Investigation of a helicopter harsh landing based on signals from installed sensors

Full scale testing of actual aircraft structures is one of the important methods of structural design experimental validation. Such testing is also used to support creation of future use strategy of ageing aircraft. Influence of hard landings on the structural integrity is one of the key issues in the process of helicopter service life extension for ageing aircraft, such as the Polish Air Force Mi-8/17 helicopters. An experimental vertical drop test simulating a hard landing has been one of the tasks in the European Defense Agency’s „ASTYANAX” research project. The aim of the test was to verify the extent of structural damage for landings occurring in the permitted velocity range (i.e. below 3,05 m/s). A Mi-8 helicopter decommissioned from the Polish Air Force has been used for the test. Various measurement systems were used in the test: deformation measurements with strain gauges, Bragg gratings and PZT sensors as well accelerometer systems and landing gear cylinder displacement meters. In addition, after each drop test step, a visual NDI as well as comparative analysis of three-dimensional surface deformation (made with optical scanners) took place. A measurement of 3D coordinates of discrete control points has also been performed. Preliminary analysis of the experiment results is presented in the paper.

[1]  Richard E. Zimmerman,et al.  Aircraft Crash Survival Design Guide. Volume 3. Aircraft Structural Crash Resistance , 1989 .

[2]  Andrea Manes,et al.  Helicopter fuselage crack monitoring and prognosis through on-board sensor network , 2009 .

[3]  R. J. Hayduk,et al.  Crash tests of four identical high-wing single-engine airplanes , 1980 .

[4]  K. H. Lyle,et al.  Full-scale crash test and simulation of a composite helicopter , 2001 .

[5]  Karen E. Jackson,et al.  Occupant Responses in a Full-Scale Crash Test of the Sikorsky ACAP Helicopter , 2004 .

[6]  Karen E. Jackson,et al.  Full-Scale Crash Test of a MD-500 Helicopter with Deployable Energy Absorbers , 2010 .

[7]  Karen E. Jackson,et al.  Crash Test of an MD-500 Helicopter with a Deployable Energy Absorber Concept , 2010 .

[8]  Claudio Sbarufatti,et al.  Artificial Neural Networks for Structural Health Monitoring of Helicopter Harsh Landings , 2013 .

[9]  Yvonne T. Fuchs,et al.  Vertical Drop Testing and Analysis of the Wasp Helicopter Skid Gear , 2008 .

[10]  Edwin L. Fasanella,et al.  Finite Element Simulation of a Full-Scale Crash Test of a Composite Helicopter , 2002 .

[11]  Norman A Merritt.  AIRCRAFT CRASH SURVIVAL DESIGN GUIDE. , 1989 .

[12]  M. A. McCarthy,et al.  Numerical investigation of a crash test of a composite helicopter subfloor structure , 2001 .

[13]  Rade Vignjevic,et al.  Application of the finite element method to predict the crashworthy response of a metallic helicopter under floor structure onto water. , 2008 .

[14]  Karen E. Jackson,et al.  Overview of the National Aeronautics and Space Administration Subsonic Rotary Wing Aeronautics Research Program in Rotorcraft Crashworthiness , 2009 .

[15]  Thomas E. Pinelli,et al.  National Aeronautics and Space Administration Scientific and Technical Information Programs. , 1990 .

[16]  Karen E. Jackson,et al.  A Summary of DOD-Sponsored Research Performed at NASA Langley's Impact Dynamics Research Facility , 2004 .