This incident involved a loss of separation, in Class A controlled airspace IMC, between a Boeing 737-300 (B737) and a Gulfstream IV (GIV). The B737 was inbound to London Heathrow Airport from Munich and the GIV was inbound to Farnborough Airport from Istanbul. The two aircraft were under the control of different controllers. The loss of separation generated an ACC Short Term Conflict Alert (STCA) and both aircraft received Traffic Alert and Collision Avoidance
System (TCAS) Resolution Advisories (RA). Separation was regained after a TCAS manoeuvre by the B737 and a change of heading by the GIV.
Air Accidents Investigation Branch
2014-12-10
<a rel="nofollow" class="external free" href="https://www.gov.uk/aaib-reports/boeing-737-300-d-abek-and-gulfstream-iv-n77sw-26-february-1999">https://www.gov.uk/aaib-reports/boeing-737-300-d-abek-and-gulfstream-iv-n77sw-26-february-1999</a>