London Biggin Hill Airport (LBHA) requested that Cyrrus undertake an airspace change proposal that would permit the introduction of an RNAV Instrument Approach Procedures (IAP) to Runway 03 to improve the safety and regularity of aircraft operations to sustain all weather operations. The close proximity of LBHA to the complex and busy route structure of the London TMA created a number of technical challenges; in particular, safe and effective integration of the proposed IAP with the existing route structure serving the major London Airports.

A study was undertaken to determine the extent of the ‘flight procedure interactions’ with the 2 major London airports and potential interactions with several Standard Instrument Departure (SID) procedures from London Gatwick and London Heathrow were evaluated. The number of interactions with the London Gatwick routes was extensive and it was concluded that it was not possible to integrate the initial design of the proposed new LBHA IAP safely; consequently, a different solution was proposed which removed the interaction from the airspace used routinely by London Gatwick departures. Subsequently, a technical and statistical analysis of the London Heathrow Runway 09 Conventional SIDs was undertaken to consider potential mitigation measures that may facilitate the safe introduction of the revised RNAV IAP to LBHA Runway 03.

Twenty-one months of London Heathrow SID data (spanning all seasons) was provided as a meaningful and representative set of flight procedures to be evaluated. The minimum lateral separation between the procedures was established with the ANSP requirements based on Performance Based Navigation (PBN) criteria and an assessment technique which assesses the safe spacing between PBN routes in a tactically controlled airspace environment. Using the PHX design software and the Cyrrus MAXFLO process, it was possible to promote a solution to revise the airspace arrangements which resolved the technical erosion of safe separation between the affected SID and the new IAP. Furthermore, the minor adjustment to the promulgated SID would not be detrimental to any airline operator.

The affected aviation stakeholders agreed to the proposed solution and, as a consequence, LBHA had the confidence to engage all interested parties in the UK airspace change process to make the proposal a reality.