Pacific Southwest Airlines Flight 182

Pacific Southwest Airlines Flight 182

File:W780925-1.jpg PSA Flight 182 as it crashes over San Diego
Occurrence
Date	September 25, 1978
Summary	Mid-air collision
Site	San Diego, California
Aircraft type	Boeing 727-214
Operator	Pacific Southwest Airlines
Registration	N533PSdisaster
Passengers	128
Crew	7
Fatalities	144, including 7 on ground
Injuries	9 on ground
Survivors	0

Pacific Southwest Airlines (PSA) Flight 182, registration N533PS, was a Boeing 727-214 aircraft that collided with a private Cessna 172 while on approach to San Diego, California's Lindbergh Field on a flight from Sacramento via Los Angeles on September 25, 1978.

The Boeing crashed into North Park, a San Diego neighborhood, killing all 135 on board. The two men aboard the Cessna also perished, as did seven persons on the ground, including a family of four. Nine other people on the ground were injured and 22 homes were destroyed or damaged. With a death toll of 144 it remains the worst aircraft disaster in California history to date, and was the first Pacific Southwest Airlines incident involving fatalities.

Flight 182 had just begun its final approach into Lindbergh Field when it overtook the Cessna, which was being flown by two licensed pilots (not by a single student pilot as is often incorrectly stated). The Cessna was struck by the right wing of the Boeing, sending both aircraft crashing into the neighborhood below.

Investigators with the National Transportation Safety Board (NTSB) determined that the probable cause of the accident was the failure of the PSA flight crew to follow proper air traffic control (ATC) procedures. Flight 182's crew lost sight of the Cessna in contravention of the ATC's instructions to "keep visual separation from that traffic", and did not alert ATC that they had lost sight of it. Errors on the part of ATC were also named as a contributing factor, including the use of visual separation procedures when radar clearances were available. Additionally the Cessna pilots, for reasons unknown, did not maintain their assigned east-northeasterly heading of 070 degrees after completing a practice instrument approach, nor did they notify ATC of their course change.

The PSA pilots reported that they saw the Cessna after being notified of its position by ATC, although cockpit voice recordings revealed that shortly thereafter the PSA pilots no longer kept the Cessna in sight and were speculating about its position; at one point the 727's captain radioed the tower, "Okay, we had it there a minute ago... I think he's passed off to our right". However, the controller heard this transmission as "He's passing off to our right" and assumed the PSA jet had the Cessna in sight.

After getting permission to land, and about 40 seconds before colliding with the Cessna, the conversation among the four occupants of the cockpit (captain, first officer, flight engineer and an off-duty PSA captain who was riding in the cockpit's jump seat), was as follows:

Time	Source (and destination)	Content
09:01:11	First officer	Are we clear of that Cessna?
09:01:13	Flight Engineer	Suppose to be.
09:01:14	Captain	I guess.
09:01:20	Off-duty captain (laughing)	I hope!
09:01:21	Captain	Oh yeah, before we turned downwind I saw him at about one 'o'clock. Probably behind us now.

Actually, the Cessna was directly in front of and below the Boeing, and the PSA jet was descending and rapidly closing in on the small plane, which had taken a right turn to the east, deviating from the course assigned to it. According to the NTSB report the Cessna may have been a difficult visual target for the jet plane's pilots, as it was below them and blended in with the multicolored hues of the residential area beneath, and the apparent motion of the Cessna as viewed from the Boeing was minimized as both planes were on approximately the same course. The report said that another possible reason that the PSA aircrew had difficulty observing the Cessna was that its fuselage was made visually smaller due to foreshortening. However, the same report in another section also stated that "the white surface of the Cessna's wing could have presented a relatively bright target in the sunlight."

A visibility study cited in the NTSB report concluded that the Cessna should have been almost centered on the windshields of the Boeing from 170 to 90 seconds before the collision, and thereafter it was likely positioned on the lower portion of the windshield just above the windshield wipers. The study also said that the Cessna pilot would have had about a 10 second view of the Boeing from the left door window about 90 seconds before the collision, but visibility of the overtaking jet was blocked by the Cessna's ceiling structure for the remainder of the time.

Flight 182's crew never explicitly alerted the tower that they had lost sight of the Cessna. If they had made this clear to controllers, the crash might not have happened. Also, if the Cessna had maintained the heading of 70 degrees assigned to it by ATC, the NTSB estimates the planes would have missed each other by about 1000 feet (305 meters) instead of colliding, but the NTSB also stated that regardless of that change in course, it was the responsibility of the crew in the overtaking jet to comply with the regulatory requirement to pass "well clear" of the Cessna.

Approach Control on the ground picked up an automated conflict alert 19 seconds before the collision but did not relay this information to the aircraft because, according to the approach co-ordinator, such alerts were commonplace even when there was no actual conflict. The NTSB stated: "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."

This was the conversation in the PSA cockpit starting 16 seconds prior to collision with the Cessna:

Time	Source (and destination)	Content
09:01:31	First Officer	Gear down
09:01:34	Clicks and sound similar to gear extension
09:01:38	First officer	There's one underneath - I was looking at that inbound there!
09:01:42	Sound similar to nose gear door closing
09:01:45	Captain	Whoop! (involuntary groan as co-pilot pulled up the nose rapidly in a last ditch effort to avoid impact)
09:01:46	First officer	Aaargh!
09:01:47	Sound of impact
09:01:47	Off-duty Captain	Oh (expletive)!

