NOAA Twin Otter – Drop Chute Modification

Perform all engineering tasks for the design and structural substantiation of a new drop chute for the NOAA Twin Otter aircraft

National Oceanic and Atmospheric Administration (NOAA)

Services Performed:
PEI provided design, analysis, DER approval, and installation support for development of the drop chute modification for the Twin Otter (DHC-6)

Structural Analysis and  FAA DER Approval:

  • Generate system level finite element models, baseline and modified
  • Calculation of drop chute drag loads
  • Quasi-Static analysis for aerodynamic and limit maneuver loads 
  • Global Equivalency and Detailed Stress analysis, including mechanical joints (bolted and riveted)
  • FAA DER review and approval
  • Generation of FAA Form 8110-3 for approval of modifications

Engineering Design:

  • Conducted site survey to measure and document Twin Otter (DHC-6) aircraft
  • Modeled local aircraft structure in the aft baggage compartment area
  • Designed preliminary reinforcements for drop chute cutout and installation
  • Designed preliminary drop chute components
  • After structural evaluation, completed detail design of drop chute and reinforcing structures
  • Conducted Design Reviews with NOAA engineers
  • Generated all detail part, assembly, and installation drawings

Deploying atmospheric dropsonde from Twin Otter drop chute: