Direct Answer — How Part 135 Check Pilots and Flight Instructors Are Authorized
A Part 135 check pilot (14 CFR §135.337) administers the required proficiency, competency, and line checks; a flight instructor (§135.338) delivers the required training. Both must hold PIC-level certificates and ratings, complete the applicable PIC training and checks, and complete the role-specific training in §135.339 (check pilots) or §135.340 (flight instructors). A check pilot must additionally be approved by the Administrator for the duties involved (§135.337(b)(5)). Each must also have satisfactorily conducted a check (or instruction) under the observation of an FAA inspector within the preceding 24 calendar months (§135.339(a) / §135.340(a)), with a one-calendar-month grace window on either side. The authorization is documented in the individual's training record (§135.337(c) / §135.338(c)) and in the §135.63(a)(4) individual pilot record, which must show the "check pilot authorization, if any."
Primary sources: 14 CFR §135.337, §135.338, §135.339, §135.340, §135.63. The current regulation uses "check pilot" rather than the legacy term "check airman."
For a Part 135 on-demand or commuter operator, the people who administer checks and deliver training are the load-bearing structure of the entire training program. If a check pilot's authorization lapses, every check they sign can be called into question — and so can the currency of every pilot they checked. That is why check pilot and flight instructor records belong in the same audit-readiness tier as pilot records and the training program records themselves.
FAA civil penalties for recordkeeping and qualification violations under 49 U.S.C. § 46301 reach $75,000 per violation under 14 CFR §13.301 — and a single unqualified check pilot can convert into multiple violations because each affected pilot check is a separate exposure. This article walks through the two roles, the five qualification requirements they share, the 24-calendar-month observation clock that keeps each authorization alive, and exactly which documents prove an authorization is current. It pairs naturally with the required management personnel qualifications and Part 135 surveillance-audit preparation.
Two Distinct Roles — Check Pilot vs Flight Instructor
They are frequently held by the same person, but they are separate authorizations governed by separate regulations and documented separately. Confusing them — or assuming a check pilot is automatically an instructor (or vice versa) — is a common records error.
Check Pilot
Qual: §135.337 · Training: §135.339Qualified to conduct the flight checks Part 135 requires — proficiency checks, competency checks, and line checks. Per §135.337(a), a "check pilot (aircraft)" conducts checks in the aircraft for a particular type; a "check pilot (FSTD)" conducts checks only in a Flight Simulation Training Device for a particular type.
FSTD recency rule
A check pilot (FSTD) must either fly at least two flight segments as a required crewmember for the type/class/category involved within the preceding 12-month period, OR satisfactorily complete an approved line-observation program within the period prescribed by that program (§135.337(d)). A before/after grace month applies per §135.337(e).
Flight Instructor
Qual: §135.338 · Training: §135.340Qualified to give the instruction Part 135 requires — initial, transition, upgrade, and recurrent training. Per §135.338(a), a "flight instructor (aircraft)" instructs in the aircraft for a particular type, class, or category; a "flight instructor (FSTD)" instructs only in a Flight Simulation Training Device.
FSTD recency rule
A flight instructor (FSTD) carries the identical recency requirement: two flight segments as a required crewmember within the preceding 12-month period, OR an approved line-observation program completed within the period prescribed by that program (§135.338(d)), with the §135.338(e) grace month.
"Check airman" is the old term — the rule says "check pilot"
Operators and training manuals still routinely say "check airman." The current regulatory text in §135.337 and §135.339 uses "check pilot," and distinguishes the aircraft variant from the FSTD (Flight Simulation Training Device) variant. The substance of the qualification is unchanged; only the terminology was modernized. When you search the CFR, search "check pilot."
The Qualification Requirements, Element by Element
§135.337(b) and §135.338(b) run in parallel. Both lists require the same first four elements; the check pilot list adds an explicit Administrator-approval element in (b)(5). For each, here is what it means and the document that proves it.
Pilot certificates and ratings required to serve as PIC
Check pilot §135.337(b)(1) · Instructor §135.338(b)(1)The person must hold the pilot certificates and ratings that would be required to serve as pilot in command in operations under Part 135 for the aircraft type involved. This is the eligibility floor — you cannot check or instruct in an aircraft you would not be certificated to command.
Record that proves it
Copy of the airman certificate and ratings; type rating where applicable; current medical and pilot currency records supporting PIC eligibility.
Completed the appropriate PIC training phases, including recurrent
Check pilot §135.337(b)(2) · Instructor §135.338(b)(2)The person must have satisfactorily completed the appropriate training phases for the aircraft — including recurrent training — that are required to serve as PIC under Part 135. A check pilot or instructor must themselves be a fully trained, current PIC-eligible crewmember for the type.
Record that proves it
Training records showing initial/transition and recurrent ground and flight training completion for the type (this is the §135.337(c)/§135.338(c) training-record entry).
Completed the required proficiency or competency checks
Check pilot §135.337(b)(3) · Instructor §135.338(b)(3)The person must have satisfactorily completed the proficiency or competency checks that are required to serve as PIC under Part 135. The check pilot must be current on the very checks they will administer to others.
