The Yak-39 leads into a comparison of the Yak-41 or Yak-141 with later vertical-flight aircraft. The concern is that ambitious engine and flight-control arrangements demanded more than contemporary computers could reliably manage. Similarities in layout therefore do not establish that complete aircraft offer the same capabilities. The Wright Flyer and Eurofighter Typhoon provide a deliberately extreme analogy: both can be discussed in terms of canards, but that shared feature says little about their overall performance.
Notable Point · 3:27:55-3:29:37
Why a VTOL concept depends on its flight-control system
The Yak-141 raises a concern about advanced vertical-flight ideas being limited by contemporary flight-control computers.