F-111 EBU TF30 RAM Program

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					                           F-111 Engines Business Unit

   F-111 EBU
TF30 RAM Program
    John Hall (Quality Manager)
 Greg Mason (Engineering Manager)
                                                    F-111 Engines Business Unit

Presentation Outline
•   F-111 EBU Overview
•   What is a RAM Program
•   What is a Condition Monitoring Philosophy
•   What Condition Monitoring Techniques are used
•   Performance Indicators
     – Reliability / Safety
     – Availability / Health
     – Maintainability / Cost Effectiveness
•   Applicability to other industries
•   Nine steps
                                                                  F-111 Engines Business Unit

F-111 EBU Overview
•   F-111 EBU supports the Pratt & Whitney TF30 gas turbine fleet that powers the RAAF F-111.
•   Support includes Fleet planning, Engineering, Deeper Maintenance, and Spares (and RI)
    inventory management
•   Engine facts
      – 100 plus engines managed (65 in rotable fleet)
      – Designed in the 1960s (first Turbo Fan engine built)
      – Approx $2M each ($4M in piece parts)
      – Four variants supported (will be one in two years)
      – Only TF30 operator (USN retired TF30 powered F14s in 2005)
      – Oldest fleet (time since new ~ increased risk)
                                                                     F-111 Engines Business Unit

Engine picture (now removed)

•   16 stages of compression; overall compression ratio 19:1
•   Length 19 feet, diameter 39 inches, weight 4 160 lbs, max thrust 21 000 lbs,
•   Max temp ~ 2200 ºF, Max pressure ~ 250 psia,
•   Airflow 240 lb / sec (by pass ratio 1:1), max fuel flow 55 000 lb / hr (15 lb / sec or 9 L / sec)
•   Twin spools (9600 rpm and 14400 rpm - single fan blade exerts a centrifugal force of ~ 30 000lb)
•   Eight combustion cans (arranged in an annulus), four fuel nozzles per can (primary and
    secondary flow for each)
•   Four stages of turbine
•   Variable, five zone, Afterburner
                                                                         F-111 Engines Business Unit

TF30 RAM Program
Why a RAM program?
•   To continually improve Reliability, Availability and Maintainability (quality, timeliness and cost)

What is a RAM program?
•   Essentially a management philosophy based on Condition Monitored Maintenance (CMM)
    principles ie use knowledge of individual equipment condition (engine in our case) to make
    decisions on each piece of equipment and the fleet at large.

How was the RAM program introduced?
•   In 1990 a group of people who had Condition Monitoring experience and a strong desire to
    provide cost effective TF30 maintenance, became aware of the current engine failure and Test
    Cell rejection rates and decided to act.
                                                                    F-111 Engines Business Unit

TF30 RAM Program
•   Unscheduled removal rates too high (30% of all work performed)
•   Review of engine failure modes and reasons for engine rejection at Test Cell. Identified as:
      – Main line bearing failures / oil system leaks
      – High engine vibration levels
      – Low Turbine Inlet Temperature (TIT) margin
      – Engine accessory failures
•   Repeated maintenance for same problem (addressing symptoms not cause),
•   Inefficient maintenance strategies when performing major maintenance (fixed interval, one size
    fits all)
•   Need recognised by middle managers and the RAAF TF30 RAM program was born…..followed
    by 3 years of persistence, stealth and self promotion in order to prove the concept.
•   A few early successes helped and the RAM program was formalised in 1993 (senior
    management commitment). From that time to this, it has officially had staff, equipment,
    knowledge and a goal.
•   More on RAM program implementation later in the presentation
                                                                       F-111 Engines Business Unit

Condition Monitoring - Philosophy
An effective RAM / CM program
•   must be focused and structured
Five CM Phases
•   Detection, taking readings and obtaining raw CM data
•   Diagnosis, analysing this data to determine failure mode(s) in play
•   Prognosis, decide on course of action based on failure criticality (time remaining until engine
    removal / repair)
•   Prescription, decide what scope of maintenance is reqd and perform it
•   Post Mortem, gaining feedback during repair and using it to improve CAC, build techniques,
    facilities, CM techniques!
                                                                   F-111 Engines Business Unit

Condition Monitoring Techniques
Technique selection
•   Chosen based on ability to monitor ‘important’ failure modes
•   Not chosen based on - the way we always do it, equipment offered by ‘salesman’, cheapest or
Five Techniques
•   Spectrometric Oil Analysis
•   Wear Debris Analysis
•   Vibration Analysis
•   Gas Path Performance Analysis
•   Remote Visual Inspections
                                                                      F-111 Engines Business Unit

