I would be asking about the terms of the airfield operator's lease. A landlord cannot "derrogate from its grant"; i.e. it cannot grant a lease of an airfiled and then do something which in effect removes the benefit of what has been granted under the lease. The second point is that the lease will be protected as a business tenancy under the Landlord & Tenant Act 1954, unless the lease was specifically excluded from the Act at the time it was granted (there is a special procedure for doing this). This Act restricts the ability of the Landlord to recover possession at the end of the lease and gives the tenant the right to a new lease, save in limited circumstances.