tiarna
For once in my life I agree with SFFP.
If you read this thread from its inception (it is obvious that you have not -nor have you read the BOI itself) you will note that ALL the contributors who were actually there that fateful day are adament that the equipment you are talking about was NOT fitted to ZD 576 on 2 June 1994. Having done that then you may consider reading the AAIB report as well as the BOI in its entirety.
Once you have completed reading those documents you may be in a position to comment usefully to the discussion.