Apollo Air Flight DF-0301

Flight DF-0301 was a transatlantic flight which crashed into the mid-Atlantic in 1960. Though the flight's destination and origin are unknown, it is likely that the plane was flying from America to Europe, as Jack appears to be American and a stewardess in the opening cutscene has a Texan accent. It was hijacked by Jack, who was under the control of Frank Fontaine by the use of the phrase "would you kindly," which was included on a note attached to a gift that Jack carried onto the plane. The gift turned out to be a pistol, along with instructions to crash the plane at a specific location. All 89 passengers and crew were presumed dead in the crash, though in reality Jack survived and was able to return to Rapture via the nearby lighthouse, fulfilling Fontaine's plan.

Aftermath
The wreckage of the plane is briefly explorable in the first level of Bioshock, as Jack swims to the lighthouse. A large piece of the fuselage sinks almost immediately (nearly crushing Jack), but many small pieces remain on the surface, along with a raging fire from spilled fuel and many personal effects from the other passengers. The two largest recognizable pieces of debris on the surface are a wing section, engulfed in flames, and a slowly sinking section of the plane's tail, with the logo and running lights still clearly visible along with the flight's registration number. It is this tail section that crashes into Rapture a few minutes later, as Jack explores the city for the first time. The tail damages a glass tunnel, blocking it and causing flooding, but Jack is able to climb through the section and make it to the other side using an exit door at the back of the plane.

Investigation
The reason for the crash was never determined by international investigators, and many alternative theories are put forward by conspiracy theorists, such as the theory that "the frozen triangle" brought the plane down. This theory is actually close to the truth, as it attempts to explain the disappearance of planes and ship's in Rapture's vicinity. The crash is also investigated by an American nuclear submarine, which arrives to find debris still on the surface several days after the crash (perhaps longer; it is unknown how much time passes between the end of the game and this event.) The submarine is attacked by several dozen Rapture bathyspheres carrying splicers, who slaughter the crew and apparently steal the submarine and its missiles. Though this is only seen to happen in the 'bad ending' cutscene, it could have also happened after Jack left the city with the little sisters as per the 'good ending.' The submarines involvement and subsequent loss is apparently a closely guarded secret, as it is mentioned only as a rumor in "The Frozen Triangle" book from There's Something in the Sea.