Condition Monitoring Techniques
•   Spectrometric Oil Analysis (approx. 20 monitored faults)
     –   Interval every three flights and every flight in warning (same day sample, burn and analysis,
         rapid failures ie <10 enhrs)
     –   Automated trending (not just data collection)
     –   Included Oil Additions and a smoothing algorithm
     –   Trend corrected concentration and wear rate (not uncorrected concentration)
     –   Automated predictions (time to break warning / alarm levels including colour coding and
     –   Not used in isolation (WDA, Maintenance history, modification status etc)
                                  F-111 Engines Business Unit

Condition Monitoring Techniques
•   Spectrometric Oil Analysis
                                  F-111 Engines Business Unit

Condition Monitoring Techniques
•   Spectrometric Oil Analysis
                                                                  F-111 Engines Business Unit

Condition Monitoring Techniques
•   Wear Debris Analysis (faults as per SOA, provides confirmation)
     –   Interval is pre/post maintenance, as indicated by SOAP and ΔP
     –   From main engine filter (no mag plugs, particles often non magnetic)
     –   Use 15 micron Pall ‘Dirt Alert’ filter (high efficiency debris recovery)
     –   Also use 3 micron ‘Dirt Alert’ for ‘Green Run’ post major maintenance
     –   Optical microscope with digital camera (initial analysis)
     –   SEM EDX if worthy of further examination using on base NDTSL Materials Officers
     –   Stored electronically for comparison with metal map (OEM and RAAF developed)
                                                                    F-111 Engines Business Unit

Condition Monitoring Techniques
•   Vibration Analysis (approx 20 faults, balance, alignment, straightness,
    concentricity, looseness, rubs etc)
     –   Interval is pre/post maintenance and when removed serviceable (slow failures ie >200 enhrs)
     –   Transducers (accelerometers) on Fan Inlet Case, Diffuser and Turbine
     –   Data acquired by predominately using RAAF / DSTO developed Engine Vibration Analysis
         System (EVAS)
     –   Use Run up / down plots (amplitude & phase) and FFT
     –   Trending / fault isolation using various DSTO software and Vibralog / Entek software
     –   Current Development of IEVAS (portable version of EVAS)
                                                                                                     F-111 Engines Business Unit

Condition Monitoring Techniques
•   Vibration Analysis                               Engine #: P71-4048               ETC#: ETC #1
                                                                                                  Vibration Survey Report
                                                                                                                                        Date: 9/02/06
                                            Maintenance Reason:         Post N1 turbine shaft change

                                                                                                                                            CH1: FIC
    Single channel system replaced with                               8
                                                                                         Overall Vibration (OVB) Transients                 CH2: DIF
                                                                                                                                            CH3: TRB
                                                                                                                                                         OVB Pks

                                             Amplitude (mils pk-pk)
    PC based 8 channel system                                         6
                                                                      4                                                                                   TRB

•   Steady state acquisition and one slow                             3

    run-up / run-down rather than 6 to                                1
    complete vibration survey                                             40   50           60            70           80          90             100

                                                                      8                                                                     CH1: FIC
                                                                                             N1 Rotor Transients                            CH2: DIF     N1 Pks

•   Takes 2 minutes instead of 12,                                    7                                                                     CH3: TRB
                                             Amplitude (mils pk-pk)

                                                                      6                                                                                   0.82
    providing approx $200k fuel savings                               5
    per year                                                          3                                                                                   1.10


•   Provides both Transient and Steady                                0
                                                                          40   50           60            70           80          90              100
    State Peak vibration data                                         8                                                                     CH1: FIC
                                                                                                 N2 Rotor Transients                        CH2: DIF     N2 Pks
                                                                      7                                                                     CH3: TRB      FIC
                                             Amplitude (mils pk-pk)

•   Single page report generated for                                  6
    serviceability                                                    4

                                                                          60        70                    80                  90                   100
                                                                   F-111 Engines Business Unit

Condition Monitoring Techniques
•   Gas Path Performance Analysis (approx 15 faults monitored)
     –   Interval is pre/post maintenance and when removed serviceable (slow failures ie >200
     –   Normal parameters trended (N1, N2, Tt2, Tt4, Tt5, Tt7, Wf, thrust, Pt2, Ps3, Ps4, Pt7m)
     –   Also looking at Tt3, Ps3f.
     –   Acquired using PC based Engine Data Acquisition System (EDAS developed by DSTO,
         supported and maintained by Raytheon)
     –   Use OEM EPR Plots, OEM influence coefficients, plus various cross plots (DSTO)
     –   Trending using EBU developed Excel program (against same engine, average of the
         serviceable band or average engine)
     –   Fault isolation aided by various DSTO developed software
     –   Approx last 10 years of data used to trend
     –   Two Compressor wash types performed (water and detergent) at specified intervals to
         recover performance, help with corrosion.
                                                                     F-111 Engines Business Unit

