Direct Answer
There is no fixed FAA timeline for Part 135 certification. The formal application must be submitted at least 90 days before the date of intended operation, but that is a minimum lead time — not a completion date. In practice, the full FAA-described process commonly takes several months to well over a year.
How long your certification takes depends on your Flight Standards office’s workload, the complexity of the operation you request, the number and type of aircraft, and — the factor you most directly control — how complete and compliant your manuals and documents are when you submit them. The FAA uses a phase-and-gate process: you cannot advance until every item in a phase is complete, so a single unfinished manual can hold the whole clock.
The number-one cause of delay, by the common account of operators who have been through it, is incomplete, non-conforming, or inconsistent documents — drafts that bounce back for rework, each correction adding a review cycle. The hard timing anchor is 14 CFR §119.35; everything past it is workload, complexity, and rework.
Why “It Depends” Is the Only Honest Answer
Every prospective Part 135 operator wants a number: six months, nine months, a year. The reason no one credible will give you a firm one is that the FAA does not certificate on a clock — it certificates on readiness. The only hard, regulated date in the whole process is the lead time for the formal application, and even that is a minimum, not a maximum. Under 14 CFR §119.35, you must submit your formal application at least 90 days before the date you intend to operate. That tells you the earliest the formal phases can begin; it tells you nothing about when they will end.
The full process the FAA describes runs across five phases (more on those below), and you only move forward when each phase is complete to the agency’s satisfaction. Two applicants with identical aircraft and identical intended operations can finish months apart — one because its document package was clean and consistent, the other because its manuals kept bouncing back for corrections. That variability is not the FAA being arbitrary; it is the direct consequence of a gated process meeting documents of very different quality.
So instead of a fake average, this article does something more useful: it walks the five phases so you know what the clock is actually measuring, names the factors that drive it, and is blunt about the one cause of delay you can do the most about. For the cost side of the same decision, see how much a Part 135 certificate costs — timeline and cost are inseparable, because every extra month in the process is another month of carrying staff and aircraft before revenue.
Beware of any source that quotes a guaranteed timeline
If a consultant or article promises “Part 135 in 90 days” or a fixed number of months, treat it with caution. The 90-day figure in 14 CFR §119.35 is a minimum lead time before the formal phases, not a completion guarantee, and no one controls your Flight Standards office’s workload. Realistic planning means a range measured in months — often a year or more for more complex operations — and building in slack for revision cycles. Confirm the current process and your office’s situation directly with your FAA Flight Standards office.
The questions that sit right next to this one: how to get a Part 135 certificate (the full step-by-step), why Part 135 applications get rejected (the rework that eats your timeline), and the certification application checklist (what a complete package contains).
The Five Phases: What the Clock Is Actually Measuring
The FAA describes air-carrier and air-operator certification as a five-phase, three-gate process. The key mechanic — and the reason document quality drives your timeline — is the gate: all items in a phase must be successfully completed before you can pass the gate into the next phase. There is no advancing on partial work. This phase-and-gate model is FAA guidance describing how the agency manages certification — it is not numbered CFR text. The only hard regulatory date inside it is the 90-day formal-application lead time in 14 CFR §119.35.
Phase 1 — Pre-application
Variable — driven by your readinessThis phase begins when you first inquire about or request an application. You signal intent to your Flight Standards office and complete the pre-application requirements, often through informal meetings. The calendar cost here is mostly your own preparation time — but the scope decisions you make now (the kinds of operations and aircraft you propose) set how long every later phase will take.
Phase 2 — Formal Application
≥ 90-day lead time; ~30-day FAA review before the formal meetingThis phase begins when the FAA receives your formal application and all required documents. Under 14 CFR §119.35 the application is due at least 90 days before intended operation, and the FAA generally needs about 30 calendar days to review the formal application package before the formal application meeting. An incomplete submission here does not advance — it gets returned, resetting your momentum.
Phase 3 — Design Assessment
Often the longest phase — scales with revision cyclesThe FAA reviews your manuals, programs, and proposed procedures in depth to confirm they comply with the regulations and produce safe operations. This is where timeline most often balloons: the more revision cycles your documents require, the longer this phase runs. A complete, internally consistent manual set is the single biggest thing that keeps this phase short.
