Safety experts confirm that current separation levels for heavy aircraft would be sufficient for the new Boeing 747-800, which is 15% heavier than similar aircraft.

The need for a safety assessment

Given its weight, it was possible that additional separation would have been needed for the new B747-800 to ensure that wake vortex turbulence would not be a risk to other aircraft.

This would have placed the separation required somewhere between the existing heavy aircraft group and the A380, which is larger, and would have resulted in the need for controllers to apply additional separation rules.

Study results

A joint project involving Boeing, FAA, EASA and EUROCONTROL was tasked with advising ICAO on separation requirements.

A data collection campaign using ground-based LIDAR measuring equipment allowed the experts to demonstrate that, despite the size of this new version of the Boeing, existing separations for heavy aircraft may be safely utilised.

This was explained by the design of the aircraft wing and flaps, which generates turbulence closer to the fuselage, as opposed to existing versions of the B747 where turbulence is generated closer to the wing tips.

The experts were able to prove that, although the turbulence affecting the B747-800 model is greater in strength, it would decay rapidly because of how it is generated.

Good news for airport capacity

The fact that additional separation rules will not be required for this aircraft is good news for the network, particularly since one of the launch customers for the new Boeing 747-800 in Europe is Cargolux.

There are currently many complete B747-8 airframes in storage at the Boeing factory at Paine Field waiting for the certification process to be completed (expected any day now), following which deliveries to the airlines will commence.

A stepping stone to enhance capacity

This project is a breakthrough for the European network but it is also a stepping stone to other short-term work which will significantly enhance capacity.

The work of the scientific community, combined with the emergence of more reliable measuring technology, have allowed the existing wake vortex separation rules to be reviewed.

This is a step forward which could increase throughput at airports by up to 7%.

There was a feeling that aircraft were in general over separated – but this was not supported by hard facts and data to guarantee the safe reduction of aircraft separation.

A methodology has now been developed by the safety and technical experts in close cooperation with the FAA. This will make it possible to introduce other enhancements in the short term.

Eurocontrol press release

Photo’s: M. van Leeuwen Z.A.P.P.