Condition Monitoring Techniques
•   Remote Visual Inspection / Videoscopes (monitors corrosion, erosion,
    cracking, oil leaks, P/N and build checks)
     –   Interval is pre and post maintenance, special servicings, as reqd (slow failures ie >200
     –   Access to Fan, majority of LPC, front/rear of HPC, majority of combustion area, front of HPT
         and rear stages of LPT (access often limited by imagination)
     –   Use latest generation 4, 6 and 8 mm videoscopes
     –   Features include stereoscopic measurement, working channel, digital image / video capture
         and comparison, improved optics / light source / portability
     –   Under investigation in-situ blending and NDT
                                                                   F-111 Engines Business Unit

Engine Inductions
•   To provide an insight into how this CMM philosophy is used on the TF30 a number of initiatives
    will be discussed. The first is engine inductions.
•   Every engine removed for deeper maintenance is prepared for induction into work. This involves:
     – data collection eg test cell run and existing CM data (five techniques), configuration data
          (ECs incorporated) and lifing data (LCF and other lifed components).
     – Analysis of above data
•   The goal is to tailor the maintenance to be performed so that:
     – minimum necessary / optimal work is carried out,
     – maximum engine life is produced,
     – highest probability of successful engine test post maintenance
     – reduced support costs
•   This work scope is documented in a ‘work requirement’ and is conveyed to maintenance
    supervisors at an induction meeting (chaired by RAM staff). NB: Scheduled maintenance such
    as OH and HSI have a fairly standard ‘work requirement’.
                                                                       F-111 Engines Business Unit

Engine Failure Modes
•   The second initiative is to use the Condition Monitoring and reliability data to target Engineering
    Changes / Build techniques that will best help improve TF30 RAM outcomes.
•   Essentially we are doing the post mortem phase in a systematic manner ie various Tech info /
    reports raised during engine repair are reviewed in an attempt to not just repair the engine but to
    eliminate that failure mode throughout the whole fleet. Sounds simple, but isn’t!
•   Challenges are many, some are:
      – too busy / not enough staff, no dedicated RAM focus on long term opportunities (bush fires
         are raging, no time available to build a fire engine)
      – concentrate on treating symptoms, forget to remove the cause
      – time, effort, cost to develop and implement ECs is often daunting
      – Not enough ECs introduced to RAAF fleet
      – Unnecessary ECs introduced to RAAF fleet (fixed a problem we didn’t have)
      – management administrata (distracted from the goal of improved RAM outcomes)
                                                                  F-111 Engines Business Unit

Engine Failure Modes
•   Some TF30 examples are:
     – ECs, 25 relevant mods introduced during current OH series (23 worked; only 4 in 7 years
       during late 80s - mid 90s, more to come!)
     – Build Improvements, numerous processes to improve engine ‘condition’ eg 5 bearing
       housing lug clearance software
     – Facilities, numerous but some are:
          • upgrade bearing cleaning, inspection, repair facilities
          • upgrade plasma spray room, welding workshop
          • dehumidified engine storage
     – Equipment, continual but some are:
          • purchase of DCCMM
          • purchase of air bed run out table
          • digital blade moment weighing / automated patternising
          • bearing flushness indicating system
     – Old engine but new processes / equipment / facilities
                                                                    F-111 Engines Business Unit

Maintenance Interval Extensions
•   Maintenance Interval Extension (Scheduled via FLP and via MIER)
     –   In 1990, scheduled intervals were 750 / 1500 enhr for HSI and OH. Pre pacer were 550 / 1100.
     –   We are currently exploring a 1000 / 2000 enhr schedule via a Fleet Leader Program that is
         validated by previous P&W ASMET testing for the USAF and USN.
     –   Initial goal was 1200 / 2400 but this is looking unachievable without JP8+100 and TBC NGVs.
         Latest Mission Profile Analysis also shows increased AB lights.
     –   Additionally, all engines approaching scheduled maintenance are reviewed for extension. Due to
         variability of build, use & repair history it is inevitable that many engines can safely operate
         beyond scheduled maintenance. Some can not! This process relies heavily on CM, build / lifing
         data etc
     –   RAAF TF30 DM currently produces 7200 enhr per annum using 100+ staff and associated
         spares; MIER produces 3000 additional enhr with <5 staff and limited spares - saves money,
         safety not compromised! Was 15 OH / yr in early 80s, now 7.
                                           F-111 Engines Business Unit

Performance Indicators (1990 VS 2005)
•   Reliability / Safety
•   Availability / Health
•   Maintainability / Cost Effectiveness
                                                                  F-111 Engines Business Unit

