# Maintenance Check Interval Escalation Savings Calculator

> Source: https://netray.co/tools/maintenance-check-interval-escalation-savings-calculator
> Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems.
> Section: Free Tools

## Short answer

Estimate annual and multi-year savings from extending a base check interval: checks avoided, direct cost saved and aircraft days regained.

## Category

maintenance

## Industry

Aerospace MRO

## Audience

- Maintenance program engineer
- Fleet technical manager
- Airline finance

## Tool

**Kind:** calculator

**Currency:** $

**Inputs:**

#### Current check interval

**Key:** interval

**Type:** number

**Default:** 24

**Min:** 1

**Step:** 1

**Unit:** months

#### Proposed escalation

**Key:** escalation

**Type:** slider

**Default:** 10

**Min:** 0

**Max:** 40

**Step:** 1

**Unit:** %

**Help:** Increase in interval, subject to approval by the authority.

#### Aircraft in fleet

**Key:** fleet

**Type:** number

**Default:** 20

**Min:** 1

**Step:** 1

**Unit:** aircraft

#### Direct cost per check

**Key:** check_cost

**Type:** number

**Default:** 450000

**Min:** 0

**Step:** 10000

**Unit:** $

**Help:** Labor, materials, outsourced work and routine findings.

#### Downtime per check

**Key:** downtime

**Type:** number

**Default:** 20

**Min:** 0

**Step:** 1

**Unit:** days

#### Value of one aircraft day

**Key:** day_value

**Type:** number

**Default:** 25000

**Min:** 0

**Step:** 1000

**Unit:** $/day

**Help:** Margin lost or lease cost incurred per day on the ground.

#### Horizon

**Key:** years

**Type:** number

**Default:** 10

**Min:** 1

**Step:** 1

**Unit:** years

**Outputs:**

#### New interval

**Key:** new_interval

**Expr:** interval * (1 + escalation / 100)

**Format:** months

#### Checks per year, current interval

**Key:** checks_before

**Expr:** fleet * 12 / interval

**Format:** decimal

#### Checks per year, new interval

**Key:** checks_after

**Expr:** fleet * 12 / new_interval

**Format:** decimal

#### Checks avoided per year

**Key:** checks_saved

**Expr:** checks_before - checks_after

**Format:** decimal

#### Annual saving

**Key:** annual_saving

**Expr:** checks_saved * (check_cost + downtime * day_value)

**Format:** currency

**Primary:** true

**Description:** Direct check cost plus value of the downtime avoided.

#### Aircraft days regained per year

**Key:** days_regained

**Expr:** checks_saved * downtime

**Format:** integer

#### Saving over the horizon

**Key:** horizon_saving

**Expr:** annual_saving * years

**Format:** currency

**Primary:** true

**Chart:**

#### Annual saving vs interval escalation

**Type:** line

**X:** escalation

**From:** 0

**To:** 40

**Steps:** 20

**Series:**

- annual_saving

**Disclaimer:** Escalation requires supporting reliability data and approval under your maintenance program. Longer intervals can increase findings per check, which this model does not capture.

## Content

**Intro:** 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.

**Sections:**

#### How to use the calculator

**Body:** 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

**Body:** 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.

**Bullets:**

- 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

**Body:** 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

**Body:** 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.

**Cta:** 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.

**Faq:**

#### Does a longer interval always save money?

**Answer:** 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?

**Answer:** 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?

**Answer:** 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?

**Answer:** 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.

## Search terms

check interval escalation calculator, maintenance interval extension savings, C check interval extension, maintenance program optimisation, aircraft downtime cost calculator, MPD escalation savings, base check cost per year, fleet checks per year calculator

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