PSA Flight 182: The 1978 San Diego Mid-Air Collision

Introduction

The mid-air collision between a Boeing 727 commercial airliner and a Cessna 172 training aircraft over a San Diego neighborhood on September 25, 1978, remains one of the worst air disasters in U.S. aviation history. The ill-fated aircraft was Pacific Southwest Airlines Flight 182. All 135 people on board the PSA flight — including seven crewmembers — the two pilots in the Cessna, and seven people on the ground were killed in the crash. The accident prompted an immediate review of existing air-traffic control procedures around busy airports and led to the greater mandatory use of radar for air-traffic control, rather than reliance on visual contact with other aircraft by pilots.

This paper traces the events leading up to the collision, describes the accident itself, explores the possible causes, presents eyewitness accounts, and reviews the aftermath — including the effect of the crash on regulations governing air-traffic control around busy airports.

Note: The crash was the single worst airline disaster in U.S. history at the time and remains the single worst aircraft accident in California's history (Stich, 2005, p. 175).

Chronology of Events Leading to the Accident

At 0816 Pacific Standard Time (PST) on September 25, 1978, a Gibbs Flite Center Cessna 172 departed Montgomery Field, California, on an instrument training flight. A flight instructor and a certified pilot who was receiving instrument flight training were the only two occupants of the aircraft ("Aircraft Accident Report," 1979, p. 2).

The Cessna flew to Lindbergh Field — also known as San Diego International Airport — where it practiced Instrument Landing System (ILS) approaches on one of its runways. After completing a second practice approach, it began a climb-out to the northeast at approximately 0857 PST.

At 0859:01 PST, the Lindbergh tower controller cleared the Cessna to maintain Visual Flight Rules (VFR) conditions and to contact San Diego approach control. The Cessna pilot did so immediately, and the San Diego approach control acknowledged radar contact, instructing him to maintain VFR conditions at or below 3,500 feet and to fly a heading of 070°.

Pacific Southwest Airlines Flight 182 was a regular commercial passenger flight operating between Sacramento and San Diego with a stopover in Los Angeles. After its scheduled stopover in Los Angeles, Flight 182 departed at 0834 PST on an Instrument Flight Rules (IFR) plan with 128 passengers and 7 crewmembers on board. The aircraft was flown by the first officer; the captain conducted most of the air-to-ground communications, and a deadheading company pilot occupied the forward observer seat in the cockpit.

At 0853, Flight 182 reported to San Diego approach control while flying at 11,000 feet. It was cleared to descend to 7,000 feet. At 0857, Flight 182 reported that it was descending from 9,500 to 7,000 feet and that the airport was in sight. The approach control then cleared the aircraft for a visual approach to runway 27, and the pilot acknowledged the clearance.

At 0859:28, the approach controller advised Flight 182: "there was traffic at twelve o'clock, one mile northbound." The crew acknowledged the message five seconds later with "we're looking."

At 0859:39, the approach controller informed Flight 182: "additional traffic's twelve o'clock, three miles, just north of the field, northeast bound, a Cessna one seventy two climbing VFR out of one thousand four hundred." At 0859:50, the co-pilot responded with "Okay we have got that other twelve."

At 0900:15, the approach controller informed Flight 182: "traffic's at twelve o'clock, three miles, out of one thousand seven hundred." The information was acknowledged by Flight 182 a few seconds later through the messages "got 'em" and "traffic in sight."

At 0900:23, the approach controller asked Flight 182 to "maintain visual separation" and to contact Lindbergh tower. Flight 182 acknowledged.

At 0900:31, the approach controller advised the Cessna pilot that there was "traffic at six o'clock, two miles, eastbound; a PSA jet inbound to Lindbergh, out of three thousand two hundred, has you in sight." The Cessna pilot acknowledged with: "One golf, roger."

At 0900:34, Flight 182 contacted Lindbergh tower and reported that they were on the downwind leg for landing. The tower acknowledged and informed Flight 182 that there was "traffic, twelve o'clock, one mile, a Cessna."

Note: The description of events leading up to the mid-air collision is based on the official NTSB Aircraft Accident Report released following its inquiry into the accident in April 1979 (pages 2–4).

