The Douglas B-18 Bolo is an American twin-engined medium bomber which served with the United States Army Air Corps and the Royal Canadian Air Force (as the Digby) during the late 1930s and early 1940s. The Bolo was developed by the Douglas Aircraft Company from their DC-2 as a replacement for the Martin B-10.

The Douglas Aircraft Co. developed the B-18 to replace the Martin B-10 as the U.S. Army Air Corps' standard bomber. Based on the Douglas DC-2 commercial transport, the prototype B-18 competed with the Martin 146 (an improved B-10) and the four-engine Boeing 299, forerunner of the B-17, at the Air Corps bombing trials at Wright Field in 1935.

道格拉斯B-18「大刀」式轟炸機 （Douglas B-18 Bolo）是一款於1930年代中期由 道格拉斯飛行器公司 按 DC-2 為藍本改良開發的 轟炸機，整體性能並無出眾之處，但她仍然取代了 B-10轟炸機 作為美軍主要戰術轟炸機運用。 但有相當多數量的B-18在1941年12月在日軍偷襲珍珠港時遭炸毀，剩餘的B-18在 第二次世界大戰 期間服務於 美國陸軍航空軍 及 加拿大皇家空軍，用於海上戰鬥巡邏的轟炸機，並在1942年擊沉過 U型潛艇。

B-18轰炸机，（英文：B-18 Bomber），是20世纪30年代后期 道格拉斯 飞机公司为 美国陆军航空队 研制的双发动机 中型轰炸机。 B-18轰炸机具有较好的抗损毁性和较低的造价， [1-2] 是美军在珍珠港事变之前的主要轰炸机型，但其缺乏自卫武器、载弹量小和动力不足的缺点，限制了其作战能力 [1-2]。 B-18轰炸机于1934年开始研发，1935年研制成功，1936年投产，1937年列装入役，共生产了370架 [2]。 1942年初，美国军方采用 B-17轰炸机 替代B-18轰炸机执行一线作战 …

The Douglas B-18 Bolo was an American medium bomber used by the United States Army Air Corps (USAAC) during the late 1930s and early 1940s. It was primarily employed for coastal defense and anti-submarine patrols before and during World War II. Description.

The B-18 Bolo bombers were the response to the United States Army Air Corps' 1934 request for a bomber with greater bomb load and greater range than the then-standard B-10 bombers. Though not the most capable among the contestants, the design's lower price gave it the competitive edge needed to win the contract.

In January 1936, the War Department ordered 133 Douglas B-18s and thirteen Boeing YB-17s. This decision has been widely criticized, both at the time and by later historians, given that the B-17 would go on to become one of the most effective bombers of World War II, while the B-18 was largely obsolete by the time the U.S. entered the war.

The Douglas B-18 (DB-1) was a military version of the Douglas DC-2 designed to meet the requirement for a coastal-defense, multi-engine bomber. It was designed for a USAAC competition, announced on August 6, 1934, to find a modern replacement for the assorted twin-engine Keystone biplane and Martin B-10 bombers.

2023年8月14日 · Versatility was one of the B-18’s defining characteristics. Designed for multi-role missions, it was employed to hunt German U-boats, protect vital shipping lanes, and patrol coastlines. The Bolo’s adaptability meant that it could still perform essential tasks even as more technologically advanced aircraft entered service.

The Douglas B-18 was designed to meet a 1934 requirement of the USAAC. This called for a bomber with a range of 2000 miles carrying a ton of bombs, at a speed of at least 200 mph. The Douglas DB-1 design competed with the Martin 146, a modernised B-10, and the Boeing 299, the later B-17. The B-18 was the cheaper and more conservative solution.