Tricky words

1. a commercial airline flight between two distant points that departs late at night and arrives early in the morning; indicating a long-distant flight that leaves late at night
4. - to conceal, cover, mask; to make indistinct, difficult to use
6. - unfavorable, bad or poor; acting or going against you
9. -to force sth upon a person or thing
11. a final transition phase of an aircraft landing, from a steady descent path to touchdown
13. - stopping or ceasing for a time; alternately functioning and not functioning or alternately functioning properly or improperly
16. another word for stand or apron or sometimes used for runway at an airport; a paving material formerly used for a road, airport runway, etc. (tarmacadam)
17. having a natural tendency towards sth; having a downward direction, slope
19. not to allow light to penetrate or pass through

2. a set of limitations within which a technological system especially an aircraft can perform safely and effectively; a cover
3. a person who travels sectretly by hiding in an aircraft, or a ship, not paying the fare
5. to throw (cargo, supplies, etc.) overboard from a boat or airplane to lighten it or make it stable in an emergency; to dump fuel in flight
7. - to (cause to) become thinner toward one end
8. irregular motion of the plane or of one of its parts caused by turbulences in the airflow
10. an increase in air pressure cause by the forward speed of the aircraft
12. – to change direction or course or turn aside, to move diagonally away from the centerline or correct path; to change direction clockwise (for the wind)
14. avoiding or seeking to avoid (trouble or difficulties); hard to catch or obtain
15. unintentionally, without being aware
18. a slope or inclination