•  
  •  
 

Abstract

General aviation rules of thumb (ROTs) for density altitude and true altitude are examined and developed. Both ROTs originate from the same basic principle of hydrostatic balance, but differ significantly in the assumptions made regarding the atmospheric temperature profile. While the ROT for DA assumes a standard atmospheric vertical temperature lapse rate, the ROT for true altitude requires information regarding the observed layer-mean temperature of the atmosphere. Since the layer-mean temperature between the aircraft and the surface is typically unknown, it must be inferred from the temperature at a single level by again assuming a linear lapse rate. This method is shown to perform poorly in cases of strong lower-tropospheric temperature inversions. Direct comparisons of the two ROTs are made to highlight the gross errors that can occur if the two are misused for one another.

Acknowledgement.docx (11 kB)
Acknowledgment

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.