Aircraft Reliability Programme: From the Programme Document to the Monthly Review

What you need

Bring:

• your programme, or the Word template;
• technical logs and monthly hours and cycles, including the history your programme needs;
• existing approved alert levels and open actions;
• component and task records, when included in your programme.

You need an engineer to check data and a reliability group to decide actions. Registers work on every plan. File reading, imports, calculations and Word reports need Pro.

EASA sets the obligation. FAA AC 120-17B provides methods.

Step 1 — Download and write the programme

Your programme defines what to monitor and who acts.

Download the Word template. Use one programme per aircraft type. Ask:

Help me understand what I must complete in this programme.

Metis explains the requirements. Adapt the template before seeking approval.

Yellow marks something you can change:

• Click a yellow word. If a small arrow appears, pick from the list. The usual answer is already selected.
• Click a yellow ☐ to tick it. The usual small-fleet choices are already ticked.
• Type your own facts over yellow [e.g. …] examples: names, document references, registrations, MSNs and dates.

Keep text that is not yellow. If it does not describe how you work, change it. Highlight your change yellow for the reviewer.

Under Reliability reports are prepared by, choose our CAMO or a contracted reliability service. Your CAMO keeps every decision.

Check both tables. Keep their headings unchanged.

Make the choices agree with your procedures. The usual values are not regulatory thresholds. Check coverage using the appendix.

Step 2 — Confirm with Metis, then submit for approval

Checking the read-back catches missing facts before you submit the programme.

Open the programme's project page. Click Add document, then Add file. Choose your filled-in Word document. Click Add document to keep it in the project. You can also add a document already in Memory.

In a chat pinned to that project, ask:

Read our reliability programme and show me the settings and fleet before using them.

Metis shows the settings, fleet and any problems. It names facts still containing examples, such as Organisation: not filled in. Type each missing fact where Metis points you. Check the new read-back. Then confirm the settings and fleet.

Metis records your confirmation in a project note and tells you when it succeeds. Settings confirmation is not programme approval.

Submit the programme for approval by the route chosen in section 1. Keep the approval record with the document.

After approval, remove highlighting and grey hints from the issued copy. This does not change the confirmed settings, so Metis does not ask again. Changed settings or fleet details require another confirmation. Other wording changes still follow document control.

Step 3 — Set up the registers

Registers keep your records together for future imports and reports.

Set up the registers for our confirmed programme.

Metis finds existing registers and proposes any missing ones. Check the columns before agreeing to creation. Keep these labels; brackets show choices.

Aircraft hours and Aircraft cycles are optional aircraft totals. Done at is the interval used since the previous task accomplishment. Use the same unit as Interval.

A blank Engineer check means intake raised no check reason. It is not engineering sign-off.

Step 4 — Load history and confirm each file layout

History gives your report a basis for comparison.

Upload your XLSX, XLSM or CSV exports. Ask:

Map these files to our reliability registers. Show me what each column means before importing the history.

Metis previews sheets, headings and rows. Confirm columns, units, dates, number format, codes and aircraft identities. Hours can use rows or labelled month columns. Replace unreadable layouts with a suitable export.

Identify source totals for the same aircraft and months, if available. Metis compares PIREP, MAREP and removal counts against them. Resolve differences before importing.

Check Metis's summary of additions and skipped identical records.

Ask Metis to remember this mapping for later uploads. Missing workbook sheets or mapped headings need correction. Metis shows the difference before you confirm a new mapping. Renaming a CSV file does not change its mapping.

Step 5 — Upload each month and check marked rows

One request handles your monthly files and shows what needs checking.

Upload all the month's files together in the programme's project. State the months to add:

Add September 2026 using our saved source mappings. Tell me what needs checking.

Metis uses your saved mappings and reports:

• which files matched, and which need a mapping;
• new rows, skipped duplicates and dates outside the requested months;
• rows marked To check and changes to records already held;
• confirmed additions after importing;
• remaining data checks, alert-level reviews and overdue actions.

Unreadable dates stay for review. If a layout changed, check the difference Metis shows. Confirm the new mapping before it is saved or used.

Technical-log rows receive To check for:

• a missing or unreadable date, or missing aircraft;
• a pilot report, maintenance report or removal without a usable ATA chapter;
• both PIREP and MAREP marked;
• an unrecognised Reported by, Operational event or yes/no flag value;
• unreadable delay minutes, or unreadable or negative aircraft hours or cycles;
• a decimal comma when the mapping does not say the source uses decimal commas;
• the same date, aircraft and log page as an existing or incoming row, but different content;
• an existing Check reason, or a row already marked To check in the source.