Phase 4 — Performance Assessment
Driven by training, proving runs, and schedulingThe FAA observes and validates that your operating systems actually perform as designed — that crews are trained and directed effectively and operations match the manuals. This phase involves operating an aircraft to demonstrate your system in practice, so its length depends on training completion, proving activities, and lining up FAA observation with your schedule.
Phase 5 — Administrative Functions
Final issuance once all gates are clearedThe FAA issues your certificate and your operations specifications (OpSpecs). Reaching this phase means the substantive work is done — and it also marks the start of your continuous recordkeeping obligation, which runs for the life of the certificate.
A note on the phase model and a 2024 change
The five-phase, three-gate model is the FAA’s published description of its certification process — FAA guidance, not regulatory text, and the agency can revise it. Notably, effective January 24, 2024, the FAA adopted a process intended to increase applicant readiness before initial certification across several certificate types (including Part 135). The practical message is consistent: the FAA wants applicants ready before they enter the formal process, and readiness — complete documents, qualified personnel — is exactly what protects your timeline. Confirm the current process with your Flight Standards office.
Two of these phases turn on documents you will live with for years. For what comes out the other end, see operations specifications (OpSpecs) explained and OpSpecs, MSpecs & LOAs explained; the certificate scope you request in Phase 1 also determines whether you pursue a single-pilot, basic, or standard certificate, which materially changes how long the process runs.
The Four Factors That Actually Drive Your Timeline
Strip away the marketing promises and there are four real variables behind how long Part 135 certification takes. Two are largely outside your control; two are largely within it. Knowing which is which is how you build a realistic plan — and where to spend your energy.
FAA Flight Standards office workload
Mostly outside your controlCertification competes for finite FAA inspector time against surveillance of existing operators and other applicants. A busy office, staffing changes, or a queue of applications can extend your calendar regardless of how perfect your package is. You cannot control this — but you can avoid adding to it with rework, and you can have an early, honest conversation with your office about its current situation.
Complexity of the operation you request
Set early, then mostly fixedA single piston aircraft, VFR, day-only operation is a fundamentally shorter project than a multi-aircraft turbojet operation requesting special authorizations. Every additional aircraft type, every special authorization, and every added kind of operation expands the manuals, the training, and the assessment the FAA must complete. Requesting only what you genuinely need at first is one of the most effective timeline decisions you make.
Completeness and conformity of your documents
Largely within your controlThis is the big one. Because the process is gated, an incomplete, non-conforming, or internally inconsistent document set cannot advance — it bounces back, and each correction is another review cycle measured in weeks or months. A complete, conforming, internally consistent package is the closest thing to a timeline accelerator an applicant has. It is also the factor most applicants underestimate.
Stability of your application mid-process
Largely within your controlChanging key management personnel, adding an aircraft type, or altering the kinds of operations mid-certification can trigger re-evaluation and reset progress. Under 14 CFR §119.51, changes such as new aircraft types or operational changes generally require advance notice and FAA review. Locking your scope and your people before you apply keeps you moving forward instead of looping back.
Where to spend your energy
Two of these factors come down to people. The required management personnel qualifications determine who must be in place and qualified before you apply, and operational control in Part 135 is a concept the FAA will probe throughout — getting both settled early keeps your application stable.
The #1 Cause of Delay: Incomplete and Inconsistent Documents
If you take one thing from this article, take this: the most common reason Part 135 certifications run long is not the FAA’s pace — it is the applicant’s documents. This is the consistent account of operators and consultants who have been through the process, and it follows directly from how the gates work. The FAA cannot pass you to the next phase until the current phase is complete and acceptable. An unfinished manual, a document set that contradicts the operations specifications you are requesting, missing required-management-personnel qualification records, or version-drift between documents all stop you at a gate — and every round of corrections is another review cycle.
The painful part is that document problems compound. A correction in the Design Assessment phase can ripple into the training program and the operations specifications, generating more revisions. Meanwhile your required management personnel are on payroll and your aircraft is sitting. This is exactly why understanding why Part 135 applications get rejected is a timeline exercise, not just a compliance one.
Document problems that stall you at a gate
- Manuals that are incomplete or not acceptable to the FAA.
- Documents that contradict the OpSpecs you are requesting.
