ジェネラル・ダイナミクス・エレクトリック・ボート
In May 2013, Navantia announced that a serious weight imbalance design flaw had been identified which will delay the delivery of the first submarine to the Spanish Navy until possibly 2017. Lengthening the submarine created additional buoyancy. Navantia signed on the US company General Dynamics Electric Boat to help solve the excess weight.