Visualize a 44-ft-long and 15-ft-high aircraft with a 116-ft wing span and a
gross takeoff weight of 25,600 lb. The plane takes off automatically and climbs
to 65,000 ft where it travels for 42 non-stop hours across 14,000 nautical
miles. Meet the Global Hawk, the future of unmanned reconnaissance spy vehicles.
The Northrop Grumman Ryan Aeronautical Center, the same company that built
Lindbergh's Spirit of St. Louis some 70 years ago, is building the aircraft for
the U.S. Air Force. It will provide field commanders with high-resolution
surveillance images in near real time via satellite.
Beyond meeting stringent performance requirements, design engineers had to
over- come major challenges:
A $10-million unit fly-away price requirement
A thirteen month time limit to provide an airframe for systems testing
Required integration of the aircraft's complex surfaces, structures, and
Given these challenges and timetable, Ryan replaced a second-generation
wireframe CAD system with Pro/ENGINEER mechanical design automation software
from Parametric Technology Corp. (Waltham, MA). Using this system, the Ryan
Aeronautical Center facilitated a concurrent engineering strategy and
implemented Integrated Product Teams (IPTs). And, they completed design without
a hard prototype.
Ryan estimates that Pro/ ENGINEER, in conjunction with the IPT program,
helped cut development time in half. In the future, the company plans to further
expedite production by capitalizing on the system's manufacturing simulation
capabilities to generate manufacturing process plans, tools programs, and
Enhancing team strategies. IPTs were a key focus of the company's concurrent
engineering effort. All IPT groups work from a common budget split by product
rather than department. For instance, the Global Hawk project included airframe,
avionics, software, payloads, ground segment, and systems integration teams,
among others. Subteams within the air- frame IPT consisted of several major
disciplines, including designers, manufacturing engineers, stress analysts,
tooling personnel, and other specialists.
Ryan Aeronautical Center Vice President Claude Hashem, who is in charge of
the Global Hawk program, notes that the level of dedication Ryan invested in the
IPT strategy helped create a new aircraft and engineering culture, one where
communication is key and core design requirements systematically guide product
detail development. The Global Hawk was the Center's first project in which
electronic models were gospel, rather than drawings. And, as Hashem points out,
because all IPTs had common access to the established design specifications and
evolving electronic models, they were able to go back and confirm that each
product iteration continually met larger design goals.
"Pro/ENGINEER's ability to allow teams to communicate instantly, on-screen,
through electronic mock-ups made it the cornerstone of our communication process
and aided our ability to always stay focused on our design requirements,"
explains Ramirez. "We still printed out drawings, but when we had a question,
the electronic model was the law."
Electronic modeling. Members of the IPT teams used Pro/ENGINEER to design the
Global Hawk's structures and harness and cable routing, as well as its fuel,
environmental, bleed-air, and hydraulics subsystems. This capability allowed the
Ryan Center to launch a concurrent engineering design process built around
electronic models. After the teams established initial product design