A333 / C550, vicinity Madrid Barajas Spain, 2022
A333 / C550, vicinity Madrid Barajas Spain, 2022
On 13 July 2022, an Airbus A330-300 inbound to Madrid and descending on the 32L ILS and a Cessna Citation 550 which had just departed from Torrejón Air Base lost separation. The aircraft came within 400 feet vertically and 0.6nm horizontally after the Citation failed to follow its assigned and acknowledged departure clearance. A TCAS RA "DON’T CLIMB" message was annunciated on the A330 as the opposite-direction Citation, which the A330 crew subsequently reported having had briefly in sight, passed just above it. Detection of the conflict risk to ILS traffic inbound to Madrid was delayed by sub-optimal civil/military ATC coordination.
Description
On 13 July 2022, an Airbus A330-300 (C-GHLM) operated by Air Canada on a scheduled international passenger flight from Toronto to Madrid as ACA 824 and a Cessna Citation 550 (U20.03) operated by the Spanish Navy on a nonscheduled domestic passenger flight from the Spanish Air and Space Force base at Torrejón to Palma de Mallorca came into close proximity in day VMC. The event took place when the Citation began to cross the final approach flight paths to runways 32L and 32R at Madrid. A TCAS RA was annunciated on the A330 but as it was descending, no change of intended flight path was required.
Investigation
Once made aware of the event, which was not until some three weeks after it had occurred, the Spanish Commission for the Investigation of Accidents and Incidents (CIAIAC) carried out an Investigation using recorded ATC data from the units involved and QAR data from the A330.
Flight Crew and Controller Experience
It was noted that the 49-year-old A330 captain had a total of 17,639 hours flying experience including 146 hours on type. He had previously flown the Airbus A318/320/321 on which he had had a total of 13,011 hours flying experience, which included 8,980 as captain, and prior to that had completed 1,178 hours as a DC9 first officer, all of this experience with Air Canada. The 49-year-old first officer had a total of 19,000 hours flying experience of which 400 hours were on type, and the 51-year-old relief first officer had a total of 13,500 hours flying experience of which 930 hours were on type. The Cessna Citation captain had a total of 1,480 hours flying experience of which 1,120 hours were on type and the first officer had a total of 480 hours flying experience of which 240 hours were on type.
The 57-year-old Executive Controller of the Madrid ACC EDN sector (Civil Takeoff) had held a licence for almost 23 years and had been stationed at the Madrid Centre for almost all of that time. The 61-year-old Sector Planner for the EDN Sector had held a licence for almost 28 years and had also been stationed at the Madrid Centre for most of that time. The 54-year-old runway 32L TWR controller had held a licence for over 19 years and had been working in Madrid TWR positions for 12 years. The GND and TWR controllers at Torrejón both had the necessary military qualifications.
What Happened
Madrid was operating in northerly configuration - landings on 32L and 32R and takeoffs from 36L and 36R. The Citation requested and received startup clearance from the Torrejón GND controller, then called the Madrid EDN (Departures) sector. It was agreed that the aircraft and another one not involved on the subsequent conflict but also heading to the same destination would depart from runway 22 on a NANDO 3H SID. A couple of minutes later, the two controllers spoke again and the EDN Sector controller confirmed that after liaising with the APN (Madrid Arrivals) sector that space would be created on the ILS approach to runway 32L at Madrid so that the two military aircraft could take off and follow the agreed (left turn) departure route. They subsequently agreed that when the two aircraft reached 6,000 feet, they would be transferred to the EDN Sector.
Madrid ATC Sectors in relation with the locations of Madrid (LEMD) and Torrejón (LETO). [Reproduced from the Official Report]
However, whilst the Citation was at the runway 22 holding point, Torrejón Radar controller then instructed the Torrejón TWR controller to transfer the flight direct to the EDN sector. This was being coordinated between the two controllers for a departure within the next 4 minutes when the Torrejón radar controller changed their mind and told TWR to transfer the flight to them on departure but this was not acknowledged by TWR. The Torrejón Radar controller then coordinated with the EDN Sector that the departure would be a left turn onto a radar heading of 080° climbing to 8000 feet.
