Pacific Southwest Airlines Flight 182

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PSA Flight 182
Accident summary
Accident type Airplane collision in the air
place San Diego ( USA )
date September 25, 1978
Fatalities 144 (7 on the ground)
Injured 9 (on the ground)
1. Aircraft
Aircraft type Boeing 727-214
operator Pacific Southwest Airlines
Mark N533PS
Departure airport Sacramento airport (USA)
Destination airport San Diego Airport (USA)
Passengers 128
crew 7th
Survivors 0
2. Aircraft
Aircraft type Cessna 172
operator Gibbs Flite Center, Inc.
Mark N7711G
Departure airport Montgomery Field
San Diego (USA)
Destination airport Montgomery Field
Passengers 0
crew 2
Survivors 0
Lists of aviation accidents

Pacific Southwest Airlines flight 182 was the flight number of a scheduled flight of Pacific Southwest Airlines from Sacramento to San Diego , which on September 25, 1978 collided with a small aircraft in the air . In the resulting crash, all 137 people on both aircraft were killed. In addition, seven people died on the ground. Nine people on the ground suffered injuries. The cause of the accident was errors by the pilots of Flight 182 and air traffic control. It was the worst aircraft accident in the history of the United States to date , until American Airlines Flight 191 crashed eight months later.

The accident

the accident

The weather conditions on September 25, 1978 were unusually warm due to the Santa Ana winds . The outside temperature at this time was 29 ° C, temperatures of up to 37 ° C were expected for the rest of the day. There was almost no wind. At the time of the collision, visibility was 16 kilometers (10 miles).

The Boeing 727 of PSA with the aircraft registration number N533PS had completed 24,088 flight hours, the three engines were of the Pratt & Whitney JT8D-7B type . Pacific Southwest Airlines Flight 182 was a frequently used morning commuter flight to Lindbergh Field Airport in San Diego. The flight had started in Sacramento with a short stopover in Los Angeles . The launch in Los Angeles took place at 8:34 a.m. local time. At the time of the accident, flight captain James E. McFeron had flown more than 10,000 hours on the Boeing 727 . In the cockpit were also the copilot Robert E. Fox, the flight engineer Martin J. Wahne and the off-duty PSA captain Spencer Nelson, who flew on the jump seat.

There were two pilots on board the Cessna at the time of the accident. The light aircraft took off from Montgomery Field at around 8:16 a.m. PST (local time) . One pilot was a 32-year-old flight instructor. He held a license for single- and multi-engine aircraft, an instrument flight rating , a commercial pilot license and an instrument flight instructor rating (IFR). The second pilot was 35 years old and a sergeant in the US Marine Corps . He was in possession of a license for single and multi-engine aircraft as well as a commercial pilot license. He was in training to become an instrument pilot. At the time of the accident, he was practicing the instrument approach under the supervision of the flight instructor . The flight was carried out under visual flight rules , for which no flight plan is prescribed. At the time of the accident, the trainee pilot was wearing a hood that is customary for IFR training and restricts the field of vision.

The pilots of the PSA reported to the tower that they had the Cessna in sight after they had been informed of the position of the small aircraft by the air traffic controller. However, the recordings of the cockpit flight recorder showed that shortly afterwards the PSA crew had lost visual contact with the N7711G and were making assumptions about its position. The tower's records show that the pilots radioed the tower

"Okay, we had it there a minute ago ... I think he's passed off to our right"

"Okay, we had it a minute ago ... I think it passed [flew past] on our right."

- NTSB, AAR795

However, the pilot understood that the Cessna was just passing by to the right and therefore assumed that the Boeing still had visual contact with the Cessna. After the Boeing 727 had received permission to land, about 40 seconds before the collision with the Cessna, the conversation between the four people in the cockpit revolved around the Cessna, which was no longer in sight. However, the conversation was ended by the captain with the words:

"Oh yeah, before we turned downwind, I saw him at about one o'clock, probably behind us now"

"Before we turned into the counter-approach, I saw him at about one o'clock, probably already behind us."

- NTSB, AAR795

In fact, the Cessna was flying just in front of and below the 727. The Boeing was descending and caught up with the Cessna very quickly.