- Missing required-management-personnel qualification records.
- Version-drift — multiple drafts with no clear current version.
- Records the FAA requests that you cannot quickly retrieve.
What a timeline-friendly package looks like
- Complete, conforming manuals at first submission.
- Documents internally consistent with the OpSpecs requested.
- One identifiable current version of every document.
- Personnel qualification records filed and retrievable.
- Anything the FAA asks for produced in minutes, not days.
The rework loop is the timeline killer
A document that bounces back does not just cost the days to fix it — it costs a full review cycle. Your corrected document goes back into the queue, waits for FAA attention, and may surface a follow-on inconsistency that triggers yet another cycle. Two or three of these loops can turn a months-long certification into a year-plus one, while every carrying cost keeps running. The way to win the timeline is not to go faster than the FAA — it is to never enter the rework loop in the first place.
Related reading: General Operations / Maintenance Manual requirements · What records a Part 135 operator must keep · Part 135 pilot records required by the FAA · Certification application checklist
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FileFlo does not get you certified, file your application, or write your manuals — but it attacks the #1 delay cause you control: document chaos. It gives your application documents and manual revisions one version-controlled, classified home, so the current version is always identifiable and the FAA’s review is not slowed by missing or conflicting files. After certification, it keeps the operating records you must maintain audit-ready. Starter at $89/mo, Professional at $299/mo. 5-day free trial, no credit card required.
How to Avoid Self-Inflicted Delay (You Cannot Rush the FAA — You Can Stop Slowing Yourself Down)
There is no trick to make the FAA move faster, and anyone selling one is selling the 90-day minimum lead time of 14 CFR §119.35 as if it were a finish line. What you can do is eliminate the self-inflicted delay that turns a clean certification into a slog. The FAA’s own January 24, 2024 emphasis on applicant readiness points the same direction: come prepared, and the process moves. These are the levers that actually matter.
Hire and qualify your management personnel before you apply
Have your Director of Operations, Chief Pilot, and (where applicable) Director of Maintenance in place and qualified, with their qualification records assembled, before you enter the formal phase. Personnel gaps and last-minute changes are a classic source of re-evaluation and reset.
Submit complete, conforming manuals the first time
The Design Assessment phase rewards completeness. A manual set that is finished, acceptable to the FAA, and internally consistent with the operations specifications you request keeps you moving through the gate instead of cycling through corrections.
Request only the authorizations you actually need at first
Every extra aircraft type and special authorization expands the assessment. Start with the scope you need to launch, get certificated, then amend later through the OpSpecs amendment process. A leaner initial request is a faster initial process.
Lock your scope and people before you submit
Changing aircraft types, personnel, or kinds of operations mid-process can trigger re-evaluation — and under 14 CFR §119.51, certain changes require advance notice and FAA review. Decide, then apply; do not discover your operation while the FAA is assessing it.
Keep one organized, version-controlled document set
When the FAA asks for a document, produce it in minutes with no ambiguity about which version is current. A scattered set across drafts, emails, and drives slows the FAA's review and your own responses — and invites the version-drift that creates findings.
FileFlo is the proof layer, not the certification consultant
To be unambiguous about what FileFlo does and does not do: FileFlo is a compliance document intelligence platform that classifies, indexes, version-controls, and tracks expirations on your compliance documents. It does not obtain your certificate, file your application, write your manuals, conform your aircraft, interact with the FAA, broker any deal, or provide legal, financial, or tax advice. Your certification team, your required management personnel, and your aviation attorney own that work. What FileFlo does is eliminate the document chaos that drives the #1 delay cause — keeping your application documents organized and version-controlled during certification, then keeping your operating records audit-ready for the life of the certificate. The FAA controls the clock; not entering the rework loop is the part you control, and that is the part FileFlo helps with. (FileFlo does not claim SOC 2 certification.)
Once you are certificated, the same document discipline keeps you out of trouble on the back end. See how to prepare for a Part 135 FAA surveillance audit, the truth-in-leasing aircraft lease records under §91.23, and — if a charter broker is in your distribution — charter broker compliance under 14 CFR Part 295. For single-pilot operators, the single-pilot operator records path is a lighter, and typically faster, certification profile.
Is buying an existing certificate the faster route?
