This explains how to fly in sections of dalaran that are marked as "No Fly Zones" as well as what I think is going on and why it works.
There is so much explaining because it really does help you to actually do the exploit.
I assume this exploit appeared when Blizzard enabled the ability to fly above dalaran without being dismounted.
The trick involves transitioning from a "safe zone" (flying allowed), to the "no fly zone" you wish to fly in, then into a *Different* "safe zone", and then back again into the same "no fly zone", all before the server validates your flying status.
Before Blizzard added the fly above dalaran zone, two different safe zones were never next to each other, making this flaw in logic impossible to produce, but rare enough that it wasn't found in bug testing.
I assume each player has a list containing zones (part of the city) you pass through.
When your cross zones, something is added to this list, making a note of it. Periodically, the list is checked to enforce 'no fly zones'.
These checks tend to happen when you do something interesting, like bump into something, start moving, or stop moving.
I assume to to save memory, duplicates are not added to the list [important, in my theory anyways].
This is what the list looks like in the situation I create in the screen shots below.
1. Krasus Landing (Fly Zone)
2. Roads of Dalaran (No Fly Zone, Add Debuff)
3. Zone Above Dalaran (Fly Zone, Remove Debuff)
Roads of Dalaran (No Fly Zone) <- not added because already on list #2
*stop moving*
note: you must start from a hover, the drawing is misleading
Now the list will be evaluated, assuming you made those transitions without bumping into a building or stopping, which would cause it to evalute early.
The end result should be you inside a no fly zone, but without a debuff, which is in fact what happens.
This is not the same as bouncing back and fourth between an invalid and valid zone, and is the key the the entire trick.
What you need is 2 *different* valid zones next to each other. I think the easiest to learn with is the border between Krasus' Landing and the streets of Dalaran because you can use buildings to find out exactly where the border to the sky zone is.
If you try this several times and get the debuff, you are probably going from Valid Zone A, to Valid Zone B, and not passing through the invalid zone in betweem them. You NEED to pass through the invalid zone before entering the Sky Valid Zone.
Also remember to start this from a hover (don't be parked on a building or the server will give you the debuff early).
If you read my long winded explaination above, you will understand why once you do this trick, you cannot transition to another one without getting the debuff.
Rough representation of zones in Dalaran:
You can also start on a wall but it is MUCH more difficult because you need to climb to the sky zone and back down all before your position is evaluated by the server.
The results:
By the way, its pretty crazy that the grass around 'The Violet Citadel' and 'The Beer Gardens' behind the alliance only area, actually removes the no fly zone debuff! They did not do so before the sky zone was added... pretty bizarre.
