Mention the Black Hawk helicopter and the first thing most people think of is the 1993 incident in Somalia where the Sikorsky-manufactured helicopter became famous for all the wrong reasons. A best-selling book and Hollywood movie tends to trump the day in, day out work that's been performed by the helicopters for more than 30 years. But if the Bell UH-1 Huey was synonymous with "military helicopter" during the 1960s and 1970s, the UH-60 Black Hawk (and its siblings) has taken its place ever since.
The UH-60 Black Hawk is actually just one member of a large family of helicopters. The military designates the variants of the H-60 with a prefix indicating their intended purpose: there's the utility UH-60; search and rescue/medical evacuation HH-60; anti-submarine SH-60; multi-mission MH-60; or the staff transporting VH-60. (No word on the designation for the stealth version used in the Osama bin Laden raid.) The company designation for the model is S-70.
The helicopter is used by every branch of the U.S. armed forces and several other government agencies, including the Customs and Border Patrol and the Drug Enforcement Agency. More than 30 foreign countries operate at least one variant of the S-70 family, some as close as Canada and Mexico, others as far away as China.
On a trip earlier this year to learn about Sikorsky's speedy X-2 helicopter program, we visited the company headquarters in Stratford, Connecticut. On our way to the flight test office, we were able to take a tour of the factory where the S-70 helicopters roll off the assembly line and are test flown before being delivered to the wide range of customers. Here's a sampling of what we saw -- and how the signature U.S. military helicopter gets put together.
Above, an unpainted UH-60M sits on the flight line just outside the factory doors, awaiting its first ground run before preliminary flight testing. Some of the helicopters are painted before flight test, while others are flown with only the primer colors on the various components.
Photos: Jason Paur/Wired.com
Bare S-70 airframes enter the factory at the far left of the picture above. Components are added to the airframes -- including engines, transmissions, wiring, avionics and interiors -- by the time the helicopters work their way down to the other end of the assembly line.
More than 3,000 S-70 variants have rolled off the assembly line since the first helicopter entered service back in 1979. Since 9/11, the Connecticut factory has been very busy: Today, it's producing helicopters at a rate averaging five per week.
This factory has a long history producing military aircraft. During World War II, F-4U Corsair aircraft were built here by the thousands. Today the different variants of the S-70 helicopter are built in Stratford side by side. In the picture above an MH-60R Sea Hawk destined for the Navy is in the foreground, while UH-60M and HH-60M Black Hawks are being assembled in the background.
Photos: Jason Paur/Wired.com
First flown on Oct. 17, 1974, the S-70 helicopter was designed as a replacement of the UH-1 Huey. The helicopter entered service in 1979 and first entered combat in Granada in 1983. Since then it has served as the workhorse helicopter in every conflict from the invasion of Panama to the killing of Osama bin Laden.
Once the major components such as the engine, landing gear and controls are added at the first few stations on the assembly line, the electronic systems and avionics are added. The nose of the MH-60R above will eventually be packed full of tools from infrared and visible cameras to radar and sonar. The "Romeo" has the ability to perform a wide variety of missions from anti-submarine and anti-surface ship warfare, as well as search and rescue and special operations support.
Photos: Jason Paur/Wired.com
And you thought rewiring the bathroom was a challenge. In addition to the wide range of electronic observation systems used on some of the S-70 variants, the modern helicopters also come equipped with tools aimed at making the pilot's job easier.
The picture above is taken from the left cabin door looking forward toward the cockpit. Depending on the S-70 variant, the large interior could be filled with anything from troop seating for up to 14 or medical stretchers for six.
Photos: Jason Paur/Wired.com
Inside the main cabin of an HH-60M Black Hawk medevac helicopter, there's seating for two crew members, along with the litters for patients. The medevac helicopter has come a long ways since the Bell 47 -- familiar to M*A*S*H* viewers -- where patients were transported outside on the landing skids.
The litter platforms inside the Black Hawk can be lowered and raised with the four white buttons on the panel seen on the right. Additional litters can be placed on the floor of the cabin. The panel on a medevac Black Hawk also includes built in oxygen and suction for each of the three litter positions on each side of the cabin.
