Pioneer flight under escort

Solar Impulse successfully landed in Morocco on 5 June. The Network Manager and the Flow Management Positions of all ACCs involved worked hand-in-hand to open up an invisible but effective and safe shield to escort it throughout its journey across the busy European skies.

• See this animation showing how Solar Impulse flew through Europe's crowded skies, protected from the other traffic by the Air Navigation Service Providers and the Network Manager. Note: the representation of the flight stops when it first passes over Madrid (local holding and final descent not represented).

The Solar Impulse Project

The objective of Solar Impulse is to promote renewable energies and to demonstrate to people how today’s technologies can provide renewable forms of energy. If this is within reach in a demanding domain such as aviation, it can also be done in day-to-day life.

Since its historical 26 hours non stop flight and with the flight from Switzerland to Morocco, Solar Impulse has demonstrated that a solar-powered airplane can fly day and night using no fuel. The next challenge is to fly round the world in 2014 in a new aircraft, currently being built.

Solar Impulse, as a pioneering project, is a wonderful source of inspiration, reaching far beyond aviation activities.

Flying day and night on solar energy

The chances of success depend also of the in-flight energy management. In order to have sufficient energy to fly during the night, the aircraft must collect solar and potential energy during the day.

The flight profile follows a continuous slow climb up to FL285 during the day and flies at a lower altitude during the night (at about 5,000 ft, depending on the terrain below). When this altitude is reached, Solar Impulse flies horizontally until the next sunrise.

Everything you need to know about Solar Impulse is here: www.solarimpulse.com

ATM operations for a historical moment

Unlike last year’s flights, longer flights require a climb to higher altitudes where the aircraft could potentially interfere with commercial traffic, at a very low speed.

As Solar Impulse flights require very specific weather conditions, there are only a limited number of opportunities for it to take to the skies. So, the day of the flights cannot be predicted long in advance.

Solar Impulse is also very sensitive to turbulence, including wake turbulence caused by medium and heavy aircraft. The flight was operated mostly in visual flight rules (VFR), with some exemptions.

The flight to Rabat

Solar Impulse (call-sign HBSIA) departed from its base in Payerne, Switzerland on 23 May and landed in Madrid on 24 May 2012 for a technical stop over before reaching Rabat in Morocco, with a flight executed on June 5 2012.

A few days before departure, the planned trajectory was analysed and coordinated between the Solar Impulse ATC specialists, the Network Manager and the Air Navigation Providers (ANSPs) involved.

Some time after take-off on Tuesday 5 June 2012, Solar Impulse began its slow continuous climb up to FL285. It reached this altitude by the end of the afternoon, then started descending to lower level, waiting for the appropriate landing conditions in Rabat.

The NMOC tailor-made assistance

The Network Manager Operations Centre in Brussels supported Solar Impulse in various ways. The team showed great enthusiasm to provide support on top of their regular work. Their expertise was required during the days leading to operations and even the months preceding the flight.

They were key in liaising with the Air Navigation Service Providers and the Military authorities.

They were the channel for disseminating all relevant information to the ACCs, via the FMPs to prepare for and to update flight operations.

Strategic preparation

Solar Impulse provided precise trajectory descriptions in the input format of the NM simulation tool. The System for traffic Assignment and Analysis at a Macroscopic level (SAAM) is an integrated system for wide or local design, evaluation, analysis and presentation of Air Traffic Airspace / TMA scenarios. As such, it was used to run simulations to assess the traffic impact for different trajectory options during the strategic phase.

The results showed where potential hotspots were likely to appear, giving indications for trajectory selection.

The tactical phase

During the tactical and execution phase, the NMOC experts made sure the appropriate awareness and knowledge reached the actors involved, as required for seamless operations.

Although the flight was in VFR, it flew in airspace with many IFR flights. The Network Manager Operations Centre (NMOC) supported the ACCs with simulations of its routeing (accurate prediction of entry/exit into ATC sectors), network assessment (traffic loads of the crossed radar sectors and military restricted areas) and coordination with the FMPs.

Beyond the operations

The Network Manager is proud to have been able to contribute its ATM expertise in support of the unique Solar Impulse adventure.

Together with the enthusiastic collaboration of the ATC Centres, we have been able to show that it is feasible to accommodate such flight profiles in dense traffic areas. We believe the lessons learned with these flights will help demystify the implications of such atypical profiles on Air Traffic Management.

We hope our contribution will also go beyond the operations. Radar positions transmitted by the various ATC Centres were consolidated and recorded by the NMOC systems. This data can be used to support Solar Impulse application for a world record recognition.

We wish Solar Impulse pioneers a very smooth return flight and a fruitful preparation of their next challenge, the round-the-world trip!

The Network Manager cares for environment

The Solar Impulse project and the values it conveys are well in line with EUROCONTROL and the Network Manager’s commitments for ‘green ATM’.

In the context of the Single European Sky (SES), EUROCONTROL puts its environmental expertise at the service of its Member States, the European Commission (EC) and the aviation community to help measure, monitor and mitigate the impact aviation is having on the environment.“Once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return.”  Leonardo da Vinci.

More particularly the Network Manager established the Flight Efficiency Support Function with the purpose to improve flight efficiency and reduce fuel emissions. Related activities include tactical airspace management, identification of opportunities (offering the use of shorter routes).

Continuous Descent Operations is another good example of NM projects providing a response to environmental challenges. CDO reduces CO2 emissions by almost 500.000 tones/year and noise impact by around 1-5 dB/flight.

Related links

• Flight Efficiency Training