High Quality Content by WIKIPEDIA articles! Adam Air Flight 172 was a serious incident involving a Boeing 737-300, registered PK-KKV, flying on a scheduled domestic passenger flight in Indonesia between Jakarta and Surabaya. Officials stated the aircraft passed safety checks prior to its departure. On 21 February 2007, the plane bent on landing, with the fuselage cracking in the middle of the passenger section. All six of Adam Air`s remaining 737s were immediately grounded, but five of them were back in regular service later that year. This incident has caused further concerns regarding the safety of flights operated by Adam Air, which has received much criticism after the 1 January 2007 crash of Flight 574. The cause of the February 2007 incident is still under investigation.