Adam Air Flight 172 was a scheduled domestic passenger flight from Soekarno–Hatta International Airport to Juanda Airport, Surabaya. On 21 February 2007, the Boeing 737-300 operating the flight made a hard landing at Surabaya and suffered cracking of the fuselage in the middle of the passenger section. All six of Adam Air's remaining 737s were immediately grounded, though five of them were back in regular service later that year. This incident caused further concerns regarding the safety of flights operated by Adam Air, which had received much criticism after the 1 January 2007 crash of Flight 574.