The Boeing took less than 20 seconds to fall 2600 feet (790 meters) to the ground, during which this final conversation took place inside the cockpit of the out of control jet:

Time	Source (and destination)	Content
09:01:49	Captain	Easy baby, easy baby.
09:01:50	Unknown	Yeah
09:01:51	Sound of electrical system reactivation tone on voice recorder, system off less than one second
09:01:51	Captain	What have we got here?
09:01:52	First officer	It's bad.
09:01:52	Captain	Huh?
09:01:53	First officer	We're hit, man! We are hit!
09:01:55	Captain (to tower, in a calm voice)	Tower, we're going down. This is PSA.
09:01:57	Tower	OK, we'll get out the (emergency) equipment for you.
09:01:58	Unknown	Whoo!
09:01:58	Sound of stall warning
09:01:59	Captain (to tower)	This is it, baby!
09:01:59	Unknown	Bob
09:02:00	First Officer	(conversation deleted by NTSB as not germane)
09:02:01	Unknown	(conversation deleted by NTSB)
09:02:03	Captain (on intercom, to passengers)	Brace yourself.
09:02:04	Unknown	Hey, baby.
09:02:04	Unknown	Ma, I love you.
09:02:04.5	Electrical power to recorder stops

Investigators determined that Flight 182 struck the ground in a high speed nose down attitude, while banked 50° to the right. Seismographic readings indicated that the impact occured at 09:02:07, about 2.5 seconds after the cockpit voice recorder lost power. The coordinates for the Boeing crash site according to the NTSB report are 32°45′N 117°08′W. The largest piece of the Cessna impacted about six blocks away.

In the aftermath of the devastation on the ground, a controversy renewed in San Diego about why such a busy airport should be situated in a heavily populated area. Despite relocation proposals in search of an alternative to San Diego International Airport, the destination for Flight 182 remains in use and is the busiest single-runway commercial airport in the United States.[1]

As a result of the collision the National Transportation Safety Board recommended the immediate implementation of a Terminal Radar Service Area around Lindbergh Field to provide for the separation of aircraft, and also recommended an immediate review of control procedures for all busy terminal areas. The impact of these recommendations is reflected in today's arrangement of airspace around Lindbergh Field; a Class B area (formerly referred to as a Terminal Control Area) now exists around Lindbergh to provide for the separation of all aircraft operating in the area.

A dissenting opinion in the NTSB crash report by member Francis H. McAdams strongly questioned why the unauthorized change in course by the Cessna was not specifically cited as a "contributing factor" in the final report; instead, it was listed as simply a "finding", which carries less weight. McAdams also "sharply disagreed" with the majority of the panel on other issues, giving more weight to inadequate ATC procedures as another "probable cause" to the incident, rather than merely treating them as a contributing factor. McAdams also added the "possible misidentification of the Cessna by the PSA aircrew due to the presence of third unknown aircraft in the area" as a contributing factor. The majority panel members did not cite this as a credible possibility.

Of the two licensed pilots in the Cessna, one, 32 year old Martin B. Kazy Jr., possessed single-engine, multi-engine and instrument flight ratings, as well as a commercial certificate and an instrument flight instructor certificate. The other, 35 year old David Boswell, possessed single-engine, multi-engine ratings and a commercial certificate and was at the time of the accident practicing instrument flight under the instruction of Kazy in pursuit of his instrument rating.

One of the victims on board PSA Flight 182 was Alan Tetelman, president of Failure Analysis, en route to investigate a U.S. Navy plane crash.

Staff photographer Hans Wendt of the San Diego County Public Relations Office was attending an outdoors event with a still camera, and was able to take two photographs of the falling Boeing after the collision with the Cessna.[2]  Cameraman Steve Howell from local TV channel 39 was attending the same event as Wendt, and captured the Cessna on film as it fell to earth.

For its coverage of the disaster, The San Diego Union-Tribune was awarded a Pulitzer Prize in 1979 for "Local, General, or Spot News Reporting."[3]

In a fact-following-fiction scenario, the NBC telemovie Emergency!: Survival on Charter #220 (effectively a two-hour Emergency! episode filmed after the show was no longer a weekly series) was aired in March 1978, six months before the accident involving PSA Flight 182. It detailed the accidental daytime mid-air collision of a Douglas DC-8 airliner and a much smaller two-person aircraft and the resulting crash in a residential area of Los Angeles County.

See also

• List of accidents and incidents on commercial airliners
• List of notable mid-air and runway collisions
• Aeroméxico Flight 498, a 1986 collision over a heavily-populated southern California neighborhood, similar to PSA Flight 182, which finally spurred regulatory bodies into action and led to mandatory collision avoidance equipment.
• St. Augustine High School, located close to the PSA Flight 182 crash site

References

• National Transportation Safety Board report NTSB-AAR-79-5
• Macarthur Job (1996). Air Disaster Volume 2

External links

• The full report of the NTSB investigation - PDF file, 1.8 MB
• The full report of the NTSB investigation - PDF file, 5.3 MB (alternate link)
• Aviation Safety Network accident description
• Article about Flight 182 on PSA History Page
• Notable California Aviation Disasters Website listing significant aviation accidents in California
• San Diego magazine 20th anniversary article about the PSA Disaster - Archived copy from www.archive.org
• "Death Over San Diego", Time Magazine, Oct 9 1978
• TV Channel 10 (in San Diego) 25th Anniversary article with eyewitness accounts
• PSA Crash Page with map
• Pre-crash photos of 727 N533PS
• Audio of communications between ATC and PSA Flight 182 - WAV file, 535 KB