"Time to Flight," Feature Article, August 2007

time to flight

Remodeling the avionics in hundreds of
C-130s can't be done in a day, or a year. A manufacturer is working to speed things up.

This story was prepared by staff writers in collaboration with outside contributors.

One of the basic tools used in the defense of the United States is the C-130 Hercules military transport aircraft. Flown by the U.S. Air Force, Navy, and Marine Corps, the ruggedly built Hercules has been adapted for low-level attacks, close-in combat support, space capsule recovery, search and rescue, medical evacuation, aerial refueling, weather mapping, reconnaissance, electronic surveillance, fire fighting, aerial spraying, and disaster relief. C-130s are in service in 60 countries worldwide.

More than 2,000 of these four-engine turboprops have been built, and many in service are 30 years old. Now, the government plans an avionics modification program that will add another 20 years to the service life of these aircraft. Avionics, a contraction of "aviation electronics," includes flight control, navigation, and communication systems.

By 2014, the noses and cockpits of up to 400 aircraft are to be gutted, re-equipped, and rewired. As many as 70 Hercs are to be modernized each year.

Major benefits include standardized aircraft controls, so any qualified crew can fly almost any C-130, which is not the case now. The new avionics will have easy-to-comprehend digital displays replacing aging analog systems. What's more, Hercs will at last be fully qualified for international flight.

The Boeing Co. has designed the hardware for the avionics modification program, or AMP, for the C-130 Hercules, and hopes to land a large piece of the contract to carry out the remodeling. In order to leverage its position as a candidate for the job, the company has been working to streamline the task of installing the new electronics. By using model-based instructions, the company says, it has so far been able to boost the productivity of mechanics by 57 percent from its original estimates of work time.

The gain includes less time spent interpreting paper drawings on the shop floor, better availability of kits and parts, and a shorter learning curve.

Model-based Instructions

The responsible Boeing unit, Integrated Defense Systems in St. Louis, calls the gains so far "very conservative." The calculations are based solely on shop-floor hours worked on the first aircraft and hours projected for the second.

C-130 AMP managers believe they can cut the turnaround time per aircraft by one-third, from six months to four.

Model-based instructions, or MBI for short, are shop-floor work instructions generated from 3-D engineering models of the aircraft. The culmination of years of virtual manufacturing efforts throughout the aircraft industry to get paper off the shop floor, model-based instructions give mechanics the same 3-D images the designers have. The C-130 instructions were developed with Digital Process for Manufacturing software from Delmia in Auburn Hills, Mich. Delmia is the digital manufacturing brand of Dassault Systèmes in Suresnes, France.

About 350 C-130s are to be modified at the Warner Robins Air Logistics Center at Robins Air Force Base, Ga., and at the Ogden ALC in Utah. The first two C-130 avionics modifications were done at Boeing's San Antonio depot, which specializes in fast-turnaround modifications of military aircraft. Winning full-rate production of the C-130 AMP would be worth more than $4 billion to Boeing.

"We found that many programs within the company had used elements of virtual manufacturing," said one Boeing engineer. "Nobody had taken it to its fullest capability. We did."

Inside the C-130: The cockpits and avionics in hundreds of planes will be updated to extend the service life of the Hercules fleet.

Boeing's model-based instructions focus on four areas: producibility and ergonomic analyses; generating 3-D work instructions from digital models; providing networks for distributing online engineering data that is current and cannot be changed; and electronic buyoffs based on the MBI, which will relieve inspectors and customers of the need to interpret blueprints.

In the logistic centers and depots, mechanics can access instructions in real time with durable, portable wireless Tablet PCs, even if they are working on top of the aircraft or deep inside it. Engineers assign shop-floor tasks to fill an eight-hour workday. Originally, time spent looking for information and interpreting drawings was rarely less than two hours a day and sometimes more than five, engineers noted.

Soon after Boeing landed the C-130 avionics design contract in 2002, engineers realized that they would need work instructions specific to each aircraft, which could not be done effectively with the existing paper-based methods.

Before they were model-based, work instructions were stacks of a dozen to 50 2-D CAD drawings (even though most engineering information is in 3-D formats) plus text descriptions for each task. Inevitably, there was a standard notation, "install per view," which often forced the mechanics to interpret what the prints showed. This led to frequent searches for missing information, delays while engineers sorted through all the paper, wasted time, errors, and rework.

From 14 to One

Meanwhile, Boeing was confronting one of the largest and most complex modification programs in aviation history. After all, it was reducing the avionics of 14 distinct versions of the C-130 to just one.

What's more, Boeing does not own the legacy data, so part of the job was a large reverse-engineering effort. After 20 years of modifications, often at multiple depots and logistics centers, there were wide variations in parts and wiring on aircraft in service. The big differences between as-designed and as-received aircraft entailed long learning curves.

Herculean task: The tangle of wiring when the cockpit control panels are pulled out of a C-130 indicates the complexity of avionics modification.

"With MBIs, we are able to move the designers' intentions in the engineering drawing into the hands of the mechanics," said Boeing Phantom Works engineer Keith Mason, a specialist in work instructions. "We can cut two to three hours of interpretation out of the liaison engineer's workday." Phantom Works is Boeing's manufacturing R&D unit.

Engineers explained that the model-based instructions solution to the shop-floor paper problem required digital graphics for each nose and cockpit task of each C-130, and hyperlinks to the text-based instructions and processes, of which Boeing has thousands.

The instructions were integrated into the Boeing manufacturing execution system called I-GOLD, which manages sequencing, schedules, and buy-offs. To ensure that configuration control and version management are maintained, Boeing also had to prevent data editing in the instructions.

Simpler Handoffs

Identifiable results include simplifying handoffs between mechanics, such as when additional help is called in, and helping mechanics orient themselves to tasks and positions inside the aircraft. In addition, instructions incorporate shop-floor tribal knowledge, i.e., how tasks are actually performed.

The instructions also capture non-conformances and discrepancies. With an "iCapture" button on the main instruction screen, mechanics can record a snapshot of a problem as it occurs and add it to the model. Phantom Works engineers expect this to minimize future version control and configuration management challenges.

Model-based instructions are being scaled up quickly from just a handful of tasks on the first aircraft. Some 28 instructions have been identified for the second aircraft. Between 200 and 300 have been earmarked for subsequent aircraft. This points to the adaptability and scalability of model-based instructions.

The engineers noted that productivity gains are based on catching problems before designs go out to the shop floor. "These tasks are not always obvious," an engineer said. "It might seem like just common sense, but common sense can be very hard to convey. Many fixes seem simple until you get into them. That is where Delmia really helped us out."

Implementation of model-based instructions for the C-130 modification program received an award for Acquisition Excellence from Warner Robins and a Boeing Silver Eagle for process improvement, teamwork, quality, and on-time delivery.

Updates in the avionics modification program include digital heads-up displays that are said to give aircrews tenfold gains in situational awareness compared to the old analog cockpit instruments plus weather radars and terrain-following radars for low-level combat operations. The C-130 modification program also includes the Boeing 737 commercial airliner flight management system, which equips all the modified aircraft for international flights.

The aim of the avionics modification program is to extend aircraft life, but it delivers more than that. It will make the planes more effective in the service of the country and, just as important, will better serve the men and women who depend on the equipment and supplies the C-130s bring them.