Attack Helicopter Evaluation AH-56A Cheyenne Compound Helicopter
Attack Helicopter Evaluation AH-56A Cheyenne Compound Helicopter

Author: John N. Johnson

Publisher:

Published: 1972

Total Pages: 153

ISBN-13:

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The US Army Aviation Systems Test Activity (USAASTA) conducted an Attack Helicopter Evaluation of the AH-56A Cheyenne Compound Helicopter during the period 15 April to 15 June 1972. The AH-56A was tested at Yuma Proving Ground, Arizona and Mammoth Lakes, California. This evaluation was conducted to provide data for use in determining Advanced Aerial Fire Support System effectiveness model inputs, validating material need requirements, and validating contractor claims. The forward area concealment evaluation was conducted by the US Army Combat Developments Command Aviation Agency and the maintenance characteristics evaluation was conducted by the US Army Aviation Systems Command. The performance and handling qualities testing consisted of 49 test flights totaling 42.2 flight hours. The pusher propeller was a major contributor to several enhancing performance and handling qualities characteristics.

Army Preliminary Evaluation YAH-IQ Helicopter with a Flat-Plate Canopy
Army Preliminary Evaluation YAH-IQ Helicopter with a Flat-Plate Canopy

Author: James R. Arnold

Publisher:

Published: 1975

Total Pages: 40

ISBN-13:

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The United States Army Aviation Engineering Flight Activity conducted a limited evaluation of the level flight performance and handling qualities of a YAH-1Q helicopter with a flat-plate canopy from 17 through 19 June 1975 at the Bell Helicopter Company flight test facility at Arlington, Texas. During the test program, eleven flights for a total of 4.4 productive hours were flown. A loss in maximum airspeed for level flight was determined when compared to the AH-1G (Bell Helicopter Company data indicate 5 to 7 knots). The primary effect of the flat-plate canopy on handling qualities was a noticeable decrease in directional stability. The one deficiency determined during the evaluation was the internal reflection from external light sources on the flat-plate canopy during night flight. Five shortcomings were noted during the evaluation. Further testing should be conducted to determine the effect of the decreased directional stability on the accuracy of rocket fire.

Engineering Flight Test of the YCH-47B Helicopter Army Preliminary Evaluation I, II and III.
Engineering Flight Test of the YCH-47B Helicopter Army Preliminary Evaluation I, II and III.

Author: Norman A. Mattmuller

Publisher:

Published: 1969

Total Pages: 166

ISBN-13:

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The Army Preliminary Evaluation of the YCH-47B helicopter was conducted by the US Army Aviation Systems Test Activity at Philadelphia, Pennsylvania in three phases during the period 1 March 1967 to 31 August 1967. The improvements in hover and level flight performance were defined and the change in flying qualities from those of the CH-47A helicopter were evaluated. An objectionable level of noise and vibration was encountered during testing; however, a significant reduction in vibration was achieved by the reduction of recommended rotor rpm from 230 to 225. An expansion of the 16,000 pound external load flight envelope to that of the helicopter with internal loads was substantiated with the exception of bank angle limitations. As a result of stress checks performed in turn maneuvers, the bank angle envelope was reduced to avoid excessive fatigue damage on aft rotor head control components. (Author).

Army Preliminary Evaluation III and IV YCH-47C Medium Transport Helicopter
Army Preliminary Evaluation III and IV YCH-47C Medium Transport Helicopter

Author: Jerry L. Jester

Publisher:

Published: 1970

Total Pages: 148

ISBN-13:

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Army Preliminary Evaluation (APE) consisted of vibration noise level tests and a re-evaluation of the stability and control characteristics modified by the incorporation of engineering changes to correct the handling qualities deficiencies found during APE II. APE IV was a re-evaluation of the vibration characteristics which was required because of structural modifications incorporated in the aircraft following APE III. The helicopter showed significant improvements in trimmability, static and dynamic longitudinal stability and lateral-directional stability as compared to aircraft flown during APE I and II. The longitudinal stability improvements permitted sustained hands off flight. The vibration levels experienced during APE IV were improved over APE III. The aircraft met all requirements except two of the detail specification and two of the military specification.