Pacific Southwest Airlines Flight 182

Pacific Southwest Airlines Flight 182

File:W780925-1.jpg Hans Wendt's photograph of PSA Flight 182 falling
Accident
Date	September 25, 1978
Summary	Mid-air collision
Site	San Diego, California
Total fatalities	144 (7 on ground)
Total injuries	9 (on ground)
Total survivors	0
First aircraft
Type	Boeing 727-214
Operator	Pacific Southwest Airlines
Registration	N533PSdisaster
Flight origin	Sacramento Int'l Airport
Stopover	Los Angeles Int'l Airport
Destination	San Diego Int'l Airport
Passengers	128
Crew	7
Survivors	0
Second aircraft
Type	Cessna 172
Operator	Gibbs Flite Center, Inc.
Registration	N7711G
Flight origin	Montgomery Field San Diego, California
Crew	2
Survivors	0

Pacific Southwest Airlines (PSA) Flight 182, registration N533PS, was a Boeing 727-214 commercial airliner that collided over San Diego, California with a private Cessna 172 on September 25, 1978. The death toll of 144 makes it the deadliest aircraft disaster in Californian history to date, and it was the first Pacific Southwest Airlines incident involving fatalities. It was also the deadliest plane crash in the history of the United States until American Airlines Flight 191 went down eight months later.

The Boeing crashed into North Park, a San Diego neighborhood, killing all 135 on board. The two men aboard the Cessna died, as did seven people on the ground, including a family of four. Nine others on the ground were injured and 22 homes were destroyed or damaged.

Incident

Monday morning, September 25, 1978, was an unusually warm day in San Diego. Southern California was experiencing what locals call a "Santa Ana" day, and people in the San Diego area would later experience 100 degree temperatures as the day wore on. At the time of the accident the winds were calm, the temperature 85 degrees F., the visibility 10 miles.

Pacific Southwest Airlines flight 182 was a popular early-morning commuter flight en route to San Diego's Lindbergh Field. The flight had originated in Sacramento, then had a brief stop over in Los Angeles. At the controls were Capt. James E. McFeron (with over 10,000 hours flying time in the B-727), co-pilot Robert E. Fox, and flight engineer Martin J. Wahne. As it neared the end of its flight, heading downwind in an easterly direction and just beginning its final approach into Lindbergh Field at about nine in the morning in full sunlight and clear weather conditions, it overtook a small Cessna aircraft from behind and collided with it. The Cessna was being flown by two licensed pilots (not by a single student pilot as is often incorrectly stated). One Cessna pilot was 32-year-old Martin B. Kazy Jr., who 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, a U.S. Marine Corps sergeant, possessed single-engine, multi-engine ratings and a commercial certificate and was at the time of the accident practicing ILS approaches under the instruction of Kazy in pursuit of his instrument rating. They had departed from Montgomery Field, and were navigating under VFR which did not require the filing of a flight plan. Boswell had been wearing a "hood" to limit his field of vision, much like a welder's hood, as is normal in ILS training.

# = Nonpertinent word * = Unintelligible word () = Questionable text (()) = Commentary
Communication between PSA 182 and controllers
Time	Source	Content
08:59:39	San Diego approach control	PSA one eighty-two, additional traffic's ah, twelve o'clock, three miles just north of the field, northeastbound, a Cessna one seventy-two climbing VFR out of one thousand four hundred
08:59:39	Flight engineer	Yeah ((Sound of laughter))
08:59:39	First officer	Very nice
08:59:41	Flight engineer	He really broke up laughing I said so I'm late
08:59:48	((Off duty captain relays an anecdote until 09:00:10))
08:59:50	First officer	Okay we've got that other twelve

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:

# = Nonpertinent word * = Unintelligible word () = Questionable text (()) = Commentary
Time	Source	Content
09:01:11	First officer	Are we clear of that Cessna?
09:01:13	Flight Engineer	Supposed to be
09:01:14	Captain	I guess
09:01:15	First officer	(Fifteen)
Between 09:01:15 and 20	Unknown	((Sound of laughter))
09:01:20	Off-duty captain	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 report issued by the National Transportation Safety Board (NTSB), 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 instead of turning to 90 degrees, the NTSB estimates the planes would have missed each other by about 1000 feet (305 meters) instead of colliding. Ultimately, the NTSB maintained 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:

