Complex sentence: BA proceeded to rationalise their fleets, retiring many overlapping types, the One-Eleven being gradually phased out for the more modern A320 and Boeing 737 jetliners, the last aircraft was removed from regular service with BA in October 1992.
Split into simpler sentences: BA proceeded to rationalise their fleets, retiring many overlapping types, the One-Eleven being gradually phased out for the more modern A320 and Boeing 737 jetliners. The last aircraft was removed from regular service with BA in October 1992.