1. Reflections on 50 years in R&D
Professor Phil Ruffles
March 8th 2011
I have spent my whole career in R&D including over 40 years with Rolls-Royce
During this time I was faced with many challenges and will talk about some of these today.
I will draw out some important lessons from this experience

2. RB211 and Trent Family Variants -9 Engines sold and on Order
RB ,Trent sold,2600 on order
Aircraft
RB211-L1011,B747,B757,
B 767 Tu 204
Trent - A 330 A340 A350
A 380 B777 B787
71 Trent Operators
Revenue 40bn to date,35bn New engines on order. Aftermarket is additional
Through most of my career I was involved with the RB211 and Trent programmes. The early days were very difficult and led the Company into Receivership in 1971 when the programme was almost cancelled. However the engine has now been under continual development of over 40 years and is the engine of choice by many of the worlds airlines.

3. The Launch – 29 March 1968
The launch of the RB211 was both a great challenge and a great achievement. Sir Denning Pearson (Chairman) and Sir David Huddie (Managing Director) were its champions..
They knew the stakes were high as the alternative was to sink into oblivion. They both resigned just prior the Company going into receivership and received much criticism
However events have proved that they were right in their judgement to proceed although Sir David said in later life. We simply took on more than we could cope with.

4. RB211 Advantages of three shafts
Picture and Chart which summarises the benefits of 3 shaft engines
The engine had three shafts which gave it a significant advantage over its competitors.
This benefit has become more pronounced in recent years with the Trent family which have a higher by-pass ratio and overall pressure ratio.

5. RB211-06 Designed for market leadership through technology
33,260 lb thrust in 1966
-06 was unable to meet increasing demand for thrust during aircraft development
Subsequently redesigned for 40,600lb from April to October in 1968 to become -22C
Uprated to 42,000lb (-22B) to compensate for weight growth
Notable advances were the Hyfil fan, composites replacing metal in the IP compressor static members and the overall increase in temperatures and pressures.

6. RB211-Scale of advance Performance advance Thrust +95% Cruise sfc -21%
Noise -19PNdB
Turbine entry temp. +150ºC
Pressure ratio 17 > 25
Airflow x 3.7
RB (1972)
Conway RCo43 (1965)
45in. dia.
Weight 8861lb
Weight 4855lb
85.5in. dia.
It is difficult for people today to comprehend the size of the task that was undertaken. The engine was twice the diameter and thrust of the Conway but was 5ins shorter in length. It had a bypass ratio of 5 and turbine entry temperature some 150C higher. The final weight (bare engine) was double that of the Conway but the original weight was 6900lb and sfc was 21% less. The Conway and Spey pretty well represented our best technology and so we had to develop new technology on the programme.
In order to meet the weight and performance targets many technology advances had been included including extensive use of composites, an annular combustor and highly loaded compressor stages. Little of this technology had been adequately validated.
The risks in the shafting system were understood but I don’t think we expected as much trouble for the intershaft bearing as actually occurred.

7. RB The Hyfil fan
The Hyfil fan offered a 300 lb weight and two per cent fuel consumption benefit
High risk of Hyfil was recognised so a Titanium alloy alternative was designed in parallel
as early as 1969 Hyfil blades were experiencing integrity problems
replacement with Titanium blades allowed continued testing
The Hyfil blade was replaced by the Titanium blade in Spring 1970
All of the other composites at the front of the engine also had to be removed thereby increasing the engine weight.

