What Should Be Included in a Pre-Buy Inspection on a Used Airplane?

A Comprehensive Pre-Buy Inspection Covers 9 Key Areas

When you're considering purchasing a used airplane, the pre-buy inspection is arguably the most crucial step. It's your opportunity to gain a deep understanding of the aircraft's true condition before committing to the investment. This isn't a quick walk-around; it's a meticulous examination designed to uncover both current issues and potential future risks.

A robust pre-buy inspection should always delve into these 9 essential areas:

1. Engine: Beyond just running, compressions, borescope findings, and maintenance history are vital.
2. Airframe: Structural integrity, evidence of damage, and the condition of control systems.
3. Avionics: Functionality, database status, software versions, and any inoperative items.
4. Maintenance Logs: A complete, organized record of the aircraft's life, including all airframe, engine, and propeller logs.
5. Airworthiness Directives (ADs): Verification of compliance for all mandatory ADs.
6. Service Bulletins (SBs): Review of both mandatory and non-mandatory SBs for manufacturer recommendations.
7. Corrosion: Especially critical for aircraft from coastal or humid environments, looking beyond surface-level issues.
8. Damage History: Identification of past repairs, major alterations, and their quality.
9. Overhaul Quality: For overhauled components (especially engines), understanding who performed the work and their reputation.

Start with the Aircraft Records: The Story of the Airplane

One of the first and most critical components of any pre-buy inspection is a thorough review of the aircraft's maintenance records. This includes the airframe logs, engine logs, and propeller logs, ideally tracing back to the aircraft's original manufacture or as close to it as possible.

These logbooks are the airplane's autobiography. They reveal:

• Damage History: Evidence of accidents, incidents, and subsequent repairs.
• Major Repairs & Alterations: Details of significant work performed.
• Recurring Issues: Patterns of problems that might indicate underlying issues.
• Missing Time: Gaps in records that could hide critical information.
• Required Inspections: Proof that annuals, 100-hour inspections, and other mandated checks were completed.
• AD Compliance: Documentation of all Airworthiness Directive compliance.
• Component Replacements: When and by whom major components were replaced.
• Consistent Maintenance: Whether the aircraft has been regularly and properly cared for.

Red Flag: Incomplete, disorganized, or missing logbook entries are a significant warning sign and should prompt further investigation or reconsideration.

The Engine: A Deep Dive Beyond Just Running

The engine is the heart of the airplane and often its most expensive component. A pre-buy inspection must go far beyond a simple run-up. It requires a detailed examination to assess its current health and predict future reliability.

Key engine inspection points include:

• Compression Checks: To evaluate cylinder health.
• Cylinder Borescoping: To visually inspect internal cylinder walls, valves, and pistons for pitting, corrosion, and other wear.
• Total Time & Time Since Overhaul (TSOH): Critical operational metrics.
• Oil Leaks: Identification of recurring or significant leaks.
• Maintenance History: Review of engine-specific log entries for consistent care.
• Trend Monitoring: Looking for patterns in oil consumption, CHTs, EGTs, and other data that might signal impending issues.

At Paragon Flight MX, our experienced technicians perform hundreds of engine inspections annually, understanding the nuances that differentiate a healthy engine from one with hidden problems. We know that a quick 'thumbs up' isn't sufficient when evaluating such a critical and costly component.

Pay Attention to Who Did the Engine Overhaul

The quality of an engine overhaul can significantly impact an aircraft's value, reliability, and safety. It's not enough to simply know an engine has been overhauled; understanding who performed the work is crucial.

During a pre-buy, you should investigate:

• Overhaul Facility Reputation: Was the overhaul performed by a reputable, specialized engine shop known for quality work?
• Shop Longevity & Warranty: Is the shop still in business and do they stand behind their work with a warranty?
• Documentation: Is there comprehensive documentation supporting the overhaul, including parts used and procedures followed?

An overhaul performed by an inexperienced shop, a general maintenance facility without specialization, or a company no longer in business can lead to significant headaches and expenses down the road if service or warranty issues arise.

The Airframe Matters Just as Much

While the engine often gets primary attention, the airframe's condition is equally vital. A thorough inspection extends beyond surface-level aesthetics to the structural integrity and operational systems of the aircraft.

A detailed airframe inspection includes:

• Opening Panels: Accessing internal areas not typically visible.
• Structural Examination: Looking for evidence of damage, poor repairs, or fatigue.
• Control Systems: Checking cables, pulleys, and linkages for wear, proper tension, and function.
• Landing Gear: Inspecting components for wear, leaks, and proper operation.
• Corrosion Inspection: This is paramount, especially for aircraft based in coastal, island, or humid environments like Florida. Technicians must look beyond surface corrosion into hidden areas, behind panels, and within inspection zones where moisture can accumulate and cause significant structural damage.

ADs and Service Bulletins Are a Big Deal

Understanding the compliance status of Airworthiness Directives (ADs) and Service Bulletins (SBs) is a non-negotiable part of a pre-buy inspection.

• Airworthiness Directives (ADs): These are mandatory compliance items issued by the FAA (or equivalent authority) to correct unsafe conditions. All applicable ADs must be complied with and properly documented.
• Service Bulletins (SBs): Issued by the aircraft manufacturer, SBs recommend actions to improve safety, reliability, or performance. While some are mandatory, many are not. However, even non-mandatory SBs are important because they highlight known issues or recommended improvements from the manufacturer. Ignoring them can lead to future problems or reduce the aircraft's value.

A comprehensive pre-buy will meticulously review both AD and SB compliance records.

Avionics Can Get Expensive Fast

Modern avionics suites are complex and costly. Buyers often focus on the engine and airframe, overlooking the significant expense an inoperative avionics component can represent.

During a pre-buy, avionics checks should include:

• Functionality Test: Verifying all installed avionics are operational.
• "Inoperative" Stickers: Any such sticker is a red flag. The reason for inoperability, repair cost, impact on legal operation, and potential underlying electrical issues must be determined.
• Database Status & Software Versions: Ensuring navigation databases are current and software is up-to-date.
• Overall Condition: Physical inspection for damage, wear, or poor installation.

A single inoperative item can easily cost several thousand dollars to repair or replace, making this a critical area of inspection.

A Good Pre-Buy Should Take Time

The depth of a pre-buy inspection necessitates a significant time commitment. Depending on the aircraft's size, complexity, and condition, a thorough pre-buy will typically take at least a full day, and often longer.

Be wary of any shop or mechanic that promises a quick pre-buy. Rushing through the process often means:

• Not opening panels to inspect hidden areas.
• Inadequate review of logbooks.
• Insufficient documentation of findings.

The goal is a clear, detailed report of findings from nose to tail, providing a comprehensive understanding of the aircraft's condition.

What the Final Output Should Look Like

Upon completion of a pre-buy inspection, you should receive more than a casual verbal assessment. The output should be a detailed, written report that includes:

• Current Discrepancies: A list of all identified issues.
• Damage & Corrosion Findings: Specific locations and severity.
• Logbook Issues: Any gaps, inconsistencies, or red flags in the records.
• Deferred Maintenance: Items that require attention but may not be immediate airworthiness concerns.
• AD & SB Concerns: Unresolved or improperly documented compliance.
• Inoperative Items: A list of non-functional equipment.
• Engine & Avionics Findings: Specific details from these critical systems.
• Estimated Costs: Potential costs associated with identified issues.

This comprehensive report provides the clarity needed to make an informed purchasing decision, allowing you to understand if the airplane is clean, average, risky, or one to pass on entirely.