In the past, engine aft fairing heat shields have typically been titanium castings.  With the 737 Next Generation, these components were converted to titanium 6Al-4V sheet metal details fabricated in either a “U” shape using hot sizing or a “V” shape using Superplastic Forming (SPF).  This conversion saved approximately 20% in both cost and weight.  When the 787 was being designed, the engineers were looking to develop a sheet metal version of their heat shields hoping to achieve similar savings.  However, the 787 design was considerably different from the 737 due to “plume suppressors” which no longer allowed the details to be simple “U” or “V” shaped.  Also, the operating environment was more severe with the sonic db level being higher and the temperature being hotter.  The 787 design contains SPF details as well as the first Boeing Commercial Airplane application of Superplastic Forming and Diffusion Bonding (SPF/DB).  The SPF/DB stop-off technology being used contains several innovative process developments that are covered by patent applications.  Some of the heat shield components are fabricated using the world’s first applications of fine grain 6Al-4V titanium, also covered by patent applications, that was developed to SPF at 1450 °F instead of 1650 °F which is used for standard grain material.  Due to the temperature requirements, 6Al-2Sn-4Zr-2Mo titanium had to be used for the lower skin and the internal components that touch the skin.  The 787 heat shield assemblies are estimated to save approximately 15% in both cost and weight.   The 747-8 program has designed heat shields that are very similar to the 787 except the sonic environment does not require the side skins be as stiff so SPF/DB components are not being used.  The 777 is investigating converting to the 787 design that would include SPF/DB hardware.