Lumbar Load Variability in Dynamic Testing of Transport Category Aircraft Seat Cushions

The Federal Aviation Administration (FAA) has standards and regulations in place that require aircraft seating systems protect occupants in the event of a crash. These standards require dynamic testing to substantiate the safety of seating systems. In a vertical impact, the seat bottom cushion plays a vital role in controlling the load transferred to the occupant’s spine. Repeat testing has identified large test uncertainty. To identify the source and magnitude of the observed uncertainty, existing data were combined with a series of tests specifically designed to evaluate these factors. The analysis identified that a significant amount of irreducible test uncertainty was inherent to the test method and type of Anthropomorphic Test Devices (ATDs). The maximum observed uncertainty was 340 lb and appears to be a function of the specific foam tested. This amount of load uncertainty corresponds to an injury risk probability range of 40%. The testing also identified areas of reducible uncertainty that can be minimized by controlling certain variables. These include ATD initial position, ATD construction consistency and degradation, and ATD interactions with armrests. Reducible uncertainty may have a larger effect on the lumbar load than the irreducible uncertainty. These results highlight the need for a standardized vertical calibration for ATDs used in vertical tests. Analysis of the results led to a better understanding of testing uncertainty and to the development of best practices for minimizing test uncertainty. These best practices are provided as an Appendix to this report.

• Record URL:
  https://www.faa.gov/data_research/research/med_humanfacs/oamtechreports/2020s/media/202109.pdf
• Record URL:
  https://rosap.ntl.bts.gov/view/dot/57228
• Corporate Authors:

  FAA Civil Aerospace Medical Institute

  6500 S MacArthur Boulevard
  Oklahoma City, OK  United States  73125

  Federal Aviation Administration

  Office of Aerospace Medicine, 800 Independence Avenue, SW
  Washington, DC  United States  20591
• Authors:
  • DeWeese, Richard L
  • Moorcroft, David M
  • Taylor, Amanda M
• Publication Date: 2021-3

Language

• English

Media Info

• Media Type: Digital/other
• Features: Appendices; Figures; Photos; References; Tables;
• Pagination: 24p

Subject/Index Terms

• TRT Terms: Aircraft cabins; Anthropometry; Aviation safety; Best practices; Cushioning materials; Dummies; Dynamic tests; Load transfer; Seats; Spinal column; Uncertainty
• Subject Areas: Aviation; Safety and Human Factors; Vehicles and Equipment;

Filing Info

• Accession Number: 01778623
• Record Type: Publication
• Report/Paper Numbers: DOT/FAA/21/09
• Files: NTL, TRIS, ATRI, USDOT
• Created Date: Aug 3 2021 3:31PM