Transcript International Business - Mr. Petrucci

Aviation Maintenance
Management
Why We Have to Do Maintenance
Chapter 1
THIS DAY IN AVIATION



January 28
1871 — The last balloon to
leave Paris during the
Persian siege takes off with
orders for the French fleet
to bring food and supplies
to replenish the French
capital, an armistice having
been signed.
The flight of the General
“Cambronne” ends a
period of almost exactly 5
months during which the
advantages of balloons
were put to efficient use.
THIS DAY IN AVIATION

January 28
1945 — The Burma
Road is reopened.

THIS DAY IN AVIATION

January 28
1945 — The USAAF 8th
AF observed its 3rd
birthday with a 1,000
plane raid on Germany.

Aviation Maintenance Management








Introduction
Design & The Role of the Engineer
Role of the Mechanic
Types of Maintenance
Reliability & Redesign
Failure Rate Patterns
Other Maintenance Considerations
Summary
Introduction





Schedule pressures, parts shortages,
equipment deficiencies, regulatory and agency
compliance inspections, union pressures etc..
Technology advancements and diverse equip
require perpetual training
Parts issues – no parts, cannibalization,
aircraft on ground, weather conditions
Personnel issues – financial, family, substance
abuse, late, no-show, vacations, trng, meetings
– impact (touch labor)
Unscheduled Maintenance
Managerial Challenges

Aircraft out of service impacts –





crew training and readiness
Lost of revenue (no passengers – and maint/labor
costs)
Loss of customer loyalty (customer is price based)
Intent of course not to make you an expert
maintenance manager but to expose you to the
various influences and the functions and
techniques of the job
Knowledge is power
Modern Day Aircraft Maintenance

Aircraft require preventive or corrective
maintenance at frequent intervals


Kind of operation; environmental conditions; storage
facilities avail; age and construct of aircraft
Maintenance Man-hours per Flying hour
(MMH/FH)

Cost to maintain a particular type of aircraft
Modern Day Aircraft Maintenance


Cost of ownership – fuel, wash, oil, tires etc…
Scheduled maintenance



Goal is to correct any deficiency before it occurs
Checks cost money – labor and parts, fluids costs and
loss of passenger revenue when not flying
Total up all Maintenance associated costs
subtract from revenue from aircraft and you get
profit or loss
Design & Role of Engineer

We can design perfect systems on paper
but we can not build perfect systems in
the “real” world



Nothing is perfect
Good, Fast, Cheap
A design engineer may be limited from
making the perfect system by technology
or the state of the art within any facet of
the design effort


Limited by ability, technique or economics
Economics may force a redesign with reduced
tolerances, cheaper materials and gap between:
 perfect and “perfect” realism
Role of the Mechanic

For the mechanic the gap between “perfect” &
“perfect” realism always changes &
predominantly for the worse




Components or systems tend to wear out from use or lack
there of (time or environmentally related)
Misuse may cause premature deterioration or degradation
of the system or even outright damage
The engineer’s responsibility is to design the
system with as high degree of perfection within
reasonable limits/constraints
The mechanic’s responsibility is to combat the
gap between ideal & realism during the
operational lifetime of the equipment
Two Types of Maintenance

Preventive Maintenance (PMs)


Scheduled Maintenance


Performed at regular intervals – to prevent deterioration
of the system to an unusable level and to keep it
operational – often referred to as:
Performed – daily, every flight, every 200 flight hours, or
every 100 cycles (takeoff & landings)
Unscheduled Maintenance

Various, unpredictable intervals maintenance actions
are required to restore a system that may require
extensive testing, troubleshooting, adjusting,
replacement, restoration, or complete overhaul of parts
or subsystems
Maintenance Defined






Cost of Ownership and scheduled maintenance
are 2/3 of equation
Unscheduled Maintenance – random failures
Reliability studies have led to MTBF (Mean
Time Between Failure) – components / system
guesstimated reliability factor
Induced failures – FOD, damage from servicing
vehicles, maintenance malpractices
Inherent failures – delamination of composites,
substandard bearings, inefficient seals etc.
No defect – A-799 or fault within tech data
limits (require expenditure of maintenance
resources)
Reliability & Redesign

Reliability



“A measure of the probability that an item will
survive to a specified operating age or time,
under specified operating conditions, without a
failure”
no amount of maintenance can be performed to
increase the systems inherent level of designed
in-level of perfection
Redesign


When the reliability decreases & a higher level of
“perfection” is desired – redesign may take place
Needs to be weighed if the performance
improvement justifies more maintenance & thus
the increase in maintenance costs – ideally the
Failure Rate Patterns (MTBF)



All systems or components fail at the same rate or
exhibit the same patterns of wear out and failure
The maintenance performed is related to those rates
and failure patterns (Table 1-1 pg. 10)
“Infant mortality” – early high failure rate in
component’s life




“getting the bugs out”
Causes” poor design, improper parts, incorrect usage etc..
These characteristics of failure make it necessary to
approach maintenance in a systematic manner to
reduce peak periods of unscheduled maintenance
Several techniques have been designed to combat
this:
Three Maintenance Management
Techniques

Three Maintenance Management
Techniques


Equipment Redundancy



Equipment redundancy, line replaceable units, &
minimum aircraft dispatch requirements
Duplicate systems – primary and a backup
(radios, navigation devices, flight control systems,
computers)
Instrumentation within cockpit can signify status
Line Replaceable Units (LRUs) – black
boxes

Designed to allow easy removal and replacement
to reduce out of service timer of aircraft
Three Maintenance Management
Techniques

Master Minimum Equipment List (MMEL)


Lists ALL equipment for the aircraft model – list is tailored to its
MEL
Minimum Equipment List (MEL)


List of equipment that the aircraft may be inoperative
but still allowed to fly as long as it does not affect the
safety & operation of flight – Tailored to mission
Determined by manufacturer and sanctioned by the
regulatory authority (FAA)
Three Maintenance Management
Techniques

Minimum Equipment List (MEL)





Concept of the MEL is to allow the deferral of
maintenance without upsetting mission requirements
Maintenance must be performed within some set of
guidelines (1, 3, 10, or 30 days or cycles required)
depending on operational requirements of the system
Pilot may always require or defer maintenance per the
MEL
Maintenance MUST abide by decision…. (his call)
“Takes a college education to break it & a high school
education to fix it.”
Minimum Equipment List (MEL)

Dispatch Deviation Guide (DDG)


Configuration Deviation List (CDL)



Instructions for maintenance not necessary obvious to the
mechanic – tying up cables, capping off connectors, taking circuit
breakers out to prevent inadvertent power-up of equipment
during flight while maintenance is being performed and any other
precautionary steps that need to be taken
List of information of equipment or panels etc. that may be
missing or added per that aircraft model
All lists can be found in the aircraft logbook
3 techniques help minimize the workload and reduce
service interruptions due to maintenance
Summary




The purpose of aircraft maintenance is to
ensure the aircraft will remain airworthy
throughout its operational life
Still haven’t reached perfection even with
advances in technology
3 maintenance techniques help manage
maintenance actions
Not all aircraft maintenance activities will be
organized or operated in the same manner but
the programs and activities will be the same