They appeared in several publications around the world including the cover of Time magazine. Another television cameraman, covering the same event in North Park, also managed to capture footage of the falling Cessna wreckage. Cause of the Crash

Probable Cause: 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)

Contributory Cause: The NTSB report also cited the air traffic control procedure as a contributory cause to the accident. Specifically, the procedure which "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.)

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

Personnel Qualifications, Aircrafts and Weather Conditions: All flight crew personnel on both the aircrafts including the pilots abroad the Cessna were qualified. The personnel in the San Diego approach control and the Lindbergh tower were also adequately qualified and experienced. The aircraft used on Flight 182 (a Boeing 727-214, N533PS), was owned and operated by Pacific Southwest Airlines, Inc. was within prescribed weight and balance limitations for the flight. The Cessna 172M, N77llG, owned and operated by Gibbs Flite Center, Inc., was similarly within prescribed weight and balance limits for the flight. The Weather conditions in and around San Diego at the time of the accident were clear and the visibility was considered as good for 10 miles. ("Aircraft Accident Report," 1979, p. 5-6) Hence, it was concluded by the NTSB that none of these factors contributed in any way to the accident.

Dissenting Opinion: One of the members of the NTSB disagreed with the findings of the majority regarding the probable and contributory causes of the accident and recorded his dissent in the Aircraft Accident Report. According to his dissenting opinion, the inadequacies of the air traffic control system should have been cited as a "probable cause" rather than a "contributory cause" of the accident. In support of his contention, the dissenting member argued that the San Diego approach control had the capability of providing either vertical or lateral separation and should have used the procedure for the control of both aircraft. Had such a procedure been used, the accident would not have occurred; hence, in the opinion of the dissenting member, the failure by the aircraft traffic control to do so was a direct and probable cause, rather than an indirect and contributory cause of the accident. (Ibid. 39)

Moreover, the dissenting member also cited a number of factors that, in his opinion, were contributory. For example, he argued that the approach controller failed to restrict Flight 182 to a 4,000-foot altitude while it was within the Montgomery filed area; if such altitude restriction had been issued, the accident would possibly not have occurred. He also cited the failure of the Cessna to maintain the assigned heading of 070o, the fact that two separate facilities were controlling traffic in the same airspace, the failure of the San Diego Approach Control to react to the 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 failure of the controller to advise PSA 182 of the direction of movement of the Cessna as additional contributory factors. (Ibid. 40-41) All of these points were also noted by the majority in the NTSB report but were briefly stated in the conclusions rather than being cited as contributory factors.

Alternative Viewpoint About the Cause of the Accident

Rodney Stich in his book Unfriendly Skies cites another cause for the accident, which appears nowhere in the NTSB report; the allegation that the flight-crew of flight 182 was hung-over from a late night party at Sacramento and was dead-tired as most of them had no more than two hours of sleep before the initial leg of flight...

He bases his argument on the testimony of Helen Rhea from Los Angeles, who was a passenger on flight 182 from Sacramento and had disembarked at Los Angeles. Helen later recalled her conversation with a flight attendant, Debbie McCarthy, during the flight to Los Angeles who had disclosed that she had been at a party in one of the crew motel rooms at the Sacramento Airport from eleven p.m. until 5 a.m. And the entire crew had been there. Large quantities of whisky were allegedly consumed at the party and Debbie herself had confessed to being "very tired" and had remarked: "All of the crew is really hung over." (Stich 2005, p. 175).
The fact about the party and the tiredness of the crew is further corroborated by the CVR recording of Flight 182, before leaving the terminal at Los Angeles, when a female flight attendant asks the captain, "Tired, are you?" And the captain responds, "I'm dragging. It was a short night." (Quoted by Stich, 2005, p. 176) Stich also alleges in his book that the American pilot's union (ALPA), who knew of the partying, obstructed disclosure of the evidence about crew fatigue and the press distorted and suppressed the real facts in order to protect their valuable airline advertisers -- unfairly diverting blame for the accident towards the pilots of the Cessna who were incorrectly reported as being "student pilots." (Ibid. 179) Stich goes on to suggest that the NTSB itself was involved in the cover-up as it carefully omitted the sections in the CVR, which reflected absence of sleep and the tiredness of the crew.

How The Accident Affected Regulations on Air-traffic Control

Since the NTSB report had cited the air traffic control procedure, which authorized the controllers to use visual separation when the capability for radar separation existed, as a contributory cause of the accident, it recommended a number of measures relating to controlled airspace around busy airports. These recommendations as well as public and media attention on the mid-air collision resulted in a number of changes in the Federal Aviation Regulations (FAR) on flying.

The NTSB made four "urgent" and "priority" action recommendations in its inquiry report on the accident to the Federal Aviation Administration (FAA):

Implement a Terminal Radar Service Area (TRSA) at Lindbergh Airport, San Diego, California. (Class I-Urgent Action)

Review procedures at all airports which are used regularly by air carrier and general aviation aircraft to determine which other areas require either a terminal control area or terminal control radar service area and establish the appropriate one. (Class II-Priority Action)

Use visual separation in terminal control areas and terminal radar service areas only when a pilot requests it, except for sequencing on the final approach with radar monitoring. (Class I, Urgent Action)

Re-evaluate its policy with regard to the use of visual separation in other terminal areas. (Class II, Priority Action). ("Aircraft Accident Report," 1979, p.37)

The NTSB's recommendations were eventually implemented and the airspace around Lindbergh Field, for instance, is now declared Class B area in which separation of all aircrafts is provided by the Air Traffic Control (ATC). The controlled airspace procedures were streamlined and simplified to remove confusion. For example, as per the Federal Aviation Administration's (FAA's) Aeronautical Information Manual, IFR operations in any class of controlled airspace now requires that a pilot must file an IFR flight plan and receive an appropriate ATC clearance; standard IFR separation is provided to all aircraft operating under IFR in controlled airspace, and it is the responsibility of the pilot to insure that ATC clearance or radio communication requirements are met prior to entry into Class B, Class C, or Class D airspace.

Conclusion

The Flight 182 disaster over San Diego remains one of the biggest and most horrific air disasters in the U.S. aviation history, which 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 in the U.S.

References

Aircraft Accident Report." (1979). National Aircraft Safety Board. Retrieved on July 25, 2006 at http://www.psa-history.org/museum/NTSBAAR7905.pdf

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

Shess, T. (1998). "This is it!" San Diego Magazine online. Retrieved on July 25, 2006…