Revisiting the Basics of FAA Airport Improvement Program (AIP) Grant Assurance Compliance and Enforcement in 2026

Federal Airport Improvement Program (AIP) funding has long been a cornerstone of airport development in the United States. The Federal Aviation Administration (FAA) has invested many billions of dollars into airport infrastructure, safety, and planning over the years. In exchange, airport sponsors agree to comply with a series of legally binding obligations known as federal grant assurances.

While the concept of grant assurances is not new, their practical significance has never been greater. Legislative changes, updated FAA grant assurance language and guidance materials, and continued enforcement activity under 14 C.F.R. Parts 13 and 16 have reinforced the need for airport sponsors, tenants, and users to understand how these obligations are interpreted and enforced today.

This article revisits the fundamentals of grant assurances, explains how they interact with the FAA’s compliance mechanisms, and highlights what has changed—and what has not—in the current regulatory environment.

Federal Grant Assurances: The Legal Foundation of Airport Compliance

Federal grant assurances are contractual obligations that arise when an airport sponsor accepts federal financial assistance. They are incorporated directly into grant agreements and, once accepted, bind the sponsor for the duration of the obligation period — often up to 20 years, and in some cases, indefinitely.

There are currently 39 individual and distinct grant assurances, addressing subjects such as:

• Airport operations and maintenance
• Access to airport facilities on reasonable and non‑discriminatory terms
• Prohibition on exclusive rights
• Proper use of airport revenue
• Fee and rental structures designed to promote self‑sufficiency
• Preservation of sponsor authority and control

These assurances are not aspirational guidelines. They are enforceable federal obligations designed to protect the public’s taxpayer funded investment in airports and to ensure that federally assisted facilities remain available to the public as part of the national aviation system.

As discussed in earlier Aviation Pros articles, grant assurances apply broadly—to large commercial service airports, small general aviation facilities, municipal sponsors, airport authorities, and, in some contexts, to state aviation agencies.

What’s Relatively New: Updated Grant Assurances and Legislative Influence

In 2024, Congress enacted a new FAA Reauthorization Act, prompting the FAA to issue updated AIP grant assurances in 2025. While the revisions did not fundamentally alter the structure of the grant assurance framework, they reinforced several key themes:

• Continued emphasis on safety and operational integrity
• Clarification of airport revenue use and financial accountability
• Alignment of grant assurances with evolving federal policy priorities

For airport sponsors, the takeaway is not that compliance standards have been radically rewritten, but rather that the FAA expects active, informed compliance with current grant language—not reliance on outdated interpretations or historical practice.

Importantly, these updated assurances apply prospectively to new grants, but enforcement actions often require the FAA to interpret multiple generations of grant assurances over the life of an airport’s federally funded improvements. This adds complexity to compliance assessments and dispute resolution.

On February 20, 2026, the FAA officially replaced Order 5190.6B with Order 5190.6C, the updated Airport Compliance Manual. This comprehensive update continues to provide guidance on federal obligations, now including new policies on self-sustainability, land use, and revenue diversion.  Key updates include:

• Financial & Rates: Substantial updates were made to chapters regarding airport financial reports, rates and charges, and self-sustainability (Chapters 17 & 18);
• Revenue Management: New guidance regarding the resolution of unlawful revenue diversion (Chapter 16);
• Land Use & Property: Revised guidance on federal obligations from property conveyances (Chapter 3);
• Compliance Process: Changes to the overall compliance program (Chapter 2) and dispute resolution (Chapter 5);
• Through-the-Fence: Updated guidance on residential through-the-fence agreements and security requirements (Chapters 7 & 20); and
• Grants Watch List: The manual details the "Grants Watch List" for airports with unresolved compliance issues.

Part 13: The FAA’s Informal Compliance Tool

Most airport compliance disputes begin under 14 C.F.R. Part 13, which governs the FAA’s informal investigative and enforcement procedures.

Part 13 allows any person with knowledge of a potential violation of federal airport obligations to bring concerns to the FAA. Complaints may be submitted in writing or even orally and are typically handled by FAA regional or district offices.

