Eaton Aerospace Oil Debris Monitoring Technology

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Eaton Aerospace Oil Debris Monitoring Technology

• Presentation to the
• Aircraft Builders
• Council, Inc.
• September 26, 2006

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Why Monitor Oil Debris?

• Engine Wear
• Predict Engine Failure

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Bearing/Gear Life Cycle, Stage One
Run-in stage Initial Wear particles are several
hundred microns in size. The size and rate of
particle generation decrease as the engine is run
in.
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Bearing/Gear Life Cycle, Stage Two
Normal Operation Stage Debris generation
reaches a low rate equilibrium.
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Bearing/Gear Life Cycle, Stage Three
Failure stage Primary Mode indicated by
escalating quantity of of 250400 micron
particles. Secondary Mode - marked by the
generation of much larger debris
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Sample Debris Particles
110 µg bearing RCF particle
Extruded Rolling Contact Fatigue (RCF) spall
flake, ca. 300 µm diameter
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Product Evolution

• Mag Plug (visual inspection)
• Very simple
• Inexpensive
• Thread-in designs
• Requires lock-wiring
• Oil loss when inspecting
• Labor intensive

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Product Evolution

• Chip Collector w/SCV
• (visual inspection)
• Relatively simple
• Inexpensive
• Thread-in or quick disconnect designs
• No lock-wiring on QD
• No oil loss when inspecting

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Product Evolution

• Electric Chip Detector /SCV (remote indication)
• Alerts crew when debris is captured
• Eliminates periodic checks
• Some false indications due to normal wear
  particles
• Aircraft wiring required

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Drivers for Advanced Oil Debris Monitoring

• CBM (Condition-Based Maintenance) - reduce
  maintenance burden by eliminating routine
  inspections
• PHM (Prognostic Health Management) - reduce
  IFSDs, remote engine changes, unscheduled
  maintenance
• Reliability reduce frequency of oil system
  break-ins and associated maintenance-induced
  problems
• Commercial power-by-the-hour, remote diagnostic
  programs, low IFSD rate, high dispatch
  reliability, improved ETOPS
• Military autonomous maintenance,
  self-deployment, elimination of ground support
  facilities

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Some Requirements for Advanced Debris Monitoring
Systems

• Failure detection reliability
• detects all debris-producing, oil-wetted failures
  in a timely manner (avoidance of IFSDs, AOG,
  secondary damage, remote engine changes)
• causes no, or at most, minimal false alerts
• provides a verification process to support
  maintenance decisions (e.g. engine removal)
• Prognostic capability
• Communication with FADEC, EMU, CEDU, etc.

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QDM (Quantitative Debris Monitor) Technology
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GE90 for Boeing 777

• First Commercial Aircraft Engine with Advanced
  Oil Debris Monitoring System
• Over 7 million engine flight hours since 1995

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GE90 Debris Monitoring System Hardware

Signal conditioner generates digital pulse when
debris particle exceeds preset mass threshold
Three-phase vortex separator separates air and
debris from oil
QDM (quantitative debris monitoring) inductive
debris sensor - generates signal when particle is
captured
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Signal conditioner
DMS Hardware Mounted on Fan Case
Vortex separator
Sensor
Oil Reservoir
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Operating Principle 3-Phase Vortex Separator
Debris separation efficiency 75 to 95 Air
separation efficiency 95 Oil separation
efficiency 99.8
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3D DMS Design
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Debris Tracking
3D DMS Design
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QDM Operating Principle - Sensor
Magnetic field
Sense coil
BIT coil
Chips of different mass arrive
Magnet
Magnetic pole piece
Output pulses for a small and a large particle
QDM sensor is a passive, magnetic, inductive
sensor that collects, retains, and indicates
capture of, individual ferromagnetic chips
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• QDM System Performance
• Counts ferromagnetic particles that exceed a mass
  of 50 µg (M50Nil), equivalent to a 230 µm dia.
  sphere.
• For inductive sensors, sensitivity is a function
  of particle mass (not linear size), magnetic
  properties, shape.