8. RB211-The review of early milestones
Mid 1967
Mar 1968
Aug 1968
Jan 1970
Mar 1970
Nov 1970
Feb 1972
Apr 1972
Feb 1973
RB detailed design commenced at 33260lbs thrust
RB order received at 40600lbs thrust
First run of -06 engine
First run of -22 engine
First flight of RB211 in VC10
First flight of L1011
Type approval obtained for 42000lbs at ISA+3,
40600lbs at ISA+15
L1011 obtains type approval – airline service starts
Type approval obtained for lbf at ISA+15 (-22B)
34 development engines were built, compared with today’s usual six or seven
36 flight engines were sent to Lockheed, compared with today’s usual seven or eight
The programme was a fast programme when compared with both previous and subsequent programmes. It depended on their being no major setbacks.
The first RB started design in mid 1967 and the engine ran at the end of August 1968 following a week of abortive attempts to start it due to failure of the Lucas fuel system. We adapted a Conway system which was used for many months before the Lucas system was ready.
The first RB ran in Jan 1970.First flight in the VC10 occurred in March 1970,fitted with a Titanium fan blade, using the third -22 engine after a very short flight clearance test on the second. The first flight on the L1011 was in Nov 1970,10 months after the first run.
The Company went into receivership on Feb 4th 1971.
Certification was achieved in April 1972, 27months after first run and Entry into Service was in the same month. This was four and a half months after the planned date.
By today's standards this was a fast program, even more so because of the enormous technical problems that had to be overcome in such a short period of time.

9. RB211-06 Realising 40,000lb thrust
RB211-06, Engine 5 – Test Report (Jan 1969):
Seizure of LP spool during initial attempts to start engine
Strip revealed distorted blades, severe foul with seal segments
Turbine module from Engine 3 fitted to resume testing
After 19hrs 40mins, several Hyfil fan blades were found damaged
Hyfil assembly removed and Titanium assembly fitted to resume testing
Surge at 36,000 lbf after 21hrs 34mins (day temperature: -7°C)
Engine rejected from test due to seized HP spool
Strip examination revealed HP turbine blade foul with seal segments
Thermal deterioration of the flame tube had also occurred
Best performance to date!
RB211-06, Engine 7 (March 1969):
Engine achieved 40,000lbf but surged and seized on run-down due to HP turbine blade failure
The first -06 engine run was deficient in both performance and durability. The engine suffered HP NGV bulging after a run to about 20,000lb thrust and a turbine temperature of 1400K. Performance was awful and numerous problems were identified on strip. Progress over the next few weeks was slow and our customers were getting anxious.
In November 1968, it was declared that we had to realise 40,000lb thrust by end March 1969 in order to demonstrate confidence in the engine. This was no mean feat.
Engine 5 was built to a better standard and ran during a very cold spell in January, good for producing thrust. After some initial problems we got underway with the performance curve. All was looking good at 36,000lb but on accelerated to 40,000lb thrust, the engine surged and sized on shutdown, an HP turbine blade had failed, a fairly regular occurrence at that time.
The next attempt was made on Engine 7 in March but the day temperature was higher and the engine performance was worse than Engine 5.We were therefore in for a hot run and knew the hardware would not last for long, perhaps only a few seconds.
When the day temperature was at its lowest (7C) at 5.00am in the morning, we performed a performance check at 25,000lb, then accelerated slowly to 40,000lb thrust and remained on condition just long enough to get an ADR scan. The engine surged as the throttle was pulled back and then caught fire!!
We had met the goal and pronounced to the world that 40,000lb thrust had been achieved. We said it performed as predicted!

10. RB211-06 Realising 40,000lb thrust
‘The Evidence’ !

11. RB211 Early development problems
Fan blade integrity
Poor performance of compressors and turbines
Combustion chamber and NGV cooling, cracking and collapse
HP turbine blade cooling/fatigue (IPNGV excitation)
Deletion of composites and strengthening of engine structure
IP NGV performance
Operability
Temperature traverse
Engine overweight
LP blade profile changes
We had an enormous number of problems to address. All the composite materials were taken out of the engine and after this the engine was re-designed many times equating in effort to about ten complete redesigns. We had nine different standards up to initial production followed by the conversion to the -22B standard after 12 months service operation.
Performance was a major problem because it was so poor, required a lot of effort and prevented us running the engine at the right conditions to test it mechanically. Also the unreliability of the engine, even at moderate powers, made it difficult to run for sufficient time to expose new problems. Progress was therefore very slow throughout 1969 and 1970.The life of the hot section was awful and the HP turbine blade suffered a variety of mechanical and thermal failures throughout the program. At one stage we were failing turbine blades after only a few minutes running.