Key characteristics of Part 13 include:

• No formal pleading requirements
• No strict deadlines for FAA determinations
• An emphasis on fact‑gathering and informal resolution
• Advisory, non‑binding outcomes

Part 13 investigations often involve correspondence between the FAA and the airport sponsor, requests for documentation, and exchanges intended to clarify facts and determine whether the FAA has jurisdiction over the allegations.

While Part 13 is informal, it should not be dismissed as inconsequential. How an airport sponsor responds—both substantively and procedurally—can significantly influence whether a matter is resolved informally or escalates to formal enforcement.  It can also impact timing, approval and funding of subsequent grant funding approvals by FAA.

Crucially, a Part 13 investigation does not preclude a later Part 16 proceeding. In practice, Part 13 frequently serves as the gateway to more formal action.

Part 16: Formal Enforcement of Grant Assurance Obligations

When informal efforts fail or when the FAA determines that formal adjudication is warranted, disputes may proceed under 14 C.F.R. Part 16, which establishes the rules of practice for federally assisted airport enforcement proceedings.

Part 16 differs from Part 13 in several important ways:

• Only parties “directly and substantially affected” may file complaints
• Complainants must demonstrate good‑faith pre‑complaint resolution efforts
• Strict procedural deadlines govern pleadings, responses, and appeals
• Proceedings are handled by FAA headquarters rather than regional offices

Part 16 cases focus on alleged violations of grant assurances, surplus property deed restrictions, the Anti‑Head Tax Act, and related federal obligations. They are administrative adjudications, not civil lawsuits, and are designed to bring airports back into compliance rather than to award damages.

Potential outcomes include:

• Director’s Determinations
• Orders of compliance
• Corrective action plans
• In extreme cases, impacts to future grant eligibility

For airport sponsors, Part 16 proceedings are resource‑intensive and highly technical, often requiring careful coordination between legal counsel, airport management, and operational staff.

How Grant Assurances Drive Part 13 and Part 16 Disputes

Grant assurances are not merely background obligations—they are the substantive standards against which compliance is evaluated in both Part 13 and Part 16 matters.

Common grant‑assurance‑driven issues include:

• Allegations of unjust economic discrimination
• Claims involving exclusive rights
• Disputes over access restrictions or lease terms
• Questions regarding airport fee and rental structures
• Alleged diversion or misuse of airport revenue
• Maintenance and operational deficiencies affecting safety or access

The most commonly alleged violations are Grant Assurance 22 (Economic Nondiscrimination - providing fair and reasonable access without unjust discrimination) and Grant Assurance 23 (Exclusive Rights – prohibition on granting exclusive rights for aeronautical activities). Whether these issues remain in the informal Part 13 realm or advance to Part 16 often depends less on the underlying allegation and more on documentation, sponsor engagement, and the FAA’s assessment of systemic compliance risk.

Practical Implications for Airports and Airport Users

For airport sponsors, tenants, and users, several practical lessons emerge from the current enforcement landscape:

1. Grant assurances are enduring obligations, not one‑time conditions tied to a single project.
2. Updated grant language matters, particularly for airports receiving new federal funds.
3. Part 13 investigations should be taken seriously, even though they are informal.
4. Part 16 proceedings are procedural and unforgiving, making early compliance efforts critical.
5. Clear documentation and consistent policies – applied transparently and consistently - remain the strongest defenses against compliance disputes.

Understanding how grant assurances, Part 13 investigations, and Part 16 enforcement fit together allows airport stakeholders to manage risk proactively while continuing to operate efficient, safe, and financially sustainable facilities and businesses.

Federal grant assurances remain the cornerstone of the FAA’s airport compliance program. While the tools used to enforce those obligations—Parts 13 and 16—have existed for decades, legislative and FAA policy guidance updates, as well as continued enforcement activity, underscore their ongoing relevance.

For today’s airport and airport business decision‑makers, the message is clear: compliance is not static, and neither is the FAA’s interpretation of airport obligations. Staying informed, engaged, and proactive is essential to navigating the evolving intersection of federal funding and airport operations.