Momentum - November 2017 - 15

TODAY'S

ENGINEERING

ROLLS-ROYCE LOOKS TO CORNER
COMMERCIAL MARKETS, MILITARY NEXT
Rolls-Royce recently secured an
incremental order from United Airlines
to provide additional Trent XWB engines
and service support. This followed the
airline's recent announcement that it will
update and expand the number of longrange, twin-engine wide-body Airbus
A350 aircraft on order from 35 A3501000 to 45 A350-900.
To maintain competitiveness with the
Boeing 787 Dreamliner and 777-300ER,
Airbus worked with Rolls-Royce for over
a decade to develop the Trent XWB, a
variant of the Trent 1000. The new
engine features a two-stage intermediate
pressure turbine instead of a single stage
like previous Trent engines.
The latest and most powerful model,
the Trent XWP-97, which powers the
Airbus A350, recently received formal
flight certification from the European
Aviation Safety Agency (EASA) and
will enter service in late 2017. (This
certification came within a week of EASA
certification of the Trent 1000 TEN engine,
which will power all variants of the 787,
also to enter service later this year.)
The Trent XWP-97 produces up
to 97,000 lb at takeoff. Rolls-Royce
achieved the increase in thrust through
a combination of new high-temperature
turbine technology, a larger engine core,
and advanced fan aerodynamics.
With over 1600 Trent XWP engines
ordered by 40 customers worldwide, RollsRoyce is currently experiencing a
manufacturing backlog of more than 1500
engines (or over 6 years of production)
from its U.K. and Germany facilities.
But the backlog of Trent XWP orders
isn't hampering momentum, as the
company aims to corner military sales
as well. Rolls-Royce additionally laid out
an offering of the BR725 powerplant,
designated F130 for military purposes, to
the U.S. Air Force B-52 Stratofortress fleet.
Rolls-Royce expects an imminent
announcement from the USAF for a
new request for information for a "reengining" of the B-52's Pratt & Whitney

MOMENTUM

The Rolls-Royce Trent XWB-97 engine, pictured here on in production in
Derby, U.K., is the latest and most powerful variant of the Trent XWB.
The Trent XWB-97's increased level of thrust relative to the Trent XWB84 is achieved through a combination of new high-temperature turbine
technology, a larger engine core and advanced fan aerodynamics.
(Photo credit: Rolls-Royce)

Rolls-Royce recently secured an incremental order from United Airlines to
provide additional Trent XWB engines and service support to United Airlines
after the airline increased its order of Airbus A350-900 aircraft, pictured here.
(Photo credit: Airbus)

TF33-P3 engines. From as early as 1982,
the USAF has considered re-engining
B-52s to improve range, fuel burn, and
reduce the smokiness of the original
powerplants, although the company
acknowledged that there is-as of yet-
no stated program for such a project.
The F130 would incorporate lessons
learned from the 700 series of RollsRoyce engines as well as the Trent-series
commercial powerplant. F130-series
engines are already in USAF service
aboard the Northrop Grumman RQ-4
Global Hawk, the Bombardier E-11A
BACN, and has been chosen to power

the new Compass Call aircraft, the
Gulfstream G650. Rolls-Royce estimates
it would take approximately 650 engines
in total to equip a fleet of 72-75 B-52s,
accounting for one F130 engine replacing
every two TF33-P3 engines.
Although the Rolls-Royce would plan
to integrate as an "integrator" as well
as engine provider, the change from an
eight-engine layout to four could create
airframe issues the USAF may not want to
manage, such as ground clearance from a
single, larger fan, weapon recertification,
and maintenance issues.
By William Kucinski, SAE International

November 2017 15

http://profiles.sae.org/william_kucinski/

Momentum - November 2017

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