A Programmatic Approach to On Condition Maintenance Chad Wogoman NAVAIR T58 FST Frank Eason NAVAIR H46FST

Page 2 Background – Where we started Purchased 80 COTS Honeywell Model 8500C Balancer/Analyzer, as existing equipment was not supportable (1.56 M, FY 96) Engine Front Frame Cracking #1 Safety Issue - Vibration due to poor RT&B causing cracking - Excessive #1 Bearing oil leakage, ingested by engine, caused in-flight emergency engine shut downs - Costs squadron man-hours and engine replacement Premature structural and hinge point failures experienced New RT&B procedure successfully developed to eliminate engine front frame cracking DCC-81 Modified rotor blades (105K, FY 97) Elimination of Whirl Tower saved $5M Annually Drive to utilize equipment to its capacity

Phase I Getting Started and Setting the Foundation

Page 4 Initial Testing and Instrumentation COTS equipment could collect vibration data COTS software needed to automate the O level aspect of the analysis Develop the frequency models of the engine and drive train Optimize sensor locations through surveys and initial testing Collect data that can help establish good vibration limits Validate the system approach before fleet implementation Learn the Aircraft

Page 5 Data Analysis Software Merely collecting data without having tools to drive real world interpretation will lead to failure Limits and data collection sequences must be modifiable by the Navy Engineering Staff - Older Vibration Equipment required the vendor to modify software any time a change was needed Software should keep it simple for the end user Maintenance manuals should interface with analysis system Analysis Software is Key

Page 6 System Training Teach the theory, not just the how Instructional and practical/hands-on methods required Share results Empower the user to be a part of the system developments/enhancements Technical representatives at the sites are key to success Communicate system benefits through training

Phase II Periodic Vibration Checks

Page 8 Slow methodical implementation 100 hour/phase checks increased knowledge Gained momentum as troubleshooting tool Maintenance time decreased Data review identified issues we never could have seen with previous test methods Allowed us to evaluate effectiveness before spending a lot of money Avoids false removals / A799 rates Able to grant high time component life extensions Fleet demand drove follow-on buy of 30 more 8500C units (780K, FY 98) Early steps realized significant savings

Page 9 Five Significant Case Examples High Speed Shaft Resonance High Speed Shaft Adapter Imbalance Main Electrical Generator failures Service life extensions for aft transmissions Excessive engine vibrations

Page 10 High Speed Shaft Resonance Problem Damaged torque sensors Erroneous torque readings Findings Spline wear allowing resonance in HSS HSS resonance undetected with previous equipment Pilots troubleshooting by throttling the engine back and causing resonance Spectral analysis equipment can detect resonance Resolution Inspection of spline wear implemented Check for resonance with use of narrowband equipment when erratic torque readings reported Pilots instructed to operate at 100% Nf/Nr Damaged Torque Sensors Emergency Shutdown 20 g’s Old Equipment did not detect

Page 11 High Speed Shaft Adapter Imbalance Problem Increase in shaft removal & rejection Seals failing Engines and transmissions were being removed Findings Periodic vibration checks expanded to in flight regimes revealed HSS levels as high as 26 g’s Balancing procedures at vendor and depot facilities found to be inadequate Resolution Balance machines updated and match set balancing implemented Improperly Balanced Adapter Ground limit 5 g’s Hover limit 3.6 g’s 120 KIAS regime recorded vibe levels above shutdown limit (20gs)

Page 12 Electrical Generator Failures Problem Catastrophic generator failures Failures causing in-flight hazards & emergency shutdown Findings Change in scheduled maintenance allowing generators to run to failure Resolution New vibration check procedure identifies degraded generators before catastrophic failure Scheduled overhaul replaced with vibration check (on- condition) Saves ~900K per year Bearing Housing Damage Rotor Contacted Stator

Page 13 AFT Transmission Life Extensions Problem High time of Aft Xmsn is 900 hours Life extensions granted without data Untimely failures resulted Findings Failures can be detected by vibration analysis Resolution Mandatory submittal of vibration data required for life extensions If able to eliminate resonance the Xmsn may be able to extend to 1800 hours 1X of Spur gear 2X 3X 4X 5X Multiple Harmonics of Spur Gear Collector/spur gear mesh Sideband spacing at spur Gear 1 per speed. Multiple sidebands

