747 Improvements

THE first of 60 Rolls‐Royce RB 211– 524 C2 turbofans to incorporate modifications bringing it up to—524 D4 upgrade standard was recently completed and tested by British Airways at Heathrow. These engines (including some spares) power 12 of the airline's Boeing 747–236 aircraft and it is hoped tht enough of the power‐plants will have been completed by the end of the year. The contract which was negotiated in 1985, envisages the completion of all 12 aircraft in two years from the commencement of improvements.