The Boeing Company
Method to re-loft a redesigned jet engine primary exhaust nozzle for an existing airplane to provide clearance to aircraft heat shield structure to prevent contact, fracture, and liberation of portions of the nozzle which might cause hazard to continued safe flight

Abstract:

A nozzle having a forward portion skewed downwards and an aft portion translated downwards provides sufficient clearance between the nozzle and the heat shield structure to prevent contact in the event of large deflections (e.g., as associated with a fan blade Out (FBO) condition). Such large deflections must be accounted for to meet federal aviation regulations and gain airplane CFR 14 Part 25 Certification.