Thanksgiving is now four weeks away and Iowans who plan to celebrate the holiday somewhere else ought to be buying their plane tickets soon. Des Moines travel agent Terry Beach says as terrorist fears fade, her business has picked up and good airfares are flying away.Beach says she’s pleased many clients are overcoming their misgivings about flying following the September 11th attacks. She says those who are considering traveling during the Thanksgiving holiday need to firm their plans and buy their tickets quickly. She says airlines have cut back flights, so there’s less space available. She says airfares seem to go up and down on a daily basis.Beach says some clients are still spooked by the memory of last month’s terrorism, while others have clearly moved on with their lives.She says some Iowa travelers are already making vacation plans into February and March.