Sikorsky S-70 & H-60 family
Intended as the successor of the highly successful Bell UH-1 family, this Sikorsky helicopter has achieved a similar success. Model S-70, in US military service known as the H-60, comes in both land based and ship based version. The former are mostly named Black Hawk, the naval version is called Sea Hawk. Both are generally the same, but have a different gear. The S-70 is characterised in particular by the side view silhouette, which resembles an air foil shape. The bottom of the helicopter is nearly flat from the nose to the vertical stabiliser, while the top of the fuselage is rounded with the highest point being near the main rotor mast. This top includes the engine and gear box housing, with the straight engine nacelles placed next to the rotor assembly. After the rotor mast, the fuselage gradually tapers towards the vertical stabiliser with a four blade tail rotor at the top, on the right side. The connected horizontal stabilisers hinge at the base of the vertical fin, and can be tilted 30-40 degrees up and down. In the hover, they are usually tilted down, a typical S-70 feature. The helicopter always has a wheeled gear of the tail gear type. The single wheel main gear is attached to the side of the forward fuselage, between the cockpit and cabin. The tail gear is at the end of the cabin or at the end of the tail boom, depending on the version.
Different versions
The different versions of the S-70 & H-60 family can be recognised by looking at
- the number of wheels on the tail gear
- the location of the tail gear
- the shape of the main rotor blade tips
- whether the tail boom can be folded
- the presence of a disk shaped radome under the forward fuselage
- the presence of a refuelling probe under the right side of the nose
More details will follow later.
Confusion possible with
Harbin Z-20
The Chinese looked very well at the Sikorsky S-70 when Harbin developed the Z-20 medium-lift helicopter. The resemblance is striking! The cabin windows are a bit different and the underside of the fuselage seems to be flatter. Other differences are even more subtle. (photo: 中国新闻社/WikiMedia)
Boeing-Vertol YUH-61
This was the competitor of the YUH-60, evaluated as possible replacement of the UH-1 Huey family. They don't look that different, but the YUH-61 has a nose gear configuration, more separated engine nacelles and no distinct air foil silhouette. (photo: US Army/WikiMedia)