NATS has recently consulted on changing the transition altitude (TA) in part of the SE of England to 6000ft to match the TA under the London TMA. Although the TA is generally 3000ft throughout the UK it is 6000ft or 5000ft under certain controlled airspace as listed in the AIP ENR 1.7.2 We supported changing to 6000ft but argued that the multiple TAs are too complex and the CAA should change the TA to 6000ft everywhere and be done. The different TA areas are not marked on charts and are difficult to remember. We also think that in due course the TA throughout Europe may change to 18,000ft.
There are some issues related to reduction in the space between the ground and the base of controlled airspace when atmospheric pressure is high - this has an impact mainly on gliding.
Also the quadrantal rule as applied to IFR traffic does not apply in the UK below the TA and there is concern about that. You can read the LAA response here.
7th July 2011