DRI THE DEVELOPMENT OF DITCHING and WATER IMPACT DESIGN LIMITS PRESENTED AT INT’L CABIN SAFETY CONFERENCE NOVEMBER 15-17, 2004 LISBON, PORTUGAL DYNAMIC RESPONSE INC. (DRI) FEDERAL AVIATION ADMINISTRATION (FAA-TC)

DRI SBIR WATER IMPACT PROGRAM PHASE I Feasibility of Methodology PHASE II Perform Full Scale Tests, Model and Correlate Model For Existing Scale Model Ditching test Evaluate FAR27/29 Water/impact/Ditching Regulations & Compliance Develop Preliminary Water impact Design Limits PHASE III Develop Military Helicopter KRASH Models Evaluate Correlation Techniques/Procedures Develop Design Envelopes (DLE) - Water Impact/Ditching Develop DLE Procedures --- Civil helicopters --- Military helicopters

DRI IMPACT ENVELOPES

DRI SIGNIFICANT QUESTIONS 1.Can modeling simulate /represent the significant aspects of full-scale impact and scale model ditching tests? 2.Can analytical modeling be an effective tool in the development of crash design criteria?

DRI ASPECTS OF WATER IMPACT AND DITCHING Kinematics BehaviorKinematics Behavior Overall responseOverall response Discrete location responseDiscrete location response FailuresFailures Design parametersDesign parameters Seat-occupant performance/toleranceSeat-occupant performance/tolerance Trends & relationshipsTrends & relationships

DRI FULL SCALE WATER IMPACT TESTS Tests of UH-1H Test S1 26 fps vertical Test S2 28 fps vertical 39 fps longitudinal

DRI OVERALL RESPONSES & KINEMATIC BEHAVIOR

DRI FLOOR ACCELERATION

DRI PRESSURE RESPONSE

DRI FLOOR PULSE

DRI FLOOR VERTCAL PULSES – GROUND, WATER, REGULATIONS

DRI SIGNIFICANT QUESTIONS 1.Can modeling simulate /represent the significant aspects of full-scale impact and scale model ditching tests? 2.Can analytical modeling be an effective tool in the development of crash design criteria?

DRI DESIGN CONSIDERATIONS- SEAT LOAD LIMIT 26 FPS VERTICAL WATER IMPACT NO SEAT LOAD LIMIT 14.5G SEAT LOAD LIMIT

DRI DESIGN CONSIDERATIONS – EA OLEO Vs. SKID TYPE GEAR Floor pulse Kinetic energy

DRI TRENDS – SEA STATE VS. CALM SEA

DRI S2/S1 Pressure Trend Comparison; Analysis Vs. Test

DRI DITCHING COMPLIANCE

DRI DITCHING COMPLIANCE PROCEDURES Scale Model Testing - rigid, deficient, misleading, costly Similarity to Existing Designs - questionable basis Pressure Calculations - static flotation analysis Vertical Load Factor Calculations - stall speed, no sink velocity Procedures - under-estimate pressure & acceleration

DRI DLE for WATER IMPACTS

DRI DLE-DITCHING APPLICATION

DRI KRASHSOM-HIC RESULTS

DRI DLE CONSIDERATIONS

DRI APPLICABILITY TO FAR 25; TRANSPORT CATEGORY AIRCRAFT FAR 25, FAR 27 and FAR 29 HAVE: Ditching Envelope Seat Dynamic Test Requirements Mass Item Retention Acceptance Criteria Compliance Procedures Different Levels but Many Similarities

DRI SUMMARY SBIR Tests/Correlation and Applications - 2 Full Scale Water and 35 Scaled Ditching Tests - Aircraft Weights: 10, , lb. GTOW - Design Requirements & FAR Regulations Development of Civil Design Limit Envelopes – - Occupant –Seat Integrity - Structural and Mass Retention Integrity Development of Ditching and Water Impact Design Criteria and Procedures Utilization of DLE to Evaluate Design Strength, Operational Conditions, Acceptance Criteria, and New Designs Applicability of DLE Concept and Procedures to FAR25 Transport Category Airplanes