Maintenance Guide

Aircraft Maintenance Tracking for Flight Schools

What the FAA requires, what manufacturers recommend, and how to track it all without a spreadsheet.

FAA-Required Inspections

Per 14 CFR 91.409 and related regulations, these inspections are legally required:

InspectionIntervalRegGrounds?
Annual Inspection12 calendar months91.409(a)Yes
100-Hour InspectionEvery 100 hours time-in-service (tach / aircraft hours)91.409(b)Yes
Transponder Check24 calendar months91.413Yes
Pitot-Static Check24 calendar months (IFR)91.411Yes (IFR)
ELT Inspection12 calendar months91.207(d)Yes
Airworthiness DirectivesPer specific AD14 CFR 39Yes

Manufacturer-Recommended Items

For a typical Cessna 172 fleet, manufacturers recommend:

ItemIntervalTypical Tracking
Oil & Filter ChangeEvery 50 hoursHobbs
50-Hour InspectionEvery 50 hoursHobbs
Spark Plug ServiceEvery 100 hoursHobbs
Brake InspectionEvery 100 hoursHobbs
Engine Compression CheckEvery 100 hoursHobbs
Magneto TimingEvery 500 hoursHobbs

How Av8Book Tracks Maintenance

  • Set due items by Hobbs hours, tach hours, or calendar date
  • Warning thresholds alert you before items come due
  • Auto-grounding: when a threshold is crossed, the aircraft pulls itself off the schedule
  • Squawk logging from the ramp — instructors file squawks after flights
  • Grounding squawks auto-ground the aircraft with audit trail
  • Return-to-service workflow with audit logging
  • Org-wide maintenance dashboard: overdue, due-soon, and open squawks
  • Hobbs/tach auto-updated from flight completions