MIL-HDBK-516 airworthiness certification criteria

MIL-HDBK-516 provides airworthiness certification criteria that military authorities use to assess whether an aircraft design can fly safely. The current revision is MIL-HDBK-516D, dated May 29, 2026. It replaced MIL-HDBK-516C. (ASSIST document record)

The handbook supplies technical criteria for an assessment. The responsible service approves the certification basis, evaluates the evidence, and issues an airworthiness approval through its own process.

What is MIL-HDBK-516?

MIL-HDBK-516 is the military handbook titled Airworthiness Certification Criteria. It covers fixed-wing and rotary-wing air systems, including crewed and uncrewed designs. Authorities use it to define the technical basis for a particular aircraft's airworthiness assessment. (ASSIST scope)

Airworthiness concerns safe flight within approved limits. Revision D defines it as the property of an air system configuration to safely attain, sustain, and complete flight in accordance with approved usage limits. (MIL-HDBK-516D, foreword and section 1.2) A successful mission demonstration does not by itself establish that basis.

The criteria address structures, flight technology, propulsion, aircraft subsystems, avionics, and computer systems.

The handbook is guidance. The cover expressly prohibits citing the handbook itself as a requirement. It also distinguishes airworthiness criteria from a complete aircraft design specification. (MIL-HDBK-516D, cover and section 1.1)

That distinction matters when preparing a contract or compliance plan. Identify the approved criteria and evidence obligations for the program. A bare instruction to comply with the entire handbook leaves applicability and acceptance unresolved.

Is MIL-HDBK-516C still current?

MIL-HDBK-516C is superseded by revision D. The Acquisition Streamlining and Standardization Information System (ASSIST) lists these releases and identifies D as active. (ASSIST revision history)

However, a publication update does not identify the approved basis for every aircraft. Department policy and existing certification records may name an earlier revision.

For example, Department of Defense Instruction (DoDI) 5030.61, issued December 3, 2024, still names MIL-HDBK-516C in paragraph 3.8, which covers airworthiness design criteria. Record both the latest publication and the revision approved for the program. Resolve any transition with the responsible authority. (DoDI 5030.61, section 3.8)

What are tailored airworthiness certification criteria?

Tailored criteria are the standards and methods of compliance selected or adapted for a particular air system. Revision D allows tailoring through the applicable service approval process. Each change needs a rationale. (MIL-HDBK-516D, section 1.4)

The certification basis considers configuration, flight profile, intended use, and operating environment. Tailoring can remove inapplicable material, modify applicable material, or add criteria for capabilities the handbook does not cover.

A new criterion needs both a standard and associated methods of compliance. Revision D also says the tailoring rationale should indicate whether an equivalent level of safety is maintained or the baseline level of safety is altered. Any alteration to that level needs approval under service procedures. (MIL-HDBK-516D, sections 1.2 and 1.4)

Consider a proposed change to an aircraft's equipment. The useful question is which approved design assumptions the change affects. That directs the assessment toward relevant criteria and evidence.

How does the Air Force use MIL-HDBK-516?

The Air Force uses applicable handbook standards and methods of compliance within an approved certification basis. The Technical Airworthiness Authority (TAA) reviews and approves that basis. Tailoring requires TAA approval and an appropriate level of safety. (DAFI 62-601, section 3.2.3)

Department of the Air Force Instruction (DAFI) 62-601, dated June 30, 2025, describes planning, assessment, risk acceptance, and approval. Before first flight, the program conducts an assessment against the approved basis. Areas of noncompliance produce identified hazards and risks.

Developmental flight testing may supply evidence unavailable before first flight. The instruction therefore distinguishes first-flight assessment from the later assessment supporting operational approval. Operating limitations can help bound the approved use while risks are addressed. (DAFI 62-601, sections 3.2.4 through 3.2.7)

For a review, ask for the approved basis, compliance findings, accepted risks, and the resulting approval. A completed test report is evidence within that chain.

How does NAVAIR flight clearance relate to the handbook?

Naval Air Systems Command (NAVAIR) flight clearance is a service mechanism for authorizing an aircraft configuration and its operation. The handbook provides technical criteria; the clearance establishes the approved conditions for flight.

The September 1, 2023 edition of the Navy's general flight and operating instructions identifies this certification route. It directs Navy and Marine Corps airworthiness certification through NAVAIR flight clearances or authorized assessments under NAVAIRINST 13034.1. (CNAF M-3710.7, section 7.1.1)

That edition also distinguishes standard configurations covered by approved operating publications from changes needing separate clearance treatment. The NAVAIR flight clearance guide explains the clearance question in more detail.

