Helicopters are blocked on my server, if someone attempts to buy from the Airwolf vender, they get RPC erorr, kicked, and then lose their scrap. This is terrible, obviously, but there's no permenant way to disable this NPC.

You can do something really simple to prevent the dialog, like the following code.

object OnConversationStart(VehicleVendor vendor, BasePlayer player, ConversationData conversationData)
{
    player.ChatMessage("Vehicle vendors are disabled.");
    return false;
}​

This would apply to the boat vendors as well, so will need to be tweaked to determine if it's a heli vendor, probably by inspecting the conversation data.

Another option you could try would be to delete the airwolf npcs. A plugin like Anti Entity might work.

WhiteThunder

You can do something really simple to prevent the dialog, like the following code.

object OnConversationStart(VehicleVendor vendor, BasePlayer player, ConversationData conversationData)
{
    player.ChatMessage("Vehicle vendors are disabled.");
    return false;
}​

This would apply to the boat vendors as well, so will need to be tweaked to determine if it's a heli vendor, probably by inspecting the conversation data.

Another option you could try would be to delete the airwolf npcs. A plugin like Anti Entity might work.

Sadly, AntiEntity & ComponentBlocker both don't work, even with the prefab for him being disabled in these plugins, he will still spawn.

Ok here's the code to completely disable the airwolf vendor npc.

bool? OnNpcConversationStart(VehicleVendor vendor, BasePlayer player, ConversationData conversationData)
{
    if (conversationData.shortname == "airwolf_heli_vendor")
    {
        player.ChatMessage("That vendor is disabled.");
        return false;
    }
    return null;
}​

Same can be done for the boat vendor by matching the string "boatvendor", but anyone wanting to try that should be warned that it also disables the vending machine option. It would have to be a little more sophisticated to block specific dialog options. I may add something like that to the Vehicle Vendor Options plugin eventually.

go to the vendor and f1 ent kill