Trans LVL vs. Trans ALT

[jetalc]

Transition Altitude is the highest altitude available.

Transition Level is the lowest flight level available.




.

Ummmm...no. Look at an approach plate - that's the transition altitude and FL they're talking about. Availability of the lowest FL depends on pressure in the area.

 

[TonyC]

Transition Altitude is the highest altitude available.

Transition Level is the lowest flight level available.

Ummmm...no. Look at an approach plate - that's the transition altitude and FL they're talking about. Availability of the lowest FL depends on pressure in the area.

Ummm, yes.

The Transition Altitude published on the approach plate is the highest altitude available. You cannot fly or be assigned a higher altitude. Anything above that would have to be a Flight Level.

The Highest Altitude available, or Transition Altitude, is determined by the State Agency (that would be the FAA here in the US of A) and might be based on any number of variables.

The Lowest Flight Level available, or Transition Level, is also determined by a number of things, one of which MIGHT be the local barometric pressure. It might be a fixed Level, as it is in the majority of the US, or it might vary. Consequently, it may be published on the approach plate, or it may be part of the ATIS.

I tried to read the poster's question and answer it directly without branching out into complicated scenarios and exceptions. My answer was succinct and absolutely correct.


For a more in-depth explanation and discussion, try this. For an explanation tailored more for the non-pilot, Wikpedia's flight level should work nicely. To quote Wikpedia, "A vertical region extending from a defined transition altitude to the lowest available flight level is known as the transition layer - pilots will use altitude based on the local pressure below this level, and flight levels above. The altitude of the lowest flight level varies from country."



.