Can someone explain what "C = .04 Vso2" means as the "denotes required rate of climb?". I assumed the point at 6500 ft altitude and 60,000lbs landing weight will mean that the required rate of climb is within the limitations but after calculating this to an approach climb gradient, the answer does not require the limitation of a minimum approach climb gradient of 2.7%.

So the main question is: What does the dotted line mean and what has the C = .04 Vso2 has to do with it?

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I interpret the dotted line to indicate the conditions needed to meet the minimum required performance, as specified in CAR1 (the certification standards used when the DC-4 was originally built.). Conditions to the right of the line are "Good", to the left of it are "No Good". I.E. if you had a gross weight of 60,000 lbs, and were configured as specified, the aircraft would not be able to meet the required performance at any altitude above ~6400 Ft.

I believe the "C=blah etc" statement is referencing the airspeed used to determine these performance results. C= Calibrated Airspeed, VsO² is stall speed in this specific configuration, and I'm guessing that the ".04" means 4% above said stall speed.

I hope this has only confused the question tremendously, and as solely my opinion, is worth precisely what you have paid for it. YMMV. Do not attempt at home. This offer not valid.

  • $\begingroup$ Might be that it means rate of climb is 4% of stall speed, not 4% above it. As an example if that lower point is around 275ft/min, then that would be 4% of 68 knots (which could be reasonable for Vso?) $\endgroup$
    – BowlOfRed
    Nov 11 '17 at 7:33

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