Boise, ID – Firefighters in the drought-parched West could have an even tougher job this summer. The federal government is ending its contract for 33 large air tankers due to questions over their airworthiness. The action follows last month's Natioal Transportation Safety Board report on three tanker crashes between 1994 and 2002 that killed seven crew members. The tankers' average age is 48 and some are more than 60 years old. The planes are operated by private companies under contract to the Interior and Agriculture Departments, including Hawkins and Powers Aviation of Greybull. Fire officials say they'll contract for more large helicopters, helitankers and single engine air tankers.