Airworthiness And Flight Characteristics Test Of A Sixth Year Production Uh 60a PDF Download

Testing was conducted to obtain performance data for inclusion in the sixth year production UH-60A helicopter operator's manual. A total of 58 productive flight hours were flown at five different test sites between 3 and 20 October 1983 and 29 February and 18 September 1984. The out-of-ground effect hover gross weight capability was 16,526 pounds for 95 percent intermediate (30 minute limit) rated power available at 4700 feet pressure altitude and 35 C temperature. The increase in equivalent flat plate area of the sixth year production aircraft configuration over the first year configuration over the first year configuration was 5 square feet in level flight at a referred rotor speed (N sub R/sqare rot theta) of 258 revolutions per minute. Of this increase, 2.5 was attributed to the External Stores Support System fixed provision fairings, 1.5 sq ft to the external mounting brackets of the AN/ALQ-144(V) infrared countermeasures set and M130 chaff dispenser, and 1.0 sq ft to numerous other minor external changes. However, throughout the N sub R/square root theta range, the difference in power required between the first and sixth year production aircraft does not equate to a constant Fe. A limited investigated did not completely account for the power differences noted when flying at different dimensional conditions that produce the same nondimensional thrust coefficient.