During certain stages of the 2010 Northern Daylight Savings schedule, it witnessed the introduction of the 77A into the LHR route - primarily on CX257/256. When the 2011 ones arrive on March 27 according to the schedules, the route will see an increase in the weekly frequency of that aircraft to 10x weekly. Between March 27-August 31, not only will CX257/256 be operated by the 77A daily, so will CX253/254 every Mon, Wed, Fri (The remainder of the 4x weekly will remain as the 74A). Then from September 1-October 29, the 77A frequency of CX253/254 will increase further to 5x weekly operating Mon, Wed, Thu, Fri, Sat (only on Tue and Sun will the 74A operate) supplementing the daily 77A for CX257/256. This will bring the overall 77A weekly frequency for LHR to 12x weekly. No changes to CX251/255/252/250 as they will continue with the 74A.

Not a surprising development with reports that the 77Ws are to replace the 744s.