Airlines will soon be asked to replace rivets in more than 800 Boeing 727s that were made with what is now considered an outmoded bonding process, a regional Federal Aviation Administration official said. Darrell Pederson said in Seattle Tuesday that the agency was very close to issuing a notice of proposed rulemaking, which can be followed by an airworthiness directive after public comment. Under such a directive last April, airlines had to replace more than 7,000 rivets on 100 older Boeing 737s at a cost of about $8 million. Meanwhile Wednesday, an Eastern Airlines 727 was grounded at Logan International Airport in Boston after an inspection revealed a 3-inch crack in its fuselage, the FAA said. The fuselage crack, found near the plane's No. 2 engine, was discovered Tuesday while the crew was conducting a special inspection.