--- a/src/ai/default/default.cpp	Fri Mar 30 22:17:47 2007 +0000
+++ b/src/ai/default/default.cpp	Sat Mar 31 01:16:17 2007 +0000
@@ -1424,7 +1424,7 @@
 		if (t != NULL) {
 			// Find a random oil rig industry
 			in = AiFindRandomIndustry();
-			if (in != NULL && in->type == IT_OIL_RIG) {
+			if (in != NULL && GetIndustrySpec(in->type)->behaviour & INDUSTRYBEH_AI_AIRSHIP_ROUTES) {
 				if (DistanceManhattan(t->xy, in->xy) < 60)
 					break;
 			}