Performance Indicators (1990 VS 2005)
•   Reliability & Safety

     –   In Flight Shut Down (IFSD) rate
           • In early 1990s was 0.6 / 1000 enhrs or 4.5 per annum
           • 2005 was 0.07 / 1000 enhrs or < 1 per annum or 84% reduction c/w early 1990s
           • Compares favourably with F404 fitted to RAAF F/A18 which has an IFSD rate of 0.28 /
               1000 enhrs
           • Oct 96-Jan 01 achieved 4.5 years with no IFSD
           • Goal - continually decrease IFSD rate; 0.02 achievable for TF30 within 5 years (97%
               reduction c/w early 1990s
                                                                  F-111 Engines Business Unit

Performance Indicators (1990 VS 2005)
•   Reliability / Safety

     –   Unscheduled Engine Removal Rate (UERR)
          • In early 1990s was 7 / 1000 enhrs or 55 per annum
          • 2005 was 3 / 1000 enhrs or 21 per annum or 65% reduction c/w early 1990s
          • Most removals FOD (6) and engine accessories (5).
          • Without FOD UERR was 6 / 1000 enhrs in 1990 and 2.1 / 1000 enhrs in 2005 or a 70%
             reduction c/ w 1990.
          • Goal - continually decrease UERR rate; focus on FOD control initiatives and accessory
                                                                F-111 Engines Business Unit

Performance Indicators (1990 VS 2005)
•   Reliability / Safety

     –   Average Time On Wing (ATOW) NB: engines removed serv for AF servicings not counted
           • was 160 enhrs (or 1 year installed), now 300 (2 years installed)
           • c/w RAAF F/A 18 F404, currently 400* enhrs (2.3 years installed)
                                                        * was 300 three years ago
                                                                F-111 Engines Business Unit

Performance Indicators (1990 VS 2005)
•   Reliability / Safety

     –   Major Repair Arising Rate (MRAR)
          • In early 1990s was 1.2 / 1000 enhrs or 9 per annum
          • 2005 was 0.4 / 1000 enhrs or 3 per annum or 66% reduction c/w early 1990s
          • Approximately half of the Major Repairs have been due to FOD
          • With FOD removed 0.9 /1000 enhrs (1990) and 0.2 / 1000 enhrs (2005) or 78%
             reduction c/w 1990s
          • Goal - continually decrease MRAR rate; focus on FOD control initiatives…….FOD very
                                                                     F-111 Engines Business Unit

Performance Indicators (1990 VS 2005)
•   Availability / Health
     Good in 1990, slightly better in 2005 - no ‘bare firewalls’

     –   Engines serviceable above fit
           • average of 8 early 1990s when fleet was 69 engines and 18 aircraft with engines fitted
             (EAR 3.6 : 1)
           • average of 7.5 in 2005 when fleet was 65 engines and 22 aircraft with engines fitted
             (EAR 3:1)

     –   Fleet Health (total engine hours available to be used until next scheduled maintenance;
         provides a contingency buffer and insight into future DM workload requirements)
           • average of 21 000 enhrs (stable) early 1990s
           • average of 24 000 enhrs (increasing) in 2005
                                                                     F-111 Engines Business Unit

Performance Indicators (1990 VS 2005)
•   Maintainability / Cost effectiveness
     –   Maintenance cost (labour, spares, etc) was $31M per annum and increasing in 1991 dollars
         (or $46 M in 2005 dollars)
     –   Maintenance cost was <$20M in 2005 or 56% reduction c/w 1991
     –   $3.5K per ENHR flown in 1991 ($5.1K / ENHR in 2005 dollars)
     –   $2.5K per ENHR flown in 2005 or $1.9K per ENHR made in 2005
     –   Maintenance costs should decrease further as RAAF F111 approaches PWD (currently
     –   Interesting trend - in 1990 RAAF used 12 LSA (Engineering, Fleet Planning, Logistic ie TSA
         / RIM / SIM) and 250+ DM staff; in 2005 we used 40 LSA and 105 DM staff ie we have
         found it to be extremely cost effective to invest ‘up front’ in planning / analysis and save
         ‘down track’ in DM costs (labour and spares)
                                                        F-111 Engines Business Unit

Applicability to other industries

RAM applicable to high cost and / or critical process industries (eg civil
  aviation, mining, rail, paper, power, racing, manufacturing etc)

Must be in a position to implement (organisationally, culturally, disciplined
  approach, technically, long term view and commitment)
                                                          F-111 Engines Business Unit

RAM Program Implementation
     1.   Justify             (Commitment)
     2.   Baseline            (KPIs)
     3.   Target              (Failure modes that hurt most)
     4.   Select              (Appropriate CM techniques)
     5.   Resource            (Team of people, equipment)
     6.   Train               (CM techniques and CMM philosophy)
     7.   Implement           (hard work, discipline, attention to detail)
     8.   Monitor             (review KPI progress / failure modes)
     9.   Adjust              (fix the bits of the program that aren’t working)

Beware of pitfalls, use a facilitator if possible

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