OT Safety Bulletin

Safety Awareness – Independent Inspections

Independent inspections are an important part of airworthiness and are a requirement, see OTAR Part 43.111.

Common errors that lead to these being ineffective are:

1. A complex maintenance task that has numerous independent inspection requirements that are grouped together under one independent inspection task. 

Grouping under one maintenance task line entry will result in a high probability of a maintenance error.  HIGH RISK.  Components or maintenance tasks that meet the requirements for ‘Independent Inspections’ should be treated as individual items to be completed and inspected.

For example, replacement of an engine.  Consideration should be given to engine controls – connection points, mounting points, rigging checks, borescope blanks, security & locking of engine cowlings or ‘C’ ducts, software configuration, FADEC components replacement etc...  These should have their own individual independent inspection.

2.  Terminology – Independent Inspection, or is it a Duplicate Inspection?  Which term should be used

Terminology has changed, and organisations should be using the term ‘Independent Inspection’.  Duplicate Inspection is old terminology where it required two persons who held an authorisation to issue certificate release to service (CRS) for that particular inspection.  This is no longer required.

The first signature of the independent inspection is completed by the person authorised to issue a certificate release to service for the particular aircraft type or component.  The second signature attests to the satisfactory completion of the work recorded and that no deficiencies have been found.  Both signatories should also consider the whole maintenance accomplished.

3.  Using incorrect maintenance actions

Using incorrect terminology to describe the actual maintenance task and describe the purpose of the independent inspection.

Example; ‘#1 Engine Replacement - Independent Inspection as required’.

This does not describe what the second person is attesting to the satisfactory completion of or to what standard.  Using ‘as required’ is too vague.

Reminder – terminology that should be used and may be a combination of:

• Function – eg Leading-edge spoilers retract on selection of flap lever to position….
• Sense – eg under carriage free fall drops at …….
• Operation – eg iaw a specific maintenance task….
• Locking – eg engine control lever correctly wire locked….
• Assembly – eg flap assemble installed iaw specific maintenance….

4.  Document recording actions

A common error is forgetting to add the following, which is a requirement, beside the statement:

• Signature; and
• OTAR Part 66 licence or validation number and/or authorisation number; and
• Date and time of entry.

Ensure that your independent inspections are clear, completed and recorded correctly.