Rolls-Royce Pushing Ahead With Trent 1000 Ten For Boeing 787
Rolls-Royce says that by August it expects to have demonstrated a new high-pressure turbine (HPT) destined for its Trent 1000-Ten engine, which is being offered to power the prospective Boeing 787-10. Assembly of the first full development engine is scheduled before year-end.
The plan is the latest move in the continuing improvement of the Trent 1000 (T1000) powerplant that started life as the 70,000-pounds-thrust T1000A, which was certificated simultaneously in Europe and the U.S. in August 2007. Approval covered seven planned variants (Trent 1000A, -C, -D, -E, -G, -H and -Z) offering takeoff thrust levels of up to almost 78,000 pounds. Last year, the manufacturer introduced the upgraded 70,000-pound-thrust T1000 Package B model, which is scheduled to be followed in 2014 by the further-improved 74,000-pound-thrust Pack C engine.
Almost 12 months ago, RR unveiled the latest T1000-Ten variant offering 76,000 pounds thrust and availability in 2016. According to program executive Pat Robertshaw, the –Ten–so dubbed to represent claimed characteristics of “Thrust, Efficiency, New technology”–could have been launched without a related 787-10 airframe development. The -Ten is expected to offer a three-percent saving in “lifetime” fuel burn “equivalency” compared with Pack B Trent 1000s.
To meet Boeing requirements for a “more electric” engine, the Trent 1000 does not use bleed air; rather, power is taken from the intermediate-pressure (IP) spool instead of the HP spool (as on other Trent family members). The IP power takeoff drives the 787’s electrical power system, with RR claiming improved engine handling and operability.
The T1000, which powered the 787’s first flight and its first commercial service, was the first engine to be certified on the airframe and the first to be approved for 330-minute extended-range twin-engine operations (ETOPS). More than 700 engines are covered by orders received from (or options let to) some 23 customers.
Characteristics of the Trent 1000 variant include “advanced pro-active engine-health systems” to monitor flight performance and a 10:1 bypass ratio, plus a low hub-to-tip [speed] ratio. The T1000-Ten is designed for all 787 variants, R-R having a memorandum of understanding with Boeing to offer the engine for the prospective 787-10X development.
It will sport advanced HPT cooling and a new, more-efficient and higher-flow intermediate-pressure compressor (IPC) that will save weight on the 787-8. A “modulated” HP air system is designed to reduce fuel burn while improving performance retention to suit different take-off situations, according to R-R.
A new HP compressor (HPC) design has been demonstrated on the Airbus A350’s Trent XWB powerplant and in the European Union-integrated New Aero-engine Core-concepts (NEWAC) project, which includes advanced combustor technology, “active” systems and heat management. In the first three stages of the HPC, the -Ten uses bladed discs (blisks) previously employed on the Trent XWB.
The variant is expected to enter service on the 787-8 and -9 from 2016 and on the planned -10X two years later. Current development already under way includes demonstration of advanced seals, fan-case dressings and disc architecture–the latter being scheduled to run this year.
A 500-cycle demonstration is scheduled during the coming three months and R-R plans to fly the -Ten on the FTB in early 2015. The certification target is the third quarter of that year, with four or five months of Boeing flight testing to follow soon after. Service entry is expected by mid-2016, following first-quarter aircraft certification.
Last month R-R expected the T1000 Pack C to be certified within “the next month or two”–perhaps in time for this week’s show. The upgrade is aimed at offering “76,000 [pound-thrust] ratings with margin” to meet 787-9 power requirements and provide increased performance for the 787-10X. The T1000 “won seven out of the past ten European sales campaigns,” according to Robertshaw.
The manufacturer describes its Pack C development–scheduled to enter service on 787-8 and -9s from next year–as “very challenging.” In May, 787-7, -8 and -9 Pack C flight-test engines were in “the last stage of build” ahead of expected delivery before the end of June. A 150-hour type test has been completed successfully, with the designated “cyclic” development engine having completed 200 1,000-cycle tests; air-systems and operability certification testing also is complete.
The third flight-testbed Pack C engine (FTB3) was expected to begin an 18-flight sequence during May, by which time test engines FTB1 and FTB2 had completed eight and nine flights, respectively.
R-R is continuing to develop T1000 maturity with a “robust program of continuous improvement” that will see the Pack B 787-8 fleet leader engine undergo 24,000 cycles. A 3,000-cycle test has been completed, with a further 2,000-cycle trial under way last month.
Up to the 787 fleet’s grounding earlier this year, the Trent 1000 had recorded 50,000 flying hours during 28,000 flights, the lead engine having accumulated 3,800 hours and 1,100 flight cycles. RR claims an engine despatch reliability rate of better than 99.9 percent, with no in-flight shutdowns, but did not state whether there had been instances of engine thrust being “reduced to ‘flight idle.’”