8
$\begingroup$

In 1978, a Pacific Southwest Airlines aircraft collided with a Cessna 172 while approaching the San Diego airport in California. The GA aircraft was piloted by a student, and crossed the approach trajectory of the B727, killing 144 people.

enter image description here
Source

To my understanding, ATC was not aware of the Cessna actual location, The airliner crew didn't see the Cessna, and the Cessna was not wrong being in this airspace near a busy regional airport.

What changed after this accident to make such situation impossible?

$\endgroup$
3
  • $\begingroup$ Are you looking for changes specifically in the San Diego area, or more generally? $\endgroup$
    – DeltaLima
    Sep 6 '17 at 23:21
  • 2
    $\begingroup$ The Cessna was being piloted by two licensed pilots, both of which held commercial pilot certificates. $\endgroup$
    – Ron Beyer
    Sep 7 '17 at 3:21
  • $\begingroup$ @DeltaLima: More generally. $\endgroup$
    – mins
    Sep 7 '17 at 5:41
8
$\begingroup$

The recommendations from the NTSB report are:

  • Implement a Terminal Radar Service Area (TRSA) at Lindbergh Airpot, San Diego, CA
  • 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 a terminal control radar service area and establish the appropriate one.
  • Use visual separation in terminal radar service areas only when a pilot requests it, except for sequencing on the final approach with radar monitoring.
  • Re-evaluate its policy with regard to the use of visual separation in other terminal areas.

The most direct change stemming from this accident is the establishment of a TRSA at Lindbergh on May 1, 1979. (It is now a class B area).

Also in 1979 the Lindbergh tower was equipped with some upgrades, including minimum safe altitude warning and conflict alert enhancements.

The other recommendations are fairly vague and I find no indication what, if any action was taken on them. But as Gerry pointed out in comments, this accident put emphasis on the FAA's effort to create TCAS. From the TCAS II V7.1 Intro booklet:

In 1978, the collision between a light aircraft and an airliner over San Diego served to increase FAA's efforts to complete development of an effective collision avoidance system.

The see-and-avoid system is still very much in use. Visual approaches are still used. There really were no immediate systemic changes made in response to the accident. Mostly it was just airspace configuration around KSAN and enhancements to the radar system there. But, like every accident, the NTSB and FAA learned from it and took steps to improve safety. The FAA releases pamphlets appropriately titled, "Lessons Learned," about what can be taken from different types of accidents.

$\endgroup$
2
  • $\begingroup$ It also put emphasis on the FAA's effort to create TCAS. From the TCAS II V7.1 Intro booklet: In 1978, the collision between a light aircraft and an airliner over San Diego served to increase FAA's efforts to complete development of an effective collision avoidance system. $\endgroup$
    – Gerry
    Sep 7 '17 at 12:16
  • $\begingroup$ @Gerry Good find. Thanks. Edited your quote in to improve the answer $\endgroup$
    – TomMcW
    Sep 7 '17 at 13:43
3
$\begingroup$

In addition to TomMcW@'s answer, the FAA also installed ILS systems at both KMYF and KCRQ and implemented Class B airspace around KSAN.

The Cessna wasn't just allowed near busy airspace, they were specifically doing ILS training at the airfield executing a missed approach under VFR.

Adding ILS systems at GA airports didn't directly change ATC procedures or airspace definitions, but it result in fewer GA aircraft needing to use KSAN for training.

Furthermore, PSA 182 did report traffic in sight but they continued their landing procedure anyway once they lost visuals. The fact that ATC didn't know precisely where the Cessna was and recognition that accidents happen even when aircraft report that they are maintaining visual separation also directly lead to Class B airspace being implemented at KSAN:

As a result of the crash, the NTSB recommended the immediate implementation of a Terminal Radar Service Area around Lindbergh Field to provide for the separation of aircraft, as well as an immediate review of control procedures for all busy terminal areas. This initial rule did not include small, general-aviation aircraft. Therefore, on May 15, 1980, the Federal Aviation Administration, 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.

(Wikipedia: Pacific Southwest Airlines Flight 182)

$\endgroup$
1
  • $\begingroup$ That quote from Wikipedia is misleading to the point of being incorrect. VFR-IFR sep in Class B is only one of: 1.5NM radar sep, 500' vertically, or visual separation. (And that's only if the other aircraft weighs more than 19000 pounds; otherwise the radar separation drops from 1.5NM to target resolution.) $\endgroup$
    – randomhead
    Aug 26 '21 at 14:29

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.