b'Engineer Innovation | AerospaceFigure 1: For airplanes where structural flexibility is important, a coupled aerodynamic and structural certification-by-analysis approach is needed.With 45 years of combined experiencesystems, while the AC stage gives Flight controls: Laws of flight control in aircraft design, development andapproval to operate the aircraft. validated by integrated simulation certification, Robert Lind and Andrewand flight test.McComas of TLG Aerospace are noThe process is similar for other strangers to these challenges.worldwide regulatory agencies. TheThe integrated full-vehicle model is Occupying one floor of an unassuming,FAA requires certification by test or byultimately validated by the flight test six-storey building on Seattles Lakeanalysis validated by test. The industryand must be shown to be accurate or Union, their modest office belies thecalls it certification by analysis (CBA).conservative. The certification experience and expertize that has aThese analyses are made using a fullauthorities ensure that the analysis will client list reading like a whos who ofvehicle model that is validated by ayield a safe result. The original modern day aviation. TLG Aerospaceflight test over a specified range of theequipment manufacturer (OEM) is has helped numerous customersflight envelope, as agreed upon intypically concerned about limiting receive FAA certification in the U.S. at aadvance by the certification authority.conservatism to avoid excess weight low cost and in a short time,The full vehicle model includes: and missed performance. something they have achieved with surprising efficiency. Aerodynamics: A combination ofThe TLG Aerospace approach to computational fluid dynamics (CFD),certification with CFDCertification by analysislow order methods, wind tunnelWhat has changed is the balance FAA aircraft certification involves threeand handbook analysis validated bybetween how much analysis you can stages: design certification, productionpressure and strain measurements indo and how much you can use in the certification (PC) and airworthinessflight test; certification process, says Lind, certification (AC). The design Structures: Finite element analysisDirector of Engineering, FAA flight certification stage involves the(FEA) and handbook calculationsanalyst designated engineering approval of design safety, operabilityvalidated by ground vibration testingrepresentative (DER), FAA flutter DER, and durability, with type certificate(GVT) and static load in ground test; TLG Aerospace. This is a really exciting (TC) for new designs and supplemental Mass properties: Computer- development in my 30 years in the type certificate (STC) for modifiedaided design (CAD) and weightsindustry. As CFD codes and computers designs. The PC stage gives approval tobookkeeping validated by weighing;have become more capable, we can manufacture parts, components andand certify faster and cheaper.Simcenter STAR-CCM+ runs robustly, accurately and repeatedly with simple processes and best practices.Andrew McComas Engineering Manager and Aerodynamicist TLG Aerospace32'