At this point, the Cessna had made a curve to the east, deviating from its assigned course. According to the report of the National Transportation Safety Board (NTSB), the Cessna could have been difficult for the crew of the Boeing 727 to make out because the small aircraft was located below the Boeing and therefore blended in color with the settlement area below. The proper movement of the Cessna was put into perspective by the direction of flight of the Boeing, as both were on approximately the same course. This contrasts with the statement that the white wing of the Cessna should have been a bright and conspicuous target in the sunlight.

A study to determine the visibility conditions of the NTSB came to the result that the Cessna was optically almost in the middle of the cockpit window between 170 and 90 seconds before the collision. Subsequently, the position of the Cessna was below the edge of the window because the Boeing pilots were seated too low, or out of sight or covered by the windshield wipers. For the pilot of the Cessna, the Boeing was only visible for about 10 seconds through a side window due to the design of the small aircraft ( shoulder- wing aircraft ), namely about 90 seconds before the collision.

At no point did the crew of Flight 182 inform the tower that they had lost visual contact with the Cessna. Had she clearly communicated this to the pilots, the collision might have been avoidable. If the Cessna had stayed on its pilot-assigned course of 70 ° instead of turning to 90 °, the two aircraft would have missed each other by about 1000  ft (300  m ).

In the end, the NTSB comes to the conclusion that it was the responsibility of the pilots of Flight 182 to maintain a sufficient lateral distance to the Cessna when overtaking, in compliance with the applicable regulations, regardless of their course change.

The Approach Control noticed an automatic collision warning 19 seconds before the collision, but not forwarded them to the Boeing since, according to the coordinator approach ( approach co-ordinator ) such warnings happen frequently, though no immediate risk of collision existed. The NTSB report states:

“Based on all information available to him, he decided that the crew of Flight 182 were complying with their visual separation clearance; that they were accomplishing an overtake maneuver within the separation parameters of the conflict alert computer; and that, therefore, no conflict existed. "

“Based on all the information available to him [the controller] he came to the conclusion that the crew of flight 182 met the requirements for the lateral clearance, that they carried out an overtaking maneuver taking into account the minimum distance but below the alarm threshold of the automatic collision warning and therefore none There was a risk of collision. "

- NTSB, AAR795

At this point in time, PSA 182 initiated a right turn by 180 ° in order to turn into the final approach onto runway 27 of the airport. The Cessna was just below the Boeing at this point, both aircraft were on course 090, when the aircraft collided at 9:01:47 a.m. (PST) at an estimated altitude of 2,600 ft (approx. 790 m). The Cessna with the registration number N7711G was completely destroyed by the impact. At Boeing, parts of the right wing and the tail unit were damaged. The wreck of the Cessna fell to the ground with the rudder partially detached and bent. As a result of the collision, the right wing of the PSA 182 was so badly damaged that the aircraft became uncontrollable. The kerosene tank in the area was torn open and the kerosene flowing out had ignited.

Flight 182 hit 4830 meters northeast of the airport , Lindbergh Field , with about 50 ° bank and with the nose tilted down in a residential area of San Diego called North Park , approximately 3500 ft (1100 m) from the crash site of the Cessna, on the ground . Recordings from some seismographs show that the impact occurred about 2.5 seconds after the cockpit voice recorder stopped recording at around 9:02:07 a.m. (PST). The crash site was near I-805 , right next to the intersection of Dwight and Nile streets . Most of the debris was distributed in a field from northeast to southwest towards Boundary Street . A total of 144 people died, including 30 Pacific Southwest Airlines employees who were on a dead-head flight to the PSA San Diego site. The fatalities also included two professors from the University of California, Los Angeles , the medical sociologist Leo G. Reeder and the metallurgist Alan S. Tetelman , as experts on the fracture behavior of technical materials on the way to another site of the accident. 22 residential buildings in a neighborhood of four apartment blocks were destroyed or damaged. At the time of the accident, it was the aircraft accident with the most deaths in civil aviation in the United States.

