Managing Your Helicopter Condition-Based Maintenance Program

1. How to Manage your Condition-Based
Maintenance Program
Helitech International
September 24, 2013
Helitech International
September 24, 2013
D.B. “Danny” Green
US JHSIT HFDM, HUMS IWG Member, HUMS
Reporting Member of the HAI Technical
Committee, IHST HeliShare OGP Lead

2. What to Expect Today
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What not to Expect Today
• Sales Pitch (I’m only selling proven
Who/What is IHST
concepts not endorsing products)
Define CBM
• Extensive Vibration Training
CBM Terminology
• Engineering, Theory and or Scientific
Why Use CBM?
Debates
– Benefits
• We will not discuss recent events
– Potential Disadvantages
How do we do it?
Equipment Offerings
– References
Interactive Case Studies
A basic understanding of the
principles of CBM, its “interaction”
with a proactive SMS
Helitech International
September 24, 2013

3. Helitech International
September 24, 2013

4. IHST’s attitude towards safety:
• IHST takes a proactive attitude that anyone’s helicopter
accident belongs to all of us.
• Accidents affect our collective reputation as providers of
air transportation and suppliers of air services…
• We don’t need to accept accidents or a high industry
accident rate, and it affects our profitability if we do so.
– Jack Drake, IHST JHSAT Accident Analysis Group
– Presented at ISASI 2008
Helitech International
September 24, 2013

5. WSJ, 9/5/2013
North Sea Crash Underscores Poor
Progress in Helicopter Safety
Civilian Chopper Crashes Have Remained Flat Over Decade
The fatal crash of a Eurocopter oil-rig helicopter in the North Sea last month
underscores stalled progress in reducing commercial helicopter accidents worldwide.
In spite of advances in cockpit technology and enhanced pilot training, helicopters'
global safety record has failed to improve dramatically over the past few years—
.
and still lags far behind standards for airliners
WSJ 9/5/2013 By: Andy Pasztor and Daniel Michaels
Helitech International
September 24, 2013

6. Helitech International
September 24, 2013

7. WHAT is CBM?
From Wikipedia, the free encyclopedia
Helitech International
September 24, 2013

8. Condition-Based Maintenance
From Wikipedia, the free encyclopedia
Condition-based maintenance (CBM), simply described, as
maintenance when need arises. This maintenance is
performed after one or more indicators show that equipment is
going to fail or that equipment performance is deteriorating.
This concept is applicable to mission critical systems that
incorporate active redundancy and fault reporting. It is also
applicable to non-mission critical systems that lack redundancy
and fault reporting.
Always keeping in mind the required FAA/CAA inspection
programs with an emphasis on value added tasks.
Helitech International
September 24, 2013

9. in other words…
If it aint broke, don’t
fix it!
Helitech International
September 24, 2013

10. CBM Benefits
CBM has some Benefits over planned maintenance:
•Improved system reliability
•Enhanced Safety
•Decreased maintenance costs
•Increased Readiness
•Operation and Support cost benefits
• Reduction of human error influences.
•Other Intrinsic Benefits:
•Increased pilot confidence
•The ability to monitor health of an entire fleet, regardless of physical location
• As the program matures, the potential to predict when certain faults will
occur, based on historical data and specific aircraft data
•The ability to more effectively plan maintenance actions over the long-term
Reference the IHST HUMS Toolkit (IHST.ORG) for complete details
Helitech International
September 24, 2013

11. Disadvantages
Some potential disadvantages are:
•High equipment costs (initially and to maintain)
•Possible Increased Manpower
•Increased Training
•Increased IT/Support
•Increased number of components (the VHM/HUMS
system itself) that must be maintained
•Increased weight/Decreased carry capacity
Helitech International
September 24, 2013

12. Aviation Maintenance
Options
(A Travel Through Time)
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September 24, 2013

13. Run to Failure or
FIX it When it BROKE!
Post WWII (PMI)
The Somewhat Present (PdM)
Helitech International
September 24, 2013

14. What Does CBM Look Like?
REF. Bubba’s Aviation Maintenance consultants
Helitech International
September 24, 2013

15. What Does CBM Look Like?
CBM
Present Present/Future
(FAA/CAA Required)•HUMS
Past
Fix it When Its Broke
Helitech International
September 24, 2013
•Scheduled Inspections
•Scheduled Maintenance
•Scheduled Overhauls
•Time Lifed Parts
•ADs, SBs, ACs ,CEBs
•FOQA
•VHM
•Advanced Sensing
Technologies
•MSG3
•HFDM
•PdM
•CBM
•RCM

16. Where do we want to be?
Predictive Maintenance Potential Failure P-F Curve
P
Point where
failure starts
Point where failure
can first be detected
Point of failure
F
Time
John Moubray, Reliability Centered Maintenance II
Helitech International
September 24, 2013

17. How Do we Do CBM?
Helitech International
September 24, 2013

18. Then why do we do it?
SAFTEY, SAFETY ,SAFETY, SAFETY, Maintenance
Benefits, SAFETY, SAFETY, SAFETY…!
Helitech International
September 24, 2013
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19. Our CBM Program Philosophy:
One of the key rules by which or organization operates is to
involve the right people in decisions that affect procedures and
equipment. Our entire CBM philosophy is based on that principle.
Safety is above and beyond without question or hesitation our first
and foremost objective!
Our next objective is to minimize unplanned maintenance or at a
minimum, identify and address it on our terms.
Our Analysts interface with Maintenance constantly and seek the
counsel of Subject Matter Experts who are subject to change
depending on the issue in question and/or the aircraft type.
Seek the wisdom of ten rather the knowledge of one.
We also keep management and operations abreast of any
situations so they can make any necessary changes in equipment,
tools or personnel.
Helitech International
“
September 24, 2013
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20. Tools/Tricks of the
Trade
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September 24, 2013

