The Difference Between OEM vs. PMA Parts: What You Need to Know

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In aviation procurement, Original Equipment Manufacturer (OEM) aircraft parts still lead the market, but cost-efficient parts produced under Parts Manufacturer Approval (PMA) are steadily gaining ground.

As we head into 2027, airlines and overhaul shops are increasingly using more PMA material. According to 2025 Aviation Week’s Inside MRO/Naveo survey of aftermarket professionals, nearly 60 percent of respondents expect PMA purchases to increase over the next three years.

Survey feedback suggests that challenges with OEM part availability and long lead times are among the top reasons buyers consider PMA parts, even when they prefer OEM alternatives.

Whether you’re managing inventory for an MRO facility, purchasing for an airline, or sourcing components for an aviation business, understanding the distinction between these two categories is crucial for safety, compliance, and cost-effective operations.

This guide breaks down the differences between OEM and PMA parts and explains what “certified aviation components” means so you can make informed buying decisions every time.

What Are OEM Aircraft Parts?

OEM stands for Original Equipment Manufacturer. OEM aircraft parts are produced by the same company that originally designed and manufactured the component used in the aircraft’s initial build.

Key Characteristics of OEM Parts:

OEM parts are typically associated with:

Original engineering design and specifications.
The original producer controls manufacturing.
Strong traceability to the original production source.
Documentation aligned with the OEM’s quality systems.

Why Buyers Choose OEM Parts:

Many procurement teams prefer OEM parts because they offer:

Confidence in design compatibility.
Proven performance history.
Standardization across fleets.
Support and warranty considerations, depending on the program.

OEM parts are often the default choice, but they can come with higher costs and longer lead times depending on availability.

What Are PMA Aircraft Parts?

PMA stands for Parts Manufacturer Approval. PMA parts are replacement or modification parts produced by a manufacturer other than the OEM, but they have been approved by an aviation authority for use.

In the United States, this approval is typically issued by the FAA, while aviation authorities such as EASA in Europe have similar approval processes. PMA parts are widely used in commercial aviation when properly documented and approved for their intended application.

How PMA Parts Are Approved:

To receive PMA authorization, the manufacturer must demonstrate that the part:

Meets airworthiness requirements.
Matches the original part in form, fit, and function (or meets an approved design alternative).
Produced under an approved quality system with controlled processes.

A properly approved PMA part is considered a legitimate certified aviation component.

OEM vs PMA Aircraft Parts: What Is the Difference?

The simplest way to understand OEM vs PMA aircraft parts is this:

OEM parts come from the original manufacturer.
PMA parts come from an approved alternate manufacturer.

Both can be airworthy and compliant when sourced and documented correctly.

Here is a quick comparison:

Category	OEM Parts	PMA Parts
Manufacturer	Original manufacturer	Approved alternate manufacturer
Approval path	OEM production and certification process	Regulatory approval (FAA PMA or equivalent)
Typical cost	Higher	Often more cost-effective
Availability	Can be limited	Often more flexible supply options
Documentation	OEM traceability and paperwork	PMA approval documentation and traceability
Use case	Common for standard replacement	Common for cost control and availability

Are PMA Parts Safe and Legal to Use?

Yes, PMA parts can be safe and legal to use when they are:

Approved for the specific aircraft or engine application
Properly documented
Installed and maintained according to regulations and approved procedures

A common misconception is that PMA automatically means lower quality. In reality, PMA parts must meet strict standards and demonstrate compliance with regulatory requirements before they can be sold as approved replacement parts.

What Does “Certified Aviation Components” Mean?

The phrase certified aviation components refers to parts that meet regulatory airworthiness requirements and are eligible for installation in approved aircraft systems.

Both OEM and PMA parts can be certified components, but the key is documentation; a part is only as acceptable as the paperwork and traceability that support it.

Buyers should always confirm:

Proper certification documentation (such as FAA Form 8130-3 when applicable).
Clear traceability to an approved source.
Correct part numbers and eligibility for installation.
Compliance with operator requirements and maintenance program standards.

Why Buyers Choose PMA Parts

PMA parts are often used as part of a strategic procurement plan, especially when operators want to reduce costs without compromising compliance.

1. Lower Total Cost:

PMA parts are frequently priced below OEM alternatives, helping reduce maintenance costs over time.

2. Better Availability:

Many PMA suppliers maintain strong inventory positions, which can help reduce AOG risk and shorten repair timelines.

3. Supply Chain Flexibility:

Having more than one approved sourcing option helps procurement teams avoid delays caused by limited OEM availability.

According to the Aviation Week survey, 88 percent of respondents cited price compared to OEM parts as being moderately, very, or extremely important, and 91 percent cited challenges obtaining OEM parts as at least moderately important in their decision to purchase PMA parts.

When OEM Parts May Be the Better Choice

Even though PMA parts offer advantages, OEM parts may still be preferred in situations such as:

Specific warranty requirements.
Operator policies that restrict PMA use.
Components with limited PMA availability.
When standardization across fleets is a priority.

The right choice depends on the aircraft program, the operator’s internal requirements, and the part category.

Procurement Tips for OEM and PMA Parts

If you are sourcing OEM or PMA parts, these best practices can help reduce risk and improve purchasing outcomes:

Confirm Eligibility:

Make sure the part is approved for the aircraft, engine, or system where it will be installed.

Verify Documentation:

Ensure the component is supported by proper certification and traceability. Do not treat paperwork as a formality. It is a core part of compliance.

Evaluate the Supplier:

Whether you are buying OEM or PMA, supplier reliability matters. A reputable supplier should be able to provide:

Clear sourcing details.
Consistent documentation.
Strong quality processes.
Responsive customer support.

Balance Cost and Downtime:

The lowest price is not always the best value if lead-time delays affect aircraft availability. Consider total operational impact, not only unit cost.

The Bottom Line on OEM vs PMA Parts

Choosing between OEM and PMA aircraft parts is not simply a matter of brand preference. It is a procurement decision that should be based on compliance, documentation, application, cost, and availability.

Both OEM and PMA parts can qualify as certified aviation components when they meet regulatory standards and are supported by proper traceability.

For procurement teams, the best approach is to work with a supplier such as Source One that specializes in certified aviation components, including hard-to-find parts with full traceability and documentation.

Whether you need OEM or PMA parts, our team can help you navigate your options and find the right solution for your operation.