This should be a comment, but it will run long. Here's what you note
However I'm surprised that some of the answers have implied that there's something trivial, invalid or unscientific about experimenting without a testable hypothesis: i.e. it's "just playing about" or "just demonstration".
Let me try to explain why there is a problem with a scientific experiment that has no hypothesis.
Assume you are going to do action A to 'see what happens' as a scientific experiment.
There are two possible outcomes:
a) nothing happens
b) X and Y occurred after A
Both outcomes are described incompletely (not scientifically).
In case of a), let us assume that we want to repeat the experiment. To do that, and to arrive at the same result one must know what was observed. However, once you define what you are observing (and how) you have effectively defined a hypothesis.
Similarly, in the case of b), if you do not specify if you were observing for event Z (obviously you were observing if X and Y would occur), the experiment can not be repeated (might yield different results), so the results can not be taken as scientific.
For the results of the experiment to be scientific I think you need repeatability, which must include the definition of the hypothesis and the testing method.
If none is given it is definitively not clear how were you testing (i.e. testing for anything will be different for different people). Therefore I support the opinion that you are not talking about an experiment.
However, as long as you can describe what you were doing (and it was controlled), you can extract the hypothesis that you were effectively testing and turn the experiment into formal one.
If your test was not controlled then it was an accident, as per original Bacon's definition.
EDIT:
You might want to read upon this article, too (do check the references though). Maybe research is better suited in this case.
Best Answer
Fly against isn’t functioning as a single phrase here.
To fly in this case just means to work, to be successful, with a slight connotation that the risk involves skirting the rules of some authority. Against is in the sense of running an experiment against some configuration of circumstances. So the example could be rephrased:
Edit: The OED doesn’t document this figurative usage of fly, so it’s presumably not just colloquial but also fairly new. Urban Dictionary does; it’s currently their eighth-ranked definition for it, with a good example: