Nos. 23295, 23300, 23750, 23751. Argued November 3, 1970. Decided May 27, 1971. Mr. Jerry D. Anker, Washington, D.C., for petitioner in Nos. 23,295 and 23,300. Mr. Marvin J. Martin, with whom Mr. W. Stanley Churchill, Wichita, Kan., was on the brief, for petitioner in Nos. 23,750 and 23,751 and intervenor in Nos. 23,295 and 23,300. Mr. Joseph E. Mayer, Atty. National Labor Relations Board, for respondent. Messrs. Arnold Ordman, General Counsel, Dominick L. Manoli, Associate General Counsel, Marcel