High Temp limitation for LNAV/VNAV?

[Checks]

I understand the reason for the cold weather limitation on LNAV/VNAV approaches but why on earth is there a limitation for high temps?

Look at any RNAV approach and view the notes.

Anyone have an idea?

Thanks in advance!

 

[340drvr]

Just a guess......hotter air is too thin to provide the resolution accuracy required? Same reasons for RVSM at high altitudes, or the old pre-RVSM 2000' split between useable levels.

 

[Airboss]

http://books.google.com/books?id=Yk...wAg#v=onepage&q=lnav/vnav temperature&f=false

 

[Singlecoil]

My guess would be that the approaches are generally designed with a range of flight path angles in mind. When the air is hotter than standard, actual altitude is higher than indicated. In very hot air, it may be hard to get down from the initial altitude on the approach. They don't want you to have to do exceptional measures to keep the thing on the glidepath.