A TEAM of investigators from the Air Accident Investigation Branch last night travelled to Merseyside to begin their probe into the crash of the light aircraft in Liverpool Bay.
They will today analyse the taped recordings of conversations between the stricken aircraft and air traffic controllers at Liverpool John Lennon Airport.
The Piper Cherokee did not have a black box recorder and the investigation team will have to piece together the last moments of the flight from wreckage retrieved from the Irish Sea.
The Civil Aviation Authority is informed about any accidents involving aircraft in the UK.
They in turn can ask the branch, which is part of the Department of Transport, to probe any serious incidents.
Branch investigations can last between one month and up to a year.
Liverpool John Lennon Airport spokesman Robin Tudor said: "The scene will be at first treated as a crime scene by Merseyside Police and they will work closely with air investigators.
"I do not believe this aircraft had a black box - there is no prerequisite that aircraft of this size have them.
"The investigators will look at the air traffic control transcripts to try and work out what happened."
The first Piper Cherokee took to the air in 1963. It is regarded as being tough and stable with excellent handling ability.
It has a cruising speed of 143mph and is used for training or as a light pleasure aircraft across the world.
