Airworthiness and Maintenance Requirements
The Airworthiness Framework
Airworthiness in Canada rests on the type certificate, the certificate of airworthiness, and the continuing airworthiness obligations that keep an aircraft in a condition for safe flight. A candidate must understand that an aircraft's airworthiness is a continuing status, not a one-time event: it must be maintained in accordance with the applicable maintenance schedule, and any defect that affects safety must be addressed before further flight.
Maintenance Releases and Certification
A maintenance release is the legal statement that work has been performed and the aircraft is airworthy. It must be signed by an appropriately rated person and must reference the work done and the applicable standards. Traps here include confusing the maintenance release with the annual inspection, and assuming any licensed engineer can sign off any task regardless of rating, endorsement, or type training.
Defects, MEL, and Deferred Items
A common question area is the minimum equipment list (MEL). The key concept: the MEL permits operation with specified equipment inoperative, subject to the stated conditions and procedures. It does not authorize flight with an unsafe condition, and it cannot override an airworthiness limitation. Candidates should be able to distinguish a defect that must be rectified before flight from one that may be deferred under the MEL.
Worked Example
An aircraft has an inoperative item listed in the MEL. The question asks whether it may be dispatched. The correct reasoning: check the MEL entry for the conditions (such as required crew procedures or a time limit), confirm the item is not prohibited by an airworthiness directive, and ensure a maintenance release documents the deferral. If any condition is unmet, the aircraft is not dispatched.
Rule of Thumb
"Airworthy = conforms to type design + is in condition for safe operation." If either half fails, no MEL entry saves the flight.