Hello
With the introduction of the 747 (http://forum.simutrans.com/index.php?topic=9864.msg93279#msg93279 (http://forum.simutrans.com/index.php?topic=9864.msg93279#msg93279)) there is a problem. The airport infrastructure (runways and taxiways) can support the weight below the weight of the load. The plane is introduced on January 1, 1970.
To fix the problem, introduce appropriate new infrastructure or increase the weight bearable by those present. The plane weighs about 240t without load, the load will reach 300/350t.
Giuseppe
Thank you for pointing that out - will amend.