What you're describing is (on balance of probabilities) Chromium Based Life.
First of all we need to address what we mean when we say 'X-based life'. Carbon based life for instance means that the organic compounds on which that life is based relies on Carbon as a 'binding agent' (simplification but functionally correct). That is to say, Carbon forms the basis of all terrestrial life because it allows several other elements to connect to it at once, allowing for the highly complex molecules on which life relies to create things like DNA and store energy in chemical form.
The property that Carbon has that allows this to happen is called Valency. Carbon has a valency of 4, and for life to form the complex compounds necessary to replicate itself this is pretty much a minimum number. So, the first thing you need is a metal of high valency on which to base a metal-based lifeform, and second, you need lots of it.
The reason why Carbon works as an essential ingredient for life is that comparitively speaking, there is so much of it lying around. Estimates tell us that around 0.5% of all mass in the universe is Carbon. This may not sound like a lot, but by comparison to other elements, it's positively abundant.
Unfortunately, while there are a few other elements with high valency, most are either non-metals (silicone) or they are very rare. On balance, the best mix of valency and abundance that is also a metal is Chromium.
Chromium is capable of a valency of 6, meaning that it is capable of even more efficient complexity than Carbon is, but it's also less abundant, with only 0.0015% of the mass of the universe being Chromium. This is more than 30 times less than Carbon, so it is less likely to form by a long way. Hexavalent Chromium is actually quite toxic to humans as most exotic organic candidates are, but if you have a world where you just happen to have a great abundance of Chromium and a lack of Carbon for some exotic reason, then such a life form may occur.
What would it be like? Exotic. That's about all we can tell for sure. Not all metals act or even appear the way you think of them doing so; it is possible that Chromium based life would have heavy hard metal shells and the like but bear in mind we are carbon based and are not made of diamond, and certainly aren't as hard as it. If carbon is scarce, then potentially so is oxygen so this increasingly exotic lifeform may well breathe fluorine instead. If it did, then you're probably dealing with life that exists at very low temperatures by comparison to us. They may have come from fluorocarbon lakes instead of water - there are so many unknowns that it is almost impossible to predict how such life would function or what they would look like.
As for such creatures being electrical, well technically so are we. Our muscles, senses, brains etc. are all connected via an electrical network called the Central Nervous System. If there are animals among your Chromium based life, they would likely be electrical as well for the same reasons we are; it's the most efficient way of operating.
But, the idea of helicopter or other vehicle based life is less likely. We're not talking transformers here; we're talking organic shapes and forms that evolve according to the needs and environment of their planet. Spinning rotors and wheels, while great in theory, are a function of being able to break down a machine into parts which is something evolution doesn't like. Making a creature with a wheel is impossible if you want to keep the entire creature within a single skin as much as possible. That said, we're already in a hypothetical conjecture that is pretty remote in terms of probability, so (as they say), anything is possible.