Thanks Dan. Interesting post, and a lot of food for thought.By the way, I've tried using ADE to find errors in an airport too, but the errors you are looking for are not things such as orphaned nodes, disconnected parking, etc. I believe what we are looking for is facility data (frequencies, coordinates and other such variables) that are corrupted. I've been using BGLNavEditor and AirportInspector tools from Sors Herves.
If couatl is requesting parking information, and facilities.dll is (somehow) returning a null (e.g., CYHO), maybe this is not being caught.
But I will use Sors' tools as well, and look for weird comm and nav frequencies, names, and latlons.
Edit: Argh, but why then only when coming from the Atlantic !?