The review found that the change had delivered the safety benefits that had been anticipated in the proposal submitted by NATS.
The departure routes had not been changed since the airport opened in 1987. Since then the original aircraft types using the airport, such as the Dash-7, which flew at reasonably slow arrival and departure speeds, have been replaced by newer, faster aircraft, less able to fly the original departure path. The departures were therefore amended to reflect the routes actually being flown and to ensure these safer flight paths were published for airlines to use, in line with international requirements.
The change was implemented in May 2009 following a NATS proposal and consultation with the aviation industry, local authorities and MPs in 2008.
Every UK airspace change is subject to a 12-month review to assess whether the revision has met the required operational and safety aims. In this particular case, due to the local interest in the change, the CAA also made a study of the environmental impact.
The CAA found that in all cases the revision to the departure routes had met the projections first indicated by NATS when it submitted the proposed the change. Aircraft are now safely flying the route and, from an environmental perspective, the impact predicted in the consultation document is being reflected on a day-to-day basis.
The full review can be read here: CAA review