PPRuNe Forums - View Single Post - T/O Downwind -v- power available ?
View Single Post
Old 17th Sep 2001, 04:11
  #61 (permalink)  
Nick Lappos
Guest
 
Posts: n/a
Post

ACORN,
This is a good thread, with lots of opposing views (always better than all those "me too" posts from which nothing new is learned)


Acorn said:

"Downwind departure or arrival may mean the ground effect in the hover is reduced (blown away) therefore a larger power requirement. ................ a groundspeed of variable speeds up to 30kts therefore achieving no ground effect. Although you may be close to the ground you will recieve no help from either translationl lift of ground effect therefore effectively requiring out of ground effect power requirements."


Nick sez:
It is good old fashioned pilot lore that ground effect can be "blown away" or that a large groundspeed will negate ground effect. This is quite mistaken, as the ground effect is related only to the proximity to the ground relative to the wing or rotor span, and the amount of induced power that is being consumed. A previous post on the thread discussed this more fully, you might want to peek back.

[ 17 September 2001: Message edited by: Nick Lappos ]