Aircraft Defects Under Part-ML: Report to Rectification

When you own and fly an aircraft, a defect should leave a trace through three distinct stages: a factual report, a decision made through the applicable qualified path, and evidence of rectification when the work is complete. Combining those stages into one vague status makes it difficult for you as owner, the Pilot in Command (PIC) or maintenance personnel to tell what has actually happened.

Under EASA Part-ML, reporting a defect does not authorise further flight. Nor does an administrative “closed” label prove rectification. The records need to show what was observed, who made the relevant decision and on what basis, what remained open, and which evidence supports eventual closure.

This article focuses on a non-complex motor-powered aeroplane of 2,730 kg maximum take-off mass or less within Part-ML, outside the air-carrier AOC exception, and particularly on Part-NCO operations. Other aircraft and operational contexts have their own scope details. The applicable aircraft configuration, operating rules, Minimum Equipment List (MEL), maintenance data and contracted continuing-airworthiness arrangements can change the decision path.

What are the three records in a defect case?

The word “defect” is often used for an observation, an assessment and a maintenance conclusion as if they were the same thing. They are not.

Stage	What the record establishes	What it does not establish by itself
Report	What was observed, when, where, by whom and in which flight or ground context	Diagnosis, authority to continue operating or rectification
Decision	Who assessed the item, the applicable basis, scope, conditions and limit	That maintenance work has already been performed
Rectification	What work was performed, when, by whom and which release evidence applies	That unrelated open items are also closed

Keeping these stages separate does not require three unrelated systems. It requires clear record types and links. A Journey Log entry can point to the report; an unrectified item can appear on the current deferred-maintenance list; the later maintenance record and Certificate of Release to Service (CRS), where required, can link back to the same case.

For the flight-record context around the initial observation, see the aircraft Journey Log guide.

How should a pilot report an aircraft defect?

Record the observed facts as soon as practical. A pilot does not need to diagnose the failed component before making the report. Waiting for a confident diagnosis can erase useful detail and delay visibility.

A useful report includes:

aircraft identity;
first date and time identified;
reporter and role;
associated flight or ground event, where relevant;
phase of flight or ground context;
the indication, sound, behaviour, damage or other condition observed;
whether it was continuous, intermittent or repeated;
immediate crew action, if any; and
any photographs or supporting references, without treating them as the decision.

Neutral wording is stronger than an unsupported conclusion. “Right landing light did not illuminate during the post-flight ground check” records a test result. “Landing-light relay failed; aircraft serviceable by day” adds both a diagnosis and an operational conclusion that the reporter may not be entitled to make. AMC1 ML.A.403 treats an observed equipment malfunction as a defect even before its cause has been diagnosed; an “observation” label must not downgrade it.

For relevant Part-NCO operations, NCO.GEN.105(a)(8) requires the PIC to record utilisation data and all known or suspected defects after the flight or series of flights in the aircraft technical log or Journey Log. A safety-relevant issue found on the ground should still enter the applicable reporting process promptly; the owner's process should not create a blind spot merely because no completed flight row exists yet.

Why must the report remain visible?

The report needs to reach the people who manage the aircraft's current context. For a typical pilot-owner, that means keeping the report in the aircraft record, coordinating with the person or organisation responsible for continuing-airworthiness management where contracted, involving maintenance personnel where assessment is needed, and making the current information available to the next PIC—even when that is the owner on the next flight.

A message can alert another person, but it should not be the only durable trace. Messages are easily separated from the aircraft identity, the first-detected date and later decisions. A structured record keeps the issue in view across time and remains understandable if a different pilot later uses the aircraft.

Visibility also means preserving uncertainty. If an observation has not yet been assessed, the record should say so. It should not default to a reassuring state such as “minor,” “deferred” or “safe to fly.” Those labels are decisions, not absence of data.

What is the first safety question under ML.A.403?

