The preliminary designing was complete, and the first American-built De Haviland model was ready to fly on October 29, 1917.

Figure 11 does not tell quite the complete story of De Haviland production, since in August and September, 204 De Haviland planes which had been built were shipped to France without engines and were there knocked down to provide spare parts for other De Havilands in service. These 204 machines, therefore, do not appear in the production total. Adding them to the figures above, we find that the total output of De Haviland airplanes up to the end of December, 1918, was in number 4,587.

DE HAVILAND-4. USED FOR OBSERVATION, RECONNAISSANCE, COMBAT, DAY BOMBING, AND DEFENSIVE FIGHTING.

Engine, Liberty 12-cylinder, 400-horsepower. Weight, empty, 2,391 pounds. Weight, full load, 3,582 pounds. Ground speed is 124.7 miles per hour. Speed at 10,000 feet, 117 miles per hour. Speed at 15,000 feet, 113 miles per hour. 10,000 feet is reached in 14 minutes with full load. Ceiling, 19,500 feet.

UNITED STATES DE HAVILAND 9-A.

This is the American development of the British DH-4.

Jan. 0
Feb.▎ 9
Mar.▏ 4
Apr.▌ 15
May█████ 153
June███████████ 336
July████████████████ 480
Aug.████ 128
Sept.█████████████████████ 653
Oct.████████████████████████████████████ 1097
Nov.██████████████████████████████████ 1036
Dec.███████████████ 472