FLIGHT

entry into service,” says Trent XWB programme
director Chris Young. “So we’re prepared
to carry on investing in the product between
us,” he adds.
The extra flying using the A380 – which
first got airborne with the Trent XWB installed
in February 2012 – facilitated additional systems
tests and provided an opportunity to
take the powerplant through its paces under
extremely cold conditions.
The cold weather flying tests were performed
in Iqaluit in Nunavut, Canada, where
temperatures were -23˚C (-9˚F).
“This is all about proving the long-term
service maturity of the engine and just carrying
on getting experience in representative
environments,” says Young.
The engine installed on the A380 is the
same one used for the most recent phase of
certification testing, and is “very close” to the
final configuration that will power the A350
on its first flight later this year.
flightglobal.com
“There are a few minor changes as always
around things like pipe routings and some of
the last minute external changes that we’ve
found but overall it’s very representative of
the bill of material, which is why it makes
sense to carry on flying and getting the evidence
and data from it,” says Young.
“It’s millions of dollars to do
[the blade-off test] and we
like to be confident”
CHRIS YOUNG
Trent XWB programme director, Rolls-Royce
Certification of the Trent XWB was awarded
by the European Aviation Safety Agency on 7
February following successful completion of
the critical full engine blade-off test, conducted
using 58 Bed at Rolls-Royce’s factory in Derby,
UK. This was preceded by a blade-off test using
TRENT XWB
DEVELOPMENT
GROWTH TRENT XWB FOR A350-1000 TAKES SHAPE
WHILE THE baseline A350-900
is powered by the 84,000lb
(374kN)-thrust Trent XWB-84,
the -800 shrink will be
equipped with the de-rated
XWB-75, or XWB-79 for hot-andhigh
operations.
The stretched A350-1000,
however, requires the
97,000lb Trent XWB-97
growth variant to preserve the
type’s transpacific range capability
for customers such as
Cathay Pacific.
The XWB-97 will retain the
same fan diameter, mounting
points and nacelle aerolines as
its less powerful siblings, and
derive much of its extra thrust
via increased fan flow. A larger
core will be required to power
the fan, and this will feature
turbine blade tip clearance control,
upgraded materials and
advanced cooling technology.
The result, Rolls-Royce hopes,
is the extra thrust capability
can be delivered with no impact
on specific fuel consumption or
on-wing life.
With development work for
the baseline XWB-84 essentially
complete, Rolls-Royce is
ramping up activity on the
XWB-97, which has entered
the component-level design
phase ahead of the start of
assembly of the first test engines.
The preliminary design
review milestone was passed
in early January.
“Now it’s all-systems-go, to
do the very detailed individual
component design and manufacture
and to start pouring the
castings and cutting the metal
as we go through this year in
order to get the first parts in
store for the first prototype engine
and go towards that first
engine run around the middle of
next year,” says Trent XWB programme
director Chris Young.
TESTBED TALKS
The first A350-1000 is scheduled
to fly in mid-2016, a year
ahead of entry into service.
“Both ourselves and Airbus
think that for the overall maturity
of the product, doing a flying
testbed [for the XWB-97] is
a beneficial thing to do,” says
Young. “We are in discussion
with Airbus about exactly what
the approach is that we take
for the 97k engine.”
Flight tests of the XWB-97
engine should “most likely”
start in the second half of
2015, he says. The first engine
run is scheduled for mid-2014.
Options include redeploying
the A380 as the testbed, or
fitting a Trent XWB-97 to an
A350-900 test aircraft. Using a
twin-engined A350, however,
would involve more stringent
regulatory requirements and
the engine would have to be
“more mature” before flying
could begin, says Young. A decision
between the A380 and
A350 is expected “towards the
middle of this year”.
Some key advances being
introduced in the XWB-97 are in
the turbine and combustion sections,
and include shroudless
turbine blades, tip-clearance
systems and advanced materials
and coatings. Rolls-Royce
claims to have achieved 80%
commonality with the baseline
XWB-97 engine in terms of linereplaceable
units.
The third build standard for
Rolls-Royce’s Environmentally
Friendly Engine programme is
being installed on the testbed
in Bristol, UK and will demonstrate
technologies aimed at
extending turbine life. There will
also be a cyclic endurance test.
“Apart from just proving it in
a representative environment
as we did with builds one and
two, it’s now about starting to
prove the full-life capability as
an advanced de-risk of the 97k
engine,” says Young. �
only a fan module at the company’s Dahlewitz
site in eastern Germany on 2 November, which
provided the “data and confidence” to move to
the full engine test in the UK on 29 November.
“It’s lots of millions of dollars to do [the full
engine test], and we like to make sure that
we’re completely confident in the successful
outcome of that test before we go into it,” says
Young, adding that the fan module test is conducted
to identify any “last-minute design
tweaks” that may be required.
Conducting the full engine blade-off test inside
58 Bed threw up a host of technical challenges,
as the Trent XWB has the biggest fan
built by Rolls-Royce, as well as the biggest individual
blades. The high energy levels involved
meant the company’s engineers had to
be sure 58 Bed – the newest and most modern
test facility on the Derby campus – was structurally
capable of hosting the demonstration.
“That was the first time we’ve done a big
fan indoors – it had always been an outdoor
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19-25 February 2013 | Flight International | 25