PPRuNe Forums - View Single Post - Final Aib world
Thread: Final Aib world
View Single Post
Old 7th Apr 2020, 17:28
  #17 (permalink)  
Skyjob
 
Join Date: Jan 2000
Location: FL410
Posts: 860
Likes: 0
Received 0 Likes on 0 Posts
The difference is in the procedure design.
For LNAV/VNAV approaches, no changes are made to the coded crossing altitudes, procedure temperature restrictions are in place to mitigate flying a flatter profile.
For all approaches minima on the altitude reference are corrected for cold weather operations, including LNAV/VNAV minima, as they are correcting for lowest altitude above ground to make a decision, nothing to do with coding of the approach.

So:
  • if you fly an ILS, you correct all altitudes as the angle is fixed;
  • if you fly APV or LNAV/VNAV, you do not correct altitudes coded for the profile as they are protected by temperature usage on the chart;
  • if you fly any approach below 0 C you must use temperature corrections for the minima on the reference selector as this is read by temperature prone instruments (altimeter).
  • if you fly to a DA based on RAD ALT, this temperature correction is not required s this instrument is not prone to temperature errors (hence no correction for LVP using RAD ALT
Skyjob is offline