Confusion in the Cockpit and the Collision

At 0900:41, the first officer, who was at the controls of Flight 182, called for five-degree flaps. The captain asked, "Is that the one (we're) looking at?" The first officer answered, "Yeah, but I don't see him now."

Flight 182's flight crew continued to discuss the location of the traffic, indicating considerable confusion in the cockpit. At 0900:44, Flight 182 told the local controller, "Okay, we had it there a minute ago," and at 0900:50: "think he's passing off to our right." At 0900:52, the captain said, "He was right over there a minute ago," and the first officer answered, "Yeah."

At 0901:11, after the captain told the local controller how far they intended to extend their downwind leg, the first officer asked, "Are we clear of that Cessna?" The flight engineer answered, "Supposed to be"; the captain said, "I guess"; and the pilot in the forward observer seat responded, "I hope." At 0901:21, the captain observed, "Oh yeah, before we turned downwind, I saw him about one o'clock, probably behind us now." At 0901:38, the first officer called out, "There's one underneath," and one second later added, "I was looking at that inbound there." This was the last recorded conversation from the cockpit of Flight 182 before the collision.

The NTSB investigation report, drawing on eyewitness accounts, records that both aircraft were proceeding in an easterly direction before the collision. Flight 182 was descending and overtaking the Cessna, which was climbing. Just before impact, Flight 182 banked slightly to the right, and the Cessna pitched nose-up and collided with the right wing of Flight 182 ("Aircraft Accident Report," 1979, p. 4). Just before the impact, the captain — probably anticipating the collision — exclaimed "Whoop!" and the first officer moaned "Aghhh!" The Cockpit Voice Recorder (CVR) recorded the sound of impact at 0901:47 ("CVR Transcript," n.d.).

The Cessna broke apart immediately on impact and exploded. Parts of the Boeing's right wing also separated. Following the impact, Flight 182 entered a shallow right descending turn, leaving a trail of vapor-like substance from the right wing. A bright orange fire erupted near the right wing and intensified as the aircraft descended. The aircraft remained in the right turn until it struck the ground at 0902:07, falling onto Dwight and Nile streets, just west of Interstate 805. The Cessna wreckage crashed into the area of 32nd and Polk streets, a few miles from the San Diego Zoo.

Flight 182's CVR after the impact records the captain asking, "What have we got here?" and the first officer responding, "It's bad. We're hit, man, we are hit!" The captain is also recorded saying "This is it!" and "Brace yourself," while another crewmember exclaimed "Ma, I love you!" just before the aircraft struck the ground in a heavily populated residential area of San Diego ("CVR Transcript," n.d.).

Eyewitness Accounts

The eyewitness accounts of the crash reveal a story of indescribable horror. The plane was split apart into millions of pieces on impact, flinging bodies and human remains into houses, onto rooftops, on lawns, and into the street. Walls were splattered with human remains. One body smashed through a car's windshield, killing a mother and her daughter inside (Stich, 2005, p. 178).

Several eyewitnesses spoke of the crash years later. Radio executive Joe Gillespie recalled, twenty years after the event: "I remember that day as if it happened yesterday" (Shess, 1998). Gary Jaus, a rookie officer at the San Diego Police Academy at the time, was assigned the task of combing through the wreckage for victims' identification. He recalled: "There were no faces on the bodies. There were no bodies to speak of — only pieces. One alley was filled with just arms, legs and feet…" Jaus noted that he was only able to perform his grim duty without becoming ill because he had previously worked at a mortuary. Even so, in his own words, he "wasn't ready to see the torso of a stewardess slammed against a car" (Ibid.).

Robert Osby, then a battalion chief with the San Diego Fire Department and later the fire chief, supervised the rescue efforts at the disaster site. He recalled that firefighters, through prompt and professional action, were able to contain the fire to a remarkably small area — only two sides of one short block of Dwight Street. He also noted that the plane had crashed into a working-class neighborhood on a Monday morning when most residents were at work; had it fallen on a weekend, the death toll on the ground would have been far higher (Ibid.). Another reason the fireball was contained was that the aircraft did not fall in a glide path parallel to the ground but crashed nose-first.

