Summary Wilmington Trust SP Services (Dublin) Ltd and others v Spicejet Ltd [2021] 1, has provided guidance on the English law doctrines of illegality and frustration. Whilst this specific dispute relates to overdue aircraft lease payments and particular government restrictions on the use of Boeing 737-Max 8 aircraft, the Court’s findings will be interesting to others grappling with debtors seeking to rely on Covid-19 related restrictions in defence of a breach of contract claim. In Wilmington Trust, the claimant aircraft lessors sought summary determination of their claims for outstanding amounts under three lease agreements. In its defence, Spicejet argued that it was not obliged to pay the monies sought because, amongst other reasons,