Sir Peter Mathieson, who once claimed he did not know his own £421,667 salary, announced earlier this year he would not seek a third term when his current contract expires in early 2028.
It comes as Public Health Scotland figures showed just 66.7 per cent of A&e patients were admitted, transferred or discharged within four hours during the month of August.
Ian Haggis and the 16-year-old boy were pronounced dead at the scene after the plane came down in a remote field near Drymen, Stirlingshire, shortly before 4.45pm on Friday.