My apologies, the Airprox was in May, it is discussed in the July Airprox review
This is the correct article
2025107 19 May 25 1809
A320 (CAT) Unk Obj
N5132 00004W E Central London FL90 London TMA
(A)
The A320 pilot reports that the flight departed from LHR RW09R, on the BPK6J SID initially and then an eastbound heading over London. Whilst over central London at FL90 in clear skies at a speed of 250kt IAS, both the Captain and First Officer saw a bright white object pass overhead from the opposite direction. The object appeared to be approximately 2-3m in size at the very least, it may have been larger as it filled a good proportion of the windshield. There was no appreciable separation vertical or horizontal. The First Officer observed that it was triangular in shape. The Captain only saw the object for a second or two in peripheral vision so could not reliably comment on the shape. No markings were identified. The object did not appear on TCAS. The encounter was immediately reported to London control
Reported Separation: 10m V (above)
Reported Risk of Collision: NR
The Swanwick TC Radar controller (NE departures) reports that at 1810 [the A320 pilot] reported a drone sighting at FL90, 10NM west of [London City Airport], it was grey. This information was passed on to Heathrow Approach also.
The NATS Safety Investigation reports that the pilot of [the A320] reported that an object passed within about 10m of the aircraft as they were passing 9000ft, approximately 5NM west-northwest of London City Airport. Safety Investigations was subsequently informed by the UK Airprox Board that the event had been submitted as a drone Airprox.
The pilot stated that the object āwent over us, probably within about 10 metresā. The NE DEPS controller informed the Heathrow Intermediate Director, the Heathrow Tower Supervisor was also informed.
Analysis of the radar by Safety Investigations indicated that there were no associated primary or secondary contacts, associated with the drone report, visible on radar at the approximate time of the event.
They concluded that the pilot of [the A320] submitted an Airprox report in response to the sighting of a drone whilst approximately 5NM west-northwest of London City airport.
It has been estimated that the UAS was at 9000ft.
Safety Investigations reviewed the radar at the time the pilot of [the A320] reported the sighting, however, no radar contacts associated with the drone were visible.
UKAB Secretariat reports that an analysis of the NATS radar replay was undertaken and a single primary return was seen at 0.2NM ahead of the A320 to the east of Central London at 1808:50 when the A320 had been at 9200ft. There were no further similar returns detected on radar.
In the Boardās opinion the reported altitude and/or description of the object were such that they were unable to determine the nature of the unknown object.
Applicable Contributory Factors: 4, 6
Risk: The Board considered that providence had played a major part in the incident and/or a definite risk of collision had existed.
both the Captain and First Officer saw a bright white object pass overhead from the opposite direction. The object appeared to be approximately 2-3m in size at the very least, it may have been larger as it filled a good proportion of the windshield. There was no appreciable separation vertical or horizontal. The First Officer observed that it was triangular in shape.
How high do migratory swans fly?