A frequent question from people staring down a long timeline: can I just buy a company that already holds a Part 135 certificate and skip the wait? Sometimes that path is pursued, but it is not a guaranteed shortcut around the FAA. A certificate is tied to its holder, its approved manuals, its personnel, its operations specifications, and its aircraft. Under 14 CFR §119.51, changes such as a merger or acquisition, a new kind of operation, or a new aircraft type generally require at least 90 days’ advance notice and FAA review of the operations specifications — and a material change can trigger significant re-evaluation. You also inherit the target’s compliance history, open findings, and record quality.
Whether acquisition is genuinely faster than certificating fresh is a deal-specific question for an aviation attorney and the FAA, not a rule of thumb. Either way you land in the same place: an operator that must prove, with documents, that it meets the requirements. The full trade-off is in buying an existing Part 135 certificate, and the compensation-or-hire line that determines whether you even need a certificate is in Part 91 vs Part 135: compensation or hire — with the enforcement context in the FAA illegal-charter crackdown.
Build the SMS deadline into your timeline
Whatever your certification timeline looks like, it now runs alongside a fixed industry deadline: under the 2024 final rule, Safety Management System (SMS) requirements apply to Part 135 operators, with a single compliance date of May 28, 2027. New applicants need to account for SMS as part of getting ready, not as an afterthought — and an SMS is itself a body of documents and records that must be maintained. If you are certificating now, plan your manuals and records to include it from the start.
The details: the FAA Part 135 SMS 2027 deadline and Part 135 SMS requirements.
Frequently Asked Questions
How long does Part 135 certification take?
There is no fixed FAA timeline. The hard regulatory floor is in 14 CFR §119.35: the formal application must be submitted at least 90 days before the date of intended operation. But 90 days is a minimum lead time for one phase, not a typical finish time. In practice, the full FAA-described certification process commonly takes several months to well over a year, depending on your Flight Standards office's workload, the complexity of the operation you request, how many aircraft and special authorizations are involved, and — the factor you most control — how complete and compliant your manuals and documents are when you submit them. Incomplete or non-conforming submissions that bounce back for rework are the single most common reason certifications run long. Source: 14 CFR §119.35; FAA Part 135 certification process guidance.
What is the Part 135 certification timeline, step by step?
The FAA describes its air-carrier certification as a five-phase, three-gate process: Phase 1 Pre-application (you signal intent and complete the pre-application requirements), Phase 2 Formal Application (you submit the application and required documents — due at least 90 days before intended operation under 14 CFR §119.35), Phase 3 Design Assessment (the FAA reviews your manuals and programs in depth), Phase 4 Performance Assessment (the FAA validates that your procedures and training actually work, including operating an aircraft), and Phase 5 Administrative Functions (the FAA issues the certificate and your operations specifications). You cannot pass a gate into the next phase until every item in the current phase is complete, which is why an incomplete document set stalls the whole clock. The phase-and-gate model is FAA guidance, not regulatory text — confirm the current process with your Flight Standards office.
Why does Part 135 certification take so long?
Three things stretch the timeline: FAA workload, operation complexity, and — most controllable — the completeness of your documents. The process uses gates: all items in a phase must be finished before you pass into the next one, so a single incomplete or non-conforming manual can hold the entire certification at a gate. The most common finding from people who have been through it is that document and manual problems, not the FAA's pace, are what drag certifications out: drafts that are not acceptable to the FAA, manuals that contradict the operations specifications you are requesting, missing required-management-personnel qualifications, or version-drift between documents. Each round of corrections adds a review cycle and weeks-to-months of calendar time. A clean, complete, internally consistent document package is the closest thing to a timeline accelerator an applicant has.
How long is the 90-day Part 135 application requirement, and is that the whole timeline?
No. Under 14 CFR §119.35, an applicant must submit the formal application at least 90 days before the date of intended operation. That 90 days is a minimum lead time before you start the formal phases — it is not the total certification time and it is not a promise of completion in 90 days. After the formal application is accepted, you still move through Design Assessment and Performance Assessment, each of which can take months depending on how many revision cycles your documents require and how the FAA's workload lines up. Treat the 90-day figure as the earliest the formal clock can start, and budget far more calendar time for the full process. Source: 14 CFR §119.35.
