CRJ700 subject of emergency AD

The FAA has issued an emergency AD on Bombardier CRJ700s that limits center-tank fuel quantity to 1,500 pounds at takeoff and flight paths to within 30 minutes of an alternate airport. The directive (2003-02-51) cites instances of cracked fuel feed lines and damaged transfer couplings due to vibration and fuel-line misalignment in the center tank. The problem could cause the center tank to overfill and leak, the FAA said. Incidents of uncommanded fuel transfer between the center tank and wing tanks prompted a March 12, 2002 emergency AD that increased the CRJ700’s normal mission fuel requirements.