Determination of causes

Graphic animation of the events: X - PSA 182 ♦ - Cessna 172

The National Transportation Safety Board found in the investigation report that the " probable cause" for the crash was the violation of air traffic control procedures by the PPE pilots. The pilots of Flight 182 had lost sight of the Cessna and had not reported the loss of sight to the responsible air traffic controller . In doing so, they acted contrary to his instructions: "keep visual separation from that traffic".

Another “contributing factor” related to the visual separation procedures , although radar clearances would have been available.

It was also noted that the pilot of the Cessna unknown reasons the assigned northeastern heading of 070 ° einhielten ( "heading") after making a landing approach under instrument flight rules had finished, nor informed the air traffic controllers about this change of course.

The NTSB report writes:

“According to the testimony of the controllers and the assistant chief flight instructor of the Gibbs Flite Center (owner of the Cessna), the 08:59:56 transmission from approach control to the Cessna only imposed an altitude limitation on the pilot, he was not required to maintain the 070 ° heading. However, the assistant chief flight instructor testified that he would expect the [Cessna] pilot to fly the assigned heading or inform the controller that he was not able to do so. "

“According to the testimony of the air traffic controllers and the assistant chief flight instructor of the Gibbs Flite Center (owner of the Cessna), the radio message from the approach controller to the Cessna at 8:59:56 a.m. contained an altitude restriction for the pilot, who did not have to follow the course of 070 ° maintained. However, the assistant chief flight instructor stated that he would expect the [Cessna] pilot to keep the assigned course or to inform the controller that he could not keep the course. "

- NTSB, AAR795

In a dissenting opinion in the report, a member of the investigative commission, Francis H. McAdams, criticized the fact that the unauthorized change of course of the Cessna was not explicitly identified as a "contributing factor" in the commission's report. It would simply have been classified as a "finding" that would have less weight.

McAdams also contradicted the majority of the commission to the effect that the misconduct by air traffic control should have been classified as a “probable cause” for the accident, instead of only being classified as a “contributing factor”. In addition, the incorrect identification of the Cessna by the PSA pilots due to the presence of a third, unknown aircraft, should also have been rated as a “contributing factor”. The majority of the panel did not want to mention this as a credible possibility in the report.

documentation

The photographer from the Public Relations Office of the City of San Diego, Hans Wendt, who was participating in an outdoor event at the time of the accident, was able to photograph the crash of the Boeing 727 after the collision with the Cessna. The cameraman Steve Howell of the local TV station channel 39 attended the same event as Wendt and filmed the crashing Cessna. The magazine The San Diego Evening Tribune , forerunner of The San Diego Union-Tribune , was for her report on the disaster in 1979 with the Pulitzer Prize in the category of Local, general, or Spot News Reporting Award.

Consequences

Computer graphics of the collision of PSA 182 with N7711G

In the aftermath of the accident, the public debate flared up again in San Diego as to why such a busy airport is located in the middle of a densely populated area. Efforts have been made to find alternatives to San Diego International Airport , but Lindbergh Field is still the busiest commercial airport with only one runway in the United States.

As a result of its investigations, the NTSB recommended the immediate establishment of a Terminal Radar Service Area around the San Diego Airport to better ensure the separation between the aircraft. In addition, a review of air traffic control procedures at all busy airports was recommended. However, this recommendation did not include general aviation small aircraft . The Federal Aviation Administration (FAA) took this as an opportunity to set up " Class B airspace " on May 15, 1980 , which is supposed to ensure the separation of all aircraft in the approach area. In addition, all aircraft, regardless of their size, now had to observe a "positive radar control", that is, all aircraft were subject to radar control within the airport airspace, the use of a visual separation, as was still permitted in 1978, was thus prohibited.

San Diego's approach control was expanded to a larger area in 1994. For this purpose, a TRACON called Southern California Terminal Radar Approach Control was set up, which extends north-south from north Los Angeles to the Mexican border and east-west from the Laguna Mountains east of San Diego to the Channel Islands on the south coast California has.

At the time of the accident, Lindbergh Field Airport was the only airfield in San Diego County with an instrument landing system (ILS). As a direct consequence, the airports of Montgomery, Gillespie fields and McClellan-Palomar Airport were equipped with an ILS.

