The FAA proposed rule mentions that:
The FAA type certificated the MU–2B
airplane in November 1965; the type
certification basis was Civil Aviation
Regulation (CAR) 10, which required
compliance with a combination of CAR
3 standards and special conditions. CAR
3 standards did not require a cockpit
checklist for the MU–2B, nor was the
airplane required to demonstrate the
ability to complete the takeoff climb
with one engine inoperable.
But it doesn't make any comments about whether or not the MU-2 does meet the required OEI climb gradients in the modern FARs. It seems likely that it does, but does anyone know for sure? It would seem pretty crazy to fly a type that can't climb with an engine failure. Thats like flying a single engine airplane with twice the risk.