Services

Flutter

All aircraft must be free from flutter for flight safety and per airworthiness requirements.

TLG performs certification aircraft flutter analyses for all required aircraft configurations and conditions. We also plan and participate in the required ground and flight testing and subsequent analysis.

Aircraft Flutter

Flutter analysis ensures the aircraft is safe and free from flutter at all points in the flight envelope. Flight flutter tests must be performed to demonstrate the accuracy of the analysis and prove the airplane is safe to operate. Flutter is critically dependent upon airspeed because the dynamic pressure in the airstream provides the energy for the self-feeding oscillations. Therefore, we perform analyses at higher air-speeds than what other design aspects require. Not only do civil airworthiness regulations require this, but it also provides a margin of safety in speed.We model the airplane interaction between structural vibrations and unsteady aerodynamics using an engineering tool such as MSC. Nastran. These models show whether an airplane will respond in a stable or unstable fashion to an atmospheric disturbance.Typical design features that contribute to good flutter characteristics include: stiff, lightweight structure, mass-balanced or hydraulically stiffened control surfaces and structural mass concentrated toward the wing or tail leading edges.

Flutter Services

  • Flutter Evaluation
  • Design for Aeroservoelastic Stability Margin
  • Full Aeroservoelastic Calculation Capabilities
  • Feasibility Studies
  • Product Development
  • Engineering Project Management
  • Feasibility Studies
  • Report Generation
  • Whirl Flutter Analysis
  • Flight and Ground Testing for Flutter Certification
  • Simulation of Failure Modes including FCS Failure
  • Structural Failure and Engine Blade-out Conditions
  • Flutter Flight Test Plans
  • Test Attendance
  • Flight Clearance
  • Data Analysis

Tools

Our engineers calculate airplane structural vibration modes with a Finite Element Model (FEM). Validation of these models is from a Ground Vibration Test (GVT) of the actual as-built airplane or component. We validate aerodynamic data taken from Computational Fluid Dynamics (CFD), wind tunnel tests, and certification flight testing.