Lately I've logged a few hours in the Fokker 70 by Project Fokker Jetline. It's an excellent model - much more stable and easier handling I think than either of the regional jets we currently have in primary service. I developed some basic textures to go with our fleet. This chart shows the takeoff and landing speed for the Fokker jets. It can be pretty handy, but do know that it is in kilograms not pounds.
Using the data from this chart I developed some very simple formulas you can use to determine takeoff and landing speed for typical configurations. The first one is for takeoff, flaps 15, all speeds in knots. V1 is equal to Vr and TOW is takeoff weight in pounds; for midscale-weights just add 5 knots to get V2:
V1 = Vr = 47 + TOW / 1100; TOW= takeoff weight in pounds
V2 = Vr + 5
For landing, Vref with flaps 42:
Vref(flaps 42) = 0.77 * LWT + 61.6; LWT= landing weight in thousands of pounds
Here's an example for a very typical configuration. The Fokker 70 has an empty weight of 61000 lbs, and a maximum takeoff weight of 83820 lbs. KLM uses these aircraft heavily in their CityHopper services in Europe and the F70 is fitted with 80 seats. Let's be generous and assume a 75% load factor, so on average 60 of the seats are filled, and passengers bring luggage (to simplfy things we won't worry about the difference between Summer and Winter weights) so the total passenger payload is say 12000 lbs. A one hour flight will burn an estimated 4100 lbs of fuel, but the rules require an additional 5400 lbs for reserves (holding, diversion, and contingency) so that's 9500 lbs of fuel. The takeoff weight then is 82500 lbs.
V1=Vr = 47 + 82500/1100 = 122 knots
V2 = 127 knots
On arrival the weight will be about 78400 lbs, so the calculated Vref speed for flaps 45 is:
Vref45 = 78.400 * 0.77 + 61.6 = 122 knots.
In my experience the takeoff values are a tad low for the Project Fokker 70, but they come close and I think are pretty useful as a basic reference.
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