The Extradition (Hijacking) (Amendment) Order 1977
Whereas extradition treaties have come into force between the United Kingdom and Finland and between the United Kingdom and the United States of America which replace the treaties with these States specified in Schedule 2 to the Extradition (Hijacking) Order 1971(a) as amended by the Extradition (Hijacking) (Amendment) Order 1972(b):

And Whereas other States have become parties to the Convention for the Suppression of Unlawful Seizure of Aircraft signed at The Hague on 16th December 1970(c) ...