Aircraft Airworthiness Directives: Complete Compliance Guide

Aircraft Airworthiness Directives (ADs) are mandatory safety improvements required by the FAA. Understanding AD compliance requirements protects safety, legal airworthiness, and aircraft resale value.

What are Airworthiness Directives

AD Definition:

• FAA-mandated safety improvements
• Address unsafe conditions in aircraft/components
• Legally binding—compliance required
• Apply to specific makes, models, serial numbers
• Cannot legally fly without compliance

Types of ADs:

• Emergency ADs: Immediate compliance before next flight
• One-time ADs: Single inspection or modification
• Recurring ADs: Periodic inspections (e.g., every 100 hours)
• Life-limited ADs: Replace component at specific intervals

Finding Applicable ADs

Research Methods:

• FAA AD database: Free online search by make/model
• Aircraft logbooks: Should document all compliance
• Type certificate data sheet: Lists known ADs
• A&P mechanic: Professional AD research service
• Commercial services: $50-$200 comprehensive reports

What to Search:

• Airframe make and model
• Engine make and model
• Propeller make and model
• Appliances (autopilot, avionics, etc.)
• All installed STCs and modifications

AD Compliance Costs

Range of Costs:

• Minor inspection AD: $200-$500 labor
• Typical one-time AD: $1,000-$5,000
• Major structural AD: $10,000-$50,000+
• Recurring inspection AD: $300-$1,000 per occurrence
• Life-limited part replacement: $5,000-$100,000+ (engine, prop)

Examples:

• Cessna 172 wing spar AD: $15,000-$30,000 inspection/repair
• Piper wing spar AD: $10,000-$25,000
• Lycoming crankshaft AD: $500-$2,000 inspection
• Beech rudder AD: $5,000-$15,000 modification

Compliance Documentation

Required Records:

• AD number and revision
• Date of compliance
• Method of compliance used
• Recurring AD: Hours/calendar next due
• A&P signature and certificate number
• Return-to-service statement

Logbook Entries:

• Clear reference to specific AD
• Detailed compliance method
• Next due if recurring
• Permanent record maintained

Alternative Methods of Compliance

AMOC (Alternative Method of Compliance):

• Different approach achieving same safety level
• Requires FAA approval before use
• Can save time or money
• Must document AMOC approval

Impact on Aircraft Value

Outstanding ADs:

• Reduce value 100% of compliance cost minimum
• Often reduce value 150-200% of cost
• Buyer uncertainty increases discount
• May make aircraft unfinanceable

Recent Major AD Example:

• Cessna 172 wing spar AD (2020)
• $20,000-$30,000 compliance cost
• Aircraft with outstanding AD: $30,000-$50,000 value reduction
• Complied aircraft maintain normal value

Pre-Purchase AD Research

Buyer Due Diligence:

• Independent AD search before purchase
• Verify all ADs complied with
• Check logbook entries match AD database
• Calculate recurring AD future costs
• Factor into purchase price

Red Flags:

• Missing AD compliance documentation
• Recurring AD overdue
• Vague logbook entries
• Seller unfamiliar with AD status
• Recent ADs not addressed

Recurring AD Management

Tracking Methods:

• Spreadsheet with due dates
• Aviation maintenance software
• A&P mechanic tracking service
• Calendar reminders
• Annual inspection reminder

Budget Planning:

• List all recurring ADs
• Calculate annual cost
• Set aside monthly reserve
• Plan for upcoming expirations

Frequently Asked Questions

What happens if I don't comply with AD?

Aircraft legally unairworthy and cannot fly. Flying with outstanding ADs: FAA violations with fines up to $27,000 per day, certificate suspension/revocation, insurance void, liability exposure if accident occurs. Compliance mandatory before any flight.

How to find all ADs for my aircraft?

Search FAA AD database (free) by airframe, engine, propeller, and appliance makes/models. Cross-reference with logbooks. Professional AD search service $50-$200 provides comprehensive report. Annual inspection should verify all AD compliance current.

Who pays for AD compliance when buying aircraft?

Typically seller complies before sale or reduces price by compliance cost (often 150-200% of actual cost due to uncertainty). Negotiate in purchase agreement. Outstanding ADs significantly reduce aircraft value and financing approval odds.

How much do Airworthiness Directives cost?

Varies widely. Minor inspection: $200-$500. Typical one-time AD: $1,000-$5,000. Major structural AD: $10,000-$50,000+. Recent Cessna 172 wing spar AD: $20,000-$30,000. Budget $2,000-$5,000 annually for typical single-engine aircraft AD compliance.

Can I defer AD compliance?

No, unless AD specifies grace period (rare) or applies only to commercial operations. Emergency ADs: Compliance before next flight. Most ADs: Compliance by specified date, hours, or calendar time. No legal way to defer mandatory ADs for Part 91 operations.