12. Rolls-Royce Receivership-February 4th 1971
Engine 10011, fitted with a package of performance modifications, returned best performance to date on evening of Feb 3rd 1971
The SFC shortfall was approx 8% with thrust close to 40,000lb
This demonstrated the engine’s potential and had a major bearing on the events that followed
The receiver allocated 12 development engines compared with the previous 18 - this required a clear focus on priorities
Contract with Lockheed was re-negotiated with technical spec eased
HP turbine blade was fixed, turbine sealing improved and further performance improvements made
14 months after bankruptcy the engine entered service at 40,600lbs, 41/2 months late, derated and overweight!
12 months later thrust was fully recovered and SFC target met.
Feb 4th 1971 is a day that everyone in RR at the time will remember. The previous evening we performance test on Engine This engine was fitted with improvements to the IP compressor, increased capacity IP and LP turbines, and an improved turbine flow path. The engine returned the best performance to date. The sfc was about 8% above specification at sea level (51/2 % at cruise) and thrust capability was close to 40,000lb.Whilst the result did not save us from receivership, the engines potential had been demonstrated and this had a major bearing on the events that followed.
. The focus of attention then moved to reliability and certification, but performance still needed to be better. The receiver had allocated 12 development engines compared with the 18 in the program at that time. Our work was prioritised more carefully. This was the best thing he did as we had more time to concentrate on the technical issues
The contract was re-negotiated with Lockheed and the technical specification was eased, notably with respect to thrust at EIS, weight and starting.
The HP turbine blade vibration problem was fixed by increasing the gap between the HP blade and IP NGV and an interlock was fitted to the shroud. Our first type test was passed at very much derated conditions in the third quarter of 1971.
Three different standards of flight engine were delivered to Lockheed during 1971 (24 engines), all of which had to be cleared in about 12 months.
The engine entered service with Eastern Airlines at the original thrust of lb, four and one half months late and somewhat overweight. Twelve months later the thrust was recovered, and the fuel consumption was achieved.

13. RB211 Early service problems
HP turbine life (800 hours initially)
Fan disc
LP location bearing
Accessory reliability
HP compressor stators
HP compressor surge
Combustion liner life (800 hours initially)
Rate per 1,000 hours
1973
1974
Fan disc
Surge/ compressor damage
Other reasons
Turbine blade/combustion liner deterioration
-22 total engine-caused removals
’72
6900hours of bench running has bee accumulated at EIS but only a small amount of this was on the correct standard of engine or at high conditions. Cyclic endurance was minimal as all the effort had gone into getting through the type test which we achieved only two weeks before certification and EIS.
Reliability was far worse than we feared. In the early days the IFSD rate rose to about 0.6 per 1000 hours and removal rate averaged 1.2 per 1000 hours. The intershaft bearing was the main cause of IFSDs but not the only one by any means. The Combustion liner and HP turbine blade had a life of about 800hours initially and remained at about 3000hours until we fitted the cast blade in 1980.
Over Christmas 1972 we had the first fan disc failure to be followed by the second a few days later. The operation was kept going by inspecting discs every 50 cycles and fitting new discs every 400 cycles until they were replaced bydiscs with 6/4 Titanium material. New discs were available in about 6 months and fitted across the fleet in about a year. We discovered that the cyclic life of certain types of Titanium was sensitive to time on load, making our lifing methodology invalid. Our quick response to this problem earned us respect for our customers.
The -22B engine in 1973 was introduced in It had revised HP compressor aerodynamics to improve performance. The engine had a nasty habit of surging on take-off at rotation, particularly on the first start of the day. It was even worse when the No2 engine swallowed snow from the top of the fuselage and on one occasion all three engines surged. Eastern Airlines alone suffered no fewer than 170 events before the problem was fixed.
There were a number of contributory factors , but he primary one was the poor thermal response of the compressor casing (too fast) combined with a tendency to go off centre which deteriorated surge margin at twice the normal rate.. A warm up procedures was used to alleviate the problem before it was fixed by redesigning the compressor casing s.
Many other problems that had to be addressed over the next 10 years before the engine achieved a respectable standard of reliability. Most notable amongst these was the HP turbine blade which I will address in a minute.

