1987 — Jan 15, Planes Collide, Sky West Air & private plane, Kerns, UT — 10

— 10  NTSB. Aircraft Accident Rpt. (NTSB/AAR-88-/03). Midair Collision of Skywest…, 1988.

— 10  Planecrashinfo.com. “Accident Details. Skywest Airlines/Private, SLC, UT, Jan 15, 1987”

 

Narrative Information

 

NTSB Executive Summary:

 

“On January 15, 1987, about 1252 mountain standard time, SkyWest flight 1834, a Swearingen SA-226TC (METRO II), and a Mooney M20 collided in flight over Kearns, Utah, in visual meteorological conditions. The two pilots and six passengers aboard the METRO II and the two pilots aboard the Mooney were killed in the accident which occurred within the confines of the Salt Lake city airport radar service area.

 

“The issues examined in this report include the see-and-avoid concept as a means to prevent midair collisions, radar controller training and performance, pilot responsibilities to avoid controlled airspace until receiving proper clearance to enter, and overall Federal Aviation Administration responsibilities to provide collision protection for aircraft operating near major airports.

 

“The National Transportation Safety Board determines that the probable cause of this accident was lack of navigational vigilance by the Mooney instructor pilot which led to the unauthorized intrusion into the Salt Lake City airport radar service area. Contributing to the accident were the absence of a mode-C transponder on the Mooney airplane and the limitations of the air traffic control system to provide collision protection under the circumstances of this accident.”  (NTSB/AAR-88-/03, p. iii.)

 

“A school, several homes, automobiles, and public utilities were damaged by debris from the airplanes. An estimate of the ground damage was $1.8 million according to insurance carriers.”  (NTSB/AAR-88-/03, p. 3.)

 

“The major portions of both airplanes fell into roughly a 6- by 8-block area of a predominately residential section of Kearns, Utah. The wreckage area was located about 2 miles north of SLC 2 and about 8 miles south of SLC International Airport.”  (NTSB/AAR-88-/03, p. 9.)

 

“Although both airplanes were operating in a “see and avoid” environment, the Mooney pilots were not receiving ATC services, even though their airplane was within the ARSA. This should have heightened the vigilance of the pilots, especially the instructor pilot who was performing duties of a safety pilot. The Mooney pilots certainly should have been aware of the potential for other aircraft flying in the vicinity of the arrival pattern at SLC International Airport.

 

“In summary, the Safety Board concludes that the ability of the pilots of either airplane to have seen the other airplane in sufficient time to avoid the collision was marginal. However, the Mooney pilots, primarily the instructor pilot had a better capability to see the METRO II and avoid the collision. Therefore, in spite of the limitations of the see and avoid concept, the Safety Board concludes that the failure of the instructor pilot to see and avoid the other airplane was a factor in the accident.”  (NTSB/AAR-88-/03, p. 19.)

 

“The Safety Board has cited the limitations of the see and avoid concept as causal and contributing in other midair collision accidents. 51 The Safety Board believes that the reliance on

pilots to see and avoid other aircraft in an ATC controlled environment, especially with high density traffic and high closure speeds, is unacceptable, and it has urged the FAA to institute more positive and viable measures for traffic separation.”  (NTSB/AAR-88-/03, p. 20.)

 

“…the Safety Board believes that the Final controller’s failure to detect the traffic conflict and to provide conflict advisories was an element in the events that led to the accident, but the controller’s performance is not considered causal to the accident because of the circumstances of

the conflict.”  (NTSB/AAR-88-/03, p. 22.)

 

“The implementation of automated redundancies to assist controllers in their duties is several years from total implementation. In the meantime, the Safety Board believes that initial radar training, on-the-job training, and recurrent training should include “real world” scenarios to properly prepare controllers. The Safety Board believes that the FAA’s failure to require “real world” training for radar controllers regarding ARSA (and TCA) intruders indicates a deficiency in the ATC system that should have been identified and corrected before this accident. The fact that the SLC 2 traffic pattern was so close to the final approach path to SLC and the possibility that pilots would violate the ARSA should have been identified, and procedures and training should have been provided to cope with this problem. This system deficiency suggests a lack of a proactive quality assurance program within the FAA air traffic service.

