CFM Studies New Centerline Engines, But
No New Platforms Yet
New centerline engines are under study at CFM
International even though no new platform is likely to emerge
for them for another seven or eight years.
Studies are always under way in support of the airframe manufacturers,
but there will be need for new engine development until about
2008, according to Bill Clapper, executive VP at CFMI. Until then
the engine maker will offer new technology from its Tech56 program
to GE and Snecma (joint owners of CFMI) and infuse it into its
installed base of CFM56 powerplants through upgrade kits.
Upgrades already available include a CFM56-3 turbomachinery improvement
package that decreases fuel burn by about 1% on Boeing "classic"
737s and lowers engine operating temperatures by about 15ºC
to boost time-on-wing. Taken together, the changes should reduce
engine cost of ownership by about 30%. Southwest Airlines launched
the package with a 300-kit order, and at least one-tenth have
already been installed. CFMI is bullish on the project, Clapper
said, noting that there are 4,400 CFM engines installed on more
than 1,900 classic 737s, and that most of those aircraft are expected
to remain in service for at least 10 years or more.
CFMI also is moving forward with the CFM56-5C/P for the Airbus
A340-200/300. Compared with the -5C version, the -5C/P will offer
a 1% specific fuel consumption improvement (translating into $15,000-$20,000
in fuel savings per engine per year) and reduce exhaust gas temperatures
by 13ºC. The latter should help cut engine maintenance costs
by 10%. CFMI plans to make the upgrades standard in all new-production
engines and to offer them to existing operators as kits.
"There are more than 1,000 dash 5C engines out there, and
we feel there's a market for 500 engines and upgrade kits,"
Clapper said. The first -5C/P powerplant was run in November 2001,
and flight tests on an Airbus transport were conducted last November.
Certification on the Airbus A340-300 and of the upgrade kits should
be achieved in the fourth quarter of this year. To validate expected
performance enhancements, CFMI will conduct back-to-back tests
of an upgraded -5C, running the powerplant first without the improvements,
and then with the upgrades installed.
CFMI has adopted a policy of designing all its powerplants to
meet Stage 4 noise levels. To make the 33,000 pounds thrust CFM56-5B
compliant, the company will soon certify a chevron exhaust nozzle
for the engine. In addition, CFMI is exploring an inlet treatment
for the powerplant to ensure Stage 4 compliance. The treatment
would be certified in the fourth quarter of 2004, if necessary,
"but we don't think the engine will need this to meet Stage
4," Clapper said.
Long-term improvements continue to be explored in the company's
Tech56 effort, and CFMI is not pinching pennies in this area,
according to Clapper. Despite tough times in the industry, "there
have been no cuts to our technology development plans." As
a result, a more efficient fan, a compressor and turbine section,
as well as a highly durable twin annular pre-swirl (TAPS) combustor,
are moving forward.
In contrast, counterrotating high- and low-pressure turbines are
one Tech56 improvement expected to find its way only into new
baseline engines. CFMI has run about 100 hours of endurance trials
on a counterrotating bearing and found the system's behavior to
be "good."
To leverage its technology developments, CFMI is considering whether
to offer a performance-enhancement kit aimed at CFM56-5B and -7
engines, "possibly for 2006. If there's an upturn in business
in 2006 or 2007, we would need to have the kit certified and ready
for implementation if we don't want to miss the boat," Clapper
said.
Technology from Tech56 was used in the GE90-115B, "and a
fair amount is going to be used in the new Boeing application,"
said GEAE president and CEO Dave Calhoun. "Tech56 has been
a terrific program. It really reinforces how important it is to
keep pressing on with technology programs that don't yet have
a home."
