Controllability and Ride Comfort

SCTs arc very drag sensitive. Control surfaces and stabilizer, are minimized therefore Addition­ally. for slender configurations, the lever arms may become small. Consequently, unstable con­figurations arc selected, but if stability may be achieved via artificial stabilisation, control authority against failure cases (like engine failure) and gusts or manocuvers remains more criti­cal. Many of the proposed configurations arc unable to provide the required control authority.

although – perhaps – they may achieve stability margins at the limit. Especially for some failure eases, like engine burst, missing redundancy of ailerons and elevens becomes critical for tailless configurations.

Long elastic fuselages (c. g. I0 > 90 m. 5 seat abreast) can easily provide loads of lg for crew, front and tail passengers by fuselage oscillations during ground roll, take-off rotation and in turbulence – additionally to gust loads. This not only seems inacccptablc. it really is inac – ccptablc. Only very stiff materials arc selected, weight seems to be at the limit; so a remedy seems only to be: wider, shorter fuselage with more drag and shorter range – or a completely different configuration, e g. an OFW.