Complete
00:00:00
7 9 13 16 5 18 1 10 2 8 15 14 3 12 11 4 17 6
  1. 5a Polite form of words to attract attention (2,3,6)
  2. 7a Short drive in a car (4)
  3. 8a Part of a cruciform church — patterns (anag) (8)
  4. 9a Russian revolutionary, assassinated, 1940 (7)
  5. 11a Special set of circumstances (5)
  6. 13a Defect (5)
  7. 14a Nonstandard dialect from Newcastle-upon-Tyne (7)
  8. 16a Member of the radio audience (8)
  9. 17a Nub (4)
  10. 18a Crowd body movements at a sporting event (7,4)
  11. 1d City at the confluence of the Saône and Rhône (4)
  12. 2d Filmed scene not appearing in the final cut (3-4)
  13. 3d Plaintive cry (5)
  14. 4d Festival celebrating the exodus of the Israelites from Egypt (8)
  15. 5d Policy of a country seeking to extend its control over others (11)
  16. 6d Outlay (11)
  17. 10d 1970s' news and information service, like Ceefax and Prestel (8)
  18. 12d Trial (7)
  19. 15d Special way of doing something (5)
  20. 17d Landlocked central African country, capital N'Djamena (4)