Photos: Airplane recycling taking off

Steel, found in the landing gear of planes like this Boeing 707 from a Tucson, Ariz., boneyard, is also relatively easy to recover. The metal can be separated with a magnet. Scrap dealers sell steel from boneyards to companies that make anything from new aircraft to food cans to bridges.

"Because steel has no memory when it's recycled, it can go up and down the ladder, from rebar to a surgeon's scalpel," said Bill Heenan, president of the Steel Recycling Institute.