A CRS is the signed certification by authorised staff that maintenance has been completed correctly and the aircraft or component is released to service. No aircraft may fly after maintenance until a CRS is issued — it is the legal handover from maintenance back to operations.
A Certificate of Release to Service (CRS) is the formal certification, signed by appropriately authorised staff, that specified maintenance has been carried out correctly in accordance with the applicable requirements — and that the aircraft or component is released back to service. Under EASA rules, no aircraft may fly after maintenance until a CRS covering that work has been issued.
The CRS states what was done, references the work order and approved data used, identifies who certified it and under which approval, and records the date and aircraft status. It is the legal bridge between the maintenance world and the operational world: the tech log's airworthiness statement rests on the most recent CRS.
Why it matters for flight schools
The CRS is where responsibility legally changes hands, which is why authorities and investigators go straight to it after any incident. For schools, the operational failure mode is mundane but expensive: the aircraft is physically ready Friday evening, but the CRS isn't issued or communicated until Monday — losing a flying weekend to paperwork latency. Missing or ambiguous CRS entries also surface at ARC reviews, where every maintenance event must map to a corresponding release.
How FlightLogger handles it
FL Maintenance links every work order to its CRS and pushes the release status straight to operations — the moment the aircraft is certified, dispatch sees it as available.
Frequently asked questions
Who can issue a CRS?
Certifying staff authorised under the applicable framework — for example appropriately rated staff in a Part-145 organisation, or independent certifying staff for permitted work on light aircraft. The scope of each person's authorisation defines what they may release.
Can an aircraft fly without a CRS after maintenance?
No. Any maintenance, however small, requires a release to service before flight. Flying without one makes the operation illegal regardless of the aircraft's physical condition.