LC Authority and Vocabulary Service is under maintenance!
While the ID.LOC.GOV service is under maintenance, all possible relationships between resources may not be expressed.
Full service will be restored as soon as possible. Thank you for your patience.
found: Hardersen, C. Preliminary design study of a composite main rotor blade for the OH-58 helicopter, 1978 (a.e.) t.p. (William Blackburn, Kaman Aerospace Corp., Bloomfield, Conn.)