Record that proves it
Most recent §135.293/§135.297 proficiency or competency check records establishing the person's own currency.
Completed the §135.339 / §135.340 training
Check pilot §135.337(b)(4) · Instructor §135.338(b)(4)A check pilot must satisfactorily complete the applicable training requirements of §135.339 (initial and transition check pilot training and checking). A flight instructor must satisfactorily complete the applicable requirements of §135.340 (initial and transition flight instructor training and checking). This is the dedicated check-pilot-specific or instructor-specific training — distinct from the PIC training in element 2.
Record that proves it
Records of §135.339 / §135.340 initial or transition ground and flight training completion — including, for the check pilot, training in detecting improper and insufficient training and in conducting the required checks.
Approved by the Administrator for the duties involved
Check pilot §135.337(b)(5) · Instructor see §135.340 / OpSpecsFor a check pilot, §135.337(b)(5) is explicit: the person must have been approved by the Administrator for the check pilot duties involved. A check pilot authorization is not self-conferred by the operator — it is approved by the FAA (typically reflected in the certificate holder's approved training program, OpSpecs, and/or an FAA letter of authorization). The flight instructor parallel runs through the §135.340 observed-instruction requirement and the approved training program.
Record that proves it
FAA letter of authorization, the approved training program / OpSpec paragraph evidencing the authorization, and the date the authorization was granted.
The element operators most often miss: Administrator approval
§135.337(b)(5) is unambiguous: a check pilot must have "been approved by the Administrator for the check pilot duties involved." An operator cannot simply designate an experienced captain as a check pilot internally and treat that as sufficient. The authorization flows from the FAA — through the approved training program, OpSpecs, and/or a letter of authorization — and the supporting paperwork must be retrievable. Experience and a completed §135.339 course are necessary but not sufficient without the Administrator approval on file.
The 24-Calendar-Month Observation Clock
Qualifying as a check pilot or flight instructor is not a one-time event. Both authorizations carry a recurring obligation that, if missed, silently disqualifies the person.
§135.339(a) — Check pilot observed check
A check pilot must have satisfactorily completed initial or transition check pilot training and, within the preceding 24 calendar months, satisfactorily conducted a proficiency or competency check under the observation of an FAA inspector or an aircrew designated examiner. Lapse it, and the person no longer meets §135.339 and cannot serve as a check pilot.
§135.340(a) — Flight instructor observed instruction
A flight instructor must have satisfactorily completed initial or transition flight instructor training and, within the preceding 24 calendar months, satisfactorily conducted instruction under the observation of an FAA inspector, an operator check pilot, or an aircrew designated examiner employed by the operator (§135.340(a)(2)). Same interval, same disqualifying effect on lapse.
§135.339(b) / §135.340(b) — The one-month grace window
The observation is considered to have been completed in the month required if it is completed in the calendar month before, or the calendar month after, the month in which it is due. This is the familiar "grace month" mechanic — completing in the adjacent month does not change the original due-month baseline for the next cycle.
Why a lapsed check pilot is a cascading failure
If a check pilot's 24-calendar-month observation lapses and they keep administering checks, every check they conduct after the lapse is potentially invalid — which means the line pilots they checked may not have valid currency under Part 135's checking requirements. One missed date on one check pilot can put the qualification of an entire roster in question. This is precisely the kind of expiration that should be tracked structurally, not on a sticky note.
Know whether every check pilot authorization is current — before a POI asks
FileFlo classifies check pilot and flight instructor records against the governing CFR — §135.337/§135.338 qualification elements, the §135.339/§135.340 training completion, and the 24-calendar-month observation clock — indexes them per individual, tracks each expiration, and assembles an inspector-format binder on demand. It is the document and proof layer; it does not run your training program or replace your POI. See the full Aviation compliance coverage.
What Records Prove an Authorization — and Where They Live
The authorization is documented in two distinct places, and an FAA inspector typically pulls both. Missing either one produces a finding even if the underlying training actually happened.
The individual training record
§135.337(c) / §135.338(c)
Completion of the §135.337(b)(2), (3), and (4) requirements (and the §135.338 parallels) must be entered in the individual's training record maintained by the certificate holder. This is where the §135.339 / §135.340 training completion and the underlying PIC training and checks are evidenced.
The individual pilot record
§135.63(a)(4)
The certificate holder's individual record for each pilot must include "the pilot's check pilot authorization, if any." This is where the existence and scope of the authorization is recorded alongside the pilot's certificates, ratings, checks, and route qualifications. Per §135.63(b), these pilot records are retained for at least 12 months.
