CapnVegetto said:.79-.80 all day long. Redline of .81. And yes, we had Rosemont probes. Came with the RVSM package. We had RVSM certification a year before it took effect. TAS was calculated by an instrument we had connected to the system that also calculated the SAT. You could also calculate it in the CALC mode of the GPS.
Normal cruise in the 35/36 is .76/.77. All pushing to it .80 does is reduce the range. According to the folks I have talked with a Learjet (and this was before Ski-doo jet took over) the most efficent speed for the 35/36 is .75. It is due to the aerodynamics around the wing and engine nacelle area. It is my understanding that the Risbeck XR mod has resolved much of those aerodynamic issues.
We had a pilot who insisted on flying our 35 like a 25. All he managed to do is require a fuel stop after 3 to 3 1/2 hours. The rest of us are able to get around 5 hours out of it.