The Bell HSL (Model 61) was an American 1950s anti-submarine warfare (ASW) helicopter built by the Bell Helicopter company, the only tandem rotor type designed by Bell. It had its first flight in 1953 and entered service with the U.S. Navy in 1957.

貝爾 HSL (Model 61)[3] 是一款 貝爾 於20世紀50年代的 反潛作戰 直升機，此款是貝爾唯一設計的 串聯旋翼 （英語：Tandem-rotor aircraft） 直升機。 原型機 (Model 61)於1953年3月3日首飛；其設計是為滿足 美國海軍 對 反潛直升機 的需求。 1950年6月，Model 61贏得競標，隨後海軍立即訂購三架XHSL-1用以測試。 Model 61具有矩形截面機身結構和四架共六輪起落架。 機組人員包括兩名飛行員和兩名聲納操作員。 [4] 由於需求緊迫，貝爾公司在收到三架XHSL-1合約後幾乎立即 …

Bell Model 61 / HSL 1999 Bell's only twin-rotor helicopter, and one of the few not built by Piasecki (later Boeing-Vertol), the HSL-1 was the largest US helicopter of the day and was intended to hunt submarines and kill them with the Fairchild Petrel air-to-underwater missile.

The Bell HSL (Model 61) was an American 1950s anti-submarine warfare (ASW) helicopter built by the Bell Helicopter company, the only tandem rotor type designed by Bell. The prototype Bell Model 61 first flew on 3 March 1953; it had been designed to meet a United States Navy requirement for an anti-submarine warfare helicopter.

The Bell Company’s HSL was one of the world’s first helicopters developed specifically for the antisubmarine role. Although the Germans employed helicopters from ships to search for submarines during World War II, it was an ad hoc effort using available aircraft, as were the few subsequent U.S. and British navy trials in this field.

HSL-1型直升机由一台普惠（Pratt&Whitney）R-2800-50型径向发动机提供动力输入，其出轴功率约为2400轴马力，发动机安装在机身后部，然后通过穿越机身的传动轴为前部的旋翼提供输入功率。

（1）1946年 Bell-47 成为全球第一款取得民用适航证的直升机，型号合格证编号为1号.全世界第一所民用直升机培训学校成立。 （2）1947年10月14日 Bell X-1 试验类火箭动力飞机 飞行速度达到1.06马赫，成为首次有人驾驶突破音速的飞行器.......这是美国空军第一款X系列 ...

The Bell HSL (Model 61) was an American 1950s anti-submarine warfare (ASW) helicopter built by the Bell Helicopter company, the only tandem rotor type designed by Bell. It had its first flight in 1953 and entered service with the U.S. Navy in 1957.

The Bell HSL (Model 61) was an American 1950s anti-submarine warfare (ASW) helicopter built by Bell Helicopter company, the only tandem rotor type designed by Bell. The prototype Bell Model 61 first flew on 3 March 1953; it had been designed to meet a United States Navy requirement for an...

Bell HSL-. Aircraft of the U.S. Navy... Development: Entwicklung: On 3 March 1953 the prototype Bell Model 61 first flew, it had been designed to meet a U.S. Navy requirement for an anti-submarine warfare helicopter. In June 1950 the Model 61 was announced as the winner of the competition, three XHSL-1 evaluation aircraft were ordered.