The fleet in 1990:
Registration | Type of Aircraft | C/n | G-BOAW | DeHavilland DHC-7-110 Dash 7 | 110 | G-BOAX | DeHavilland DHC-7-110 Dash 7 | 111 | G-BOAY | DeHavilland DHC-7-110 Dash 7 | 112 | G-BOAZ | DeHavilland DHC-7-110 Dash 7 | 77 |
Sources:
Fleet info: JP Airline Fleets 1990
http://www.londoncityairways.co.uk/history.htm