21. Start Here
The latest IHST Toolkit: HUMS
Helitech International
September 24, 2013

22. Before you start
Identify detailed requirements:
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Benefits vs. Cost
Available Equipment
– VHM, HUMS
– T.C., STC
– Carry-On
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Required Personnel
START HERE
ISHT.ORG
– Analyst
– Maintenance Support
– I.T. Support
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In-House or Contract Analysis
Regulatory Requirements
Contractual Requirements
I.T. requirements
Training Requirements
Helitech International
September 24, 2013

23. The latest IHST Toolkit: HUMS
Helitech International
September 24, 2013

24. Content developed
by leading
industry HUMS
experts.
Helitech International
September 24, 2013

25. Resources include
reference materials, a
listing of equipment
providers and actual case
studies.
Helitech International
September 24, 2013

26. Tools/Tricks of the Trade
Vibration Monitor Data
Vibration Spectrum Data
Vibration Signature Data
Logsheets, Inspection Forms, AOCRs
Trending
Limits/Rate of Change
Aircraft Advisories, Fault logs, Exceedences
Proper Interviews:
Pilots, Mechanics and anyone else who may know anything about the
conditions in question.
Helitech International
September 24, 2013

27. Lessons Learned
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September 24, 2013

28. Life Lessons Learned from a HUMS Analyst
1) If you are going to fly around with the added weight and cost of the
equipment…USE IT!
2) Weekly downloads are insufficient for timely and accurate analysis.
– Daily is preferred but between flights is becoming regular
practice in some operations due to the length of flights.
3) Communicate, Communicate, Communicate
– Pilots, mechanics, dispatchers, written reports, i.e. logsheets,
inspection forms AOCRs follow the clues.
4) Be curious, be nosey, be a pain in the butt, ask why 5 times, just
get the answers (we’re talking CSI stuff here)!
5) Being wrong is okay, being scared of being wrong is not. Humility
while painful, could cost or save lives!
6) When in doubt seek a higher power (someone has probably seen it
before) paralysis through analysis is unacceptable in our trade!
D.B. “Danny “ Green
Helitech International
September 24, 2013

29. Most Common Findings:
Main Rotor: Shear Restraints, Trim Tabs, Isolation Mounts,
Bearings
Tail Rotor: Bearings, Trunnions, Blades, Gearboxes
Tail Rotor Drive: Hanger Bearings, Drive Shafts, Hanger
Bearing Mounts and Airframe Cracks
Main Transmission: Output Shafts, ECU Drive
Engines: FOD, Worn Mounts, Oils Pumps, Shafts
Oil Coolers: Fan/Blower Bearings, Trash
Starters: Bearings, Brushes, Looseness
Hydraulic Pumps: Shafts, Seals, Drives and Stripped Studs
Helitech International
September 24, 2013

30. SMS
What does that have to do with SMS?
What is SMS? My simple definition is to have
programs in place to address problems before they
ever exist.
What could possible address this better than CBM
and FDM.
Helitech International
September 24, 2013

31. Interactive Vibration Case Studies…
Can you Analyze the Problem?
Helitech International
September 24, 2013
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32. AW139 Hydraulic Pump
Trending vibration increases noted in the #1 hydraulic pump drive but no limits
exceeded. After review of the log sheets, it was noted that a 100 hour hydraulic pump
inspection was performed in the previous days. The aircraft had a upcoming scheduled
hangar check, the pump was inspected based on our data and two loose studs were
found.
Helitech International
September 24, 2013

33. AW139 Worn Hydraulic Pump Case Study
Noticed increased vibration trending on the
#2 input hydraulic pump. No limits were
exceeded but when the aircraft was down
for other maintenance, the pump was
removed to inspect based on this data and
the worn pump drive shaft was found as
well as damage to the pump.
Helitech International
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September 24, 2013
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34. AW139 T/R Paddle Change
STOP WORK AUTHORITY Used
(A/C Grounded Immediately)
Helitech International
September 24, 2013

35. 430 Tail Rotor Radial
STOP WORK AUTHORITY Used
(A/C Grounded Immediately)
Helitech International
September 24, 2013

36. 430 Tail Rotor Gearbox
Helitech International
September 24, 2013

37. 430 Main Rotor F/A and Vertical Increase
Helitech International
September 24, 2013

38. Hanger Bearing Case Study
#1 hanger bearing showed increased Broad Band
Vibrations (1P and 2P were normal). After visual
inspection and rotational check for smoothness, the
bearing was greased. Grease solved problem for
several days but the problem would return (see
below). This process was repeated until the aircraft
was available for the next hangar check (very large
job, remote a/c) and the bearing could be changed.
Replacement solved the problem and upon teardown
and root cause inspection, it was noticed that the
balls were riding across the outer race once the fresh
grease would break down thus increasing the Broad
Band vibes.
9.26 mm
7.5 mm
Helitech International
September 24, 2013
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39. QUESTIONS?
D.B. “Danny” Green
Mobile 985.768.1823 Office 601.749.4059
dannygreen@chevron.com
Helitech International
September 24, 2013