Photos: Jason Paur/Wired.com
The cockpit of the S-70 has changed dramatically since the helicopter first started flying in the 1970s. The traditional round gauges have been replaced by multiple glass panel displays that show everything from flight instruments to navigation tools.
Above, work is just beginning on the cockpit of an MH-60R Sea Hawk. Other than the pedals that control the tail rotor, there is no other sign of a working cockpit with raw wiring visible where the seats will eventually be installed.
In addition to the Black Hawk and Sea Hawk variants, the Air Force also operates the Pave Hawk and the Coast Guard operates the Jay Hawk. Both variations are specialized for search and rescue. The Marines operate the self-explanatory VH-60 Presidential Hawk.
Photos: Jason Paur/Wired.com
Once finished, the interior of a modern S-70 provides today's pilots with tools to reduce their workload and increase their ability to fly in a wide range of diverse and difficult conditions. In addition to the glass panel displays that aid pilot situational awareness, a modern Black Hawk such as the HH-60M cockpit seen above includes tools such as an autopilot that includes auto-hover capabilities.
With a gross weight of 22,000 pounds or more, depending on the variant, the S-70 is more than twice as heavy as the UH-1 Huey it replaced. It has a cruise speed of more than 150 knots (173 miles per hour).
The main control stick on the right is known as the cyclic. It controls the tilt of the main rotor. Moving the cyclic forward, backward, left or right tilts the rotor disc in the same direction, moving the helicopter in the same direction. The control stick on the left is the collective, which changes the pitch of the rotor blades. Pull it up and the helicopter climbs; push it down and the helicopter descends. The nearly 4,000 horsepower available through a pair of General Electric turbine engines is controlled via auto throttles that are set during takeoff and are unlikely to be touched often during flight.
Photos: Jason Paur/Wired.com
The U.S. Army is by far the biggest S-70 customer with more than 1,900 Black Hawks that have entered service. When the Black Hawk was first developed during the early 1970s, the hope was for an aircraft that could carry more, fly faster and have better survivability than the UH-1 Huey.
One of the design attributes of the Black Hawk is the euphemistically named "ballistically tolerant rotor and drive system." Unlike fixed wing aircraft that can handle significant damage to a wing, tail or engine and continue flying, a helicopter is very susceptible to damage to its lift or control devices.
Above the main drive shaft to the tail rotor follows the top of the tail boom of a UH-60M partially protecting it from below. Because the tail rotor is located higher on the tail, an intermediate gear box is needed to deliver power. The tail rotor of a Black Hawk is 11 feet in diameter and is tilted 20 degrees from vertical. The tilt supplements the main rotor providing additional lift.
Photos: Jason Paur/Wired.com
Once an S-70 leaves the assembly line it passes through to a finishing hangar where all of the systems are checked and the main rotor blades are added. Then the helicopter is handed over to the production test pilots.
"We fly the aircraft, the target is three and a half hours of flight time for the acceptance test" says chief test pilot Kevin Bredenbeck. It usually only takes about two hours for the initial flight.
Once the aircraft has undergone its initial flight, it's brought back to the hangar and everything is checked and tightened. The helicopter is then painted and any special mission equipment, such as an external winch, is added at the company's facility in Elmira, New York
Eventually the helicopter is flown a total of 10 hours as part of the break-in to assure everything continues to work properly. Once the Sikorsky pilots are finished with it, the helicopter is flown by an acceptance pilot from whichever branch of government is taking delivery. The pilot may then deliver it to its final destination or may hand it back to a Sikorsky pilot for delivery.
With the relatively high production rate, Sikorsky pilots have been extremely busy in recent years, "last year, including aftermarket support" Bredenbeck says, "our test pilots flew over 6,700 hours."
There is no current plan to replace the S-70 family of helicopters, though Sikorsky does have plans to eventually develop a medium lift sized version of its pusher helicopter technology first used with the X2 technology demonstrator.
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