Problem Reentry flames too early

[Koloss]

Dear Orbinauts,

A strange problem came up here.
As the title says: The reentry flames come way too early - in around 90 km height with -100°C outside.
I don't know what caused it - probably an Add-on I would guess?

Does anyone have a clue where the start of the reentry flames is defined?

EDIT:





EDIT #2:
I am using Orbiter 2010 with the DGIV.

 

[boogabooga]

That seems about right. Except the temperature.

Actually, that is weird in Orbiter 2010 where the re-entry flames tend to start too late- at around 60 km or so.

 

[Urwumpe]

Generally Orbiter is a bit late on the flames. Also the temperature shown is infinite airflow temperature, not the hull temperature. You can generally say that every second, over 95% of the heat flux generated by reentry goes into the air and less than 5% are absorbed into the heat shield and the spacecraft structure. Since the air is very thin, that means that the air is getting VERY hot, because it gets more of the energy and weights much less.