Component and task records also flag missing values, invalid choices, incompatible units and conflicting findings. Invalid required values can prevent calculations.

Corrected copies of removals, task records or monthly hours already held are not imported again. Metis lists the changes. Ask it to update those existing register rows after you check them.

In each register, find To check. Read Check reason. Compare the source. Correct the row where needed. Then set Engineer check to Checked. Continue your programme's wider data checks. Blank flags do not prove completeness.

Step 6 — Propose and approve alert levels

Alert levels highlight results needing investigation.

Follow your programme's revision cycle. Ask:

Propose alert levels for our next cycle using the programme's method.

Metis returns Proposed levels using history before their effective month. It gives the calculation basis and flags incomplete history, interim levels and unavailable calculations.

Take proposals to your reliability group. After the meeting, tell Metis who approved, when, which levels and any changed values. Metis records the approved levels in one go and keeps the proposals as the record. Check its summary of approved levels, those still Proposed and every changed value. Your group makes the decision.

The latest approved level effective by the report's first month takes precedence. Older approvals remain usable but show revision due. Without approval, calculated levels say calculated, not yet approved.

For Approved alert levels only, supply the group's levels instead. Missing levels show no approved alert level; Metis makes no substitute or alert comparison.

If the comparison history has no entries, new entries appear for review. Check reminders too. Investigate significant events even without a statistical alert.

Step 7 — Prepare the report

The report brings evidence together for your reliability group.

Produce the September 2026 reliability report from this programme and its registers.

Metis returns a Word report with:

• current and previous results, where hours and cycles are complete;
• alerts, reminders, supporting entries and decision blocks;
• individual events, repetitive defects and results by aircraft;
• component and task analyses, when included;
• open actions, overdue dates, charts and data checks;
• settings, approval status and chapter totals, including zero counts.

Delays and cancellations use rates per 100 departures. Other selected operational events appear individually, without an alert threshold. Estimated hours or cycles used for repetitive-defect checks are identified.

Relevant To check rows or a missing included register make the report provisional. Missing required hours can stop it. Resolve the listed gaps and rerun. A clean report remains a draft for the reliability group. Take it to the group for review.

Step 8 — Record decisions and follow actions

Decisions give findings an outcome and owner.

Investigate the cause before proposing changes. Check entries, operating conditions and shop findings.

Complete each decision block: cause, decision, reason, action, owner and planned completion. Give a reason for No action too. Then ask:

Record these decisions in Reliability actions using the owners and dates we agreed.

Metis records your decisions. Check its confirmation and supply missing details.

Update each action's progress. Set Action status to Closed only when the responsible engineer confirms completion. Reports carry actions marked Open forward and identify overdue dates.

Follow your AMP approval procedure for maintenance-programme changes:

The report can support your airworthiness review. It does not replace that review.

Step 9 — Review components and tasks when included

These analyses help you investigate removals and assess tasks.

Supply removal records, shop findings, component quantities and task accomplishments. Ask:

Include our programme's component and task analyses in the report. Explain what needs investigation.

Metis reports component removals and failures for the period and the preceding 12 months. It lists repeated removals and pending shop findings. Pending findings count provisionally as unscheduled removals.

Check quantities and missing hours before using the rates. Component exposure uses fleet hours and recorded quantities. Investigate fault histories before drawing conclusions.

For tasks, Metis shows findings and yield: the interval used divided by the scheduled interval. The FAA criterion requires average yield of at least 90%, with none below 80%. Investigate low-yield findings. A pass does not prove effectiveness or approve interval changes.

If you exclude this task register from an MSG-3 programme, identify your alternative monitoring procedure and evidence.

Step 10 — Review small-fleet results carefully

Small fleets can produce too little data for dependable alert levels.

Explain the small-fleet cautions in our report and what we should investigate.

Metis flags periods with fewer than six aircraft of the type. Review individual events and data sufficiency. Check for missing records behind zero counts.

Consider manufacturer comparisons or pooled data where suitable. Follow Appendix I point 6.6 for pooling conditions and approval arrangements.

Step 11 — Resolve the remaining data checks

Clean records make your next report easier to trust.

List the outstanding data checks and tell me what to correct before rerunning the report.

Metis lists affected records and missing information. Correct them using this checklist. Then rerun.

Where to read it yourself

The quotations use the 2025-09-02 revision of EASA's Easy Access Rules for Continuing Airworthiness. Read the reliability programme guide for applicability.

FAA AC 120-17B provides the methods for data quality, alert levels, investigation and task yield. Its FAA approval arrangements do not replace the EASA route.