Some of my phals, especially those that grow towards the side of the pot like in Philip's link will grow a nice arching spike if left unstaked with the flowers down below the plant.
Here is one you can just see the corner of the table above the flowers and you can see the spike coming down. I'm trying to find some pictures of my natural spikes with the plant as well but no luck so far.
However other Phals I do stake, usually the ones with much thicker spikes that don't curve on their own so naturally and would break if not supported.
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Here are a couple of others where you can see the plant as well... One of these the plant is leaning a bit, but the spikes have gone the other way
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Finally, here is another where the plant is REALLY leaning in the pot, but the spikes have grown the other way and curved naturally.
I know I've had ones where the plant is leaning and the spike has gone out the same way, just don't seen to have the pictures. Just shows you they will go the way they want.
I have found some pictures of one of mine with a very thick spike that I allowed to stay unstaked, it just gracefully curved at the end and was fine. So that throws out my theory that the thicker ones need staking
Maybe they are most likely to break if staked and forced to grow straight, then the stake is removed. I don't think I've had one break if grown completely naturally, though I do still choose to stake some of them.