HURC in action. United Airlines maintenance facility's job shop cutting airplane
parts quicker with Hurco machines and controls
Inside United Airlines' new $800 million maintenance center sits a small job shop with 19 workers responsible for turning around all airplane
replacement parts in a day's time - a hefty task for a tiny operation tucked away in a behemoth 3-million-square-foot facility.
United Airlines, one of the world's largest commercial airlines with annual revenues reaching $3.8 billion, broke ground in 1992 at Indianapolis
International Airport to construct one of its major maintenance centers, and opened the first wing two years ago. Already, hundreds of narrow-body
jets - including Boeing 757s and 737s - have made pit stops in one of the eight hangars for routine tune-ups and heavy maintenance visits.
The state-of-the-art facility, one of the biggest economic development shots-in-the-arm for the growing Midwestern city of Indianapolis, is being built
over a 12-year period, and upon completion will include 11 hangars with 18 aircraft bays and will accommodate 22 aircraft at one time. As many as
350 airplanes will be serviced at the center over any 15-month period, and by year-end 2004, 7,500 employees will be working at the maintenance
center.
The Indianapolis facility is dedicated to providing two- to three-day tune ups, called C-checks, and 18-day heavy maintenance visits (HMV) for the
airline's fleet of 757s and 737s; 767s will soon be added to the maintenance facility's roster.
A C-check occurs every 15 months at which time mechanics and engineers conduct scheduled, time change work and inspection for non routine
defects. HMVs occur every four to six years depending on the model and age of the aircraft. During HMVs, mechanics remove the interior of the
aircraft, including seats, wall and ceiling panels, carpeting and floors. They also open access panels and conduct a thorough corrosion and maintenance
inspection of all areas of the aircraft. Engines are removed and pylons are inspected.
As construction of United's maintenance facility continues and staffing becomes complete, the company aims to cut the 18-day HMVs to 14-day visits,
said Carl Jacobson, team coordinator at United's job shop. The less time airplanes are grounded for maintenance work, the more productive they are
for the company. To cut HMVs by four days, teams of machinists as well as mechanics and engineers on the floor must all work efficiently.
Job shop streamlines production
"Most of the parts we machine are finished within a shift of 10 hours," Jacobson said. Turning around replacement parts and repairs quickly is integral
to the company's goal to shorten HMVs, he said.
The team of machinists are responsible for repairing and machining all worn-out or damaged airplane parts pulled from jets at the Indianapolis facility.
They fabricate or modify such parts as doublers, stringers and brackets and will make replacement parts when needed.
Everything machined for the aircraft is done in-house; nothing is outsourced. And each part that the machinists handles is different; there's no
large-batch production involved. "We focus on the part we need," Jacobson said.
To meet the work load, the demands for quick turnaround and challenges of one-at-
a-time production, Jacobson has turned to Hurco Machine Tool Products machining centers.
"Our Hurco BMC 30HT/M and our larger BMC 50/50 are our mainstays," Jacobson said. "We depend on them for 100 percent of the NC mill
work."
United's job shop uses the BMC 30 HT/M, a 15 hp vertical machining center, to cut soft aluminum and heat-treated steel. The 30-inch X-travel
coupled with the 17" x 24" Y and Z travels and a table load of 1,100 lbs., allows for machining of a large variety of parts.
The machine is a high-capacity milling center with up to 18 cu in. per minute removal rates in mild steel and a drilling capacity of 1.5" dia.
For machining of larger pieces, United uses the BMC 50/50, a 20 hp vertical machining center, with a 52-inch X travel and maximum table load
capacity of 3,300 lbs.
Both machines are equipped with Hurco's state-of-the-art Ultimaxr control, which Jacobson says is the main tool that drives the job shop's ability to
turn jobs around quickly and accurately.
"The Hurco machines have exceeded our expectations, and exceeded our requirements," Jacobson said.
User friendly controls provide operator control
The machining centers, equipped with Hurco's Ultimax controls, are user friendly and can be programmed on the floor by the machinist. Machinist
control, from the beginning of the maintenance process to the finish, is the major philosophy steering United's quick turnaround manufacturing
operation, Jacobson said.
Employees are empowered to take control of every project, he said. They work in teams, and determine among themselves how to tackle each
project. "The team approach takes a lot of structure out of the way," Jacobson said. "It's easier for them to do their jobs efficiently."
Under the team approach, work will flow quickly and efficiently, Jacobson said. "The concept is to have a self-contained shop," he said. "The same
machinist who picks up the part finishes it."
Machinists who have minimal or no programming experience can machine a part from start to finish with the help of Hurco's Ultimax control. "One of
the best aspects of the Hurco machine is the control," Jacobson said. "It's user friendly and easy to program. Most of the machinists here have little or
no NC experience, but within a week they have learned how to program their own parts. Now we don't have to wait on the programmers to get us a
program; there's much less waiting time and more production time."
Jacobson estimates that about 95 percent of the programming at United is done by the machinists. "They can go from print to part on their own," he
said.
That's particularly helpful to a machinist who has to write his own program to make a replacement part. Oftentimes, a machinist must cut a part from a
drawing provided by Boeing. The machinist, using the Ultimax control, can program the machine to cut that part, without using MDI (manual data
input) G- and M-codes, greatly reducing the programming times and enhancing production time.
The control also allows the machinist to go from CAD geometry to finished program quickly and effectively. AutoCad DXF files can be loaded directly
into Ultimax via the disk drive, making the creation of Ultimax conversational data blocks very fast. Because the DXF file contains all the part
geometry, programs are created by simply pointing and clicking the cursor on the part feature to be created.
The dual screens on the control also allow machinists to see the tool path and part shape as programming is taking place. With the dual screen,
machinists can check the part program to ensure accuracy before actually cutting the part on the machine.
As United continues the construction of the Indianapolis maintenance facility, Jacobson will have the luxury of building onto his job shop. He'll also
have the task of continuing to turn around quickly a growing number of products. He hopes that once his machinists are in place for a long period of
time and his job shop is fully staffed that the HMVs will be reduced within company goals. He says the Hurco machines are essential in attaining that
goal. |
