Boeing (Vertol) Sea Knight & Kawasaki KV107
This tandem helicopter was developed more or less in parallel with the Vertol V-114, that became the CH-47 Chinook. Vertol model 107, or V-107, received various designations in the pre-1962 area, depending on the service customer. The US Army gave it designation YHC-1A, the US Navy HRB-1 and the US Air Force XH-49A. All became versions of the H-46 in 1962 though, named Sea Knight. Later, it was built under license by Kawaski as the KV107.
The Sea Knight is a tandem helicopter with two three blade main rotors on top of pylons on top of the front and rear of the fuselage. The rear pylon is larger and slightly higher than the front one. The rotors are powered by two turboshaft engines placed on the top of the rear fuselage, in the front side of the rear pylon. The exhausts are in the side of the pylon. The Sea Knight has small sponsons attached to the rear fuselage. The two wheel main gear legs are attached to these sponsons, but cannot be retracted in them. Below the cockpit is the fixed nose gear with two wheels (excepf for the prototype that had one). Finally, the fuselage slopes up at the rear with a loading ramp. It has round cabin windows.
The Sea Knight has a short nose with many windows, including a typical large one at the feet of the crew. Note the characteristic shape of the front pylon.
The turboshaft engines of the H-46/KV107 are embedded in the sides of the rear pylon, on top of the rear fuselage. The air intakes can have different dust covers.
Different versions
The different versions of Chinook can be distinguished by looking at (amongst others)
- the shape of the cockpit windows
- the shape of the nose
- the number of wheels on the nose landing gear
- the presence of a winch on the right side, above the front cabin door
- the shape and size of the sponsons
- whether the rotor blades can be folded, visible also in the thickness of the rotor hubs
More details will follow later.
Confusion possible with
Boeing 360
This technology demonstrator can be considered a highly upgraded Sea Knight, so it also looks similar with engines embedded in the rear fuselage. The Boeing 360 is slightly smaller though, has a retractable gear and four blade rotors. (photo: WikiMedia)
Boeing (Vertol) Chinook
You can well see that the Chinook was development in the same era as the Sea Knight: many elements are similar. Apart from the pylons and three blade rotors, the cockpit windows are also alike. The Chinook is larger though, has a four leg fixed gear, long sponsons along the side of the fuselage and engines in external nacelles attached to the lower sides of the rear pylon.
Piasecki PV-22/H-21
The H-21 was the predecessor of the H-46. Both have in common the tandem rotor design and the round cabin windows, but there are many differences. The H-21 has a bent fuselage, with the rear rotor placed on top of the rear fuselage instead of a pylon. The front pylons is small. Furthermore, the H-21 has a tricycle gear with single wheels and horizontal stabilisers with large rectangular end plates.
Bristol Belvedere
The tandem rotors and four leg fixed landing gear are common for the Sea Knight and Belvedere. The Bristol helicopter however has a more slender fuselage, horizontal stabilisers with significant anhedral and all single wheel four legged gears, next to many other differences.
Yakovlev Yak-24
Yakovlev tried the tandem rotor design as well, but not many were built. Typical for the Yak-24 are the four fixed single wheel gears placed relatively far from the fuselage. It has horizontal stabilisers with end plates. The Yak has radial piston engines in the rear fuselage, more or less in the same place as the H-46.