Aviation Accident Summaries

Aviation Accident Summary OPS15IA017

Miami, FL, USA

Aircraft #1

N342UP

BOEING 767 34AF

Aircraft #2

N900QS

CESSNA 750

Analysis

This loss of required air traffic control separation resulted from the LN/LS controller issuing a landing clearance to UPS357 to a runway occupied by N900QS in position on the same runway. This resulted in UPS357 overflying N900QS by about 475 feet. Contributing to the error was the local controller's non-compliance with traffic advisory procedures, and insufficient requirements for use of memory aids to track arrival and departure operations. When issuing a landing clearance to UPS357, the local controller did not ensure the runway was clear as required by FAA Order 7110.65, Air Traffic Control, paragraph 3-10-3, Same Runway Separation and, the local controller did not advise UPS357 that an aircraft was in position on the landing runway as required by FAA Order 7110.65, paragraph 3-10-5c, Landing Clearance. Contributing to this incident was the lack of required memory aids for arrivals. Miami Air Traffic Control Tower procedures required controllers to use memory aids to indicate that an aircraft had been directed to line up and wait (LUAW), when an aircraft was issued a departure clearance, and to indicate that a runway was occupied by an airport vehicle. However, flight progress strips or memory aids were not required for arrivals and arrival flight progress strips were not used. The data available via the radar presentation on the tower display workstation (TDW) was the only information used for arrival sequencing. While the LUAW memory aide is beneficial to prevent a controller from issuing a takeoff clearance for a runway that is occupied by an aircraft in LUAW position, it did not prevent the controller from issuing a landing clearance to UPS357 nine seconds after he had directed N900QS to LUAW. There were no visual aids utilized to indicate an aircraft was on the runway to which an aircraft had also been cleared to land. According to controller interviews, the "rule of thumb" or unofficial procedure for arrivals to a runway occupied by an aircraft in position was that if the arrival reached two miles and the aircraft in position had not started departure roll, the arriving aircraft would be sent around. However, there were no visual clues or memory aids to remind the controller that an aircraft was in position on the runway except where a controller may decide to write down call-signs of arriving aircraft at the control position.

