Maintenance Check Interval Escalation Savings Calculator
Extending a base check interval cuts the number of checks per year, and each one avoided saves direct cost and aircraft ground time. This calculator quantifies both so a maintenance program proposal can be discussed in money as well as in reliability data.
Your numbers
Increase in interval, subject to approval by the authority.
Labor, materials, outsourced work and routine findings.
Margin lost or lease cost incurred per day on the ground.
Your results
Escalation requires supporting reliability data and approval under your maintenance program. Longer intervals can increase findings per check, which this model does not capture.
Annual saving vs interval escalation
Sweeps Proposed escalation from 0 to 40, holding your other inputs fixed.
Findings-per-check analysis
Optional: we can discuss how to analyse non-routine findings from your existing work order history.
Optional. The tool and every export work without this. No spam.
How to use the calculator
Enter the present interval in months, the proposed percentage escalation, the fleet size and the direct cost of a check. Add the downtime in days and the value of one aircraft day, either lost margin or the cost of covering with a spare. The tool outputs checks avoided per year, annual saving and the total over your planning horizon.
Method
Checks per year equal fleet size times twelve divided by the interval in months. Escalation lengthens the interval, which lowers the check rate. The saving is the difference in checks per year multiplied by the cost of one check including its downtime value. Treating downtime as a cost is essential because it often exceeds the direct bill.
- New interval = interval x (1 + escalation)
- Checks per year = fleet x 12 / interval
- Annual saving = checks avoided x (check cost + downtime x day value)
- Days regained = checks avoided x downtime days
Worked example
A 20 aircraft fleet on a 24 month check does 10 checks a year. A 10 percent escalation to 26.4 months gives about 9.09, saving 0.91 checks a year. With a 450,000 dollar check and 20 days at 25,000 dollars, each check is worth about 950,000 dollars, so the saving is near 865,000 dollars a year and 18 aircraft days.
Common mistakes
Assuming escalation is automatic, ignoring that deferred work moves to other checks and ignoring higher non-routine rates at longer intervals all overstate savings. The decision should rest on findings data from earlier checks, task-level reliability and approval of your authority, not on arithmetic alone.
Frequently Asked Questions
Does a longer interval always save money?
Not always. If findings per check rise with age, a longer interval can raise the cost per check. Compare findings trends before and after any extension and include the effect in the case.
What is a reasonable value for an aircraft day?
Use the contribution you lose when an aircraft is on the ground, or the cost of leasing a substitute. Operators with spare aircraft may use a lower figure than those without.
Can I use flight hours instead of months?
Yes. Convert to a consistent unit first. If the interval is in flight hours, compute the checks per year as fleet hours per year divided by the interval hours.
Who approves an escalation?
It is approved through your maintenance program change process with the competent authority involved as your approvals require. The calculator supports the business case, not the approval.
Netray can build a read-only agent over your maintenance and work order data to show non-routine findings per check, a key input to any interval escalation case.
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