Sikorsky began UH-60 helicopter production in 1978, making
the earliest delivered aircraft nearly 24 years old. UH-60A and UH-60L
helicopters are movers of men and supplies for the U.S. Army. Because of its
size, performance and survivability, the Black Hawk has multi-mission
capabilities, including movement of troops and supplies, search and rescue,
special operations, medical evacuation and command and control.
Last year the company signed an Army contract for research,
development, test and evaluation (RDT&E) of the UH-60M Black Hawk, which is
the beginning of an effort to upgrade as many as 1,200 Army fleet aircraft
during the next 25 years. This means that Black Hawks will be in operational
use to the year 2040 and beyond. With the RDT&E program underway, two
UH-60As and one UH-60L helicopter have already been inducted into the disassembly
and inspection process at Sikorsky subsidiary.
The Black Hawk has been employed in every significant U.S.
military ground operation from Grenada to Afghanistan, including service in Somalia,
featured in a movie this year entitled "Black Hawk Down". It is engaged in a
wide range of other tasks, including armed attack, electronic warfare,
humanitarian aid, fire-fighting, and executive transport.
Derivatives have been spawned for all U.S. military services
and 25 countries worldwide.
The capabilities of this aircraft were not an accident. Its
requirements were established during and after the Vietnam War era, and are a
direct result of combat helicopter shortcomings experienced during that
conflict. The lessons learned in Vietnam included the need to fly faster and
farther from higher elevations at higher temperatures while being able to
withstand ballistic hits and continue the mission.
Systems would require the ability to continue operation if
hit by small-arms fire ranging from 7.62 mm to 23.7 mm. In addition to aircraft
hardware, survival of flight personnel became a primary ingredient in the
combat design of the aircraft. The flight crew required armored, crashworthy
seats.
Redundancies Cited
If mortally hit and high-impact ground contact was inevitable,
the helicopter was required to withstand g forces of 20g forward, 20g
vertically, and 18g laterally, three times the capability of existing
helicopters. This equated to a 38 foot-per-second vertical crash, survivable by
flight crew and troops. Reliability of the design would require triply
redundant hydraulic and electrical systems, dual engines, an auxiliary power
unit, separated dual controls, a self-sealing crashworthy fuel system and other
system redundancies throughout the helicopter.
By way of history, these requirements became the
specification for the Utility Tactical Transport Aircraft System (UTTAS). Later
named Black Hawk, the specification became a production reality that has been
maintained since inception. Black Hawk's ability to save lives was experienced
in two significant crashes during hostilities in Mogadishu, Somalia. Both
aircraft had sustained multiples of hits by small-arms fire and continued their
missions, only to be severely damaged by rocket-propelled grenades, unguided
explosives capable of extreme damage to the helicopter. In other designs, it
would be highly unlikely for anyone aboard to survive the crash impact.
On Dec. 23, 1976, Sikorsky won the UTTAS competition against
Boeing Vertol's UH-61 and was awarded a contract for the UH-60A, powered by
General Electric T700-GE-700 engines. The Low Rate Initial Production (LRIP)
quantity of 15 helicopters began deliveries in October 1978, and by the
mid-1980s, production rates in excess of 100 helicopters per year were achieved.
In all, more than 1,100 UH-60A helicopters were produced for United States and
international militaries.
In 1989, the UH-60L became the production standard. Its
upgrade included more powerful T700-GE-701C engines, a transmission system with
increased ratings and durability and numerous airframe and subsystem
reliability improvements. As a result of this design progress, higher payloads,
increased hover weights, and faster forward flight speeds were achieved with an
approximate 40 percent reduction in operating and maintenance costs.
Since 1989, more than 1,000 UH-60L helicopters and its S-70
variants have been delivered to the U.S. government and international
customers. UH-60L production deliveries are planned for the Army through fiscal
year 2007, at which time production deliveries of the new UH-60M are
positioned. When naval variants are included, more than 2,500 Hawk family
helicopters have been delivered since 1978 and more than five million flying
hours have been logged. Under licensed co-production, Mitsubishi Heavy
Industries in Japan and Korean Air Industries in Korea have produced an
additional total of nearly 200 Hawk-version helicopters.
Upgrade Helos Listed
Under last year's $219.7-million RDT&E contract, the
first aircraft scheduled for upgrade is a UH-60A built in 1985 that last served
with the 507th Medical Evacuation (Medevac) unit at Fort Hood, TX. It will
provide the basis or "proof of concept" for the "A" to "M" element of the plan,
and it is hoped that the task can be accomplished on schedule and at reasonable
cost.