1000µm
These particles all have the same size but
their mass differs by 100x
250µm
12
125
65
10
1
µg
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QDM Operating Principle - System
QDM signal conditioner
Pre-set mass threshold
QDM counts discrete particles
Square output pulses to FADEC or EMU
QDM sensor
sensor output
BIT input to sensor
BIT command from FADEC or EMU
Notes 1. The signal conditioner indicates
chips above a minimum, pre-set mass threshold to
reject noise-induced false counts. 2. Limited
chip mass classification (two or more mass
levels) is possible, but this requires more
complex chip alert algorithms.
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QDM Signal Conditioner
The QDM Signal Conditioner electronics are simple
and contain no software (unless data bus
interface or multi-level mass binning is
required). Electronics can also be incorporated
into FADEC or EMU as Eaton-supplied PC-board or
licensed technology.
Approximate size 4x4x2 in. Weight .95lbs. MTBF
no field failures in 5 million hours
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Alert Algorithms and Maintenance Procedures

• Based on important characteristic of oil-wetted
  component failures ongoing particle production.
• Alert algorithms for two preset debris count
  thresholds per-flight and cumulative.
• DMS messages are generated and displayed when
  thresholds are reached or system fails BIT on
  start.
• Visual sensor inspection verifies presence of
  debris and provides first-cut problem analysis.
• Further debris analysis, using established
  techniques (e.g.SEM/EDX), verifies failure and
  supports engine or module removal decision.

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DMS alert messages
Per-flight debris count
QDM Signal
Cumulative debris count
BIT command
DMS system fault
Signal Conditioner.
MAT
QDM Sensor
FADEC
ACMS
EICAS status message
Ch.A
VHF radio downlink via ACARS
CMC
Ch.B
Remote Diagnostics program data bases
AMI software
Debris data trending
Non-volatile memory
DMS Integration and Interfaces on GE90/Boeing 777
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Maintenance Access Terminal (MAT) on 777 Flight
Deck
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EICAS Display on 777 Flight Deck
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QDM Sensors for Smaller Engines - Sump or
Scavenge Pump Inlet Installation
QDM sensor with self-closing valve for sump
QDM sensor with valve built into scavenge pump
inlet screen
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QDM..

• Indicates ferromagnetic chips with a mass above a
  preset threshold.
• Mass threshold is set so that environmental noise
  (EMI, vibration) does not cause false counts.
• Sensor collects and retains all chips for alert
  verification.
• Chip counting, algorithms and crew alert
  functions reside in FADEC, EMU, CEDU, etc.
• Includes end-to-end BIT.

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QDM..

• In its simplest form, has very simple electronics
  and no software. Mass-level categorization
  (binning) or bus communication requirements may
  add complexity, including software.
• Alert algorithms and maintenance procedures need
  to be developed by engine and aircraft OEMs,
  e.g.
• Count thresholds (number of chips per flight,
  number of chips per elapsed time interval)
• Trending
• Maintenance alerts, in-flight alerts or both

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In Service Experience

• Eatons DMS hardware has worked flawlessly
• Several failures detected during engine
  development
• Two VSCF generator failures detected in 1997
• April 8, 2002 Beijing/Paris in-flight EICAS
  status and ACARS messages enabled Air France to
  get a spare aircraft ready. After landing, a
  developing failure was confirmed.
• During 7 million flight hours, no nuisance
  indications reported. Several engines have low,
  random debris counts that have not caused alerts.

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In-Service Experience (cont'd.)

• Absence of DMS counts prevented two IFSDs that
  would have resulted from false impending-bypass
  indications due to faulty filter-?p sensors.
• Most airlines no longer perform 500-hour routine
  sensor inspections originally recommended by
  Boeing.
• Continental has 16,000 hour high-time engines
  w/o sensor inspection. Routine sensor cleaning
  not required.
• End-to-end BIT detected early harness and other
  system problems

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Conclusion

• Appropriate alert algorithms and successful
  system integration are critical for timely
  failure detection and nuisance alarm prevention.
• QDM is a proven, mature system
• over 7 million successful engine flight hours on
  GE90
• qualified for GP7200 (Airbus A380)
• selected for GEnx, and Trent 1000 engines (Boeing
  787)
• Engine monitoring and aircraft maintenance
  systems can take full advantage of QDM
  capabilities improving safety and lowering
  operating costs.