Page 14 Excessive Engine Vibrations Problem Loud audible howl on newly overhauled engine Findings All test cell runs passed Mils Broadband was acceptance criteria Mobile test cell failed to identify problem Poorly balanced compressor rotor caused damage to 8 th, 9 th, and 10 th stages of the rotor Resolution 3 spectral analyzer fielded in test cells for data collection Compressor Rotor Speed at 81% Ng Note: Fleet average for this frequency is below.2 IPS Test cell run using spectral analysis vs Broadband Note: Limit was 1.5 Mils.

Phase III Justification for Hardwiring of Aircraft

Page 16 Eng Drive Shaft Catastrophic Failure Problem Test of #1 & #2 Engine Drive Shafts indicated misalignment on Engine #1 Findings Maintenance performed and aircraft released to serviceability #2 Engine Drive shaft failed catastrophically in flight Equipment installed incorrectly Maintenance performed on incorrect shaft Resolution Human error allowed component to fly to failure Hardwiring would have prevented this error Above Limits

Page 17 AFC 433 Part 12 Purchased kits to install sensors and wiring in approximately 180 aircraft (1.2M, FY 00) Prepares aircraft for onboard vibration system expansion Solved fleet driven complaints about SE wear and tear

Phase IV Test Cell Expansion

Page 19 Initial Testing and Implementation Began initial data collection using C spectrum analyzers in late at NADEP Cherry Point - 1 at MALS-29/26 Noted significant gains by progressing towards spectral analysis - Provided means to isolate specific frequency(s) yielding greatest amount of vibration - Significant unbalance conditions noted on main rotating components  New balance machines and procedures incorporated (350K) COTS spectrum analyzers (VXP) fielded in early 2001 (235K, FY 01) Spectral analysis now used on all test cells to accept/reject engines

Page 20 Older Vibration System Costs Vibration data collected by Broadband system had falsely led fleet to reject multiple Power Turbine assemblies due to excessive vibration - GE proposed an expensive redesign of the PT bearing/housing as a viable solution COTS vibration analyzers uncovered the dominant frequency causing the vibration, which was the Gas Generator Turbine - Immediately avoided countless PT overhauls (fleet wide) - GE ceased bearing redesign effort - Yearly savings realized, using spectral analysis, due to fault isolation capabilities  PT Rotor Cost: $47,757/unit  PT Assembly Cost: $99,264/assembly

Page 21 Substantial Finding – Impending Bearing Failure Problem Engine passed test cell based upon Broadband vibration test Rejected on-wing due to audible howling Findings Spectral analysis indicated Gas Generator Turbine as the problem area Troubleshooting with the spectral analysis concluded to non-synchronous behavior, indicating spinning bearing race Large fragments found upon teardown Test cell Broadband equipment not properly configured Resolution Early detection of bearing wear possible with spectral analysis, avoiding potential catastrophic failure on-wing Vibration pattern changed un- proportional with engine speed Note concave contour of journal surface (OD was.052 in undersized as a result of spinning inner race)

Page 22 Return on Investment Spectral analyzer implementations yield significant benefits - Increased engine avg. mean time since repair - Decreased engine turn around time - Increased average net spares available Beginning of Vibration Program Operation Iraqi Freedom Implemented VXP System Operation Iraqi Freedom TAT Net Spares MTSR Beginning of Vibration Program

Phase V On-Board Systems Increase Safety

Page 24 Aft Transmission Bearing Failure Problem Aft Transmission Smoking in flight Findings Bearing Failure Gearbox failed after bearing failure resulting in sheared lube pump shaft Loss of pump caused over temp in flight Resolution 100 Phase check was not performed Automated on-board system would have prevented this human induced error NO VIBE DATA TAKEN! ?

