> ## Documentation Index
> Fetch the complete documentation index at: https://docs.flightwise.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Aircraft Maintenance Check Types System

> Understanding how maintenance check types and check items work together to track aircraft maintenance requirements

FlightWise's maintenance tracking system monitors when aircraft require maintenance through a relationship between check types (templates) and check items (actual maintenance tracking records for specific
aircraft).

## Maintenance Check Types

Check types are **templates** that define standard maintenance requirements used across your fleet. These are reusable definitions that specify:

* Name of the maintenance requirement
* Interval (hours or calendar days)
* Whether it's hours-based, calendar-based, or both

### Example Check Types

| Check Type          | Interval              | Type           |
| ------------------- | --------------------- | -------------- |
| 50-Hour Oil Change  | 50 hours              | Hours-based    |
| 100-Hour Inspection | 100 hours             | Hours-based    |
| Annual Inspection   | 365 days              | Calendar-based |
| Pitot-Static Check  | 730 days              | Calendar-based |
| ELT Certification   | 365 days              | Calendar-based |
| Annual/100-Hour     | 100 hours OR 365 days | Combination    |

## Maintenance Check Items

Check items are the **actual maintenance records** assigned to specific aircraft. When you assign a check type to an aircraft, it creates a check item that tracks:

* Which aircraft it applies to
* What type of check it is
* When it's due (hours and/or date)
* When it was last complied with

### Example Check Item

| Field                | Value               |
| -------------------- | ------------------- |
| Aircraft             | N12345              |
| Check Type           | 100-Hour Inspection |
| Due at Hours         | 2,542.1             |
| Last Complied Hours  | 2,442.1             |
| Last Compliance Date | 2024-12-15          |

## How the System Calculates Remaining Time

### For Each Aircraft

The system continuously monitors:

1. **Current aircraft hours** (from flight logs)
2. **Today's date**
3. **All active check items** for that aircraft

### Calculation Examples

**Hours-Based Check:**

| Calculation            | Value          |
| ---------------------- | -------------- |
| Due at                 | 2,542.1 hours  |
| Current aircraft hours | 2,520.5 hours  |
| **Hours remaining**    | **21.6 hours** |

**Calendar-Based Check:**

| Calculation        | Value       |
| ------------------ | ----------- |
| Due date           | 2025-03-15  |
| Today              | 2025-01-10  |
| **Days remaining** | **64 days** |

**Combination Check (whichever comes first):**

| Check Component | Due Value                      | Remaining  | Status           |
| --------------- | ------------------------------ | ---------- | ---------------- |
| Hours           | 2,542.1 hours                  | 21.6 hours | ⚠️ Most limiting |
| Calendar        | 2025-03-15                     | 64 days    | ✅                |
| **Display**     | **100-Hour due in 21.6 hours** |            |                  |

## Aircraft Status Display

The system shows the **most limiting** check for quick reference:

### Most Limiting Hours Check

| Check Type   | Hours Remaining | Status               |
| ------------ | --------------- | -------------------- |
| 50-Hour      | 29.5            | ✅                    |
| **100-Hour** | **21.6**        | **⚠️ Most limiting** |
| TBO          | 479.8           | ✅                    |

Display: "100-Hour due in 21.6 hours"

### Most Limiting Calendar Check

| Check Type   | Days Remaining | Status               |
| ------------ | -------------- | -------------------- |
| **Annual**   | **64**         | **⚠️ Most limiting** |
| Pitot-Static | 423            | ✅                    |
| ELT          | 298            | ✅                    |

Display: "Annual due in 64 days"

## Complete Workflow Example

### 1. Initial Setup

Create check types for your organization:

| Check Type          | Interval  |
| ------------------- | --------- |
| 50-Hour Inspection  | 50 hours  |
| 100-Hour Inspection | 100 hours |
| Annual Inspection   | 365 days  |

### 2. Assign to Aircraft

Add check items to aircraft N12345:

| Check Type | Due Value     |
| ---------- | ------------- |
| 50-Hour    | 2,550.0 hours |
| 100-Hour   | 2,542.1 hours |
| Annual     | 2025-03-15    |

### 3. System Monitoring

As the aircraft flies:

| Status Item            | Value               |
| ---------------------- | ------------------- |
| Aircraft hours         | 2,520.5             |
| Most limiting hours    | 100-Hour (21.6 hrs) |
| Most limiting calendar | Annual (64 days)    |

### 4. Maintenance Performed

When 100-hour is completed at 2,542.1 hours:

| Action          | Result                  |
| --------------- | ----------------------- |
| Old check item  | Marked complete         |
| New due hours   | 2,642.1 (2,542.1 + 100) |
| Hours remaining | 100 hours               |

## Visual Indicators

| Status | Indicator | Condition                |
| ------ | --------- | ------------------------ |
| Green  | 🟢        | Plenty of time remaining |
| Yellow | 🟡        | Maintenance approaching  |
| Red    | 🔴        | Very close to due        |

## Benefits of This System

### Simplicity

* One check item per maintenance requirement
* No complex component tracking needed
* Clear visibility of what's due next

### Compliance

* Never miss required maintenance
* Automatic booking prevention
* Complete audit trail

### Efficiency

* See at a glance what limits each aircraft
* Plan maintenance during slow periods
* Maximize aircraft availability

The maintenance check system ensures aircraft remain airworthy while keeping tracking as simple as possible - just track what's due and when, with the system handling all the complex calculations and
restrictions automatically.