Documents / Report
The UK Airprox Board issued Airprox Report 2013086 on an incident at 1835Z on 19 July 2013, 19.5nm west of Heathrow at FL340. An A320 captain reported a bright silver, cigar or rugby ball shaped object passing a few feet above the aircraft. No TCAS or radar returns were found, balloon releases were ruled out, and the Board judged a sun reflection off distant aircraft possible. Too little information allowed a meaningful finding, so the cause was recorded as a sighting report, risk category D.
“UK Airprox Board”1 page
2 Analysis and Investigation CAA ATSI The incident was reported to have occurred at approximately 1835, 19.5nm to the West of London Heathrow at FL340. The A320 pilot was operating under IFR in receipt of a Radar Control Service from London Control. CAA ATSI had access to area radar recording, together with the written report from the A320 pilot and the NATS Ltd investigation report. The estimated viewing aspect through the DV window is shown at Figure 1 below. Figure 1: LH DV window Viewing Aspect At the time of the reported occurrence (1835:22) the radar recording was filtered to show aircraft operating within the level band FL320 and FL390 along with unknown primary contacts, these have been circled red in Figure 2 below. Figure 2: Swanwick MRT at 1835:22 An unknown primary contact was recorded in A320’s 10 o’clock at a range of 2.2nm. This contact first appeared on the radar at 1828:53, in the vicinity of the village of Eling, approximately 30nm West of Heathrow. The unknown contact routed West and landed at White Waltham at 1846. This was identified as being a Tiger Moth aircraft which was operating at low-level and was eliminated from the investigation.
Report, cited by the archive. The PDF is mirrored here; the original link is under it. 3 pages are in the text index: search them above, or from the library's search.