Since the collision of the PSA 182 with the Cessna was due to human error, this case is now used as a case study in pilot training. The Embry-Riddle Aeronautical University uses this case as part of its curriculum as part of its subject "human factors".

The airline, which had offered scheduled flights from May 6, 1949, merged on May 29, 1987 with USAir ; the last flight under the name PSA (flight 1486 from San Diego to Las Vegas) took place on April 8, 1988. With PSA Flight 1771 on 7 December 1987, a further airliner in the PSA was involved in an accident.

Commemoration

Memorial stone in memory of the victims

In memory of those killed on board both aircraft and those on the ground, a plaque was placed in the San Diego Aerospace Museum near the Theodore Gildred Flight Rotunda . A tree was planted next to the North Park Library to mark its 25th anniversary . The library is not in the immediate vicinity of the impact point, which has since been completely rebuilt and no longer shows any traces of the crash.

On September 25, 2008, more than 100 family members and friends of the crash victims met in the North Park neighborhood to mark the 30th anniversary of the crash.

filming

2012 accident in the eighth episode was the 11th season under the English title "Blind Spot (On Course to disaster; Hiding Plane in Sight)" or the German title "Human error" in the Canadian television series Mayday - alarm in the cockpit shown .

The pseudo documentary film Faces of Death , which was released in 1978 and deals with the subject of death and dying, shows excerpts from the rescue work.

literature

  • National Transportation Safety Board report NTSB-AAR-79-5
  • David Gero: Aviation Disasters: Accidents with passenger aircraft since 1950 . 1st edition. Motorbuch-Verlag, Stuttgart 1994, ISBN 3-613-01580-3 .
  • Job Macarthur: Air Disaster Volume 2 , 1996

Web links

Individual evidence

  1. ↑ a b c d e f g h Aircraft Accident Report 79-5 (AAR-79-5). (PDF) (No longer available online.) National Transportation Safety Board , on PSA history.org, April 20, 1979, archived from the original on October 29, 2012 ; Retrieved August 16, 2009 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.psa-history.org
  2. ^ Accident report N533PS, Aviation Safety Network (English), accessed on July 16, 2016.
  3. ↑ This is It! San Diego Magazine, August 1998, accessed February 2, 2014 .
  4. ↑ Lessons from disaster. Sign on San Diego, September 21, 1998, accessed August 18, 2009 .
  5. ^ PSA Flight 182 & 1771 Memorial Page. (No longer available online.) PSA History Museum, archived from the original on July 19, 2009 ; Retrieved August 18, 2009 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.jetpsa.com
  6. ↑ John M. Chapman, Howard E. Freeman, Ralph H. Turner, Daniel M. Wilner: Leo G. Reeder, Public Health; Sociology: Los Angeles University of California: In Memoriam, 1980
  7. ↑ Kanji Ono, Christian NJ Wagner, Russell A. Westmann, Alan Ardell: Alan Stephen Tetelman, Materials: Los Angeles University of California: In Memoriam, 1980
  8. ↑ Remembrances and ironies surrounding the crash of PSA Flight 182. San Diego Magazine, January 17, 2006 filed by the original on 17 January 2006 ; Retrieved August 18, 2009 (accessed from archive.org ).
  9. ↑ 1979 Winners - Journalism - Local General or Spot News Reporting. The Pulitzer Prize, accessed August 18, 2009 .
  10. ↑ Facts about San Diego International Airport. San Diego County Regional Airport Authority, accessed August 18, 2009 (2003-2008).
  11. ^ The History of PSA. PSA History Museum, accessed August 18, 2009 .
  12. ^ Criminal Occurrence description. Aviation Safety Network , accessed August 18, 2009 (1996-2009).
  13. ^ PSA crash victims remembered at morning service. Sign on San Diego, September 25, 2008, accessed August 18, 2009 .
  14. ↑ Air tragedy remembered. Sign on San Diego, September 26, 2008, accessed August 18, 2009 .

Coordinates: 32 ° 44 ′ 37 "  N , 117 ° 7 ′ 14"  W.