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Rolls-Royce Trent XWB-84 – Five Years of Unequalled On-Wing Reliability By Howard Wheeldon, FRAeS, Wheeldon Strategic Advisory Ltd.





Already widely regarded as the most efficient in-service large civil aero-engine in the world and one that not only experienced the smoothest entry into service of any widebody engine developed by the company but also one that has subsequently achieved unequalled on-wing reliability and efficiency of operation for the airline user, the Rolls-Royce Trent XWB-84 engine has now reached a five year in-service mark on the Airbus A350 family of aircraft for which it was specifically designed.

With over 1,600 Trent XWB-84 engines on order or already delivered to airlines across the world, around 930 A350 aircraft of varying types so far ordered (Airbus had delivered 370 A350’s by the end of July) this hugely successful aircraft and the Trent XWB-84 engine that powers it has not only provided users with very beneficial cost and efficiency benefits but importantly, has provided them with the versatility of operation combined with the on-wing reliability that they require to support ever changing operational needs.

Drawing on the unique three-shaft design, advanced materials and the latest fan system technology, Trent XWB-84 balances fuel efficiency and reduced life cycle costs while delivering weight savings and improved aerodynamics. With a 15 per cent fuel consumption advantage over the earliest members of the Trent family, suffice to say that the XWB-84 travels a lot further using far less fuel than its predecessor engines whilst at the same time, has provided airline customers with world beating performance and reliability combined with environmental benefits that include reduced noise levels.

With the first Trent XWB-84 engines, those that have been in service for the best part of five years and that have travelled on average, 14 million kilometres – that’s around nine times around the world – approaching their first scheduled off-wing shop visit, suffice to say that during the first five years of Trent XWB-84 on-wing operation there have as far as I am aware been no unplanned maintenance issues requiring attention and that the engine has enjoyed a record low level of in-flight disruption.

To that end, the only two incidents involving the XWB-84 engine that I can find relate to two separate occasions when, as a precaution, the decision was taken to shut down one engine due to drinks having been spilt in the cockpit area.

In a XWB-84 update statement linked to five-year first scheduled off-wing Trent XWB-84 maintenance requirement Rolls-Royce said today that following routine inspections and as part of the scheduled shop visit process engineers had identified some indications of wear in the Intermediate Pressure Compressor (IPC) on a small number of engines that have been in service for four to five years and that are now approaching or within the first overhaul process.

In a press statement the company states that none of the engines identified have experienced any abnormal in-flight operation but that, as a precaution, the company is now inspecting all Trent XWB-84 engines of a similar service life.

There are currently just over 100 Trent XWB-84s that have been in service for in-between four and five years and having already inspected the majority of these Rolls-Royce confirmed today that signs of wear have been found on an average of only 1 or 2 IPC blades. As an additional precaution, the company has sampled a number of younger Trent XWB-84 engines and have found no unexpected wear. In addition the company said that, given the limited scale of additional work that they anticipate being required at existing planned shop visits, and that in order to address any wear found together with the ease of availability of replacement parts and spare engines, they do not expect the issue to create significant customer disruption or material financial cost.

The detailed manner in which Rolls-Royce has reacted to what is a small yet important issue in regard of the Trent XWB-84 through-life maintenance is yet another excellent example of transparency just as it also to be considered as a clear demonstration of how the company has changed in recent years.

Reacting quickly to what is a very manageable issue and one that the company does not anticipate any material financial impact or airline customer disruption, today’s confirmation of actions will I hope address any potential speculation that might result from an Airworthiness Directive which one would anticipate now being issued by the European Union Aviation Safety Agency (EASA) regulator.

On the matter of Airworthiness Directives (AD’s) it is important to realise that these are a commonplace feature and correct instrument used by aviation regulators in order to ensure compliance with necessary inspection and maintenance procedures. Rolls-Royce is one step ahead and is to be commended for acting correctly and with speed in both identifying and remedying the issue in full accordance with any likely AD.         

Trent XWB is an exceptionally great piece of UK designed and built aerospace technology and one that is streets ahead of its peers. For the record, Trent XWB-84 power plant delivers a unique lightweight three-shaft design provides a tailored solution optimised for the A350 XWB. Proven design with over 70 million hours of Trent experience incorporated at entry into service and offering module weight savings of 15 per cent and aerodynamic efficiency improvements via the use of compressor blisk technology (a turbomachine component comprising both rotor disk and blades) and optimised internal air system which reduces core air demand and reduces fuel consumption.

Trent XWB-84 power plants have a combustor with proven reliability that is also cleaner than all current and future emissions targets whilst also achieving world-beating levels of performance and noise combined with reduced operational cost thanks to the latest fan system technologies. This is the highest efficiency turbine system of any Trent family engine and is, so far, the most intense/comprehensive development programme ever to have been undertaken by Rolls-Royce – one that I would add has 6 times the level of computing power applied than in previous generation engines.

CHW (London – 11th August 2020)

Howard Wheeldon FRAeS 

Wheeldon Strategic Advisory Ltd,

M: +44 7710 779785

Skype: chwheeldon



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