View Single Post
Old 02-25-2008, 06:25 PM
  #4  
rickair7777
Prime Minister/Moderator
 
rickair7777's Avatar
 
Joined APC: Jan 2006
Position: Engines Turn Or People Swim
Posts: 39,322
Default

Assuming fixed GW, CG, and AOA...

At higher density altitude:

1) The true airspeed necessary to generate sufficient lift increases. This means that you have to fly FASTER to maintain your stall margin.

2) The reduced air density causes the AS indicator to read lower than true.
As the pilot flys faster (to keep indicated airspeed at normal values), the TAS will then be higher than at sea level.

Convienently, the amount of reduction in IAS at higher density altitudes approximately matches the required increase in TAS to maintain normal stall margins...so we just fly the same numbers regardless.


Note: your groundspeed will be higher on landing, so the distance remaining markers will go by more quickly.
rickair7777 is offline