Rolls-Royce Trent 900

Trent 900
Type	Turbofan
National origin	United Kingdom
Manufacturer	Rolls-Royce plc
First run	May 2004 (first flight)
Major applications	Airbus A380
Unit cost	US$ 46 million incl. support[1]
Developed from	Rolls-Royce RB211

The Rolls-Royce Trent 900 is a British series of turbofan engines, developed from the RB211 and is one of the family of Trent engines. It is one of the powerplant options available for the Airbus A380, along with the Engine Alliance GP7000.

Design and development

A Trent 900 on test at the Arnold Engineering Development Complex

In the early 1990s, Airbus had begun development of a larger competitor to the Boeing 747, an aircraft designated A3XX, which was later to be formally launched as the A380. By 1996, its definition had progressed to the extent that Rolls-Royce was able to announce that it would develop the Trent 900 to power the A380. In October 2000, the Trent 900 became the A380's launch engine when Singapore Airlines specified the engine for its order for 10 A380s; this was quickly followed by Qantas in February 2001.

Rolls-Royce has seven risk and revenue sharing partners on the Trent 900: Industria de Turbo Propulsores (low pressure turbine), Hamilton Sundstrand (electronic engine controls), Avio S.p.A. (gearbox module), Marubeni Corporation (engine components), Volvo Aero (intermediate compressor case), Goodrich Corporation (fan casings and sensors) and Honeywell (pneumatic systems). In addition, Samsung Techwin, Kawasaki Heavy Industries and Ishikawajima-Harima Heavy Industries (IHI) are programme associates.

The Trent 900 made its maiden flight on 17 May 2004 on Airbus' A340-300 testbed, replacing the port inner CFM56-5 engine, and its final certification was granted by EASA on 29 October 2004 and the FAA on 4 December 2006.^[2] Rolls-Royce announced in October 2007 that production of the Trent 900 had been restarted after a twelve-month suspension caused by delays to the A380.^[3]

On 27 September 2007, British Airways announced the selection of the Trent 900 to power 12 A380 aircraft,^[4] helping to take the engine's share of the A380 engine market to 52% at the end of February 2009.

The Trent 900 family powers the Airbus A380. It comes in two thrust ratings for the A380, 310 kN (70,000 lb_f) and 320 kN (72,000 lb_f) but is capable of achieving 360 kN (81,000 lb_f).^[5] It features a significant amount of technology inherited from the 8104 demonstrator including its 2.95 m (116 in) diameter swept-back fan which provides greater thrust for the same engine size, and is also about 15 percent lighter than previous wide-chord blades. It is also the first member of the Trent family to feature a contra-rotating HP spool and uses the core of the very reliable Trent 500. It is the only A380 engine that can be transported on a Boeing 747 freighter whole.^[6]

Whereas most members of the Trent family are controlled by Goodrich FADECs, engine controllers on the Trent 900 are provided by Hamilton Sundstrand, a United Technologies (UTC) company. UTC is also the parent company of Pratt & Whitney, who, with GE Aircraft Engines, is partnering to produce the Engine Alliance GP7000, the other engine available for the A380. This kind of cooperation among competitors is prevalent in the aircraft market as it provides for risk sharing among them and diversity in source countries, which may be a significant factor in an airline's choice of airframe and powerplant.

The Trent 900 will be the first Trent engine fitted with the advanced Engine Health Monitoring (EHM) system based on QUICK Technology.

Variants

Rolls-Royce Trent 970B- 84 mounted on a British Airways Airbus A380

• Trent 970B- 84 with 348.31 kN (78,300 lb_f) of thrust. In use by A380-841 of Singapore Airlines, Lufthansa, British Airways, Thai Airways International, Asiana Airlines, China Southern Airlines and Malaysia Airlines.
• Trent 972B- 84 with 356.81 kN (80,210 lb_f) of thrust. Higher thrust variant of the 970, in use by A380-842 of Qantas and also chosen by Emirates for 52 of the 142 A380s they have ordered.
• Trent 977B- 84 with 372.92 kN (83,840 lb_f) of thrust. Variant for A380-843F.
• Trent 980- 84 with 374.09 kN (84,100 lb_f) of thrust. Higher thrust variant for A380-941.

^[7]

Upgrades

The Trent 900 family of engines had their first set of upgrades marketed as the Trent 900EP; these were available for delivery from 2012. This package delivered a 1% saving on fuel burn compared to non EP engines. While one source states that this package is not available as a retro fit to previously delivered engines, Rolls Royce told Aviation Week and Space Technology that the upgrades were intended in most cases for both new engines and as retrofits.^[8] This upgrade is based on advancements made during the development of the Trent XWB (for the Airbus A350 XWB) and matches improvements made for the Trent 700 called the Trent 700EP.^[9] Block 1 includes elliptical leading edges in the compressor, smaller low-pressure turbine tip clearances, and new coating for the high pressure compressor drum, as well as an upgrade to the engine control (FADEC) software.

