26.3.1 Under the influence of alcohol or a drug

Whether a person is under the influence of alcohol or a drug is a question of fact which must be determined by consideration of all the available evidence. The mere fact that the member has imbibed alcohol or taken a drug is not suffici — ent to bring S4(13) into operation. There must be evidence that they were 'under the influence' of that substance.

The Concise Oxford Dictionary includes the following relevant definition:

under the influence colloq. affected by alcoholic drink.

Whether a person is 'under the influence' may, to some extent, be affected by the nature of the activity being undertaken. For example, a member's capacity to undertake a complex task, requiring a high level of precision and manual dexterity, may be affected by a much lesser level of alcohol consumption than would usually affect their normal daily activities.

Note, however, that there must be an effect or influence. It is not appropriate to invoke S4(13) simply because a member has breached an employment rule (e.g. no alcohol before undertaking flying duties). This is a disciplinary matter and would not have compensation implications unless the member is 'under the influence'.