European Union Aviation Safety Agency (EASA) has announced that there is an alarming trend in the number of reports of unreliable speed and altitude indications during the first flights following the aircraft leaving storage. Therefore, EASA issued a safety bulletin on pitot-static system inspections as the airline companies return aircraft to service after storage due to COVID-19 pandemic.
EASA found that the pitot tube obstructions were caused by contaminated air data systems, leding to a number of Rejected Take-Off and In-Flight Turn Back events.
“Most of the reported events concerned the accumulation of foreign objects, such as
insect nests, in the pitot static system. This contamination caused obstruction of pitot probe and
static port orifices, in some cases on multiple systems, even when the covers were installed. The
risk of such contamination was increased, if the aircraft storage/de-storage procedures were not
completely or improperly applied at the beginning, during or at the end of the storage period.”
EASA says that the bulletin applies to all aircraft that have been stored due to the COVID-19 pandemic, continuing airworthiness management organisations, maintenance organisations, and competent national airworthiness authorities.
EASA recommends management and maintenance organisations to carefully follow the maintenance instructions for cleaning and inspecting the pitot static system during the return back to service of aircraft.
The agency also recommends the airline companies to consider the EASA Guidance on ‘Return to service of aircraft from storage in relation to the COVID-19 pandemic’ during return back to service of aircraft.
The aviation industry has been hit hard by the novel coronavirus pandemic and an unprecedented number of aircraft has been grounded, causing severe financial pressure on airline companies and on their service providers.
The travel restrictions in and between countries are being gradually lifted and operators are resuming commercial passenger flights. This process requires that the aircraft that were put into storage for weeks or months, are being restored to an airworthy condition.