eaton aerospace oil debris monitoring technology l.
Skip this Video
Download Presentation
Eaton Aerospace Oil Debris Monitoring Technology

Loading in 2 Seconds...

play fullscreen
1 / 32

Eaton Aerospace Oil Debris Monitoring Technology - PowerPoint PPT Presentation

  • Uploaded on

Eaton Aerospace Oil Debris Monitoring Technology. Presentation to the Aircraft Builders Council, Inc. September 26, 2006. Why Monitor Oil Debris?. Engine Wear Predict Engine Failure. Bearing/Gear Life Cycle, Stage One. Run-in stage:

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Eaton Aerospace Oil Debris Monitoring Technology' - albert

Download Now An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
eaton aerospace oil debris monitoring technology

Eaton Aerospace OilDebris Monitoring Technology

Presentation to the

Aircraft Builders

Council, Inc.

September 26, 2006

why monitor oil debris
Why Monitor Oil Debris?
  • Engine Wear
  • Predict Engine Failure
bearing gear life cycle stage one
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.

bearing gear life cycle stage two
Bearing/Gear Life Cycle, Stage Two

Normal Operation Stage:

Debris generation reaches a low rate equilibrium.

bearing gear life cycle stage three
Bearing/Gear Life Cycle, Stage Three

Failure stage:

Primary Mode – indicated by escalating quantity of of 250–400 micron particles.

Secondary Mode - marked by the generation of much larger debris


Sample Debris Particles

110 µg bearing RCF particle

Extruded Rolling Contact Fatigue (RCF) spall flake, ca. 300 µm diameter

product evolution
Product Evolution

Mag Plug (visual inspection)

  • Very simple
  • Inexpensive
  • Thread-in designs
  • Requires lock-wiring
  • Oil loss when inspecting
  • Labor intensive
product evolution8
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
product evolution9
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

Drivers for Advanced Oil Debris Monitoring

  • CBM (Condition-Based Maintenance) - reduce maintenance burden by eliminating routine inspections
  • PHM (Prognostic Health Management) - reduce IFSD’s, 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

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.


(Quantitative Debris Monitor) Technology


GE90 for Boeing 777

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

GE90 Debris Monitoring System


Signal conditioner generates digital pulse when debris particle exceeds preset mass threshold




separates air

and debris

from oil

QDM® (quantitative debris monitoring) inductive debris sensor - generates signal when particle is captured




DMS Hardware

Mounted on

Fan Case




Oil Reservoir


Operating Principle: 3-Phase Vortex Separator

Debris separation efficiency 75 to 95%

Air separation efficiency > 95%

Oil separation efficiency > 99.8%


Air Outlet

Mixture Inlet

Debris Outlet

Oil Outlet

3D DMS Design


Debris Tracking

3D DMS Design


QDM Operating Principle - Sensor

Magnetic field

BIT coil

Sense coil

Chips of different mass arrive


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


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.


These “particles” all have the same “size” but their mass differs by >100x









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


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.


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


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.

DMS alert messages:

QDM Signal

Per-flight debris count

Cumulative debris count

BIT command

DMS system fault








EICAS status message


VHF radio downlink via ACARS



Remote Diagnostics program data bases

AMI software

Debris data trending

Non-volatile memory

DMS Integration and Interfaces on GE90/Boeing 777


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



  • 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.


  • 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

In Service Experience

  • Eaton’s 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.

In-Service Experience (cont'd.)

Absence of DMS counts prevented two IFSD’s that would have resulted from false impending-bypass indications due to faulty filter-Δp 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



  • 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.