Nature is divergent. Darwin in the Galapagos encountered an outpouring of species, no two precisely alike. Aeronautical engineering seems to go the other way. All the species in a given niche eventually resemble one another. It practically takes a specialist to distinguish one business jet from the next.
It was not always so. The early jets — Sabreliner, JetStar, Lear, Hansa, Jet Commander, Mystère 20, DH.125, all born in the early 1960s — had quite distinct personalities. The JetStar had four engines and slipper tanks on its wings, the Jet Commander had a straight mid wing, and the wings of the Hansa Jet swept forward, the Lear had huge tip tanks and a particularly ruthless-looking windshield. Horizontal tail placement was up for grabs: The Sabreliner’s horizontal tail was mounted in the fuselage, barely above the engine exhaust; the Jet Commander’s was just clear of the fuselage; the JetStar, Mystère and 125 used cruciform tails (low, middle and high respectively); and the Lear and Hansa went all the way with T-tails. (Oddly, I don’t remember a high-wing business jet, not even from the very imaginative Russian design bureaus, which, after the demise of the Soviet Union, mailed new batches of capitalist-oriented “concepts” to Jane’s All the World’s Aircraft almost weekly.)
