AIRCRAFT BRIDGING CHECK

A Bridging Check is a set of tasks required to transfer an aircraft from one Maintenance Programme to another. Every operation is unique and hence an aircraft may have been maintained to the same tasks at a different frequency or to different maintenance standards in its previous operation.

When an aircraft transitions from one operator to another, or, from one maintenance programme to another, the time in service, calendar times, or cycles of operation accumulated under the previous maintenance programme must be applied in determining tasks due times under the new maintenance program. In addition, some aircraft operators may have more stringent maintenance requirements than the aircraft manufacturer recommends.  

A ‘bridging check’ does not in itself mean a maintenance package; it is the product of a detail analysis of the transfer aircraft maintenance history in relation to the Maintenance Programme the aircraft is to be placed under. Typically, there may be some maintenance activity at the time of transfer; the amount will clearly be influenced by the current maintenance status of the subject aircraft and to the extent the Maintenance Programme has been developed.

Developing solutions for bridging maintenance requirements takes specialized skills and knowledge, often requiring the assistance of the aircraft manufacturer or specialist third-party maintenance repair & overhaul (MROs) companies. Bridging involves reviewing the task requirements of two maintenance programmes and developing a “task differences” list.

A “task differences” list does not in itself mean a maintenance package; instead, it is the product of a detailed analysis of the transfer aircraft’s maintenance history in relation to the Maintenance Programme the aircraft is to be placed under. If the aircraft reverts back to the manufacturer, the manufacturer will want to know where the aircraft falls under their own Maintenance Programme recommendations.

The key to understanding the Bridging Process is to understand that the MSG 3 AMP is a task-based Program and each task may be considered in isolation as a “Stand Alone” Task (Packaged in accordance with the operators’ maintenance plan).

Let’s consider some of the “rules” we should acknowledge:

1/ The Initial Maintenance Programme shall be based on the Manufacturer Maintenance Planning Document (MPD) – owned by the Operator and approved by the Regulatory Authority

2/ Because the Operator “owns” the Maintenance Programme it has the possibility of varying the tasks in some cases escalating even beyond the MPD (this is allowable and acceptable within MSG-3 rules)

3/ As a result it may be that the aircraft which is being imported is on a “different” Maintenance Programme than either the current Maintenance Programme or the proposed baseline Maintenance Programme (For a new Operator)

So how to treat the gaps in Task Intervals?

The possibility exists to perform a bridging check by comparing ALL task Intervals on the existing (old) Maintenance Programme with the Intervals of tasks on the proposed (new) Maintenance Programme and to determine what maintenance is required as part of the bridging process.

The addition of more aircraft to an existing schedule requires an assessment of the maintenance required to align the aircraft with the new Schedule of Maintenance.

What is the Process for Constructing the Bridging Check?

The bridging process will normally consider the following factors as a precursor to determining the appropriate task requirements:

a)   Program differences

              i.        Systems & Powerplant program

             ii.        Zonal program

            iii.        Structures program

b)   Age of the aircraft: calendar, total flight hours & flight cycles

c)   Configuration differences,

d)    Next due heavy maintenance check

              i.        Systems/Structures C-Check

             ii.        D-Check

e)   Aircraft utilization.

f)     Operating environment.

g)   Phased and block maintenance programmes.

h)   Airworthiness Directive/CMR/AWL status.

i)     Service bulletin/modification incorporation.

j)     Applicable regulatory authority requirements.

k)    Major Repairs and Modification

An Integration – Transitional work package may be produced to determine the Integration or bridging work package.

The following formula is used in respect of each and every task.

      X = Y a
                b

X = time remaining to task on new programme
Y = time remaining to task on previous programme

a = interval between task on new programme

b = interval between task on previous programme

 

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