The plane which killed 11 people at the Shoreham Airshow had damaged parts a year out of date.
The Air Accidents Investigation Branch said today that pyrotechnic pieces of the 1950s Hunter Hawker should have been changed before June 2014.
It crashed on the A27 in August and rescue work was delayed as some pyrotechnic cartridges “were still live”.
A final report is still to be issued by the AAIB.
Below: Shoreham victims
Shoreham Victims
Its update today noted a lack of training courses for civilians maintaining ex-military jets.
The Civil Aviation Authority said the report “does not contain any information” on the cause of the tragedy.
It had told the AAIB maintenance of the plane was valid.
Pilot Andy Hill, 51, was interviewed last week by police.