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Originally Posted by High_Alpha  Even on airplanes with true Fowler flaps, you can still see a large portion of the flap when it's retracted, right? |
Here's a classic schematic of a Fowler flap:
In this diagram, the flap clearly fits snugly underneath the lip. It's a bit of a slippery slope to ask how much can stick out before it isn't a Fowler flap any more. Many of the more sophisticated double and triple slotted flaps on transport category aircraft aren't typically referred to as Fowler flaps, but they do have "Fowler motion". Here's a description of the movement of a Boeing 767's single slotted flaps:
As deployment begins and the aft link stars to push the flap up, the hinged beam rotates downward so that the net flap motion is limited to aft translation with very little downward motion. This action produces a slot, and the motion continues to persist for a large portion of flap travel, thus producing a great deal of Fowler motion at low flap angles. For flap angle of 15 degrees (maximum takeoff setting), 85 percent of the available overlap is converted into Fowler motion.