14. RB211-524 and RB211-535 Thrust – lb x 1000 -524G/H (pkg 3) -524G/HT
Boeing 767
Boeing 747
Lockheed L-1011
Tupolev Tu 204
Boeing 757 70
-524G/H
(pkg 3)
-524G/HT 60
-524D4
-524C
-524B
-524D4-B 50
-524B4-B
Improved -22B
-535E4
-535F5 40
-22B
In 1970,it was realised that a further development of the engine was necessary in order to keep the Tristar competitive and to seek applications on the B747 and DC10.
Detailed design started on the -524 in 1972 and the first run occurred in October It achieved its design thrust on the second day of testing and performance was close to specification. A more ambitious target of 50,000lb was therefore set.
The engine entered service in 1977 on a heavier version of the L1101with Saudi Arabian Airlines and subsequently on the B747 with British Airways. The L1011 fitted with the had a reduced the fuel burn of 7% and increased range of 66%.
I was Chief Engineer on the RB D4 having previously been Chief engineer on the RB211-22B This engine was rated at 53,000lb thrust with a 4.5% improvement in sfc relative to the RB B. It was ordered by Qantas against a very tough delivery schedule .The development programme was disrupted by a prolonged strike. The first run was in June 1980 and delivered four fully certified engines were delivered to Boeing March It went on to take an equal share of the market with GE and P&W, thereby establishing our position on the B747
The RB was launched in 1977 to provide for the B757, the first time that RR had been the first engine supplier on a new Boeing Aircraft Boeing were naturally concerned that we had over stretched ourselves with the RB B4, RB D4 and RB C developments running concurrently. They monitored and audited us very regularly .As a result we improved our program management enormously.
The RB was further developed to become the RB G/H for the Boeing B747 and B767 programmes
Thus with the RB and RB we had improved the customer base and market share which formed a platform on which to launch the Trent engine.
-535C

15. RB211-22B/-524/-535 and Trent HP turbine blades
1979
RB211-22B/535C
Multi-pass cast DS blade HP feed Extensive film cooling 1660K
1983
RB E4
Second generation multi-pass cast DS blade 1680K
RB211-22B
Extruded blades LP feed, cut back trailing edge
Suction and trailing edge cooling
HP feed to leading edge
Interlock
1545K -1550K
1995
Trent 800 Multi-pass Single crystal Root damper HPNGV shaping Parallel shroud 40 NGVs 1840K
RB Strategy 2C-2.5C Modified interlock Multi-pass Single crystal 36 NGVs 1730K-1751K
1977
RB Equiaxed HP feed racetrack NGVs 1660K
The HP turbine blade is arguably the most important component in the gas turbine as it determines the maximum temperature that the engine can operate at.Advances are made by a combination of better materials and better cooling technology.
Rolls-Royce was the first to exploit air cooling in turbine blades with the Conway but they failed to advance the technology and in particular to change from Wrought N108 to a cast material. We therefore had little choice but to try to improve the extruded blade .We raised the life of the extruded blade from 800 hours to about 3000hours.
When the -524 was launched, the turbine disc was redesigned to provide high pressure air to the blade and a cast material was used. The cooling configuration was similar to the -22B but the HP feed allowed it to be film cooled much more effectively. It worked quite well but the disc cyclic life was poor.
A high temperature demonstrator unit was launched in the early 1970’s and by 1977 we had developed new cast blade using Directionally solidified material with HP feed. It was a designed and validated very thoroughly through carefully planned testing aimed at ensuring that the design intent had been fully achieved. The design and development approach adopted on this program marked a change in the way we tackled engineering problem. The old make it and break it approach was abandoned.
The bade has been further developed on the RB E4,the RB G/H and subsequently the Trent
The failure to develop the appropriate technology during the 1960's and early 1970's proved to be a very expensive and painful experience and one which all engineers should take to heart. Gas turbine engines are technology intense and can rapidly become uncompetitive without continuous investment.