Page 25 Head Bearing Failure Problem Post Phase vibration checked and passed Significant increases in vibration reported by the crew after only a few hours of flight Findings Repeated vibration checks verified the crew discrepancy Vib levels had risen over a short period of time Sr. Squadron officer instructed the aircraft to remain in service 7 hours later the flight was aborted by the Air Boss – aircraft significantly shaking on deck Failed head seal and bearing found Oil leakage problem was ignored Lack of lubrication led to failure Rotor head hub was close to total failure that would have resulted in a complete loss of the aircraft & crew Resolution On-board equipment would have indicated the problem immediately Figure 22 Here

Phase IV: On Board System Aircraft Integrated Maintenance System

Page 27 Eliminate Support Equipment Honeywell Rotor Track and Balance – Model 8500C+ Vibration Signature Carry – On Accessory Kit Howell Instruments Engine Check System – NP600 Purchased NRE and AIMS units (16M, FY 03 – 08) Logistics Savings Realized

Page 28 Key Features Derive Solutions Rotor Track & Balance Periodic Vibration Checks Continual Vibration Monitoring Engine Performance Checks with automatic nomograph and margin calculations Continual Aircraft & Engine Parameter Monitoring 1553 Databus interface Interface to Control Display Navigational Unit (CDNU) via the 1553 databus On Board Go/No Go indications with simple user interface for the aircrew Ground Station Software with Go/No Go indications, data archival, data review & analysis Features with immediate payback

Page 29 RT&B Displays Improves Troubleshooting Capability Polar Plot Display Track Display Measurements & Solution Display Adjustments

Page 30 Periodic Checks & Continual Monitoring User definable configurations via Engineering Ground Station Software Multiple alarming levels, which drive visibility to aircrew - Master Caution Panel - On CDNU Display - On AIMS Acquisition Unit - On Ground Station Immediate Feedback of Alarm Conditions

Page 31 Periodic Checks & Continual Monitoring Increasing Safety & Reliability Monitors: - Engine and Drivetrain Vibration Levels - Overspeeds - Overtorques - Overtemperatures - Chip and Debris Screen States - Oil Temperature and Pressure - Engine Performance Margin - Air Data (OAT, PA, KIAS via 1553B data bus interface)

Page 32 Migrating towards fully automated performance margin on the fly Potentially eliminating phase performance check requirement Potentially aiding mission planning efforts Engine Check Displays Eliminate Manual Data Entry and Plotting of Data Points Engine performance assessed on-board, resulting in immediate feedback of acceptability Complete post maintenance check flight engine setup capability

Page 33 AIMS Savings Realized Annual FCF hours using AIMS will be reduced by 1117 hrs resulting in a savings of $10,938,505 based on FY04 data FCF setup time; In addition, the time savings will easily surpass 8,000 man hours annually required to set up for FCF’s SE savings: calibration, repair, fleet readiness AIMS monitor feature has potential to uncover component anomalies, prior to catastrophic failure, inherently save parts and will increase safety Features with immediate payback

Conclusion

Page 35 System Selection Critical Understand how your system works for you Automation is good to a point No COTS system is 100% ready to go Demand control of configurations (routes & limits) Control getting drowned in mass amounts of data The system must cater to the operator and maintainer More is not necessarily better Must be simple at end user Must inform the operator/maintainer of pending problems or failures Grow the system as lessons are learned Off site analysis is not practical Must conform to new software requirements - NMCI

Page 36 Making room for growth Develop smart solutions Advanced Gearbox Diagnostics Monitoring of flight controls Flight regime recognition for engine performance calculations Automation of data management, diagnostics and prognostics RT&B “SmartChart” Technology – Tell the maintainer what is wrong with the aircraft

Page 37 Benefits are tangible We have realized a significant return Significant Cost Savings Achieved highest readiness rating Engine availability improved Back shop procedures improved Safety of flight improved

Questions?

