If they really were "doing drugs" onboard, then it would be headline news everywhere.
And yet, the reported incident didn't even warrant a mention in this article from the same day:
Drunken air rage hits a new high at Manchester Airport
Posted on Friday 27 May 2016
Manchester Airport is flying high as one the UK's blackspots for drunken air passengers, according to new figures.
At least 30 people were held between March 2014 and March 2016 by police at Manchester Airport and cases include passengers trying to smash windows and banging on the cockpit door demanding more booze.
Manchester has the highest number of incidents in England outside the main London airports and shadow transport secretary Lilian Greenwood described the figures as ``extremely concerning''.
...or in any news report since.