text: **27.**—(1) A specialist aerospace engineer, or a specialist aerospace worker, where they have 
  travelled to the United Kingdom in the course of their work. 
  
  (2) For the purposes of sub-paragraph (1)— 
  
  (a) “specialist aerospace engineer” means a person who is employed or otherwise engaged to 
  provide engineering services for the purpose of ensuring the continued operation of 
  aviation activities (including but not limited to the provision of maintenance and repair 
  services for production lines, aviation components, grounded aircraft and new aircraft); 
  (b) “specialist aerospace worker” means a person who is employed or otherwise engaged to 
  provide services for the purpose of ensuring safety management and quality assurance as 
  required by relevant standards, guidance and publications on aviation safety produced by 
  the Civil Aviation Authority or the European Union Aviation Safety Agency(**d**). 
  
  **28.**—(1) A person engaged in operational, maintenance or safety activities of a downstream oil 
  
  facility that has a capacity in excess of 20,000 tonnes, where— 
  
  (a) the downstream oil facility is engaged in a specified activity carried on in the United 
  Kingdom in the course of a business, and contributes (directly or indirectly) to the supply 