Destorage of Aircraft

Some months ago, with the support of industry and national competent authorities (NCAs), EASA developed an initial set of guidelines to help operators bringing aircraft our of storage and back to operations. After further experience and analysis the document has been updated and a revised version 2.0 of the guidelines has been issued.   

What are the main changes? 

To help you to understand what has changed we list the main changes below: 

More information on the analysis to determine return to service activities

Paragraph 3 of the document has been updated to incorprate more information to emphasise the need to consider the particularities of each case and the communication with the relevant organisations and competent authorities. The new text is: 

"The analysis should include the identification of hazards stemming from past RTS experiences, the condition of the aircraft of their fleet and organisational aspects. In addition it should be ensured that the existing hazards are to be reassessed and new hazards might have to be identified by taking the pandemic into consideration. Subsequently, the resulting required mitigating actions and maintenance work have to be determined and accomplished in order to ensure that the risks are properly managed"

Additional points of consideration on the identification of hazards

In Paragraph 3.1 on the "Proactive identification of hazards" some additional points were added after feedback from industry stakeholders. Additionally more information was added at Paragraph 3.2 on the "Reactive identification of hazards (data collection from the AMO and analysis". 

Examples of occurrences identified so far

Another useful addition to the document is the inclusion of a summary of the types of occurrences identified already during the crisis to aid help you learn from the experience of others. These examples of occurrences related to prolonged parking/storage with a serious impact on airworthiness are:

• Sticking / high friction of valves in engine bleed air system leading to pneumatic system issues during flight (e.g., bleed air loss, in one particular case this led to an in-flight shut down).
• Erroneous air data information including contaminated / blocked pitot-static systems and Angle of Attack (AOA) vanes failure.
• Fuel system contamination caused by non-adapted water drainage intervals or lack of available biocide.
• Emergency batteries, post parking or storage procedures, not at the expected state of charge.
• Depletion of aircraft parking brake accumulator pressure leading to damaged aircraft in ground incident.
• Wildlife nesting in the aircraft / engines while parked/stored, including insects and rodents.

Examples of hazards and mitigations

The texts in Paragraph 4 has been replaced with two Appendices that are aimed to provide more practical information to help organisations in the task of bringing aircraft back from storage. 

Appendix 1 covers the following examples of hazards and mitigating strategies: 

• Lack of current knowledge and skills of staff.
• Lack of sufficient staff.
• Lack of required parts and materials.
• Lack of appropriate procedures and TCH/DH instructions.
• Procedures and/or instructions are not followed.
• Lack of appropriate tools and equipment.
• Unsuitable environmental parking/storage conditions.

Appendix 2 covers the following examples of best practices: 

• Continued aircraft airworthiness status and work planning/control.
• Recordkeeping.
• Quality & safety policy, promotion and management.
• Monitoring of the RTS process and continuing airworthiness.
• Changes, novel and alternative processes.