It can't be an International Aircraft under the Chicago Convention as both Gib & the UK are under the British Crown - same as the Isle of Man or the FI - and the highest court is the UK Supreme Court sitting in London

I may yet stand correction however I suspect that Gibraltar has a similar relationship to the UK Government (MOD) as Jersey in that their allegiance is directly to the crown with matters fiscal and possibly judicial remaining under internal control.

Imagegear

I see the Daily Fail is not alone at the pinnacle of fake news reporting:

Gibraltar police stop RAF plane taking off at Gibraltar International Airport | Daily Star

Or who nicked the propellers?

I see that Daily Fail is saying:

Don't understand why the road across the runway had to be closed for so long - if report in Gib Chronicle of "a couple of hours" is correct?

Unless Atlas was at the threshold and threatening to depart without clearance, which presumably wasn't the case.

If it was a couple of hours, it must have been chaos both sides of the airfield and the border.

A case of truth imitating fiction. Just about every TV cop series has an episode where our hero - Frost/Morse/Foyle etc has to investigate an offence at a nearby Army/ RAF base and runs into an obstructive military who refuse to cooperate and are invariably made to look like total prats.