Europe needs to drop disparate national transition altitudes and standardise. Ideally it should be done throughout, but regional change would be a start, and some Nordic countries are examining that possibility.
To understand why change is desirable it's worth looking at why Europe has its current system of very low transition altitudes, unlike the long-established North American standard of 18,000ft (5,500m).
It's because the International Civil Aviation Organisation advice on transition altitude is to make it as low as possible above 3,000ft.
ICAO standards are frequently reviewed for continued relevance, but the advice on transition altitude has not been changed in the light of modern aircraft performance.
In 1944, when ICAO standards were first set, all aircraft flew relatively low because pressurisation was rare and power was piston-based. Airliners cruised at 8,000ft or less, and many did so until the 1960s when jet power began to dominate.
Under those circumstances, with most movements at low level, it made sense to transition to a common altimeter pressure setting as early as possible in the climb without compromising terrain clearance too much.
But in a world where cruising at more than 25,000ft is standard for turbine-powered aircraft, priorities have changed. So forcing pilots to fiddle with their altimeters close to the ground while busy with arrivals and departures no longer makes sense.
Source: Flight International
