Incident - March 16, 2007 - Las Vegas, Nev.
The flight, operated by Alaska Airlines Inc., was scheduled to depart from Las Vegas, Nev. en route to Seattle,Wash..
On March 16, 2007, at 0520 UTC, Alaska Airlines flight 677 (ASA677) performed a rejected takeoff while attempting to depart from runway 25R at McCarran International Airport, Las Vegas, Nevada. The rejected takeoff occurred in accordance with an air traffic control instruction canceling takeoff clearance because of a conflict with Allegiant Airlines flight 588 (AAY588) landing on runway 19L. There was no reported damage to AAY588, but ASA677 incurred a deflated tire after returning to the gate. There were no reported injuries to passengers or crew on either aircraft.
This incident was caused by failure of the LC2 controller to comply with coordination procedures and runway separation standards. Contributing was the failure of LAS ATCT management to establish procedures requiring positive separation of aircraft operating on converging runways.
On March 16, 2007, at 0520 UTC, Alaska Airlines flight 677 (ASA677) performed a rejected takeoff while attempting to depart from runway 25R at McCarran International Airport, Las Vegas, Nevada. The rejected takeoff occurred in accordance with an air traffic control instruction canceling takeoff clearance because of a conflict with Allegiant Airlines flight 588 (AAY588) landing on runway 19L. There was no reported damage to AAY588, but ASA677 incurred an overheated and deflated tire after returning to the gate. There were no reported injuries to passengers or crew on either aircraft.
At the time of the incident, two local controllers were on duty in the Las Vegas tower, designated as LC1 and LC2. The LC1 controller was responsible for arrivals and departures on runways 25L/R. The LC2 controller was responsible for arrivals and departures on runways 19L/R.
ASA677 was a Boeing 737 intending to fly from LAS to Seattle, Washington (SEA). After leaving the gate, the crew was instructed to taxi to runway 25R and did so. The crew contacted LC1 at 0518, reported ready for departure, and was instructed to taxi into position and hold on runway 25R. At 0520:26, the LC1 controller transmitted, "ASA677 no delay on the roll - cleared for immediate takeoff," and the crew acknowledged. At 0521:01, the LC1 controller canceled the takeoff clearance and the crew acknowledged. ASA677 aborted takeoff, exited the runway, and returned to the terminal. The crew requested that the airport fire department check the landing gear for potential fire or smoke. While that check was in progress at the gate, the #1 main gear fuse plug ruptured and deflated the tire. The captain directed that the passengers be evacuated into the terminal.
AAY588 was an MD-83 en route from Bellingham, Washington (BLI) to LAS. The pilot contacted LC2 at 0518 on a visual approach to runway 19L and was cleared to land. At 0519:20 the crew requested a wind check (reported as 250 degrees at 4 knots), and at 0519:21 they requested confirmation of their landing clearance. According to recorded radar data, the aircraft crossed the runway threshold at approximately 0520:13. At 0520:54, the LC2 controller transmitted, "588 can you hold short of the runway?" The crew responded, "negative, sir," and at 0521:06 stated that they had missed the hold short line but were stopped clear of the runway itself. Once the conflict with ASA677 was resolved, AAY588 was cleared to taxi to the gate.
As runways 25R and 19L intersect, the LC1 and LC2 controllers must coordinate operations to prevent conflicts. This is accomplished through verbal coordination, and also through use of a red light / green light system to effectively swap control of the intersection between LC1 and LC2. When interviewed, the LC1 controller stated that she had received the green light from the LC2 controller, and therefore believed that it was safe to clear ASA677 for takeoff. The LC2 controller stated that he had observed AAY588 at "taxi speed" on runway 19L, and decided that he could transfer control of the intersection to LC1.
With some gaps, AAY588's primary and secondary radar targets remained visible on the LAS ASR-9 radar system until reaching the intersection of runway 19L and 25R. As noted under "History of Flight," ASA677 was cleared for takeoff on runway 25R at 0520:26. The first of the three targets for AAY588 located about halfway down runway 19L was recorded at the same time. In the next 9.08 seconds, AAY588 traveled about 0.4 statute miles, representing a ground speed of approximately 139 knots. Additional recorded radar data showing both AAY588 and ASA677 was obtained from the LAS ATCT Airport Movement Area Safety System (AMASS). Radar replay images are contained in the air traffic control group factual report, part of the docket material for this incident.
