Ground effect explained
Misinformed Instructors who propel the pressure bubble myth should be asked to do a quick Yahoo search using "induced drag ground effect" so that they can learn how to tell their students the truth, and not convenient myths. We would be all the better for it. Pressure bubblers, please note:
Induced drag explained:
http://galileo.phys.virginia.edu/cla...ero/node5.html
http://www.grc.nasa.gov/WWW/K-12/airplane/induced.html
Ground effect explained:
http://www.faatest.com/books/FLT/Cha...oundEffect.htm
http://www.pilotfriend.com/training/...g/aft_perf.htm
"Many pilots think that ground effect is caused by air being compressed between the wing and the ground. This is not so. Ground effect is caused by the reduction of induced drag when an airplane is flown at slow speed very near the surface."
The quiz for today, for the bright student:
Define induced drag
define aspect ratio
explain how aspect ratio affects induced drag
explain how proximity to the ground affects aspect ratio