ML.A.403(a) states that an aircraft defect that seriously endangers flight safety must be rectified before further flight. The software, reporter, aircraft owner or app administrator should not classify a real technical condition into or out of that threshold without the applicable competence and evidence.

The safe record workflow is therefore:

capture the observation;
make it visible;
prevent an unassessed item from looking approved;
obtain assessment through the applicable decision path; and
record the outcome and basis.

“Reported” is a valid record state. It is not a flight-authorisation state.

Who can decide what happens to another defect?

ML.A.403(b) does not create one general rule that “the pilot may defer a defect.” It defines several paths whose availability depends on what equipment is affected, which operational rules apply and who is acting.

Non-required aircraft equipment

Under ML.A.403(b)(1), the pilot may defer a defect affecting non-required aircraft equipment. Whether equipment is genuinely non-required must be established from the applicable configuration, operating rules and other controlling information. A familiar label or a planned daytime flight is not enough on its own.

Required aircraft equipment

Under ML.A.403(b)(2), the pilot may defer a defect affecting required aircraft equipment when using the MEL. Otherwise, that decision belongs to appropriately authorised certifying staff. A generic checklist or remembered rule of thumb is not a substitute for the MEL path where the paragraph requires it.

Other defects in the limited Part-NCO path

Under ML.A.403(b)(3), for defects other than those covered by the first two paths, the pilot route is limited to aircraft operated under Part-NCO and requires the agreement of the aircraft owner or the contracted Continuing Airworthiness Management Organisation (CAMO) or Combined Airworthiness Organisation (CAO), as applicable. The provision includes separate wording for balloon and sailplane specialised-operation contexts; it should not be casually generalised to the aeroplane case.

This path is not shorthand for unilateral pilot deferral. The record should identify the applicable Part-NCO context and preserve the required agreement.

When those pilot-path conditions are not fulfilled

For defects other than those in ML.A.403(b)(1) and (2), ML.A.403(b)(4) places the decision with appropriately qualified certifying staff when the Part-NCO and agreement conditions in (b)(3)(i) and (ii) are not fulfilled. Required-equipment defects outside the pilot-with-MEL path are already assigned to appropriately authorised certifying staff by (b)(2). The record should identify the person acting and the relevant authority context; an application permission such as “group admin” or “editor” is not a maintenance qualification.

These paths are mutually informative, not a menu from which an owner selects the easiest option. Start with the actual defect, required-equipment status, operation and maintenance arrangements, then determine which paragraph applies. A decision under ML.A.403(b), including one made by certifying staff, does not override applicable operating or equipment requirements.

What should a documented limited decision contain?

Where the applicable path permits an item to remain unrectified for a limited period or set of conditions, document enough context for you, the next PIC and maintenance personnel to understand the decision without reconstructing a private conversation.

Include, as applicable:

the decision and precise item it covers;
the ML.A.403(b) path or other controlling basis;
identity and role or qualification context of the decision-maker;
owner, CAMO or CAO agreement where the applicable path requires it;
aircraft configuration and operating context considered;
MEL item, maintenance data or other source reference;
operational conditions, limitations and expiry or review point;
next appropriate maintenance action; and
decision date, while preserving the original first-identified date.

The result should be narrow. A decision about one landing light under specified conditions does not settle the status of a second light, a related electrical indication or a later change in symptoms. If the context changes, the earlier decision may no longer answer the operational question.

How should an unrectified defect be carried forward?

Under ML.A.403(c), a defect that does not seriously endanger flight safety must be rectified as soon as practicable from the date it was first identified and within the limits specified in the maintenance data. There is no single editorially invented deadline that fits every item.

ML.A.403(d) requires a defect not rectified before flight to be recorded in the aircraft continuing-airworthiness record system under ML.A.305 and made available to the pilot. ML.A.305(d)(6) identifies the current list of deferred maintenance as a continuing-airworthiness record.

