How Long Does FAA Part 135 Certification Take? The Five Phases and Where DCTs Fit

The honest answer to “how long does Part 135 certification take?” is: it depends — and most of what it depends on is within your control. The FAA does not run a stopwatch, but it does run a series of review gates. How quickly you pass through them is largely a function of how complete and compliant your documents are when you submit them. This guide walks the five phases, gives realistic ranges, and shows where Data Collection Tools and manuals fit.

Why there’s no fixed number

The FAA does not publish a guaranteed certification duration, and for good reason: the process is gated, not timed. Each phase ends when the FAA is satisfied that the applicant has met that phase’s requirements. A clean submission passes a gate; a deficient one gets returned for correction and re-review. The clock that matters is not a calendar — it is the number of times your materials cycle back for rework.

That is why two applicants starting on the same day can finish months apart. The one with a mature, internally consistent manual suite and well-prepared compliance documents passes gates cleanly. The one submitting drafts riddled with gaps spends the difference in correction cycles.

The five phases of certification

FAA air carrier certification follows a standardized five-phase structure. Understanding what each phase demands is the first step to moving through it efficiently.

Phase	What happens	What the applicant produces
1. Pre-application	Initial contact with the FAA; the applicant signals intent and basic scope	Pre-application Statement of Intent (PASI) and initial information about the proposed operation
2. Formal Application	The applicant submits the formal application package and meets with the certification team	Formal application, schedule of events, draft manual suite, requested OpSpecs, compliance documents
3. Design Assessment	The FAA evaluates whether the written program and manuals satisfy the regulations	Compliant manuals and Data Collection Tool responses traceable to the manual suite
4. Performance Assessment	The FAA observes whether the applicant can conduct operations as documented	Demonstration flights, inspections, and evidence the operation performs to its design
5. Administrative & Certification	Final administrative steps; the certificate and OpSpecs are issued	Final document reconciliation; acceptance of the issued certificate and Operations Specifications

Phase 1 — Pre-application

The applicant establishes contact with the FAA and submits a Pre-application Statement of Intent describing the proposed operation: type of operation, proposed aircraft, areas of operation, and key personnel. This phase sets the relationship and the framing. Time spent here getting the proposed scope right — and realistic — saves time later.

Phase 2 — Formal Application

The applicant submits the formal application package, including a schedule of events and the draft manual suite, and requests the specific OpSpecs the operation needs. This is where the depth of preparation starts to show. A thin or inconsistent manual suite submitted here guarantees friction in the assessment phases that follow.

Phase 3 — Design Assessment

The FAA evaluates whether the applicant’s written compliance system — the manuals and procedures — satisfies the regulations. This is where Data Collection Tools do much of their work: the FAA uses them to check, element by element, whether a complete and compliant procedure exists on paper. Strong DCT responses with paragraph-level citations to the manual suite are what carry an applicant through this gate.

In practice, the Data Collection Tools are by a considerable margin the single biggest source of delay in the Design Assessment phase. Getting a full set completed correctly — every answer cited to the right paragraph of a compliant manual, scoped to the applicant’s OpSpecs — takes weeks at best, and commonly several months. More applicants stall here than at any other point in certification, which is exactly why getting the DCTs done right, and done early, has an outsized effect on the overall timeline.

Phase 4 — Performance Assessment

Having confirmed the design on paper, the FAA evaluates whether the applicant can actually operate the way the manuals say. This includes demonstration flights and inspections. The question shifts from “is it written correctly?” to “does the operation perform to the written design?” — the performance half of the assessment.

Phase 5 — Administrative Functions and certification

With design and performance satisfied, the process moves to final administrative reconciliation and issuance of the air carrier certificate and the Operations Specifications. The OpSpecs issued here are the document that will govern the operator’s authorized scope from day one of operations.

Where DCTs and manuals fit

The two assessment phases — Design and Performance — are where most of the substantive compliance work lives, and they map directly onto the SAS framework operators encounter later in surveillance. Data Collection Tools are the instrument the FAA uses in both:

• In Design Assessment, DCTs check whether your manuals contain complete, compliant procedures for each element — answered with citations to where compliance is documented.
• In Performance Assessment, DCTs help confirm the operation performs to that documented design.

Because the same design-and-performance logic governs both certification and later surveillance, the discipline you build during certification pays dividends for the life of the certificate. For the mechanics of how those tools are structured and reviewed, see What are SAS DCTs? and Preparing for a SAS DCT Review. For how your authorized scope is defined and why it governs every answer, see OpSpecs Explained.

What actually drives the timeline

Some variables are outside an applicant’s control — FAA workload and scheduling among them. But the variables that most often determine duration are squarely within reach:

• Getting the DCTs completed correctly. By a wide margin the biggest single source of delay in Design Assessment. A full set of accurate, properly cited responses takes weeks at best and often several months — and incorrect or incomplete answers trigger the correction cycles that stretch a certification out.
• Manual completeness and compliance. Closely tied to the DCTs — a mature, regulation-compliant, internally consistent manual suite is what makes correct DCT answers possible and passes Design Assessment with minimal rework.
• Quality of compliance documents. DCT responses that cite the right paragraph of the current manual, and a clean compliance demonstration, keep the assessment phases moving.
• Realistic scope. Requesting authorizations the operation cannot yet support invites delay. Scope the OpSpec requests to what you can demonstrate.
• Correction cycles. Every returned submission adds a review round. Reducing the count of returns is the most reliable way to shorten the path.

The practical takeaway

You cannot make the FAA move faster, but you can give it less to send back. Applicants who invest in a complete, compliant manual suite and well-prepared Data Collection Tool responses before submission — rather than scrambling to fix deficiencies after a gate fails — consistently move through certification with fewer cycles and less elapsed time. The preparation is the timeline.

Related reading

• What are SAS DCTs? Element-Design (DA) and Element-Performance (PA) Explained
• Preparing for an FAA SAS DCT Review: What Part 135 Operators Should Expect
• OpSpecs Explained: How Operations Specifications Scope Your Certificate
• DCT vs. SOC: When the FAA Wants More Than Answered DCTs
• Certificate Construction & Review service