ANALYSIS: Controller Error & NMAC, east of Kona, on 4/25/2014

The Analysis:

The map below shows most of Hawaii. It also shows the western end of the system of six parallel routes ATC assigns for flights between Hawaii and California. And, it shows the official boundary for ATC airspace, a faint line trending northwest to southeast near the right edge of the map. The radar controller in Honolulu is responsible for control west of that line, while the FAA oceanic controller at Oakland Center is responsible for control east of the boundary. The Honolulu controller needs to establish radar contact with both flights to apply tighter (five-miles lateral or 1,000 feet vertical) radar separation standards. If radar contact is not established for both flights, then much larger (fifty-mile lateral or 1,000 feet vertical) separation must be provided.

20140425.. NMAC at R578, Hawaii Routes

In this case, in at least one news article, it was reported that the United flight initiated a dive and, twelve seconds later, the two flights were separated by 800 feet of altitude. Thus, at around 4:15PM the flights were converging nose-to-nose along oceanic route R578. The article stated that the dive was initiated on the flight deck by TCAS detecting that the flights were converging to less than the required separation standard. The altitude readouts (from Flightaware, see the links to each flight below) indicate they were all in level flight. The one flight at 34,000 feet is significant in that it blocked ATC from climbing AWE432 out of 33,000 feet, thus helped create the head-on conditions for the two flights at 33,000 feet.

The likely controller error will be assigned to either the radar controller based in Honolulu or the oceanic controller based in Fremont, CA. Both have systems designed to prevent this scenario from happening.

Here is the key flight data for the flight, UAL1205, flying from Kona to LAX (outbound to FAPIS; see green arrow in the map showing oceanic track R578):
[columns: time-lat-long-track-direction-knots-mph-altitude]

04:14PM 21.0500 -152.4833 56° Northeast 530 610 33,000
04:15PM 21.1167 -152.3500 62° Northeast 540 621 33,000
04:16PM 21.1833 -152.2000 64° Northeast 530 610 32,400
04:18PM 21.3167 -151.9333 62° Northeast 500 575 32,700
04:19PM 21.4000 -151.7667 62° Northeast 480 552 33,000

Here is the key flight data for the USAir aircraft, AWE432, flying from Phoenix to Maui (inbound from FAPIS; see red arrow in the map showing oceanic track R578). Pink background marks the time window when the two flights passed each other:

04:16PM 21.2000 -152.1333 242° Southwest 390 449 33,000
04:17PM 21.1767 -152.2353 242° Southwest 458 527 33,000
04:17PM 21.1500 -152.2500 245° Southwest 420 483 33,000
04:18PM 21.1231 -152.3448 242° Southwest 458 527 33,000
04:18PM 21.1000 -152.3500 242° Southwest 420 483 33,000
04:19PM 21.0694 -152.4542 242° Southwest 458 527 33,000

And, here is the key flight data for the USAir aircraft, AWE663, flying from Phoenix to Kona (inbound from FAPIS; veering away slightly to the right, north of the red arrow in the map showing oceanic track R578). This flight was stuck above AWE432 but had to descend through to land at the closer airport in Kona. Thus, ATC may have issued control instructions to slow down and angle off to the right for an eventual descent:

04:15PM 21.2500 -152.2833 250° West 390 449 34,000
04:16PM 21.2167 -152.4000 253° West 390 449 34,000
04:17PM 21.1833 -152.5167 253° West 390 449 34,000
04:18PM 21.1500 -152.6167 250° West 400 460 34,000
04:19PM 21.1167 -152.7333 253° West; 400 460 34,000

20140425.. NMAC at R578, PHKO-KLAXAt the time of the dive, the latitude/longitude data indicates UAL1205 was roughly at the center of the orange circle, eastbound on the Oceanic route R578. The conflicting flights appear to have passed one another somewhere in the 1416 to 1417 time window.

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Controller errors do happen, and pilot errors also happen. FAA air traffic controllers are required to apply rigid control separation standards to ensure planes remain separated. This incident occurred in the area where radar control transitions to non-radar air traffic control. It is not yet clear which separation standard was required for this incident: radar (as close as five miles apart) or oceanic (no closer than fifty miles apart). But, when two flights are nose-to-nose and level at the same altitude, odds are fairly high that the controller screwed up.

Whatever happened, FAA has the data, and the Public has a right to know the details. When FAA fails to act openly, it creates an appearance of an ineffective regulatory agency, and implies the agency works for the airlines more than for the Public. FAA needs to post all the data on this incident: the audio tapes, the ATSAP reports, the relevant ATOP messages between ATC and the flights, the conflict readouts, etc.

A transparent aviation system is a far safer aviation system, and FAA needs to start truly supporting aviation transparency.