GPS in its earlier forms is not new in the aviation business but it has taken much development to enable Thomas Cook Airlines becoming the first UK carrier to gain CAA approval to use GPS-based RNAV (Required Navigation) technology in landing approaches. RNAV is likely to be used by all civil aircraft in the future and utilises onboard computers and software linked to flight guidance systems. GPS has been used on aircraft for some time, this new advancement big advantage being that it allows ”planes to operate when ground navigational aids are unserviceable or unavailable Thomas Cook Airlines two latest-generation Airbus A330s already have RNAV hardware and software fitted and the airline has spent the past 18 months making the exhaustive preparations to be able to put it to use. The airline is now working in close conjunction with the Authority to pilot the system, largely on its Canadian and Caribbean flights. The reliability and accuracy of such GPS-based equipment means that aircraft will be able to conduct approaches to lower altitudes in poor weather. It may well lead to the ability to carry out low visibility approaches and auto lands. Curved approaches and approaches down valleys can also take place with RNAV, easing the previous challenges of difficult terrain or locations.
http://www.thomascook.co.uk