The second aircraft is a UH-60L from Fort Stewart, GA, built
in 1989, and representing an early model of this type. The last is a UH-60A
from the Naval Test Pilot School in Patuxent River, MD. This UH-60A was
delivered in 1978, the third production helo to roll off the assembly line. It
will be upgraded to the UH-60M Medevac configuration. The inducted aircraft
were chosen to represent a spectrum of age and configurations with high-time
airframe hours.
The rebuilt aircraft will have improved payload, new digital
cockpit displays, a strengthened fuselage, new composite spar, wide-chord
blades, and more powerful engines. The Army has identified these rebuilt
aircraft as "re-capitalized", and each will provide an additional 20 years of
service life with lower maintenance costs than exhibited by the current fleet.
A fourth UH-60M will be produced as a new aircraft under the program, and will
be the test and qualification model for future production of this model type.
The company will disassemble the aircraft, inspect parts,
recondition the cockpit, tail cone and tail structures, and ship the rebuilt
components and assemblies to facilities in Stratford, CT. There, a newly
manufactured cabin and transition section will be fitted with the reconditioned
components. Dynamic components will be reconditioned or replaced, and high
speed machining will be utilized to reduce cost, complexity and parts count of
new airframe components.
All UH-60A aircraft upgraded to the UH-60M configuration
will receive an improved durability main gearbox, the standard for the UH-60L.
A new glass cockpit with data bus, four multi-function displays, two control
display units, a modern flight control computer, and a new avionics suite will
be installed. With the new electronics, a narrower instrument panel can be
incorporated to significantly improve lower cockpit window visibility.
'Dual-use' Program
The UH-60M will utilize new rotor blades developed under a
"dual-use" program. This process capitalizes on development of commercial
components that can be used in military systems. Rotor blades are of composite
spar construction, replacing the current titanium spar, and are redesigned to
add 16 percent more chord. New, composite anhedral blade tips will replace the
current aluminum trapezoidal tips.
The new rotor blades provide about 500 pounds more lift than
the current blade, improved flight maneuver and speeds that are 15 to 20 knots
higher than the current UH-60L. This wide-chord blade has been tested on Black
Hawk and is being produced for the civil S-92 helicopter currently undergoing
flight certification.
A new T700-GE-701D turbo shaft engine under development by
the Army will add more power, boosting payload by about an additional 400 pounds,
and will provide a significant improvement in durability. The combination of
the improved engine, main gearbox, and resetting the clock on other components
will significantly reduce the operation and support costs of the UH-60M when
compared to earlier models.
The program faces an aggressive schedule. First flight of
the UH-60M is scheduled for 2003. Each of the four aircraft will enter a test
and evaluation program that will lead to a production decision by the Army in
2004. With that approval, fiscal year 2004 funds could be released for a
planned LRIP quantity of 10 remanufactured UH-60M helicopters, to be delivered
during 2005 and 2006. Production quantities for new UH-60M helicopters will be
established during the upcoming years, but re-capitalized aircraft will be
processed over the next 20 years, ultimately resulting in a total quantity of
about 1,200 UH-60Ms.
In an effort to maintain continued operational readiness for
the basic UH-60A, the Army will recondition a bridge quantity of about 200 UH-60A
airframes beginning in 2003. This process is sometimes referred to as a
"service-life extension program". Under an engineering service contract,
Sikorsky will identify airframe and dynamic system components that will be
repaired or replaced to extend airframe life.
Near 'Zero-time' Planned
New system components will be provided as a kit of parts to
Corpus Christi Army Depot in Texas, where the inducted aircraft will be near
"zero-timed". This means the airframes will be completely rebuilt, permitting UH-60A
operational capability to continue seamlessly until future but ultimate
induction of these airframes into the UH-60M upgrade program.
Under the U.S. Army program, the manufacturer will have
established a standard upgrade process that applies to almost all Black Hawk
models, extending use of the helicopter for 20 or more years. This is
especially important to international users that are experiencing high airframe
hours, and may be critical to those users that have mission performance
requirements that exceed current aircraft capabilities.
Between 1984 and 1994, some 280 UH-60 and S-70A helicopters
were delivered internationally, some of which have achieved very high operating
hours. These and more recently delivered aircraft are candidates for induction
in the upgrade program. As a direct benefit, the international Black Hawk
community will achieve reduced operating costs and extended life, avoiding
obsolescence or replacement with new aircraft. L
Rudolph W. Beckert is a consultant for Sikorsky Aircraft
Corp., having retired after a career of 38 years. He currently provides
consulting services to the helicopter industry through Beckert Consulting,
Inc., a company he founded in July 2000.