Add points of tangency along a helix?

GROUPS:
 Currently I have a helix wrapping 3 times as it rises from [0, 2*Pi]. I'm supposed to use the Table command to create a list of formulas for the tangent lines to use inside ParametricPlot3D. Then I would just show the points of tangency spaced at (.1 * Pi) but I have no idea how to do this. The helix also has a radius of 4 if that helps clear things up.The Mathematica code I currently have is as follows: r[t_] := {4*Cos[3*t], 4*Sin[3*t], t}; helix = ParametricPlot3D[r[t], {t, 0, 2*Pi}, PlotStyle -> {Red, Thick}, AxesLabel -> {" x", "y", "z"}, BoxRatios -> {1, 1, 2}] 
 Well, it is homework. But here's a hint: In[25]:= helix = {4 Cos[3 t], 4 Sin[3 t], t}; In[26]:= tangentVectors = D[helix, t] Out[26]= {-12 Sin[3 t], 12 Cos[3 t], 1}