THE PROCEEDINGS OF THE 17TH SESSION OF THE ICAO ASSEMBLY IN MONTREAL IN JUNE 1970 DEFINED THE VARIOUS TYPES OF ACTS CONSTITUTING INTERFERENCE WITH INTERNATIONAL CIVIL AVIATION (E.G., DAMAGE TO PLANES AND AIRPORT FACILITIES, VIOLENCE AGAINST AIRLINE PASSENGERS, ETC.) AND DESCRIBED THE VARYING VIEWS ON JURISDICTION AND ON THE QUESTION OF EXTRADITION. THE NOVEL PROVISIONS OF THE DRAFT CONVENTION PREPARED BY THE ICAO LEGAL COMMITTEE TO STRENGTHEN THE INCOMPLETE PROVISIONS IN ARTICLE II ON THE UNLAWFUL SEIZURE OF AIRCRAFT OF THE 1963 TOKYO CONVENTION PERTAIN TO THE DEFINITIONS OF PERTINENT OFFENSES, THE CONCEPTS OF AN 'AIRCRAFT IN SERVICE,' AND AN 'AIRCRAFT IN FLIGHT', AND TO THE QUESTION OF JURISDICTION. OFFENSES WHICH ARE CHARACTERIZED AS 'UNLAWFUL' ARE DESCRIBED UNDER THE CATEGORIES OF ACTS PERFORMED INTENTIONALLY, INHERENTLY DANGEROUS ACTS (E.G., PLACING OF A BOMB ON BOARD AN AIRCRAFT), AND SOMEWHAT EQUIVOCAL ACTS (E.G., CARRIAGE OF RADIO DEVICES ON BOARD AIRCRAFT). THE CONCEPT OF 'AIRCRAFT IN SERVICE' ENCOMPASSES THE TIME THE AIRCRAFT IS TAXIED OR TOWED FROM ITS PARKING PLACE IN THE HOME COUNTRY UNTIL ITS RETURN TO THAT COUNTRY. THE EXPRESSION 'IN FLIGHT' IS IDENTICAL TO THE EXTENSIVE DEFINITION FOUND IN ARTICLE FIVE OF THE TOKYO CONVENTION OF 1963. THE PROPOSED LONDON DRAFT OF THE ICAO PROVIDES THAT EACH SIGNATORY ESTABLISH JURISDICTION IN THE FOLLOWING CASES OF UNLAWFUL ACTS AGAINST AIRCRAFT: 1) WHEN ANY SUCH OFFENSE HAS BEEN COMMITTED IN THE TERRITORY OF THAT STATE; 2) WHEN ANY SUCH OFFENSE HAS BEEN COMMITTED ON OR AGAINST AN AIRCRAFT REGISTERED IN THAT STATE AND 3) WHEN THE EFFECT OF ANY SUCH OFFENSE HAS OCCURRED IN THE TERRITORY OF THAT STATE. OTHER JURISDICTIONAL MATTERS DISCUSSED INCLUDE PROCEDURES FOR HIJACKER ARREST, DETENTION, PRELIMINARY INQUIRY, PROSECUTION, AND EXTRADITION. IT IS CONCLUDED THAT THE LONDON DRAFT CONVENTION, WHEN ADOPTED, WILL BE A SIGNIFICANT CONTRIBUTION TOWARD OVERCOMING HIJACKING AND OTHER UNLAWFUL ACTS COMMITTED AGAINST INTERNATIONAL CIVIL AVIATION. (DEG)