around 100 engines and cost Pratt some $50
million. Te seal was introduced into new
production engines in mid-2017 to eliminate an
inspection requirement, but problems began to
emerge within weeks of entry-into-service on new
A320neos. Fractures caused rotor vibration and
stalling in four engines, two of which resulted in
inflight shutdowns and two in rejected takeoffs.
Te incidents led Pratt and Airbus to issue
urgent recommendations to affected A320neo
operators to make sure aircraft had no more than
one affected engine installed and banning ETOPS
flights. By the time the problem became apparent,
43 engines had entered service on 32 aircraft.
Pratt and Rolls each identified the problems,
found the fixes and have worked round the clock
with their customers to get aircraft back in the air.
What seems to be happening is the engine
manufacturers are being caught by problems
in service that were not seen in development;
even though they have all significantly increased
the amount of development testing they do to
ensure maturity at entry into service. Te Trent
corrosion issue is one that had not been seen
before, presumably because the materials used are
different, so it was not anticipated.
Te cracking issue also seems to show how
even small changes in design can cause problems.
In the GTF case, Pratt changed the knife seal—a
seemingly miniscule component—and suddenly
started seeing problems.
It also seems that these new engines are so
pushing the boundaries of technology, that the
unforeseen becomes more probable. To be fair
to the manufacturers, the airlines—and, indeed,
the regulatory and national authorities—insist on
higher and higher emissions standards coupled
with better and better fuel efficiencies. So the
engine manufacturers respond with technology.
Tey say they will increase development testing
even more for their next engines to ensure service
entry mature, but it will be hard to guarantee
there will be no new problems.
After all, if polluted city air was not foreseen as
a corrosion factor by engineers who specialize in
designing eco-friendly aero-engines, what else is
out there to surprise the industry?
—Guy Norris and Graham Warwick
contributed to this article.
“In the old days, with oil prices
climbing this far this fast,
we’d be talking about who’s going
to survive, and today we’re just
talking about the fact that
our earnings are low.”
American Airlines chairman and CEO Doug Parker.
“We need to find a way to get rid
of a lot of the legacy process in
airports. Sadly, we have a series
of vertical silos, across which
passengers have to pass horizontally.
We want the experience to be
less like a shopping trolley
bumping across railway tracks.”
Dubai Airports CEO Paul Griffiths.
“If a TSA agent was wrong a third
of the time, they’d be considered
ineffective. Why would we want to
implement technology that can be
inaccurate for a large segment of
Sen. Tom Udall (D-New Mexico), on the use of
facial recognition technology at US airports.
“The only thing skimpier than
airplane legroom are these
travel insurance plans.”
Sen. Ed Markey (D-Massachusetts), announcing the
findings of his office’s investigation into travel insurance plans
sold in the US.
“Legacy is such a bad word,
we don’t see ourselves that way.
We see ourselves as a category
of one.” ”
Southwest Airlines president and CEO Gary Kelly.