Airworthiness and Flight Characteristics Evaluation. OH-58C Interim Scout Helicopter

Abstract

•'• ''-• signtificantly improved over the OH-58A. Performance in terms of power required and fuel flow is slightly degraded when compared to the OH-58A at similar gross weights and altitudes and in general did not meet the estimates of the detail specification for the OH-58C. The handling qualities and vibrations of the OH-58C are similar to the OH-58A when operating at similar gross weights and altitudes. MThe lvmdling qualities deficiencies relative to the low speed flight characteristics were identified. e inadequate directional control; the tendency for the aircraft to pitch and yaw excesivel in rearward flight. These lead to the overall conclusion of unsatisfactory low speed flight hacteristics. Another handling qualities deficiency was an aperiodic pitch divergence. ard flight climbs at rates of climb above 1000 ft/min. This deficiency was corre • en the engine infrared exhaust stacks were replaced with standard exhaust stacks. A _btn.ian factors evaluation of the cockpit revealed one deficiency (the night vision goggle switch is easily adtivited and renders the caution/advisory panel unreadable), and fourteen shortcomings. Two maintenance deficiencies were also noted: an easily clogged transmission oil cooler system and an uncommanded disconnect of the primary directional control system during right sideward flight. A total of sewvn deficiencies and 23 shortcomings were identified. The low speed flying qualities deficiancies were observed in the OH-58A. but increased in severity due to the higher gross weight, higher altitude capability and primary mission change to Nap-of-the-Earth flight for the OH-58C. The easily clogged transmission oil cooler deficiency is common to both the OH-58A and C. The other three deficiencies are caused by OH-58C aircraft changes. Of the 23 shortcomings, 10 were attributed to the OH-58C modification and 12 shortcomings are common to both the OH-58A and C. ,I 'V *SCuflVv CLASSIFICATION OF THIS PACE(Osen Dee. Znteh* W i DEPARTMENT OF THE ARMY 6 NO, US ARMY AVIATION RESEARCH AND DEVELOPMENT COMMAND