This paper describes concerns and studies involving deck heating effects from the MV-22 exhaust impinging on the flight decks of the Navy's Amphibious Assault ships. The main concern with the MV-22 shipboard integration effort relates to the hot exhaust that impinges on the ships' flight decks during launch/recovery operations when the aircraft is in Vertical Takeoff and Landing (VTOL) mode. The initial concern was raised in 2004 aboard the LHD-1 class ships and thus a subsequent test effort was conducted to develop an insight to the phenomena. The shipboard tests were needed to quantify the temperatures, thermal footprint, and deflections of the deck structure of LHD-1 class vessel during MV-22 operations. A three-dimensional finite element model (FEM) was developed by Naval Surface Warfare Center Carderock Division (NSWCCD) and a stress analysis was validated by the test results and used to determine the thermal stresses. A fatigue analysis was also conducted to quantify the effects on fatigue life that could be attributed to the MV-22 aircraft hot exhaust. The tests and analyses were conducted to understand and quantify the long-term effects of hot exhaust on ship deck structure. The results of this test effort led to restricted turn times while the MV-22's were on board the LHD and LHA class ships. Another concern was raised with integrating the MV-22 aircraft in support of deployment with an Expeditionary Strike Group (ESG) which requested flight deck certifications aboard a few of the smaller amphibious ships. Due to the different structures of the these ships, two phases of emergent deck heating tests were conducted aboard LPD-4 class and LSD-41 class vessels in 2009 to validate NSWCCD's model analysis correlation, to develop operational thresholds and mitigation strategies, and to find an interim solution in support of the immediate deployment. To mitigate this immediate issue, manually deployable heat shields were developed as an interim solution. However, the heat shields created a heavy burden for ship deck handlers and NAVSEA is currently researching more permanent non-material solutions. Also, the current data that has been collected to date leaves questions on the effect of hot ambient temperature conditions on thermal load parameters. Further testing included land based deck heating which was conducted in 2009 at Patuxent River, MD to continue characterizing the V-22 exhaust plume and thermal effects on ship's flight deck structures, and to test for potential non-material and permanent mitigation strategies.
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