The EP2 package entered testing in May 2013 and is scheduled to be available for delivery in mid 2014. This package aims to provide a further 0.8% reduction in fuel burn on top of the improvements offered by the EP package.^[10] Changes include better sealing of the low pressure turbine, improvements to fan blade tip clearances, and other changes derived from the engines developed for the Boeing 787 and Airbus A350.^[8] EP2 passed a type certificate test by European Aviation Safety Agency on 27 November 2013^[11] and an update type certificate was issued on 11 December 2013.^[12]

Applications

• Airbus A380

Notable incidents

On 4 November 2010, a Trent 972 powered Airbus A380-842 (Registration VH-OQA) of Qantas Flight QF32 suffered an uncontained engine failure (explosion) in engine number 2 en route from Singapore to Sydney and returned to Singapore Changi Airport where it landed safely. Qantas grounded its fleet of six A380s for over three weeks after the accident pending the investigation and said it may replace up to 16 engines after identifying potential problems.^[13] VH-OQA was repaired at an estimated cost of A$139 million. The aircraft has four new engines, a repaired left wing, and had extensive onground testing and two test flights. It returned to service on 28 April 2012.^[14]

On 10 November 2010, the European Aviation Safety Agency issued an Emergency Airworthiness Directive, ordering airlines using the Trent 900 engine to conduct frequent and stringent tests, including extended ground idle runs, Low Pressure Turbine (LPT) stage 1 blade and case drain inspections and HP/IP structure air buffer cavity and oil service tube inspections.^[15] However, on 22 November 2010, the EASA eased its inspection guidelines, citing progress in the investigation. It dropped requirements for extended ground idle runs and requirements for repetitive inspections of the LPT stage 1 blades and case drain.^[16]

An investigation by Rolls-Royce concluded that the accident was caused by an oil fire and was confined to a specific component in the turbine area of the engine. The fire led to the release of the Intermediate Pressure Turbine (IPT) disc. It also said the issue is specific to the Trent 900.^[17]

Airbus determined that the IPT disk released 3 different high energy fragments, resulting in some structural and systems damage. It also concluded that segregated wiring routes were cut by 2 out of the 3 individual disk debris and as a result, engine 1 could not be shut down after landing.^[18]

On 18 November, Airbus announced it may seek compensation from Rolls-Royce for any disruption caused by the Qantas incident and the plans to reassign engines.^[19]

In a preliminary investigation report of the engine failure of Qantas Flight QF32, released 3 December 2010, the Australian Transport Safety Bureau outlined safety actions taken already, including the issuing of a safety recommendation about potential engine problems with the Trent 900.^[20] The safety recommendation relates to a possible manufacturing issue with a misaligned counterbore in some pressured oil pipes, which could lead to fatigue cracking, oil leakage, oil fire, and engine failure.^[21]

Qantas claimed on 16 December 2010 that thrust restrictions recommended by Rolls-Royce following the engine failure would have led to severely reduced payloads, making routes unprofitable.^[22]

Specifications (Trent 900)

General characteristics

• Type: Three-shaft high bypass ratio (8.7–8.5) turbofan engine
• Length: 5,478 mm (215.7 in) tip of spinner minus rubber tip to Tail Bearing Housing Plug Mount Flange
• Diameter: 2,950 mm (116 in) fan
• Dry weight: 6,246 kg (13,770 lb)

Components

• Compressor: single stage LP (fan), 8-stage IP compressor (IPC), 6-stage HP compressor (HPC)
• Combustors: Single annular combustor
• Turbine: single stage HP turbine (HPT), single stage IP turbine (IPT), 5-stage LP turbine (LPT)

Performance

• Maximum thrust: 344–357 kN or 77,000–80,000 lbf^[23]
• Overall pressure ratio: 37–39
• Thrust-to-weight ratio: 5.46–6.11 (assuming 6,246 kg (13,770 lb) mass / weight of engine and certified to 334–374 kN or 75,000–84,000 lbf of thrust)

Source: EASA Type Certificate

Cost

In 2000 Qantas were quoted a price of US$12.85 million per Trent 900.^[24] In 2012 Skymark Airlines signed a contract for 24 Trent 900s including long-term service support at a cost of US$1 billion (approx. US$46.7 million per engine).

See also

Comparable engines

• Engine Alliance GP7000

Related lists

• List of aircraft engines

References

External links

Wikimedia Commons has media related to Rolls-Royce Trent 900.

• Rolls-Royce plc – Trent 900
• FAA Trent 970 type certificate data sheet