What is the number-one cause of Part 135 certification delays?
The most commonly cited cause of delay is incomplete, non-conforming, or inconsistent manuals and documents at submission. Because the FAA uses a phase-and-gate process, your application cannot advance until every required item is complete and acceptable — so a manual that is not finished, a document set that contradicts the operations specifications you are requesting, or required-management-personnel qualification records that are missing will hold you at a gate. Every correction is another review cycle. This is the delay cause applicants most directly control: a complete, internally consistent, version-controlled document package avoids the back-and-forth that turns a months-long process into a year-plus one. It is also why getting the document organization right early is a timeline investment, not just a compliance chore.
Can you speed up Part 135 certification?
You cannot override the FAA's process or the 90-day minimum lead time in 14 CFR §119.35, and you cannot control your Flight Standards office's workload. What you can control is rework. Effective January 24, 2024, the FAA adopted a process aimed at increasing applicant readiness before initial certification — a signal that readiness up front is exactly what keeps timelines from slipping. The levers that actually shorten your calendar time are: hiring and qualifying your required management personnel before you apply, submitting complete and conforming manuals the first time, keeping your documents internally consistent with the operations specifications you request, requesting only the authorizations you genuinely need at first, and presenting a clean, version-controlled document set the FAA can review without chasing missing pieces. None of that is a shortcut around the FAA — it is the elimination of self-inflicted delay. Source: FAA Part 135 certification process guidance; 14 CFR §119.35.
Does buying an existing Part 135 certificate make it faster?
Not necessarily, and not as a way around the FAA. Acquiring a company that already holds a Part 135 certificate is sometimes pursued as a faster path than certificating from scratch, but a certificate is tied to its holder, approved manuals, personnel, operations specifications, and aircraft. Under 14 CFR §119.51, changes such as a merger or acquisition, a new kind of operation, or a new aircraft type generally require at least 90 days' advance notice and FAA review of the operations specifications, and a material change can trigger significant re-evaluation. You also inherit the target's compliance history and record quality, which can slow you down rather than speed you up. Whether buying is genuinely faster is a deal-specific question for an aviation attorney and the FAA — both paths still require you to prove, with documents, that you meet the requirements.
How does FileFlo help with a Part 135 certification timeline?
FileFlo does not get you certified, file your application, write your manuals, or interact with the FAA — those are functions of your certification team, your required management personnel, and your aviation attorney, and FileFlo does not give legal, financial, or tax advice. What FileFlo does is attack the one delay cause you control: document chaos. It is a compliance document intelligence platform that classifies, indexes, version-controls, and tracks expirations on the documents you produce during certification and the operating records you must maintain afterward. During certification that means one organized, version-controlled home for your application documents and manual revisions — so the current version is always identifiable, superseded drafts never get mistaken for live ones, and the FAA's review is not slowed by a scattered document set. After certification it keeps your pilot, maintenance, training, and authorization records audit-ready. FileFlo is the proof layer, not the certification consultant.
Don’t let document chaos add months to your certification
The #1 cause of Part 135 certification delay is incomplete, inconsistent documents that bounce back for rework. FileFlo organizes and version-controls your application documents and manual revisions during certification — so the FAA’s review is not slowed by missing or conflicting files — then keeps your pilot, maintenance, training, and authorization records audit-ready for the life of the certificate. AI document classification. 600+ document types. One-click FAA surveillance binder. Starter at $89/mo, Professional at $299/mo. No credit card required for the 5-day free trial. FileFlo does not get you certified or give legal advice — it organizes and proves your compliance documents.
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Continue your Part 135 certification reading
Reviewed by Chad Griffith, Founder, FileFlo — compliance document intelligence. Last reviewed June 15, 2026. The 90-day formal-application requirement is verified against the Cornell Legal Information Institute eCFR (14 CFR §119.35), and the amendment / advance-notice framework against 14 CFR §119.51. The five-phase, three-gate certification process — and the January 24, 2024 applicant-readiness change — are FAA guidance describing how the agency manages certification, not regulatory text. All timelines are hedged planning ranges as of 2026, not FAA guarantees; your actual timeline depends on your operation, your Flight Standards office, and your aircraft. Not legal, financial, or tax advice.