I have traveled with models many times. Only once did I get a ridiculous fee charged. (300 euros coming back from Bulgaria. Ouch)
Usually it is just the extra bag fee.
- Check your airlines baggage regulations. Some are much better than others. Factor this into the ticket price when you choose.
- Say it is "sporting equipment", they will all take things like bikes and skis which are just as big.
- Keep the box as light as possible, big and heavy is bad.
- Put your tools in your second bag. This will keep the model box lighter, and there is no chance of them coming loose and damaging your models.
- Check in online and pay for the extra bag. This means that you go straight to baggage drop and the person there will hopefully save themselves some work and just check it in.
- Don't mention the words "gas". There are regulations about transporting gasoline powered equipment. If asked say they run on Alcohol and castor oil.
- avoid connecting flights. More chances to lose your stuff.
Pat MacKenzie