noun
nonstop flight
Refers to a flight that goes from origin to destination without any intermediate landings.
東京からニューヨークまで無着陸飛行で行ける。
You can go from Tokyo to New York on a nonstop flight.
直行便 is a direct flight, which may have stops but no plane change. 無着陸飛行 emphasizes no landings at all.
Compound of 無 (mu, 'without') + 着陸 (chakuriku, 'landing') + 飛行 (hikō, 'flight').