A Man is a novel written by Oriana Fallaci chronicling her relationship with the attempted assassin of Greek dictator George Papadopoulos.
David Henderson admitted attempting to discharge a passenger without valid permission or authorisation.
The plane carrying 28-year-old Sala and pilot David Ibbotson crashed into the English Channel in January 2019.
He appeared before High Court judge Mr Justice Foxton at Cardiff Crown Court on Monday.
Henderson is alleged to have arranged The Flight carrying Sala and 59-year-old Mr Ibbotson.
The single-engine Piper Malibu aircraft was bringing the striker, who was involved in a multimillion pound transfer deal, from Nantes in France to Cardiff where he had signed for the Bluebirds.
At a hearing in October 2020, The Court heard how Mr Ibbotson's licence to fly an aircraft commercially had expired in November 2018.
The Air Accidents Investigations Branch (AAIB) reported at the start of the year that the plane had been leaking carbon monoxide during The Flight and a final manoeuvre by Mr Ibbotson to pull up the plane had caused it to Break Up mid-air.
An jury inquest into his death was postponed until after Mr Henderson's trial and is scheduled for 14 February 2022.