[miele man]

After looking at the picture in the article, I notice there is no "bottom" on the wing, i.e, no sheet metal. When the prop and engine is tilted forward for forward flight as in a normal aircraft, how is lift generated if there is no bottom part of the wing? Seems to me that airflow over and under the wing would be significantly different than in a typical aircraft.

[e_castillo]

Your are looking at the aircraft with the flaperons extended making the wing seem thicker than normal. The V22 wing is like any other fixed wing aircraft.

[Semper Vigilantis]

I believe what you are seeing is slats, spoiler, flaps, etc dirtying up the wing. Only the nacelles rotate and the wing looks completely different in level flight.

[TalonDJ]

As some others pointed it, that is an illusion. I will point out that a wing does not need a bottom to generate lift. It is better with one but not 100% needed.

[azhenfud]

I recall a French fabric two-popper had no bottom of its main airfoil - if I can find a pic of the thing, I'll post it.

The Osprey has sheeting on the underside of all its airfoils.