16. Rolls-Royce Changing pace of technology 1980-1990RB
V2500
RB G/H
Technology introduction
Emergence use of modelling/analysis tools, e.g. TACITUS
Early use of CFD, FEA etc – development of turbine key systems
Widespread us of key systems across all components
IT power and capability
During the 1980's technology was changing at an enormous pace, particularly the capability of computing systems. Our first design system, TACITUS was developed in the late 1970s and this led the way to defining a set of Key Systems in the mid 1980s with both Derby and Bristol contributing to a common approach. Up until this time they had gone there separate ways.
80’s
90’s

17. Rolls-Royce Modelling Capability 1980 to 1986
Impractical or impossible
Transient dynamic response 10
Improving Method Quality 9
Whole engine modelling (FE) 8
Rotor blade vibration analysis
Analysis time 7 6
Disc temperature prediction
Time to influence design 5 4
Disc LCF lifing
Benefit from vector processor 3
Analysis of 14 aerofoils at six operating points (Inc OGV in 3D) 2
V2500 Plan B
In 1986 I gave a presentation to the Board to seek approval for further investment in computing at a time when we were in some difficulty with the V2500 engine. This chart was used to show that if we could analyse designs more quickly we had a better chance of getting them right before hardware was released to manufacture.
The board gave approval for our first foray into the use of a vector processor. Since then our computing capability has grown enormously and there is virtually nothing that need go unanalysed prior to manufacture today. 1
1981
1982
1983
1984
1985
1986
Date (year)

18. Rolls-Royce Computer Simulation
Computer Simulation has changed the way Engineering is carried out
1960’s 1st Computers used
1970’s 1st Turbine design system(1976)
1980’s Mechanical Analysis concurrent with design.
1990’s Faster, greater complexity, more iterations
Digital Pre-assembly(Trent 800)
2000’s Simulation validation via test then used for subsequent certification
2010 Whole engine modelling & Fan Blade-Off simulation

19. RB211-535, V2500, RB211-524 improvement programmes
Attempts at performance improvement programmes through technology introduction provided mixed successes due to technology management and process difficulties
1991 was a bad year. We had already experienced major difficulties in developing the compressor for the V2500 engine in 1986 and in 1991 we failed to deliver major improvements to the RB and RB Engines. These failures had cost the Company a lot of money at the time we had just embarked on Developing the Trent engine. Confidence in Engineering throughout the Company was rock bottom
I had just been appointed Director of Engineering of the Aerospace group and so it was my job to sort out the reasons.
The engineers would argue that they lacked the technology when things went wrong, but this argument did not stand up to analysis as our technology was now quite good we having invested significantly during the 1980s. More often than not the failures were due to poor planning and resourcing, lack of attention to detail or poor communications between projects and the functional departments.
The Trent 600 for the MD11was underway (fortunately it got cancelled), the Trent 700 was launched and the Trent 800 was in prelim design. It was essential that we succeeded on these programs otherwise we would face 1971 all over again. Clearly something had to change.
After considerable debate amongst the engineering seniors we launched Project Derwent as the new stage gate New Product Introduction Process and associated changes.

20. Derwent – The new product introduction process
Stage 1
Preliminary
Concept
Definition
Audit gates
Stage 1 Exit review
Stage 2
Full Concept
Definition
Stage 2 Exit review
Stage 3
Product
Realisation
Critical design review
Design verification review
Production readiness review
Stage 4
Production
Production process check
Stage 5
Service
Support
I chose to call the initiative Project Derwent because we needed to replicate in a modern environment those things that made the Derwent V engine such a success. These were teamwork across functional boundaries, use of proven technology and the application of a set of common processes, but now we could use IT to cope with the extra complexity and ensure that all engineers operated from a common data base.
In-service review
Stage 6
Disposal

21. Integrated team and product structure
IPT structure
Product & Functional structure
Chief Engineer
Whole
System
(Product)
Etc
Chief Design
Engineer
Chief Devt.
Engineer
Sub-system
Sub-system
Team leader of
Sub-system
Team leader of
Sub-system
Component
Component
The organisation structure was aligned to the product breakdown structure. Engine systems were at one level and the gas turbine sub systems and components at another. All groups were responsible for the activity from 'Cradle to Grave‘. No longer could design pass the problem over the wall.
The new functional groups were responsible for developing the capability and the project groups were responsible for executing the projects. Some people in the project were permanent members whilst others were seconded. Some specialist tasks were performed by the functional groups.
The changes were opposed by some and others wanted to delay the changes until after the Trent program. I realised we had to make the changes and pushed ahead in two Phases, the first in late 1991 and the second in mid A new building was erected to house the Project teams called Trent Hall but it has since been named the Lombard Building after one of the Company’s famous engineers.
An independent Technical Audit team was created headed by a very senior and well respected engineer who gave me tremendous support
Better performance was evident within12 months. The Trent 700 was certified on time.. The Trent 800, was certified three months ahead of schedule at 90,000lb thrust cf 84,000lb planned.
The new company structure for manufacturing followed in 1998 enabling the engineering and manufacturing teams to come together in a single unit.
Team leader of
Component
Team leader of
Component
Team leader of
Component
Team leader of
Component
Component
Component