When this incident occurred, there were no management or supervisory personnel on duty in the tower. A controller-in-charge was assigned to supervise the shift. When the incident occurred, he notified the tower operations manager at home. In turn, the operations manager notified the Air Traffic Manager (ATM) After being briefed on what had occurred, the ATM decided to allow the LC2 controller to continue working pending review of the circumstances the following business day. He directed that a Quality Assurance Review report be completed on the incident. There were a total of three QAR reports completed by the CIC; one for the rejected takeoff (RTO), one for the go-around executed by the next arrival, and another when he was notified that ASA677 had incurred one or more flat tires as a result of the incident. The CIC also notified the regional operations center of the rejected takeoff and the tire problem.
The tower operations manager would normally review such incidents on the next business day. However, the day after the incident occurred was his day off so he was not involved in the follow-up assessment. The ATM reviewed the QAR reports and determined that because AAY588 did not actually enter runway 25R, the incident did not constitute an operational error and no formal reports outside the facility were required.
On the following Monday, March 19, the FAA's Las Vegas District Manager received an inquiry about the circumstances of the incident from a representative of the Air Line Pilots Association and began his own examination of the events. He decided that the performance of the LC2 controller was substandard and warranted corrective action. On March 20, the LC2 controller was restricted from working the LC1, LC2, and associated local assist positions pending retraining and completion of a return to duty plan. There were still no formal external reports completed on the incident until it was reported to FAA headquarters as an operational error on March 29, 2007, two weeks after it occurred. FAA quality assurance procedures require that operational errors be reported within three hours of occurrence.
Paragraph 4-35 of the LAS ATCT Standard Operating Procedures (SOP), "LC1, LC2, and LC3 Control Responsibilities," contains local direction on the handling of intersecting operations. In the configuration in effect on the night of the incident, the LC1 controller was handling traffic on runways 25L and 25R, and the LC2 controller was responsible for traffic using runways 19L and 19R. Because runways 25R and 19L intersect, LAS ATCT has developed a local procedure that uses a red light / green light system for coordinating control of the intersection and preventing conflicts. Before November, 2006, the SOP stated:
The controller who has relinquished control of the intersection shall press the button on the Runway Intersection Coordination Device (RICD) when his/her last departing aircraft is committed to pass through the intersection and ensure the light has changed to RED. The controller with arriving aircraft to intersecting runways shall press the button on the RICD when his/her last arrival has reported at taxi speed or acknowledged runway exiting instructions and ensure that the light has changed to RED.
On November 6, 2006, the SOP was amended to state:
The controller who has relinquished control of the intersection shall press the button on the Runway Intersection Coordination Device (RICD) when his/her last departing aircraft is committed to pass through the intersection and ensure the light has changed to RED. The controller with arriving aircraft to intersecting runways shall press the button on the RICD when his/her last arrival is at taxi speed or acknowledged runway exiting instructions, and ensure that the light has changed to RED.
The effect of this change was to delete the requirement that the arriving aircraft report being at taxi speed, instead allowing the local controllers to use their own judgment that an aircraft was at taxi speed and thereafter transfer control of the intersection. However, there was no local or national definition of "taxi speed" provided to controllers in conjunction with these instructions.
Following the rejected takeoff involving AAY588 and ASA677, the SOP was again amended, this time requiring that the arriving aircraft be both at taxi speed and have acknowledged turnoff instructions before control of the intersection is transferred to the other local controller. All LAS ATCT controllers received a face-to-face briefing on the change to the facility SOP implementing this requirement.
Previous LAS incidents included a March 2006 operational error report where two aircraft operating on runway 25R and 19L were cleared to depart at the same time because of miscoordination between LC1 and LC2. The LC1 controller transferred control of the intersection to LC2, who then cleared an aircraft for takeoff on runway 19L. LC1 then also cleared an aircraft for takeoff on runway 25R. The LC2 controller noticed the impending conflict and canceled takeoff clearance for the 19L departure after the aircraft had rolled about 500 feet. The incident constituted a loss of separation under FAA order 7110.65, paragraph 3-9-8, "Intersecting Runway Separation," which states in part:
Separate departing aircraft from an aircraft using an intersecting runway, or nonintersecting runways when the flight paths intersect, by ensuring that the departure does not begin takeoff roll until one of the following exists:
a. The preceding aircraft has departed and passed the intersection, has crossed the departure runway, or is turning to avert any conflict.
b. A preceding arriving aircraft is clear of the landing runway, completed the landing roll and will hold short of the intersection, passed the intersection, or has crossed over the departure runway.
That event was properly identified by the facility management as an operational error, and the LC1 controller was decertified and retrained.