 

“The apparent widespread number of TCA and ARSA intruders identified in the recent past and the number of near-midair collision reports should have prompted a systematic analysis by the FAA to develop accident prevention measures. For example, NASA ASRS reports for SLC during the months before the accident revealed several occurrences of pilots reporting VFR intruders in the SLC ARSA during vectors to land at SLC. In some of those instances, the location and circumstances were virtually identical to the location and circumstances of this accident.

 

“The Safety Board believes that a thorough review of this matter by the FAA before the accident

should have identified the potential for air traffic controllers to overlook untracked non-mode-C

aircraft in the area north of SLC 2. If the FAA had conducted such a review, the need for special

training or procedures would have been apparent.  In fact, a specific requirement that operations

out of SLC 2 be mode-C equipped could have been derived. Consequently, the Safety Board concludes that the lack of an aggressive quality assurance effort by the FAA was an element that

indirectly set the stage for this accident to occur.

 

“The present ATC system is not adequate to assure collision protection between aircraft participating in the system (generally flights operating in accordance with IFR) and nonparticipating aircraft (operating under VFR) in busy terminal areas. The ATC system must be enhanced to provide air traffic controllers with an automated (computerized) warning system to assist them in avoiding midair collisions. The system should alert controllers to an impeding traffic conflict in sufficient time so that they could take appropriate action to eliminate the collision threat.

 

“The Safety Board believes that controllers have and will continue to overlook conflicts between

IFR and VFR aircraft because of distraction, workload, and prioritizing of their duties. As long as the avoidance of collision between IFR and VFR aircraft depends on perfect human performance, i.e., vigilance and alertness of controllers and pilots, the potential for midair collisions will continue.

 

“The Safety Board believes that the FAA should expand the capabilities of its ARTS computers to include a conflict alert feature to warn controllers of an impending conflict between IFR aircraft and mode-C transponder-equipped VFR aircraft. The Safety Board understands that the computer software logic has already been developed for this feature but is not presently used because of computer processing limitations. The Safety Board has issued Safety Recommendation A-87-98 to the FAA urging it to procure additional processing capacity for these ARTS IIIA equipped terminal facilities and then add the VFR conflict alert (mode-C intruder) feature to the system. The FAA’s most recent response to this recommendation, dated March 11, 1988, stated that it was conducting a 30-day technical and operational review to determine if this conflict alert feature can be added to the terminal ATC facilities.

 

“The Safety Board believes that the facts and circumstances of this accident illustrate the need to

provide controllers with an automated warning system to assist them in preventing a midair collision between IFR and VFR aircraft. The final radar controller stated that if he had seen a VFR aircraft in the vicinity of the SkyWest aircraft, he would have alerted it through a traffic advisory or a safety alert. He stated further that he did not perceive any VFR traffic near the METRO II just before the collision. The Safety Board believes that the controller was concentrating on achieving the requisite IFR separation between the METRO II and the Mooney and was not conscious of the impending conflict between the two airplanes. The Safety Board believes that if the mode-C conflict alert feature had been available to the controller and the Mooney had been equipped with a mode-C altitude encoding transponder, the controller’s awareness may have been heightened and this midair collision accident may have been prevented. Therefore, the Safety Board concludes that the absence of this automated warning system was a contributing factor to the accident.”  (NTSB/AAR-88-/03, p. 22-24.)

 

Planecrashinfo.com: “Summary:  Midair collision with a Mooney M-20 at 7,000 ft. Ten killed on the Swearingen and none on the Mooney. Procedures and directives not followed by the Mooney pilot. Lack of navigational vigilance by the Mooney instructor pilot which led to the authorized intrusion into the Salt Lake City airport radar service area. Contributing factor was the absence of a Mode-C transponder on the Mooney airplane and the limitations of the air traffic control system to provide collision protection.”  (Planecrashinfo.com.)

 

Sources

 

National Transportation Safety Board. Aircraft Accident Rpt. (NTSB/AAR-88-/03). Midair Collision of Skywest Airlines, Swearingen Metro II, N163SW, and Mooney M20, N6485U, Kearns, Utah, January 15, 1987. Washington, DC: NTSB,  March 15, 1988. Accessed 11-15-2016 at: http://libraryonline.erau.edu/online-full-text/ntsb/aircraft-accident-reports/AAR88-03.pdf

 

Planecrashinfo.com. 1987. Accident Details. Skywest Airlines/Private, SLC, UT, Jan 15, 1987. Accessed 11-15-2016 at: http://planecrashinfo.com/1987/1987-5.htm