Question: I get why the upper wing of a biplane is a compression member (because the flying wire is attached to it at an angle) but what I fail to understand is why the lower wing is the tension member of a truss of a biplane as explained [here](https://aviation.stackexchange.com/questions/19361/why-do-older-airplanes-have-a-wing-on-both-the-top-and-the-bottom-of-the-aircraf). So my question is why is the lower wing of a biplane referred to as a tension member of a struss?

![enter image description here](https://i.stack.imgur.com/j6s1H.jpg)

Answer: 
This question is actually applicable to a power off emergency gliding situation, where your best option may be behind you.

The way the question is worded (and one of the reasons light GA air craft are generally designed with one wing and a bit more speed than old time Jennys) is that progress upwind will drain your energy source (be it altitude or fuel) much faster than downwind (note going downwind does not necessarily mean LANDING downwind).

Nor is this question in the realm of the impossible, as I once witnessed a light GA (152 or 172) on final inching into a 35 knot headwind in Armarillo, Texas one fine day (windmills are doing great out there).

So, going upwind is out. On your way upwind, always try to pick out possible landing sites like open fields or interstate highways. If there is no where to land from where you came from, that would be a poor trip plan.

Changing altitude may be an option, though going lower may be more turbulent. Abort ASAP if weather is marginal.
If you are flying into a headwind, that means that there is an area of High pressure to your right. Frequently, as you leave move further away from the low pressure area, the winds will diminish. This isn't always the case, but it is the PICs responsibility to check weather conditions along the route and the routes to any alternate destinations.