Worry not, you're protected by law. Not only in the military, but in every form of employment in the UK. Your employers are responsible for your actions...including your mistakes, your incompetence, your negligence, whatever.
The only way an employee can be held responsible is if they committed their error whilst engaged in some form of criminal activity.
All this is a good thing BTW, because it means the buck stops with the right people, ie people that can pay (because they will have insurance) when it comes to settling compensation claims.
Quite right to say that ordinary employees are not prosecuted for CORPORATE manslaughter. But they can of course be prosecuted for criminal offences including manslaughter involving negligence or neglect, not merely those involving deliberate criminal conduct. There is also a range of service offences which are relevant.
Just to add, there are exemptions in the corporate manslaughter legislation for some operations-related military activities (IMO not applicable to air display training) but they are not a general exemption of employees from prosecution for criminal offences.