Complex sentence: These faster airplanes turn the standard timetables upside-down and allow the stewardesses to spend more time in Paris... most alarming for Bernard, his three girlfriends will now be in Paris at the same time.
Split into simpler sentences: These faster airplanes change all of the existing route schedules and allow the stewardesses to spend more time in Paris. Most alarming for Bernard, his three girlfriends will now all in Paris at the same time.