# = Nonpertinent word * = Unintelligible word () = Questionable text (()) = Commentary
Time	Source	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
09:01:39	Unknown	*
09:01:39	First officer	I was looking at that inbound there
09:01:42	((Sound of thump similar to nose gear door closing))
09:01:45	Captain	Whoop!
09:01:46	First officer	Aaargh!
09:01:47	((Sound of impact))
09:01:47	Off-duty Captain	Oh # #

At about the point where PSA 182 was beginning a right 180 degree turn for its final westerly approach into Lindbergh, it had overtaken the Cessna which was directly below it, both in a 090 (due east) heading, and the two aircraft collided. The collision occurred at approximately 2,600 ft.[1] and broke N7711G to pieces, along with pieces of the 727's right wing and empennage. According to several witnesses on the ground there was first a loud metallic "crunching" sound, then an explosion and fire that compelled them to look up. The wreckage of the Cessna plummeted to the ground, its vertical stabilizer not only torn from its fuselage but also bent leftward, its debris hitting around 3500 feet northwest of where the 727 went down. PSA 182's right wing was heavily damaged, rendering the plane uncontrollable and sending it careening into a sharp right bank (clearly seen in the Hans Wendt photos), and the fuel tank inside it had ruptured and started a fire, when this final conversation took place inside the cockpit:

# = Nonpertinent word * = Unintelligible word () = Questionable text (()) = Commentary
Communication between PSA 182 and controllers
Time	Source	Content
09:01:48	Unknown	#
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	Tower, we're going down, this is PSA
09:01:57	Lindbergh tower	OK, we'll call the equipment for you
09:01:58	Unknown	Whoo!
09:01:58	((Sound of stall warning))
09:01:59	Captain	This is it, baby
09:01:59	Unknown	Bob
09:02:00	First Officer	# # #
09:02:01	Unknown	# #
09:02:03	Captain (on intercom, to passengers)	Brace yourself
09:02:04	Unknown	Hey, baby *
09:02:04	Unknown	Ma, I love yah
09:02:04.5	((Electrical power to recorder stops))

Flight 182 struck the ground 3 miles northeast of Lindbergh Field, in a residential section of San Diego known as North Park. It impacted in a high-speed, nose-down attitude while banked 50° to the right. Seismographic readings indicated that the impact occurred at 09:02:07, about 2.5 seconds after the cockpit voice recorder lost power. The jet impacted just west of the I-805 freeway, approximately 30 feet north of the intersection of Dwight and Nile streets, with the bulk of the debris field spreading in a northeast to southwesterly direction towards Boundary Street. The coordinates for the Boeing crash site are 32°44′37″N 117°07′14″W. The largest piece of the Cessna impacted about 6 blocks away near 32nd St. and Polk Ave. The explosion and fire created a mushroom cloud that could be seen for miles, and first responders on the scene reported that there was nothing left but utter destruction [2]. In total, 144 people[3] in the disaster lost their lives, including 30 PSA employees [4] deadheading to PSA's San Diego base, 7 crewmembers, the 2 Cessna occupants, and 7 residents on the ground. An additional 9 people on the ground were injured, and 22 homes across a 4 block area were destroyed or damaged. At the time it was the U.S.'s deadliest commercial air disaster, and it remains the worst in California's history.

Investigation

Sequence of events leading to the collision, X - PSA 182 ♦ - Cessna 172

The National Transportation Safety Board report (report number NTSB/AAR-79-05; released: 19-APR-1979)[5] 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. Concerning this the NTSB report states, "According to the testimony of the controllers and the assistant chief flight instructor of the Gibbs Flite Center (owner of the Cessna), the 0859:56 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."

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 a third unknown aircraft in the area" as a contributing factor. The majority panel members did not cite this as a credible possibility.

Aftermath

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.