Software changes belong in this review too. NAVAIR's software safety guidance on block clearances says a data, algorithm, or software change that affects airworthiness requires a new clearance. An unchanged equipment enclosure therefore does not settle the clearance question. (NAVAIR safety guidance)

The guide to NATOPS explains the role of Naval Air Training and Operating Procedures Standardization publications. Use the aircraft's approved operating material alongside the applicable clearance.

How does the Army handle military airworthiness?

The Army uses airworthiness releases to state approved operating conditions, limitations, and supporting requirements. Army Regulation (AR) 95-4, dated September 4, 2026, governs Army aviation maintenance and airworthiness. It superseded AR 70-62. (AR 95-4)

An airworthiness release (AWR) can establish operating procedures, inspections, and maintenance needed for safe operation. The supporting assessment can draw on analysis, modeling, simulation, and ground or flight testing.

Changes to configuration, intended use, or environment that exceed an existing approval need airworthiness review and release action. The relevant question is whether the proposed operation fits the approved conditions. (AR 95-4, section 2-13)

MIL-HDBK-516 supplies a common technical reference under department policy. The Army's approval process determines the release for the specific system. Do not substitute a general handbook checklist for that release.

What happened to DoDD 5030.61?

DoDI 5030.61 replaced Department of Defense Directive (DoDD) 5030.61 on December 3, 2024. The instruction expressly reissues and cancels the earlier directive. The older DoDD explains historical references, but the instruction is the current policy document. (DoDI 5030.61)

The instruction requires airworthiness approval before flight under the applicable component process. An assessment alone does not guarantee approval. The appropriate authority must accept residual risks, and the assessment must capture the configuration and operating limitations.

Civil certification can support a military approval when the receiving authority considers it suitable. Differences in configuration, flight profile, use, and environment still need assessment. (DoDI 5030.61, sections 3.4 and 3.10)

Approval also has a continuing context. Configuration changes and maintenance conditions can affect whether the aircraft remains within the approved basis. Department policy addresses configuration control and continuing airworthiness throughout service. (DoDI 5030.61, sections 3.6 and 3.7)

What to do next

• Identify the service authority and the approval needed for the proposed flight.
• Record the handbook revision used in the approved certification basis.
• Trace each applicable criterion to its standard, method of compliance, and evidence.
• Document tailoring decisions, unresolved findings, and the required risk acceptance.
• Check that the aircraft configuration and proposed operation fit the resulting approval.

Azcuna's ELLMENT, the E-2D Large Language Model Entity, was proposed to NAVAIR PMA-231 under Navy SBIR Phase I topic DON26BZ01-NV010. The prototype, built at private expense on publicly available doctrine, answers with a page-level citation and refuses when the documents do not support an answer. The proposal has been submitted.

Questions people ask

What is MIL-HDBK-516?

MIL-HDBK-516 is the military handbook Airworthiness Certification Criteria. The ASSIST record describes criteria for assessing fixed-wing and rotary-wing air system designs, including crewed and uncrewed aircraft. Authorities use those criteria to define a certification basis. The handbook itself is guidance and cannot be cited as a requirement.

Is MIL-HDBK-516C the latest revision?

No. ASSIST lists MIL-HDBK-516D, dated May 29, 2026, as active. It supersedes revision C, dated December 12, 2014. A program may still have an approved basis referencing C, so confirm the applicable revision with the responsible airworthiness authority before changing certification documents.

What does tailoring mean in military airworthiness?

MIL-HDBK-516D allows criteria, standards, and methods of compliance to be adapted for the system and intended operation. Tailoring needs documented rationale and service approval. It can remove inapplicable material or add criteria for uncovered technology. The rationale should indicate whether an equivalent level of safety is maintained or the baseline level is altered.

Does compliance with MIL-HDBK-516 authorize flight?

No. The handbook provides technical criteria for an assessment. DoDI 5030.61 requires an airworthiness approval under the responsible component's process before flight. The approval depends on the assessment, accepted residual risks, and defined operating conditions. A compliance checklist alone does not issue that approval.

Is DoDD 5030.61 still the airworthiness policy?

DoDI 5030.61, dated December 3, 2024, reissued and canceled DoDD 5030.61. The instruction is the current department policy. Paragraph 3.8, on airworthiness design criteria, still identifies MIL-HDBK-516C, so distinguish the policy's named reference from the newer handbook revision and the program's approved basis.

Sources

1. 1ASSIST-QuickSearch Document Details: MIL-HDBK-516 · Defense Logistics Agency
2. 2DoDI 5030.61, Airworthiness Policy · Department of Defense
3. 3DAFI 62-601, Airworthiness, June 30, 2025 · Department of the Air Force
4. 4CNAF M-3710.7, General Flight and Operating Instructions, September 1, 2023 · Commander, Naval Air Forces
5. 5NAVAIR safety guidance · Naval Air Systems Command
6. 6AR 95-4, Army Aviation Maintenance and Airworthiness · Department of the Army

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