Boeing Helicopters model numbers

The Boeing Vertol BV-347 (also known as the Model 347) is an experimental helicopter built by Boeing Vertol from a converted CH-47A Chinook. It was used to test potential upgrades for the Chinook, several of which were later incorporated into subsequent versions of the CH-47.

The Piasecki H-16 Transporter (company designation PV-15) was a tandem-rotor transport or rescue helicopter designed by Frank Piasecki and built by Piasecki Helicopter. The prototypes were evaluated by the United States Air Force and Army, but the crash of the second test aircraft led to cancelling the project.

The Piasecki HRP Rescuer (also called Harp) is a United States tandem-rotor transport or rescue helicopter designed by Frank Piasecki and built by Piasecki Helicopter. The Piasecki PV-3 was adopted as the HRP-1 Rescuer by the United States Navy, United States Marine Corps, and United States Coast Guard. An improved PV-17 variant was later produced as the HRP-2. As one of the first transport helicopters in military service, the HRP-1 was capable of carrying two crewmen and 8–10 passengers or 2,000 lb. (907 kg) of cargo.

The Piasecki PV-2 is a helicopter designed by Frank Piasecki. The PV-2 is best known for being one of the first successful helicopters flown in the United States. The PV-2 first flew on April 11, 1943. Developed as a technology demonstrator, the PV-2 brought several new features such as the first dynamically balanced rotor blades, a rigid tail rotor with a tension-torsion pitch change system, and a full cyclic and collective rotor pitch control.

The Boeing Model 360 is an American experimental medium-lift tandem rotor cargo helicopter developed privately by Boeing to demonstrate advanced helicopter technology. The aircraft was intended as a technology demonstrator, with no plans to put the type into production, and many of its design features were carried onto other programs including the RAH-66 Comanche and V-22 Osprey. The sole prototype has been preserved and is a static exhibit at the American Helicopter Museum in West Chester, Pennsylvania.

The Vertol VZ-2 (or Model 76) is a research aircraft built in the United States in 1957 to investigate the tiltwing approach to vertical take-off and landing.

The Boeing Vertol XCH-62 (Model 301) was a triple-turbine, heavy-lift helicopter project designed for the United States Army by Boeing Vertol. Approved in 1971, one prototype reached 95% completion before it was canceled in 1975. The prototype was scrapped in 2005.

The Boeing Vertol YUH-61 (company designation Model 179) was a twin turbine-engined, medium-lift, military assault/utility helicopter. The YUH-61 was the runner-up in the United States Army Utility Tactical Transport Aircraft System (UTTAS) competition in the early 1970s to replace the Bell UH-1 Iroquois helicopter. At the end of the flyoff program, Sikorsky Aircraft was awarded a contract to develop and build its UH-60A entry.

The Piasecki HUP Retriever or H-25 Army Mule, later UH-25, is a compact single radial engine, twin overlapping tandem rotor utility helicopter developed by the Piasecki Helicopter Corporation of Morton, Pennsylvania. Designed to a United States Navy specification, the helicopter was produced from 1949 to 1954, and was also used by the United States Army and foreign navies. The HUP/H-25 was the first helicopter to be produced with an autopilot and also the first to perform a loop.

The Piasecki H-21 Workhorse/Shawnee is an American helicopter, the fourth of a line of tandem rotor helicopters designed and built by Piasecki Helicopter (later Boeing Vertol). Commonly called "the flying banana", it was a multi-mission helicopter, capable of being fitted with wheels, skis or floats.