Regarding the statement: ".. you do not have to change your cruise IAS just because you are flying with a headwind, crosswind or tailwind (you may wish to increase it slightly flying into a headwind to getter better range but that is a different issue)."I'm not a pilot so to me, increasing indicated/Mach at cruise would increase fuel flows/burn and thus decrease your actual range. What am I missing?

cbrew,Yes, you are right, increased fuel flow will decrease your absolute range. Sorry if I confused you. What I meant is that for a fixed distance (flying A to :(, when flying into a headwind you can arrive at your destination with more fuel if you fly faster than your LRC or normal cruise speed. The very quick answer is that your total fuel burn will be less because despite the higher fuel flow by arriving sooner less time is spent burning fuel. There is a trade-off to be had between the increased fuel flow and the increased groundspeed giving a earlier arrival.As a simple and commonly used example, if my TAS is 200 knots and I am flying into a 200 knot headwind, my range is zero, however, if I increase my TAS to 210 at least now I am getting somewhere. Although this example is a bit ridiculous, the principle is the same.For a more technical explanation try to picture the following graph (a picture would be worth a 1000 words but I don't have a picture so you get the 1000 words).Drag (which approximates fuel flow for a jet) on the Y axis and TAS on the X axis. The drag curve will represent a flattened "U" shaped line. Max range occurs at the point where the ratio of TAS to drag (or FF) is greatest (most nm per pound of fuel). The max range (in still air)point is where a line drawn from the origin (zero drag, zero speed) touches the bottom of the drag curve tangentially. If you drop a line straight down from that point you have the best range speed. Now, if you are still with me, inject a headwind. This will be the same as shifting the TAS scale to the left by the amount of the headwind. Now draw the same line and you will see that it touches the drag curve at higher speed. Thus your best ratio of TAS to FF will occur at a higher speed.However, as a final caveat, it is customary in airline ops to avoid or minimize the headwind by adjusting your route rather than increasing TAS (if you can achieve a 10 percent reduction in average headwind component for a 9 percent increase in distance you are ahead of the game). Minimum time vs min distance flight planning.Kevin in CYOW