22. Rolls-Royce Capability Acquisition
Requirements:
Airframers
Operators
New
Product Planning
Full Concept Definition
Product Realisation
Service Support
Production
Disposal
Solutions
Facilities
People/skills
Supply Chain
Infrastructure
R&T Strategy Planning
New Capability Realisation
Technology Validation
Generic
Project specific
Research and Technology Programme
Strategic Research
Applied Research
It was necessary to give greater focus to the companies Corporate Strategy and anticipated future product needs. This chart shows how the development of technology feeds into the design process at the different stages of development, supported by a global Research and Technology programme.
The Research and Technology programme provides the vital link between the global academic network, technology validation and new product development.
UNIVERSITY TECHNOLOGY CENTRES
Global Academic Network

23. Rolls-Royce Technology Acquisition
Prior to mid 1970’s technology acquisition was determined by functions, largely with a research focus
High Temperature Demonstrator Unit 1st run in 1972
Structured Advanced engineering programmes launched in 1976 including Demonstrator engines
University Technology Centres launched in 1990
Technology Strategy linked to Corporate and Product strategy from 1995 onwards
Technology programmes key to success of Trent Engine family and growth of Company in other sectors

24. Research and technology management
Increasing cost/Reducing uncertainty/Reducing time to market
Maturity Levels
3D Compressor Blading
High Temp. Demo. Unit
Fuel Cells
Strategic research
Applied research
Validation
Wide Chord Fan
MMC Blisk
Technology Categories
The Technology programs were managed on a company wide basis and covered a range of technologies at different stages of maturity. Rigorous assessments were carried out to check for competitiveness and benefit in relationship to risk and cost. In this way a focused program is maintained.
Titanium Disc
Fuel Cells
Base
Key
Pacing
Emerging
Relative to competition: Lead/Neutral/Lag

25. The Trent Family 2060 engines delivered 2600 orders backlog
EIS 2011
EIS 1996
EIS 2007
EIS 2013
Trent XWB
84,000lb
Trent 800
95,000lb
Trent 1000
74,000lb
Trent 900
80,000lb
110
Fan diameter
2060 engines delivered
2600 orders backlog
(December 2009)
97.5
EIS 1995
EIS 2002
Trent 700
72,000lb
Trent 500
56,000lb
It is through the approach outlined above and the dedication of a very large number of very capable engineers that we have been able to develop the Trent family of engines based around the three-shaft architecture of the RB211.
Ironically we were able to retrofit the Trent 800 HP system to the -524 to give the -524G/HT which fulfilled the requirement that package 3 should have satisfied.
Each variant of the Trent, including the Trent 900 has incorporated new technology made available by the technology programs that have run in parallel with and ahead of the next engine launch.
86.5
RB G/H-T
60,000lb

26. Trent 1000 – High technology at low risk
Soluble core manufacturing of HPT blade
Active anti icing
Advanced LPT design
IP power off-take
Optimized lightweight fan system
More electric Accessories and Engine Health Monitoring

27. Developing our Engineering Talent
Directors
Chief
Engineers
Fellows
Technical
Managers
Associate Fellows
Recruits
Some External
Losses
Movement out of Engineering
Specialists
Recruits
Project
Managers
Technical
Leadership
Project
Leadership
Graduate Level Recruits
& Apprentices

28. Product Development –Keys to Success
Competitive Product Concepts
Technology acquired ahead of product development
Stage Gate Product introduction process
Formal gate reviews
Risk assessment and management
Integrated Product Teams
Robust product requirements
Work package management
Clearly defined deliverables
The best digital tools inc verification
Well trained and motivated people