Once the Citation was airborne, the Torrejón TWR controller transferred it to the EDN Sector where the controller noticed that it was “prolonging its left turn with a higher than published speed and redirected it to climb to flight level FL 160 on a heading of 080º” but received no acknowledgement. The Citation then failed to make the instructed left turn and crossed the approach path of runway 32R which “put it on a collision course with the A330 on the runway 32L localiser” which had been transferred from the Madrid APN (Approach) Sector to TWR with 8 nm to go.
The Citation continued a delayed left turn climbing through 3,500 feet over the runway 32L localiser as the A330 descended though 3,700 feet reducing separation to 2.3 nm horizontally and 200 feet vertically on converging flight paths. Six seconds later, the Citation was climbing through 3,600 feet and back between the two localisers as the A330 descended through same altitude on the runway 32L localiser and separation was 1.4 nm horizontally. After a further nine seconds, the Citation was climbing through 3,800 ft between the two localisers and the A330 was descending through 3,400 ft on the 32L localiser with a separation between them of 0.6 nm horizontally and 400 feet vertically. Thereafter, vertical separation between them began to increase and three seconds later it was 700 feet although the horizontal separation was unchanged.
The flight paths of the two opposite direction aircraft. [Reproduced from the Official Report]
Discussion
Five control units were involved in the event - three were civilian (LEMD-DEN, LEMD-AFN and TWR LEMD) and two were military (Radar LETO and TWR LETO). The LEMD-DEN sector was in charge of coordinating with LETO in respect of their departures following which any agreed coordination had to be communicated to the LEMD-AFN arrivals sector.
The initial agreement for the departing Citation to fly a NANDO 3H SID was noted to have been contrary to AIP Supplement 19/22 effective from 24 February 2022 which had been published due to the decommissioning of the ‘BRA’ DVOR/DME BRA and specified that one consequence was that the LETO runway 22 NANDO 3H SID was unavailable. The Investigation concluded that “neither the LETO TWR unit nor the Madrid TMA were aware of this circumstance at the time” but noted that since if either the SID or the after takeoff left turn substituted for it had been flown, no conflict with the A330 or any other inbound Madrid ILS traffic would have occurred.
The specific requirements for LETO runway 22 departures published in the AIP entry for LETO were clearly communicated and showed a clear limit to flight in a southwesterly direction to protect the northwesterly ILS approaches (and the climb out tracks with Madrid operations in southerly configuration (see the illustration below)
What was arguably a “critical moment” in preventing the conflict was considered to have been when the Citation checked in with the EDN Sector. On reporting that a NANDO 3H SID was being flown, the Citation was instructed instead to climb to FL160 upon which the Citation crew requested that the instruction be repeated. It was not repeated, and instead the new instruction was given to turn left onto a heading of 080º without requiring them to do so immediately and without traffic information. It was considered that “everything seems to indicate that the Citation crew were not assimilating the takeoff instructions they had been given and were failing to make the assigned turn”.
An extract from the AIP showing the LETO (Torrejón) traffic pattern chart. [Reproduced from the Official Report}
It was also considered that a second such “critical moment” had been earlier when the Citation was transferred directly from Torrejón TWR to the EDN Sector without the Torrejón Radar controller providing information on the heading and altitude previously agreed with the EDN controller.
Finally, it was noted that after the conflict had occurred, the EDN Sector controller had contacted the Citation crew to ask why they had prolonged their initial heading to the point of crossing the localisers for both runways and they had replied that “they had turned at 1 nm but that the aircraft’s turn radius was quite wide” (with no mention of their airspeed) which, given the observed modest rate of climb, was evidently a factor.
Causes/Contributing Factors: the Investigation determined “that the loss of separation occurred as a result of a failure to adhere to the authorised departure procedure (the NANDO 3H SID) by the crew of the military aircraft”.
The Final Report of the Investigation was approved on 30 November but only released online simultaneously in both the definitive Spanish version and in English translation on 16 February 2023. No Safety Recommendations were made on the basis that the ANSP ENAIRE had already made pertinent recommendations following its own internal enquiry.