Vueling A321 and Easyjet A320 near Barcelona on Aug 7th 2016, near collision

Last Update: April 25, 2018 / 13:31:27 GMT/Zulu time

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Photo of Vueling EC-MHS, Airbus A321 — Vueling EC-MHS, Airbus A321 (Photo credit: airlines470 / Flickr / License: CC by-sa)

Incident Facts

Date of incident
Aug 7, 2016

Classification
Incident

Cause
Near collision

Airline
Vueling

Flight number
VY-3001

Departure
Las Palmas, Spain

Destination
Barcelona, Spain

Aircraft Registration
EC-MHS

Aircraft Type
Airbus A321

ICAO Type Designator
A321

A Vueling Airbus A321-200, registration EC-MHS performing flight VY-3001 from Las Palmas,CI to Barcelona,SP (Spain) with 185 passengers and 6 crew, was on approach to Barcelona's runway 07L descending through 5000 feet MSL about to turn final.

An Easyjet Airbus A320-200, registration G-EZTF performing flight U2-8571 from London Gatwick,EN (UK) to Barcelona,SP (Spain) with 168 passengers and 7 crew, was on approach to Barcelona's runway 07L descending through 5000 feet turning final.

Spain's CIAIAC reported separation between the aircraft was lost, the occurrence was rated a serious incident and an investigation has been opened.

On Sep 21st 2016 the CIAIAC reported both aircraft were found at 5000 feet intercepting radial 065 (not mentioned which navigation aid was referenced) in the sequence that ATC had determined, both aircraft were about 18nm before the runway 07L threshold, one aircraft turned onto the radial from the left, the other from the right. TCAS resolution advisories were triggered on board of both aircraft, both crews complied with the advisories. Both aircraft completed a normal landing afterwards.

Transponder data suggest that the separation between the aircraft reduced to 0 feet vertical and about 1.48nm horizontal, the conflict was resolved turning the A321 downwind temporarily before vectoring the aircraft back onto final approach.

On Apr 25th 2018 Spain's CIAIAC released their final report reporting the minimum separation reduced to 200 feet vertical and 1.4nm horizontally and concluding the probable cause of the incident was:

The incident took place due to improper coordination between the Queue Manager (QM) and the executive controller for Sector T3.

The following actions led to the loss of separation between the aircraft:

- Prior to the event, no consideration was given to limiting arriving traffic.

- The Sector T3 executive controller did not follow AMAN (Arrivals Manager) procedures.

- The Sector T3 executive controller did not follow the unit’s operating
procedures when he transferred the aircraft to the Final Sector.

- The Final executive controller provided insufficient information to the aircraft.

- Use of incomplete phraseology by Final executive controller with aircraft EZY18EP.

- Approach control personnel were subjected to a high workload for an extended period of time.

- The complexity of the airspace’s structure.

The CIAIAC stated:

VLG3001 was inbound from the south of the airport, and thus contacted Sector T3, where the executive controller cleared it to wait over the RUBOT IAF at 09:00:58, since there were eight aircraft ahead of it in the approach sequence, including two with heavy wake turbulence. The controllers stated that the workload was high at that time.

EZY18EP was inbound from the north of the airport and contacted feeder Sector T4. Once at the SLL IAF, at 09:08:29, it was cleared to continue flying on heading 230° to start the approach. This clearance had been coordinated with the QM, meaning that despite having a sequence number higher than VLG3001, the aircraft began its approach.

The QM controller delayed altering its sequence number until 09:11:19, at which time the T3 controller instructed VLG3001, which was established at 5000 ft, to leave the RUBOT IAF to start its approach. Upon noticing the change in the radar label number, he asked if someone had changed the sequence. The controller reported hearing “no”, so he once again instructed the aircraft to leave the RUBOT IAF heading north.

EZY18EP was transferred to the Final approach Sector, established at 5000 ft, and received vectors to intercept the Localizer. Then, at 09:14:59, the T3 executive controller transferred VLG3001 to the Final approach frequency.

The Final approach executive controller realized both EZY18EP and VLG3001 were flying on convergent headings at the same altitude of 5000 ft. After identifying the conflict, he instructed VLG3001 to turn to heading 330° and EZY18EP to descend to 3000 ft. He later instructed VLG3001 to turn to heading 260°. These actions were insufficient to provide the required separation and TCAS RA were triggered on both aircraft, which ended up closing to within 1.4 NM horizontally and 200 ft vertically.

Both aircraft continued flying and landed a few minutes later at the Barcelona-El Prat Airport.

The CIAIAC analysed that both crews reacted correctly to their TCAS resolution advisories.

The CIAIAC analysed the actions of the QM:

The sequence specified by the AMAN tool at 09:08:28 had been validated by the Final planning controller and QM. The situation was as follows, as shown in Figure 4:

- Four aircraft in contact with feeder Sector T4 that were inbound from the north (3, 4, 5 and 6) that had not intercepted the localizer yet and had already left the SLL IAF. The first two had a heavy wake turbulence, which required them to be spaced 4 NM apart, with the next aircraft (number 5) 5 NM behind.

- Four aircraft were inbound from the south (7, 8, 9 and 10), and thus in contact with feeder Sector T3. The first of these had already left the VIBIM IAF.

- Three further aircraft (11, 12 and 13) inbound from the north and had not yet reached the SLL IAF, spaced fewer than 5 NM apart, the minimum distance required between aircraft to comply with procedures at the unit.

The QM decided to prioritize the traffic from the north over that from the south to reduce the effect of Sector T4 on the SLL IAF and shorten the average delay.

According to the statement made by the planning and executive controllers in Sector T4, the QM controller coordinated this change with them beforehand but did not immediately change the AMAN sequence. According to AMAN system data, the QM validated the first change in the arrivals management system at 09:11:19, moving EZY18EP ahead of VLG3001.

At 09:13:12 a new change was made when two other aircraft inbound from the north were moved up in the sequence, ahead of VLG3001. These changes are deemed to have been entered into the AMAN tool late. They were also not verbally coordinated with sector T3, possibly due to the high workload to which the controller was subjected.

In light of these two changes, and without evaluating whether they were appropriate given the traffic situation, the coordination was not effective, since the change in sequence was not coordinated with Sector T3, and it was reflected in the AMAN tool after it was coordinated with Sector T4. This led to confusion among the T3 controllers, which could have been avoided if the QM had coordinated the changes with said sector.

The CIAIAC analysed that the planning manager advised the final approach controller of the pending conflict when the aircraft were 4.1nm apart, the controller issued instructions to the Vueling to turn to heading 330 and the Easyjet to descend to 3000 feet with the aim to increase both horizontal and vertical separation, the controller however did not make clear the urgency of the instruction by using the word "immediately". The crews thus executed the instructions normally which proved insufficient to avoid the conflict.

The CIAIAC analysed the use of two languages (Spanish and English) during communication with the two aircraft:

The communication between the crew members and the controllers is a factor related to safety in flight. The communications contained in section 1.9 show that two different languages were used in the same Final frequency, with the possible impact on the situational awareness of the crews.

However, in the present case, the VLG3001 crew should not have been affected by this fact, since the linguistic competence level allows them to attend both languages, while the crew of EZY18EP only had a partial composition of the situation.

In this regards the scenario conditions in which the aircraft were flying, at the time when the Final controller initiated communications in Spanish with VLG3001 and the reduced distance to the localizer that the controller had to separate the aircraft by procedure, it is considered that the use of the same language should not have contributed to become worse the situation. The performance of the crews on the TCAS resolution was which ultimately resolved the conflict.