Part-way through production, the older Hamilton Standard Hydromatic hollow steel propellers were replaced by new Curtiss Electric duraluminum propellers.

• 在生产进行到一半的时候,老式的哈密尔顿标准公司的液压驅動空心钢螺旋桨被新式的寇蒂斯公司电气驅動硬铝螺旋桨替代。