In 1920, the Boeing company, under the designation Model 16, began producing DH-4 aircraft with Liberty engines. The company was selected to modify the DH-4 to the more advanced DH-4B standard. Boeing built 111 such modified aircraft for delivery from March to July 1920, and in 1923, 50 of these aircraft underwent further re-equipment at Boeing factories.
Evolution of the DH-4B
In February 1923, the U.S. Army awarded Boeing a contract for three DH-4s featuring enlarged landing gear wheels and a fuselage frame made of steel tubes, replacing the original wooden structure. These aircraft were designated DH-4M-1 (later XDH-4M-1, where ‘M’ stood for ‘modernized’). A similar conversion was carried out by the American branch of Fokker, known as Atlantic Aircraft Corporation.
The modifications proved successful, leading to Boeing receiving an order for 183 such aircraft for observation and photo-reconnaissance in the summer of 1923. Approximately 163 units were delivered to the U.S. Army from January to September 1924. Subsequently, 22 of these were converted into DH-4M-1T training aircraft with dual controls, while several more aeroplanes designated DH-4M-1K were adapted for target towing.
Marine Corps Service and Upgrades
In March 1925, the final 30 aircraft from the U.S. Army order were transferred to the Marine Corps under the designation O2B-1. The last four of these were later converted to the O2B-2 standard for day and night operations in complex weather conditions. These changes included the installation of navigation lights, radio equipment, signal flares, and improved instrumentation.
Technical Specifications
| Modification | Model 16 (DH-4M) |
| Wingspan, m | 12.9 3 |
| Length, m | 9.1 2 |
| Height, m | 2.95 |
| Wing area, m2 | 40.88 |
| Empty weight | 1333 |
| Maximum takeoff weight | 2084 |
| Engine type | 1 Piston engine Liberty 12A |
| Power, hp | 1 x 420 |
| Maximum speed, km/h | 190 |
| Cruising speed, km/h | 167 |
| Practical range, km | 531 |
| Service ceiling, m | 3900 |
| Crew | 2 crew |
| Armament | two synchronized 7.62-mm machine guns in the forward fuselage and two twin-turreted 7.62-mm machine guns in the rear cockpit, up to 181 kg of bombs under the fuselage |
Image and diagram gallery of the Boeing Model 16
 Boeing Model 16 |
 Boeing Model 16 |
 Boeing Model 16 |
 Boeing Model 16 |