Page 39 Backup slides

Page 40 Tool to reduce Total Cost of Ownership  Man-hour/Cost Savings/Readiness Improvement Replaces unreliable/unavailable Support Equipment Reduces troubleshooting time dramatically Eliminates unnecessary removal of good dynamic components due to shotgun troubleshooting approach  Operational Improvements Provides in-flight warnings of impending catastrophic failures Provides vib/engine data for fleet/FST diagnostics  Other benefits 100% compatible with existing 8500C data Easy data sharing between O, I, D and FST

Page 41 Savings Through Diagnostics  Fault-based maintenance is an expensive practice Reduces availability Drives unscheduled maintenance May involve collateral damage or flight mishap  Condition Based Maintenance (CBM) is possible if you can first assess “condition” Reduced O&S costs Increased safety, reliability and availability More efficient use of personnel through application of technology Diagnostic Systems like AIMS is a key enabler of CBM

Page 42 CH-46E CURRENT OPERATING & SUPPORT COST $9,140 Cost per Flight Hour O&S is driven by both Direct Maintenance Cost and other indirect costs. $5,100 Cost per Flight Hour DMC is driven by depot repair and overhaul of dynamic components and transmissions DMC O & S

Page 43 Cost Benefit Analysis (CBA) Technical & Maintenance Summary Life Cycle Cost ElementCH-46E AVDLR/Consumable Cost 50% to 75% Reduction in Vibration Related Maintenance Actions Low50%8.3% Med65%10.8% High75%12.5% Depot Impact Reduction in Emergency Repairs Low10%3.7% Med17.5%4.3% High25%5.6% Functional Check Flight Hours RT&B, Engine & Drive Systems percentages are for FCF hours saved RT&B45%4.74% Engine30%2.85% DT/GB25%2.37% Flt. Hr Reduction3.32% Repair Complexity Factor Factor applied to: 21% Generator Repair, 71% Engine Vibration, 6% Fwd/Aft Transmission, 2% Support Equipment 1 ~ 5 Years102% 6 ~ 10 Years78% 10 ~ END57% Technical and Maintenance Estimate (%)Applied Cost Factors (%) Reduction CBA Cost Factor Reduction (%)

Page 44 AIMS TOTAL COST AVOIDANCE FY05 $13.7 M $3.6 M $10.1 M

Page 45 BREAK EVEN POINT Based on POM 06 TAI Current Cost Avoidance 154 Installations Completed 4 TH Qtr FY 07

Page 46 BREAK EVEN POINT Based on POM 06 TAI Current Cost Avoidance 154 Installations Completed 4 TH Qtr FY 07 Actual Cost Avoidance (Installs)

Page 47 1.Based on 154 AIMS aircraft and percentages from FY Functional check flights Flight hours to perform FCF’s 4.$9791 Cost per flight hour (FY04 cost data) 5.Total cost for FCF’s in FY 04 equals $36,461,684 Input from Val/Ver flight crews. First FCF performed with AIMS was a complete card on both engines. Total time with an unfamiliar crew was under an hour. As the crew becomes familiar with the system, times continue to reduce. A very conservative estimate is a 30% reduction in flight times for FCF’s with AIMs vice using the NP600 for engine set-ups. After entire fleet has been converted to AIMS total flight hours would be reduced by 1117 hrs at a $10,938,505 savings based on FY04 data. Rotor Track and Balance timesavings have been significant as well. Due to the speed at which the AIMS system calculates solutions and the need for SE being removed, the engineering staff estimates at least a 50% reduction in the amount of time it takes to get an aircraft ready to go. Possibly the biggest value to the AIMS system is the removal of the NP600 for engine set up and the 8500C for RT&B. A typical set up for either of these pieces of gear takes 2 marines around an hour to prep for flight when all the gear is available and RFI. More often than not, the gear is down or in for cal etc. and the time it takes to get the equipment and be ready for flight can take upwards of 3-4 hours. I created a “spaghetti” diagram based on a typical scenario for the current method of FCF’s and one after AIMS is installed. Installation of AIMS will cut the need for mechs to walk to the SSE room, Cal shop etc. to get the gear. I estimate a typical walking savings of 5400 feet per FCF for a total of over 4000 miles per year that the mechs don’t have to walk to set up for FCF’s. In addition, the time savings will easily surpass 8,000 man hours required to set up for FCF’s. Quantifying AIMS Savings