Source: Preliminary report on Indian plane crash incident expected to be released on Friday.

Three sources said on Tuesday that an Indian airline jet crashed in June, causing 260 deaths. The preliminary investigation report is expected to be released on Friday, which may provide early details on what has been the worlds deadliest aviation disaster in a decade. While India investigators are expected to release their report on Friday, sources cautioned that plans could change, and it is not clear how much information will be provided in the document, which is being released around 30 days after the tragedy occurred on June 12. The Boeing BA.N787 Dreamliner aircraft bound for London began losing altitude after reaching 650 feet and crashed shortly after taking off from Ahmedabad, with 241 of the 242 people on board perishing, and the rest on the ground. According to the aviation publication "Air Current," sources familiar with the matter said that the focus of the investigation into the crash of Indian airline Flight 171 is on the operation of the engine fuel control switch. These sources reportedly said that the information on the black box does not rule out any improper, negligent, or deliberate actions before or after the aircraft apparently lost thrust before the crash.