Apols, don’t know the true source, but it will be a reliable one (It was sent to me by a Pilot)

The US’s National Transportation Safety Board is probing an
“uncommanded rollback” on a Rolls-Royce Trent 895 engine which
affected a Delta Air Lines Boeing 777-200ER on 26 November, Flight
International reports.

NTSB explains that Delta Flight 18, from Shanghai to Atlanta,
experienced loss of thrust on the right-hand engine at 39,000ft. Its
initial report elaborates: “Initial data indicates that following the
rollback, the crew descended to FL310 (approximately 31,000ft) and
executed applicable flight manual procedures. The engine recovered and
responded normally thereafter. The flight continued to Atlanta where
it landed without further incident.”

Senior investigator Bill English – due to meet Boeing regarding the
incident – is apparently “looking into” the possibility there might be
similarities to the Heathrow 777 incident which saw BA038 (G-YMMM)
suffer reduced thrust in both Rolls-Royce RB211 Trent 895-17 engines
while coming into land and fall short of the runway.

An Air Accidents Investigation Branch (AAIB) report into BA038
concluded “that the fuel flow to both engines was restricted; most
probably due to ice within the fuel feed system”. It added: “The ice
is likely to have formed from water that occurred naturally in the
fuel whilst the aircraft operated for a long period, with low fuel
flows, in an unusually cold environment.”

Flight International notes that in light of the AAIB findings, the
Federal Aviation Administration back in September “issued an
airworthiness directive calling on operators of 777-200 and -300
aircraft equipped with Trent engines to revise flight manuals to
include in-flight procedures for pilots to follow during certain
cold-weather conditions and for operations on the ground”.

English and fellow investigators are now examining the Delta
aircraft’s flight data recorder “and other applicable data and
components”. ®