CG render of PSA 182 colliding with N7711G

Staff photographer Hans Wendt of the San Diego County Public Relations Office who was attending an outdoor event with a still camera, and was able to take the two photographs of the falling Boeing after the collision with the Cessna. 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 Evening Tribune, a predecessor to The San Diego Union-Tribune, was awarded a Pulitzer Prize in 1979 for "Local, General, or Spot News Reporting."

Plaque honoring crash victims

One of the victims on board PSA Flight 182 was Alan Tetelman, professor of metallurgy at UCLA and president of Failure Analysis Associates (now Exponent), en route to investigate a U.S. Navy helicopter crash.

A memorial plaque honoring everyone who died on both planes and on the ground is located in the San Diego Aerospace Museum, near the Theodore Gildred Flight Rotunda. On the 20th anniversary of the crash, a tree was planted next to the North Park library, and a memorial plaque was dedicated to those who lost their lives. The library is not in the immediate vicinity of the actual crash site, which is completely rebuilt and bears no visible evidence of the crash.

As a result of the tragedy, the NTSB 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. However, this initial rule did not include small general aviation aircraft. Therefore, on May 15, 1980, the Federal Aviation Administration(FAA), implemented what is called "Class B airspace" to provide for the separation of all aircraft operating in the area. Additionally, all aircraft, regardless of size, are required to operate under "positive radar control," a rule that allows only radar control from the ground for all aircraft operating in the airport's airspace, and strictly prohibits use of visual separation, as was allowed in 1978.

San Diego's Approach Control was expanded in 1994 to service a wider area. The facility, named TRACON, (Southern California Terminal Radar Approach Control) is one of the nation's busiest approach facilities and covers the area from north of Los Angeles to the Mexican border, and from the Laguna Mountains east of San Diego to the Channel Islands off the coast of southern California.

At the time of the crash, Lindbergh Field was the only airport in San Diego County with an Instrument Landing System. As a direct result of the accident the FAA quickly installed the system at Montgomery and Gillespie fields, and at McClellan-Palomar Airport.

In recent years more efficient technology has been added at airports across the nation in the area of conflict alert. "Collision Alert," in operation at southern California's TRACON, provides the air traffic controller with visual and audible warnings if aircraft are within close proximity to each other, or if they are in a projected too-close proximity. A feature known as "Traffic Collision Alert and Avoidance System" is installed in all commercial passenger aircraft and in most commercial cargo planes. It not only gives the pilots visual and audible warnings in the cockpit when two aircraft are approaching each other, but even goes so far as to provide the pilots with a plan of action by directing them to climb or descend to avoid the other aircraft.

Because the PSA 182/Cessna collision was the result of pilot error, it is used as a teaching aid in modern flight training. The Embry-Riddle Aeronautical University, a branch of which is located in Prescott, Arizona, uses the crash in some of its "human factors" classes used in pilot curricula.

After the tragedy of flight 182, Pacific Southwest Airlines went on to operate as one of the western U.S.'s most popular and successful commercial airlines throughout the rest of the 1970s and most of the '80's. The airline, which operated its first flight on May 6, 1949, became a division of USAir on May 29, 1987; the last PSA flight leaving San Diego as flight 1486 bound for Las Vegas, Nevada, on April 8, 1988[6]. Sadly, although operating under parent company USAir, another PSA flight would be involved in a tragic event on December 7, 1987, Pacific Southwest Airlines Flight 1771.

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) had been 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.

On September 25, 2008, over 100 relatives and friends of the victims of PSA 182 gathered at Dwight and Nile streets in North Park for the 30th anniversary memorial of that fateful day [7].

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.
• Charkhi Dadri Mid-Air Collision This crash led to the Indian Government making all aircraft in Indian Aerospace to be equipped with TCAS mandatory.

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
• Accident description at the Aviation Safety Network
• Article about Flight 182 on PSA History Page
• San Diego magazine 20th anniversary article about the PSA Disaster - Archived copy from www.archive.org
• "Death Over San Diego", Time Magazine, October 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
• Tribute Video to those who lost their lives, and PSA 182
• Air Tragedy Remembered Union Tribune article about 30th anniversary tribute
• PSA Crash in 1978 A blog about the crash, with many personal accounts of the crash scene immediately after impact