The Boeing-designed B-17 bomber was assembled also by Lockheed Aircraft Corp. and Douglas Aircraft Co., while the B-29 was assembled also by Bell Aircraft Co. and by Glenn L. Martin Company.
Разработанный фирмой Boeing бомбардировщик B-17 Flying Fortress также собирался на заводах Lockheed Aircraft Corp. и Douglas Aircraft Co., а B-29 также собирали на заводах компаний Bell Aircraft Co. и Glenn L. Martin Company.