AMC1 ML.A.403(d) adds useful continuity detail: the pilot should be informed, preferably before arrival at the aircraft; rectification should occur at the next appropriate maintenance event, subject to the applicable limit; and if the item remains unrectified at that event, it should be re-entered on the deferred list while retaining the original identification date.

That means an old Journey Log note is not, by itself, an adequate current view. The PIC needs the current deferred item, its decision basis, limitations and status.

What proves rectification and closure?

Rectification is supported by maintenance evidence, not by changing a workflow status. The exact evidence depends on the work and applicable rules, but the case record should let a reviewer identify:

what maintenance was performed;
the defect or scope covered;
date and aircraft details;
maintenance data used;
person or organisation performing and releasing the work; and
the CRS or other applicable release reference.

A CRS is important evidence for the maintenance it releases. It should not automatically close a broader defect case if the release covers only part of the reported symptoms, if operational follow-up remains, or if another linked item is still open. Someone must reconcile the release scope with the report and decision.

Closure should therefore be a reasoned record event: evidence reviewed, scope matched, remaining context checked, and status updated without erasing the earlier report.

How should defect history be corrected?

ML.A.305(g) requires corrections to be made in a manner that clearly shows the original entry. In practical terms, do not overwrite a first-detected date, observation or decision so thoroughly that a later reviewer cannot see what changed.

Preserve:

the original report;
each clarification or amended observation;
decisions and their basis;
replacement or withdrawal of a decision;
maintenance evidence; and
the final closure event.

This history protects both continuity and accountability. It also prevents a recurring condition from looking new merely because somebody recreated the item.

What does a complete defect case look like?

Consider the fictional owner-flown light aeroplane and landing-light report from the Journey Log entry example. Pilot A is both owner and PIC for the flight, but those roles do not merge: the PIC report, any owner agreement required by the applicable path and any certifying-staff decision remain legally distinct. The aircraft remains no-go in the owner's coordination process until an assessment is recorded; that cautious coordination state is not itself a regulatory diagnosis.

1. Report

Pilot A records: “Right landing light did not illuminate during the post-flight ground check at BBBB on 14 July 2026. No diagnosis made.” The report links to the completed Journey entry and preserves the first-identified date.

2. Qualified assessment

The responsible person checks the actual aircraft configuration, required-equipment basis, planned operation and maintenance information. The record identifies which ML.A.403(b) path applies. It does not assume that “day flight” automatically makes the light non-required.

3. Documented limited decision, if applicable

Only if the verified facts and applicable path allow it, the authorised decision is recorded with its basis, conditions, limits, decision-maker and any required agreement. The item is placed on the current deferred-maintenance list and made available to the next PIC. If the conditions are not established, the example stops here: no further-flight conclusion is invented.

4. Rectification evidence

At the next appropriate maintenance action, the defect is investigated and rectified. The maintenance and release reference are attached to the case. The person closing the item checks that the evidence covers the reported condition and records any remaining context. The first report and interim decision remain in history.

This sequence is deliberately more precise than “pilot reported; admin deferred; mechanic closed.” It shows that reporting, legal or technical decision-making, and evidence-based closure belong to different roles and records.

Does Logga currently manage this defect workflow?

No. Logga currently provides an aircraft Journey Log with a free-text incidents and observations field, PIC signature and PDF export, plus private versioned aircraft documents. A dedicated defect register, assessed-deferral workflow and list, and maintenance-closure integration are proposed designs, not deployed product capabilities.

The workflow in this article is educational. It can help an aircraft owner define the records needed today, including where co-owners occasionally share the aircraft, but it does not imply that Logga assesses defects, authorises flight, issues a CRS or replaces the judgement of the owner, pilot, certifying staff, CAMO or CAO.

The durable pattern is report → qualified decision → current visibility → rectification evidence. When each stage has a clear record and the links remain intact, the owner or next PIC can see what is known without mistaking an observation for a decision or a status change for completed maintenance.

Contact Logga about setting up the current Journey Log and document records for your aircraft.