https://www.euronews.com/2019/01/26/...e-italian-alps
This accident, happened more than two years ago at the Alps close to Mont Blanc, reminds us how important it is to file a flight plan when cross into foreign airspace even when it is very close to border. This ski area is frequented by pilots on both sides of the border, considered virtually as local flights for many years. So there was no radio contacts with FIS. My own experience is that radio contact with FIS there is very difficult due to terrain. So the only conclusion the Italian authority could reach was that the French plane pilot was responsible for the accident solely because he did not file flight plan to cross border even though the site was just a couple of hundred meters from the French side.