January 15, 2019

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Steve Bentley MD of Sofema Aviation Services (www.sassofia.com) takes a look at the function and development of the Aircraft Maintenance Program in the EASA Compliant World.

Our mission is to share that the role of Maintenance Planning has the potential to provide significant savings whilst maintaining a fully compliant and safety focused maintenance management system.

The Role of Maintenance Planning is to provide:

· Potential for significant financial & operational savings

· A fully compliant maintenance management system

· A safety-focused maintenance management system

 

Let’s Start at the Beginning

Q Why is a Maintenance Program Required?

A To provide a structure and framework to the process of delivering the “needed” maintenance

Q Who owns the Maintenance Program?

A Under EASA Rules the Maintenance Program is owned by the Operator

Q What are the two main reasons we have a Maintenance Program?

Essentially the reason we do maintenance is either related to the need to ensure safety or to provide an economic advantage (means performing maintenance becomes cost advantageous)

 

What is the Industry View?

Apart from the safety (which is almost taken for granted)

Reliable service with on-time departure is a part of the passenger expectation,

As a result, this has made the on-time performance of an airline’s schedule a key factor, which places Airlines continuously under pressure to improve their punctuality and provide on-time performance.

 

Equipment Reality Check!

Eventually, all mechanical components or equipment’s will fail, the whole purpose then of maintenance is to not only to recognize this fact but to cope with it in the most effective way.

 

The Early Days – Means Before MSG

Maintenance has come a long way since the early days, when maintenance programs owed more to the perception of the maintenance needs, as opposed to the analyzed and justified needs.

 

Where was the Regulatory oversight?

In the early days the role of the regulator was minimal, and in part developed as a result of events, incidents and accidents. During the first half of the 20th century regulations began to gradually strengthen and the focus was on the aircraft manufacturer as the “expert” who was seen as the appropriate source of the technical competence needed for maintenance program development.

 

Hard Time Primary Maintenance

Early attempts (in the 1960s) at driving improvements related to improving the effectiveness of the maintenance process saw time limits developed which resulted in aircraft being progressively dismantled, in what became known as Hard Time primary maintenance.

All hard time components were then routed through an overhaul process and after an appropriate restoration process was considered as zero time. (means they were considered as zero life and good to go again)

Do you agree the above statement is true! – The problem was that the overhaul process did not necessarily impact the eventual life of the component)

 

The Beginning of the Modern Age – MSG is Coming

Through the 1960s representatives from both the FAA and a number of airlines formed a task force to investigate the capabilities of preventive maintenance.

Thus was born the MSG Process – (1970 MSG-1 introduced for the B747-100)

 

Take a View – the OPERATORS Perspective

  • Operators are continuously under pressure to improve their punctuality.
  • Eventually, all mechanical components or equipment will fail.
  • The whole purpose then of maintenance is to not only to recognize this fact but to cope with it in the most effective way.

 

Take a View – The REGULATORY Perspective

It is of primary importance to deliver:

  • Effective oversight of aircraft operators’ maintenance programmes.
  • Viable assessment of the management of the continuing airworthiness process.
  • Modern maintenance programmes are the result of analysis and justified needs.

In addition, the role of the regulator was also minimal, and in part developed as a result of events, incidents and accidents.

 

Into the 1960s

  •  The early attempts at effective maintenance (in the 1960s)
  •  Time limits developed
  •  Aircraft progressively dismantled
  •  All hard time components routed through an overhaul
  •  After an appropriate restoration process was considered as zero time. (Known as ‘Hard-time Primary Maintenance
  •  This means they were considered as zero life and good to go again.

Following investigations into the effectiveness of the Aircraft Maintenance Process, by both the FAA and several airlines, a number of determinations were made.

When dealing with the complex technical systems involved in air transport, the consequences of unreliable services become critical and may include:

  • High cost of operation
  • Loss of productivity
  • Incidents, and potential exposure to accidents
  • The data they gathered was analysed with the following outcomes:

 

The process of scheduled overhaul had little effect on the overall reliability of complex equipment unless the equipment has a dominant failure mode.

Dominant Failure Mode – Means that unless there was a specific item which would wear out, the entire overhaul process did not add value

Overhaul Viability – Scheduled overhaul does not have a particular impact on the reliability of a component

This calls into question the rationale in performing the overhaul

 

On Condition (OC) Maintenance

A second primary maintenance process defined as On-Condition (OC) developed.

OC requires that an appliance or part be periodically inspected or checked against some appropriate physical standard

OC determines whether a part can continue in service.

 

Appropriate Physical Standard

The purpose of the standard is to remove the unit from service before failure during normal operation occurs

OC Maintenance ensures that the component or system is maintaining conformity with the expected behaviour or standard

Any deviation will trigger the removal of the component from service.

With On-Condition Maintenance we ensure that the component or system is maintaining conformity with the expected behaviour (a standard) and any deviation will be the trigger to remover the component from service.

 

Reality Check – Scheduled Maintenance Viability

There are many items for which there is no “effective maintenance activity” for scheduled hard time maintenance.

Sofema Aviation Services www.sassofia.com and Sofema Online www.sofemaonline.com offer multiple EASA Compliant Regulatory Training for details please see the websites or email office@sassofia.com or online@sassofia.com

Tags:

Aircraft Maintenance Introduction