I did my Highers in '95/'96. I started commercial training in '97 and first job in '99. No employer has ever asked to see my results as far as I can remember. If you did standard grades or whatever they are called now then stick with Highers. Basically if you are in the SQA system then stay with that I would say. At the end of the day if you select aviation as a career it will make little, if any difference what school qualifications you have. Any UK employer will equally recognise Highers or A Levels. Good luck in whatever you decide to do. All the best.