FLIGHT

���
test before,” says Young. The move inside
was necessitated by the UK company’s decision
to decommission its outdoor test facilities
at Hucknall in Nottinghamshire, UK,
which had been encroached by housing estates
in recent years.
“It means that we can do everything that we
want to 24 hours a day and be more effective
in our operations rather than just do it a few
hours a day when we’re not annoying the
neighbours too much,” says Young.
ABSOLUTE MAXIM
In the event all went well as the blade was released
at the root and the engine ran down,
and was then shut down, in the presence of
representatives from Airbus and EASA.
The blade was released at the “absolute
maximum, red-line N1 speed, and then we
actually add a little bit of margin to make sure
that we’re comfortable that we have some
growth capability on the engine if we ever
need it in the future”, says Young. “It’s a very
arduous test that really proves the robustness
and overall capability of the engine. We effectively
do it at a higher speed than would ever
occur in a service environment. The good
news is it went very well and delivered all of
the evidence that we needed for certification,”
he adds.
The blade-off test involved the baseline
84,000lb-thrust Trent XWB-84 for the
A350-900. The more powerful, 97,000lb-rated
XWB-97 in development for the stretched
A350-1000 (see box P25) will require another
test as it features stronger, heavier fan blades
which rotate at a higher speed.
“At the minimum, we’ll do a full-fan rig
test,” says Young.
Among the final certification tests performed
for the XWB-84 was a second 150h
endurance test to clear modifications designed
to provide higher turbine temperature
margins to extend service life.
Its blade-off test was an indoor first
flightglobal.com
Rolls-Royce
“Assembly hours are coming
down nicely, as we learn how
to build the engine”
CHRIS YOUNG
Trent XWB programme director
“The low-pressure turbine rotor dynamics
was one last test that we had to do, again successfully
completed,” says Young.
The first engine (SN21002) for the A350
flight-test campaign has been delivered to the
assembly line in Toulouse for podding, following
pass-off testing and the installation of
flight-test instrumentation in Derby.
The second engine (SN21003) has also
completed pass-off testing and was due to be
shipped to Toulouse imminently. Follow-on
engines will arrive in Toulouse “at a reasonably
fast rate”, says Young. Engine four entered
pass-off testing in January.
“We’re starting to see a drumbeat of flightcompliant
engines coming very quickly
through the process and fully supporting the
needs of the Airbus programme,” says Young.
“We’re really starting to get our industrial system
proven out very well. The supply chain is
operating well, the assembly processes, and
the new production facility that we’ve put in
place is proving that it’s building the engines
to the right quality and repeatable.
“The engines we are passing off are flight
compliant and even better on performance, as
we expected them to be,” he adds.
A total of 11 Trent XWBs have participated
in the test programme to date, accumulating
more than 3,100h in ground tests and aboard
the A380 testbed.
Still under way are some final tests needed
to secure FAA cross-certification, and then the
focus will shift to securing early extended-
TRENT XWB
Airbus and Rolls-Royce are going all out for first A350 flight before June’s Paris air show
range twin-engined operations approval. The
target is to eventually certificate the A350 to fly
up to 350min from the nearest suitable diversion
airfield at single-engined flying speed.
The cold start capability of the Trent XWB
has been extended down to -26˚C after winter
demonstrations using the company’s testbed
in Manitoba, northern Canada, and this is expected
to be further lowered to -40˚C.
“We are now able to do far more full envelope
testing, which is great for the reliability
and maturity of the product,” says Young.
Between 16 and 18 engines will have been
assembled in the pre-production facility at
Derby prior to the start of series production, in
an effort to understand the optimum way of
assembling the engine and to determine appropriate
work-station content.
“Assembly hours are coming down nicely,
as we learn how to build the engine,” says
Young. Fully-fledged flow-line assembly
should begin by mid-2014, in time for the
planned ramp-up in A350 production.
“We’re very close to finalising our footprint
and layout for the full flow-line facility,”
says Young.
A couple of spare engines are being shipped
to Toulouse to support the A350 flight-test
programme in case an installed engine is damaged,
for example by foreign object ingestion.
Rolls-Royce engineers will fly on many A350
test flights to monitor engine performance.
“The engines are ready and capable to go to
their limits from day one, should Airbus
choose to do so,” says Young. “The programme
– which we’re fully supporting with
our initial flight-compliant engines – has a
very clear aim to make sure that first flight is
prior to the Paris air show.” �
For video of the Trent XWB making its maiden
flight, fitted to an Airbus A380 testbed, visit
flightglobal.com/videotrentxwb
19-25 February 2013 | Flight International | 27
Airbus