down near the runway threshold and as the nose was being lowered, the first officer noticed the SkyWest plane on the runway and applied maximum braking. USAir 1493 shortly thereafter slammed into the Skywest aircraft. Both aircraft skidded down the runway with the Metroliner crushed beneath the 737's fuselage. The aircraft veered off the left side of the runway between the extended centerlines of taxiways 48 and 49 and the wreckage came to rest on the far side of the taxiway against a closed fire station building where it caught fire. Large debris from the Metroliner including its tail, wings, and right engine were found on the runway and between the runway and the abandoned fire station.

The accident was witnessed from a plane carrying the Vancouver Canucks, who were arriving for a NHL hockey game against the Los Angeles Kings. The captain of that charter aircraft, having just landed, powered up the engines to get away from the fireball of the accident. The team was unsure if the USAir 737 was going to stop before it collided with their plane. The Canucks were shaken by the experience and the team suffered its worst loss of the 1990-91 season.

Fatalities and injuries


All 12 people (10 passengers and 2 pilots, Captain Andrew J. Lucas, and First Officer Frank C. Prentice III, both based in San Luis Obispo.) on Skywest 5569, 22 of the 89 aboard the 737 aircraft perished (20 passengers and 2 crew members-Captain Shaw and a flight attendant). Of the remaining passengers and crew aboard the USAir aircraft, two crew members and 11 passengers sustained serious injuries, 2 crew members and 15 passengers sustained minor injuries and 37 passengers received no injuries. American David H. Koch was among the survivors.

The majority of fatalities aboard the USAir 737 occurred to those seated in the front of the plane. Everyone seated in row 6 or forward was either killed or sustained major injuries. Everyone aft of row 17 escaped unharmed or with minor injuries. One reason for the higher fatality rate in the forward section of the aircraft is that the post crash fire originated in the forward cargo hold under the forward cabin, fed by a combination of fuel from the wreckage of the Metroliner and gaseous oxygen from the 737's damaged crew oxygen system. Only 2 passengers and one crew member managed to escape from the forward service (R1) door, while the main cabin (L1) door was inoperable due to damage. Only two passengers used the left over wing exit before the fire became too intense outside the aircraft. The majority of the survivors exited via the right over wing exit, with the rest of the surviving cabin occupants escaping through the rear service (R2) door. The rear passenger (L2) door was briefly opened during the course of the accident, but was quickly closed due to the spreading fire on that side of the aircraft. Multiple issues slowed the evacuation from the right over wing door including a passenger seated in the exit row who could not open the door, a brief scuffle between two men at the exit, and the seat back of the exit window seat being folded forward, partially obstructing the exit.

From the location of the bodies, authorities believed that 17 of those who died on the 737 had actually unbuckled their seat belts and died from smoke inhalation while making their way to the exits. Only two victims were found in their seats. According to James Burnett, who headed the National Transportation Safety Board (NTSB) investigation team, "I can't think of a recent accident where this many people have been up and out of their seats and didn't make it out." The captain was one of the few people who died of blunt force trauma. He received a fatal blow to the head when the bulkhead collapsed as the aircraft collided with the firehouse. The first officer was rescued through the cockpit windows by some of the first fire fighters to arrive on the accident scene.

One person who evacuated USAir 1493 died from thermal burns a few days after the accident. One of the 13 seriously injured passengers succumbed to multiple traumatic injuries 31 days after the crash. However, he was not listed as a fatality, due to language in the Code of Federal Regulations (49CFR830.2) that defines a fatality as taking place within 30 days of the accident.

Among the dead on the Skywest Metroliner were Skywest's Palmdale station manager as well as the husband of a Skywest employee in Palmdale, and an FAA Air Traffic controller who worked in Palmdale. Immediately after the crash, the Monterey California station manager, Terry Lewis, was brought in temporarily to keep the station running.

Aftermath
The first officer, who was the pilot flying the 737 during the accident leg, reported that he did not see the Skywest Metroliner until he lowered the nose of the aircraft onto the runway after landing. He also said that he applied the brakes, but did not have enough time for evasive action. Statements made by passengers who survived the crash were consistent with this testimony.

The Local Controller who cleared both aircraft to use the same runway testified before the NTSB and accepted blame for causing the crash. She said she originally thought the landing USAir plane had been hit by a bomb, then "realized something went wrong... I went to the supervisor and I said, 'I think this (the SkyWest plane) is what USAir hit.'" She testified that rooftop lights in her line of sight caused glare in the tower, making it difficult to see small planes at the intersection where the SkyWest plane was positioned. Just before the accident, she confused the Skywest plane with another commuter airliner that was on a taxiway near the end of the runway. Making matters more difficult, the ground radar at LAX was not working on the day of the accident.

The NTSB's investigation of the crash revealed that the cockpit crew of the landing USAir jet could not see the commuter plane, which blended in with other airport lights. The NTSB cited LAX's handling of the runways which placed much of the responsibility for the runways on the local controllers which directly led to the loss of situational awareness by the local controller. The NTSB also noted that during the previous performance review a supervisor had noted four deficiencies in the controller who ultimately worked the accident aircraft. These deficiencies were not addressed prior to the accident, and two of the deficiencies were apparent in the accident sequence—loss of situational awareness and aircraft misidentification.

At the time of the accident, air traffic controllers at LAX used all four runways for takeoffs and landings. One of the NTSB recommendations was that the runways be segregated with only landings or departures taking place on an individual runway. This recommendation was implemented, but not until after another incident, when on 19 Aug 2004 a B747 landing on 24L came within 200 ft vertically of a B737 holding on the same runway before executing a go around. LAX now uses the outboard runways (24R and 25L) for landings and the inboard runways (24L and 25R) for departures.

Before this accident, the Federal Aviation Administration (FAA) issued a ruling that required airlines to upgrade the flammability standards of materials on board, but the USAir plane had been built before the effective date of those requirements and had not yet been modernized. It was scheduled to be upgraded within the next year. By 2009, all aircraft operating in the United States were compliant.

Dramatization
The Canadian television series Mayday, which examines aerial incidents, their causes and results, created a documentary episode, titled Cleared For Disaster, about the accident.