CATEGORY II ARCTIC EVALUATION OF THE YCH-47A HELICOPTER.

• Main Authors: STANFORD,Ronald E., Griggs,D. Bruce
• Other Authors: AERONAUTICAL SYSTEMS DIV WRIGHT-PATTERSON AFB OHIO
• Format: Text
• Language: English
• Published: 1964
• Subjects: *HELICOPTERS; COLD WEATHER TESTS; PERFORMANCE(ENGINEERING); FLIGHT TESTING; ARCTIC REGIONS; MILITARY REQUIREMENTS; ROTOR BLADES(ROTARY WINGS); DRIVES; HYDRAULIC EQUIPMENT; ELECTRICAL EQUIPMENT; FLIGHT CONTROL SYSTEMS; HEATING; MAINTAINABILITY; HANDLING; TAXIING; Arctic; Eielson; Alaska
• Online Access: http://www.dtic.mil/docs/citations/AD0611581; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0611581

The YCH-47A helicopter was tested under arctic conditions at Eielson AFB, Alaska during the period 10 December 1963 to 6 February 1964. Testing consisted of flights both at moderately low (+ 10F to -20F) and very low temperatures (-20F to -30F) as well as ground operation down to -40F. Along with conducting an overall evaluation of the helicopter's effectiveness in a cold environment, a number of improvements to correct earlier low temperature deficiencies were tested and found adequate. This report contains a description of the test procedures, selected instrumentation data, a discussion of the deficiencies uncovered and recommendations for their correction. Problems encountered in the Arctic were instability arising from SAS (Stability Augmentation System) operation, delamination of rotor blade fiberglass skins, and extreme difficulty in ground handling on hard packed snow, ice, or similar slippery surfaces. In order for the helicopter to be suitable for low temperature operation, new or modified rotor blades with assured structural integrity must be incorporated along with other improvements recommended in this report. (Author)