Two Marine aviators whose jet clipped an Italian gondola cable, killing 20 people, waived their right to the equivalent of a civilian grand jury hearing on new charges in the case.

The additional charges of obstruction of justice and conspiracy to obstruct justice against Capts. Richard J. Ashby and Joseph P. Schweitzer will be included at their courts-martial on manslaughter and homicide charges, the U.S. Marine Corps said Monday.The court-martial for Ashby, 30, of Mission Viejo, Calif., will be held Dec. 7-18, while the court-martial for Schweitzer, 30, of Westbury, N.Y., will be held Jan. 4-15. Both men will be tried at Camp Lejeune.