German giant Lufthansa said it would have to fly an additional 18,000 “unnecessary” flights through the winter to hold on to landing slots. Even if the holidays brought a big increase in passengers — marked by thousands of flight cancellations that left travelers stranded — the rest of the winter period could be slow as omicron surges worldwide.
Landing and departure slots for popular routes in the biggest airports are an extremely precious commodity in the industry, and to keep them, airlines have to guarantee a high percentage of flights. It is why loss-making flights have to be maintained to ensure companies keep their slots.
It was an accepted practice despite the pollution concerns, but the pandemic slump in flying put that in question. Normally, airlines had to use 80% of their given slots to preserve their rights, but the EU has cut that to 50% to ensure as few empty or near-empty planes crisscross the sky as possible.
Source: Near-empty flights crisscross Europe to secure landing slots | AP News