A football banning order, made as the result of a relevant criminal conviction, remains 'unspent' (for the purposes of the Rehabilitation of Offenders Act) until it has expired. Therefore it will show up on a Basic Level check by Disclosure Scotland whenever such a check is carried out during the period which it lasts. (A football banning order made as the result of a conviction which does not to lead to imprisonment lasts between 3 and 5 years).
The length of the 'unspent' period for any additional punishment (such as a Community Order or fine) can effectively be disregarded here as it will theoretically be less than the three-to-five year period of the Football Banning Order but it can't become 'spent' until the Football Banning Order does anyway.
So your offence will show up on
any disclosure for between 3 and 5 years. However if the application for an airside pass is regarded as exempt from the provisions of the Rehabilitation of Offenders Act, then your criminal record will always show up on any disclosure for the rest of your life, as such checks will be carried out at 'Standard' or 'Enhanced' levels:
http://www.disclosurescotland.co.uk/disclosureinformation/
Whether it will impair your ability to get an airside pass is entirely up to the discretion of the issuing authority.