Organisers of the Shoreham air show were unaware of the display plans of a pilot whose jet crashed last year, killing 11 people.
An Air Accident Investigation Branch (AAIB) report found the organisers failed to carry out a proper risk assessment.
According to the report, the display director was not fully aware of the sequence of display manoeuvres the pilot was planning to carry out, the BBC reports.
Therefore, he was unable to identify where the manoeuvres would take place or which groups of people would be at risk.
Andrew Hill was attempting to perform a loop-the-loop manoeuvre when his vintage 1959 Hawker Hunter jet crashed into the A27 road on 22 August, 2015.
Mr Hill survived the crash.
A full hearing into the Shoreham air show crash is scheduled to be held in June 2016.
