Answers

2 – crossword solution:

ACROSS:  1 wake turbulence, 3 root, 5 flap, 8 walkway, 10 rib, 13 wing tip, 16 span, 17 trailing edge;

DOWN:  2 airfoil, 4 spar, 6 leading edge, 7 vortices, 9 aileron, 11 biplane, 12 winglet, 14 skin, 15 vortex

3 – reading comprehension

– they increase performance (by decreasing fuel burn and increasing range).

– they generate a forward lift component that opposes the drag produced by the wingtip vortices.

– when you are at high angles of Attack (during take-off and landing or at high altitude cruise).

– new technology allow to blend them into the wing,

4 – listening comprehension

runway 31R in the comment has become runway 41R in the subtitles.

5 – grammar

than, then, then, then, than, then, than, then, then, than