Artificial and Natural Icing Tests YEH-60A Quick Fix Helicopter.

• Main Authors: Tavares,E J, Sullivan,P J, Hanks,M L, Woratschek,R
• Other Authors: ARMY AVIATION ENGINEERING FLIGHT ACTIVITY EDWARDS AFB CA
• Format: Text
• Language: English
• Published: 1984
• Subjects: Helicopters; Flight Control and Instrumentation; Snow; Ice and Permafrost; *FLIGHT TESTING; *ICE FORMATION; *HELICOPTERS; ENVIRONMENTS; MILITARY AIRCRAFT; DAMAGE; ELECTRONIC EQUIPMENT; RATES; DIRECTION FINDING; ICE; ELECTROMAGNETIC INTERFERENCE; OPERATION; PROTECTION; FLIGHT ENVELOPE; HEAT; ACCUMULATION; AVIATION SAFETY; ELECTRONIC COUNTERMEASURES; OSCILLATION; INDICATORS; DIPOLE ANTENNAS; ROTOR BLADES; AIRCRAFT CABINS; *YEH-60A aircraft; Ice; permafrost
• Online Access: http://www.dtic.mil/docs/citations/ADA155147; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA155147

These tests were conducted to establish a moderate icing flight envelope for the helicopter with the AN/ALQ-151(V)2 countermeasures system installed. A total of 12.3 hours were flown in the icing environment. After damage to an unprotected direction finding (DF) dipole antenna during an icing encounter, the original DF dipole antennas were removed and a prototype thermoelectrically anti-iced DF dipole antenna was installed in position no. 3 (aft right side). During these tests 4 deficiencies and 16 shortcomings were noted. The two icing related deficiencies are: damage to the DF antenna element mounts and phenolic blocks caused by excessive element oscillations induced by ice accumulation; and erroneous readings on the Rosemount Icing Rate Indicator caused by electromagnetic interference from the electronic countermeasures system which prevents simultaneous safe operation of the ECM system and the blade deicing system. The two non-icing related deficiencies are: interference between the main rotor blades and the upper elements of the aft DF dipole antennas during rearward ground taxi and the inadequate cabin heat. The YEH-60A Quick Fix helicopter as originally configured (unheated DF antennas) was not suitable for flight in a moderate icing environment.