Ch-47C Fixed-System Stall-Flutter Damping

Abstract

This program was conducted to evaluate the effect of fixed-system damping on stall-induced control loads. Damping was introduced into the CH-47C aft-rotor control system by connecting the housing portion of the linear damper to the longitudinal-trim system and grounding the piston portion of the damper to the aft transmission. Five damper-rate configurations were evaluated on a helicopter with a gross weight of 40,000 pounds. Data obtained in speed sweeps at five density altitudes to 10,000 feet indicate that the rotating-system loads were reduced by 16 percent and the fixed-system loads were reduced by 22 percent. The program proved that fixed-system damping is effective in reducing stall-induced control loads. Recommendations are presented for reducing these loads by softening the swashplate support as well as by increasing the effectiveness of the fixed-system damper.

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Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1975
Accession Number
ADA014890

Entities

People

  • Joseph M. Baskin

Organizations

  • Boeing Rotorcraft Systems

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Acquisition
  • Actuators
  • Aircrafts
  • Altitude
  • Control Systems
  • Data Acquisition
  • Data Analysis
  • Dynamic Response
  • Flight Speeds
  • Flight Testing
  • Helicopters
  • Instrument Panels
  • Level Flight
  • Procurement
  • Standards
  • United States
  • Waveforms

Readers

  • Aerospace Engineering
  • Structural Dynamics.