LONDON (Jan. 16)—British Airways P.L.C. has started fitting Kevlar-reinforced rubber fuel tank linings on the first of its seven Concordes under a $40 million program to get the supersonic aircraft back into service this spring. The program also includes work to reinforce wiring in the undercarriage and improvements to the aircraft interior, and is expected to take eight to 10 weeks to complete for each aircraft, British Airways said in a prepared statement. When the modifications have been completed on the first Concorde, it will be used for in-flight testing of the tank liners and their effects on the aircraft´s fuel systems. The company then plans to modify two Concordes at a time, until the entire fleet has been completed, it added.