Factual Information

On April 12, 2015 at 0821, a loss of required air traffic control separation occurred when United Parcel Service (UPS) flight 357, a Boeing 767-300, overflew N900QS, a Cessna C750 Citation holding in position on runway 8L at Miami International Airport (MIA), Miami, Florida. The conflict was detected when the tower's airport surface detection equipment, model X (ASDE-X) alarmed. The local controller (LC) instructed UPS357 to go around and turn 10 degrees left. UPS357 was at an altitude of 200 feet and approximately ½ mile from the runway 8L threshold when the crew was told to go-around. UPS357 overflew N900QS by 475 feet. Visual meteorological conditions prevailed at the time. The 0753 Aviation Routine Weather Report (METAR) observation for MIA was wind 120 degrees true at 7 knots, visibility 10 statute miles, few clouds at 2,300 feet above ground level (agl), scattered clouds 3,500 feet agl, broken clouds at 25,000 feet agl, temperature 26 degrees Celsius (C), dew point 22 degrees C, altimeter 30.09 inches of mercury. UPS357 had departed Managua International/Augusto Cesar Sandino International Airport (MNMG/MGA), Managua, Nicaragua, at 0628 destined for MIA. N900QS was departing MIA for Chub Cay International Airport (MYBC/CCZ), Bahamas. MIA was departing traffic on runways 8L and 8R, with line up and wait (LUAW) operations in effect, and using runway 9 and 12 for arriving traffic with land and hold short operations (LAHSO) in effect. At 0819:48, the local controller directed N900QS to LUAW on runway 8L from taxiway K1. At 0819:57, the local controller cleared UPS357 to land on runway 8L. The pilot of UPS357 asked the controller about interval traffic, referring to the previous Air Canada departure from runway 8L, and was advised that traffic was no factor. At 0820:08, N900QS taxied onto runway 8L from K1. UPS357 was on final approach, about 2.7 nm from the runway 8L threshold. At 0821:04, an ASDE-X alert was generated in the ATCT. UPS357 was 4039 feet or .66 nm from the runway threshold at 325 feet agl. At 0821:10, the local controller directed UPS357 to go around, repeating the directive 6 times. He also told the pilot of UPS357 to turn left 10 degrees and advised that traffic was holding in position on the runway. Five seconds later UPS357 began to increase altitude from approximately 183 feet agl, 1706 feet or .28 nm from the runway threshold. At 0821:22 UPS357 crossed the landing threshold of runway 8 at approximately 310 feet agl. 2 seconds later UPS357 was directly over N900QS. Based on the transponder Mode C altitude, separation was approximately 475 feet vertically. UPS357 was re-sequenced for a normal landing, and N900QS departed MIA uneventfully. Tower staffing included a local controller (LC) working the Local Control North (LN) and South (LS) positions combined, a controller-in-charge (CIC), a ground controller/flight data (GC/FD) and a cab coordinator (CC). The local controller on position at the time of the incident was a front line manager (FLM) getting proficiency time on position. The FLM, as a front line supervisor, did not normally have the opportunity to work the control positions. Part of the FLM's professional requirements mandated that he be current and proficient on the air traffic controller positions he supervised. The minimum proficiency time currency requirements for the FLM were at least one hour per month on each tower and radar position. The FLM had been supervising the tower crew before signing on at the LN and LS positions combined at the LN position. The local controller had been on position for approximately one hour and considered traffic routine. He had been using runways 8L and 8R for departures and runways 9 and 12 for arrivals. An Air Canada A320 had departed runway 8R. According to the local controller, when an Air Canada aircraft departed MIA, they usually slowed down immediately after takeoff. When a departing aircraft slowed down, it affected the timing of subsequent departing aircraft in that the required separation between the two succeeding departures might not be met if the subsequent departure was cleared for takeoff too soon. Accordingly, the local controller had to take into account the reduced airspeed of an Air Canada departure when considering how much time must elapse before issuing a subsequent departure a takeoff clearance. To allow for adequate separation between the Air Canada departure and N900QS, the local controller directed N900QS to LUAW on runway 8L instead of immediately issuing a takeoff clearance. After directing N900QS to LUAW, he cleared UPS357 to land on runway 8L before UPS357 requested a landing clearance. The controller did not advise UPS357 that traffic was holding in position on runway 8L as required by FAA directives. The controller stated that cargo aircraft, such as UPS357, preferred to land on runway 8L to allow for shorter taxi time to the cargo ramp. MIA ATCT procedures required controllers to use memory aids to indicate that an aircraft had been directed to LUAW, when an aircraft was issued a departure clearance, and to indicate that a runway was occupied by an airport vehicle. However, flight progress strips or memory aids were not required for arrivals. The local controller used the information presented in the radar data blocks displayed on the Tower Display Workstation (TDW) to determine the arrival sequence. The local controller stated that he had been using runways 9 and 12 for arrivals and there had not been an arrival to runway 8L or 8R for some time. He missed the same runway conflict until the ASDE-X alarmed. He added that this oversight was compounded by distractions from an aircraft on an inbound taxi misunderstanding his hold short instructions and a report of foreign object debris (FOD) on a taxiway. After the ASDE-X alarmed, the controller directed UPS357 to go around and to turn left 10 degrees. The controller advised the pilot of UPS357 that traffic [N900QS] was holding in position. After being relieved from the local control position, the local controller filed a mandatory occurrence report (MOR) in the Comprehensive Electronic Data Analysis and Reporting (CEDAR) system. MORs are required by FAA Order 7210.632, Air Traffic Organization Occurrence Reporting, which contain a list of occurrences involving air traffic services for which the collection of associated safety-related data and conditions is mandatory. MORs are classified as significant or non-significant by the person filing the report, in accordance with standards contained in the order. According to the MIA operations manager (OM) who was on duty at the time of the event, the LC called him from the tower and advised him of the go around and ASDE alarm caused by UPS357 and N900QS. The OM directed the local controller, who filled out the required MOR, to classify the event as non-significant because the event did not constitute a significant event according to current FAA criteria. According to the MIA support manager, the MOR was changed to "significant" after receiving guidance from the FAA Eastern Service Area staff in Atlanta. According to the Quality Control Group, Eastern Service Area, the MOR in the CEDAR system was modified on April 14, 2015, to require submitters to choose either "significant" or "non-significant" when completing and submitting a report. Before then, the system defaulted to "non-significant" unless "significant" was specifically selected.

Probable Cause and Findings

The controller's issuance of a landing clearance to an arriving aircraft while another aircraft was in position on the same runway. Contributing to the incident was the controller's non-compliance with traffic advisory procedures, and insufficient requirements for use of memory aids to track arrival and departure operations.

 

Source: NTSB Aviation Accident Database

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