Hans Wendt, a staff photographer with the San Diego County public relations office who was covering an outdoor press event in North Park at the time of the accident, took two dramatic post-collision photographs of the falling Boeing 727 trailing blue-and-white smoke from its right wing as it plunged toward the ground. The images appeared in numerous publications worldwide, including the cover of Time magazine. A television cameraman covering the same event in North Park also managed to capture footage of the falling Cessna wreckage.

Cause of the Crash

According to the official majority findings of the National Transportation Safety Board (NTSB), the probable cause of the accident was "the failure of the flightcrew of Flight 182 to comply with the provisions of a maintain-visual-separation clearance, including the requirement to inform the controller when they no longer had the other aircraft in sight" ("Aircraft Accident Report," 1979, p. 36).

The NTSB report also cited air-traffic control procedure as a contributory cause. Specifically, the procedure that "authorized the controllers to use visual separation procedures to separate two aircraft on potentially conflicting tracks when the capability was available to provide either lateral or vertical radar separation to either aircraft" (Ibid.).

Note: A probable cause is a primary cause — an act or omission that is in the direct line of causation and without which the accident would not have occurred. A contributory factor is an event which possibly could have, but not necessarily would have, caused the accident.

The NTSB's opinion was based on a detailed analysis of the qualifications and experience of the pilots of both aircraft, the condition of the Boeing 727 and Cessna 172 at the time of the accident, weather conditions in the vicinity of Lindbergh Field, a cockpit visibility study, the CVR transcript, air-traffic control procedures, examination of the wreckage, and a range of eyewitness accounts.

All flight crew personnel on both aircraft, including the pilots aboard the Cessna, were fully qualified. The personnel in the San Diego approach control and the Lindbergh tower were also adequately qualified and experienced. The Boeing 727-214 (N533PS), owned and operated by Pacific Southwest Airlines, was within prescribed weight and balance limitations for the flight. The Cessna 172M (N7711G), owned and operated by Gibbs Flite Center, Inc., was similarly within prescribed weight and balance limits. Weather conditions in and around San Diego at the time of the accident were clear, with visibility rated as good at ten miles ("Aircraft Accident Report," 1979, pp. 5–6). The NTSB concluded that none of these factors contributed to the accident.

One NTSB member disagreed with the majority's findings on probable and contributory causes and recorded his dissent in the Aircraft Accident Report. In his view, the inadequacies of the air-traffic control system should have been cited as a "probable cause" rather than merely a "contributory cause." He argued that the San Diego approach control had the capability to provide either vertical or lateral separation and should have used that procedure for both aircraft. Had it done so, the accident would not have occurred; therefore, the failure to do so was, in his opinion, a direct and probable cause rather than an indirect and contributory one (Ibid., p. 39).

The dissenting member also cited several additional contributory factors. He argued that the approach controller failed to restrict Flight 182 to a 4,000-foot altitude while it was within the Montgomery Field area — a restriction that might have prevented the accident. He further cited: the Cessna's failure to maintain its assigned heading of 070°; the fact that two separate facilities were controlling traffic in the same airspace; the San Diego Approach Control's failure to react to a conflict alert warning; the possible misidentification of the Cessna by PSA 182 due to the presence of a third, unknown aircraft in the area; and the controller's failure to advise PSA 182 of the Cessna's direction of movement (Ibid., pp. 40–41). All of these points were noted by the majority in the NTSB report but were briefly stated in the conclusions rather than cited as contributory factors.

Conclusion

The Flight 182 disaster over San Diego remains one of the biggest and most horrific air disasters in U.S. aviation history, one that could have been prevented if better flight rules had been followed. The only silver lining of the appalling tragedy is that the accident prompted the implementation of stricter safety regulations around busy airports across the United States.

"Aircraft Accident Report." (1979). National Transportation Safety Board. Retrieved July 25, 2006, from

"CVR Transcript: PSA Boeing 727." (n.d.). dnausers.net. Retrieved July 25, 2006, from http://dnausers.d-n-a.net/dnetGOjg/250978.htm

Shess, T. (1998). "This is it!" San Diego Magazine Online. Retrieved July 25, 2006, from

Stich, R. (2005). Unfriendly Skies: 20th and 21st Centuries. Reno, Nevada: Diablo Western Press.