Flight Safety,. .. .The Kaman Huskie HH-43B series synchropters use engine efflux to counteract torque. They have an exhaust pipe (stovepipe) going back to the tail then pointing down from the horizontal by approximately 30 degrees. . .. .The Huskie is an intermeshing helicopter and the masts are not quite vertical. The rotors are counter-rotating, so they use the exhaust to compensate for the longitudinal pitch changes that accompany changes in torque, not for yaw.. . . . <small>[ 18 March 2002, 03:05: Message edited by: Dave Jackson ]</small>