Most critical aircraft part?

[eccles]

Brother D said:

eccles said:

Munter said:

kurt535 said:

4. main spar - things would look very bad for you if this gave up

<Shudder>: https://www.youtube.com/watch?v=-A4QZAxrb28

The main spar wasn't the culprit in that video, the wing plank was.

(What's a wing plank - I've honestly never heard the term)?

Most large aircraft don't have a main spar as such, the load bearing part of the wing is a box section made up from front and rear spars and wing planks top and bottom. The planks are usually very long milled pieces of alloy.