SAE ARP*570A 65 83573LiO 0028523 2 H AEROSPACE SOCIETV OF AUTOMOTIVE ENGINEERS. InC. 485 LEXINGTON AVENUE RECOMMENDED PRACTICE NEW YORK 17, N.Y. ARP 570 DESIGNATION OF DIRECTION OF ROTATION OF HELICOPTER ROTORS 1. Rotation of lifting rotor is defined as clockwise or counter clockwise when viewed from above heli- copter. irrUd 12-15-60 Rlvlwd 4-i5-65 2. Rotation of other than lifting rotor is defined as clockwise or counter clockwise when viewed from left and front of helicopter. PREPARED BY COMMITTEE 5-12 HELICOPTER POWERPLANT LY Wo of Automotko Cnilnooro. Ina / / L/ Crlntod In U. O. A.