noun
belly landing; gear-up landing
Aviation term for an emergency landing where the aircraft lands on its underside without deploying landing gear.
その旅客機は胴体着陸を余儀なくされた。
The passenger plane was forced to make a belly landing.
不時着 is a broader term for any emergency or unscheduled landing, while 胴体着陸 specifically refers to landing with the landing gear retracted.
Compound of 胴体 (どうたい, 'fuselage' or 'body') and 着陸 (ちゃくりく, 'landing'), literally 'fuselage landing'.