Put together, a defensible check pilot or flight instructor file is the union of the two — and it must demonstrate currency, not just historical completion. The seven items below are what an audit-ready file contains:
| Document in the file | Establishes | CFR |
|---|---|---|
| Airman certificate + ratings (type rating where applicable) | PIC-eligibility baseline | §135.337(b)(1) |
| PIC training + recurrent training records for the type | Completed appropriate training phases | §135.337(b)(2) |
| Most recent proficiency / competency check | Own currency on the checks administered | §135.337(b)(3) |
| §135.339 / §135.340 initial or transition training completion | Role-specific check-pilot / instructor training | §135.337(b)(4) |
| FAA letter of authorization / OpSpec / approved program | Administrator approval for the duties | §135.337(b)(5) |
| Date of last observed check / instruction (FAA inspector or other authorized observer) | Within preceding 24 calendar months | §135.339(a) / §135.340(a) |
| FSTD two-segment / line-observation recency (if FSTD) | Two segments within preceding 12 months, or line-observation program per its own prescribed period | §135.337(d) / §135.338(d) |
Related Part 135 records and program resources
- What Records Must a Part 135 Operator Keep — the master records checklist
- Part 135 Pilot Records Required by the FAA — the §135.63 individual pilot record
- Part 135 Training Program Recordkeeping — the program the check pilot administers
- Part 135 Required Management Personnel Qualifications — Director of Operations, Chief Pilot, DOM
- Pilot Records Database (PRD) — Part 111 reporting obligations
- What Is Operational Control in Part 135 — §1.1 definition + who holds it
- How to Prepare for a Part 135 FAA Surveillance Audit
- Part 135 Drug & Alcohol Program Records Checklist
Where the Check Pilot / Instructor Compliance Risk Concentrates
The qualification rules are identical across operator types, but the practical risk lands differently depending on how the training program is staffed.
Small single-base on-demand operators
When one or two people hold every check pilot and instructor authorization, a single lapsed 24-calendar-month observation can stall the entire training pipeline — there is no backup check pilot to administer the next round of required checks. The risk is concentration: the program has a single point of failure, and the expiration date for that one person is the most important date in the operation.
Multi-aircraft fleets with several check pilots
The risk shifts to scope-tracking: a check pilot is approved per aircraft type and for specific duties (proficiency, competency, line). A person approved on one type is not approved on another. With multiple check pilots across multiple types, the matrix of who-is-approved-for-what — each with its own observation date and, for FSTD authorizations, its own §135.337(d) recency date — becomes the thing most likely to drift out of date undetected.
Operators preparing for the 2027 SMS requirement
As Part 135 operators stand up Safety Management Systems ahead of the May 28, 2027 SMS deadline, training-program integrity becomes a Safety Assurance data point. Check pilot and instructor currency feeds the competency-assurance picture an SMS is expected to monitor — so a lapsed authorization is no longer just a training-records finding; it can surface as a Safety Assurance gap as well.
Frequently Asked Questions
What is the difference between a check pilot and a flight instructor under Part 135?
They are two distinct authorizations governed by two distinct regulations. A check pilot is qualified to conduct the flight checks required by Part 135 — proficiency checks, competency checks, and line checks (14 CFR §135.337). A flight instructor is qualified to give the instruction required by Part 135 — initial, transition, upgrade, and recurrent training (14 CFR §135.338). The same individual frequently holds both authorizations, but they are approved separately, trained under separate sections (§135.339 for check pilots, §135.340 for flight instructors), and documented separately in that person's training record. A check pilot administers the check; a flight instructor delivers the training that prepares the crewmember for it. Note the regulation now uses the term "check pilot," not the older "check airman" — the substance is the same.
What are the five qualification requirements for a Part 135 check pilot?
Per 14 CFR §135.337(b), no certificate holder may use a person as a check pilot unless, with respect to the aircraft type involved, that person: (1) holds the pilot certificates and ratings required to serve as pilot in command in operations under Part 135; (2) has satisfactorily completed the appropriate training phases for the aircraft, including recurrent training, required to serve as PIC; (3) has satisfactorily completed the proficiency or competency checks required to serve as PIC; (4) has satisfactorily completed the applicable training requirements of §135.339; and (5) has been approved by the Administrator for the check pilot duties involved. All five must be satisfied — the Administrator-approval element in (b)(5) is what many operators overlook. A pilot is not a valid check pilot merely because they are experienced; their authorization must be approved by the FAA and documented.
How often must a Part 135 check pilot be observed by an FAA inspector?
Per 14 CFR §135.339(a), a check pilot must have satisfactorily conducted a proficiency or competency check under the observation of an FAA inspector or an aircrew designated examiner within the preceding 24 calendar months. Per §135.339(b), that observation check is considered completed in the month required if it is completed in the calendar month before or the calendar month after the month in which it is due — a one-month grace window on either side. If the 24-calendar-month observation lapses, the check pilot is no longer qualified to administer checks, and every check they conduct after the lapse is potentially invalid. This is one of the most consequential recurring dates in a Part 135 training program because a lapsed check pilot can silently invalidate the currency of every pilot they checked.
How often must a Part 135 flight instructor be observed, and who may conduct the observation?
Per 14 CFR §135.340(a)(2), a flight instructor must have satisfactorily conducted instruction under the observation of an FAA inspector, an operator check pilot, or an aircrew designated examiner employed by the operator, within the preceding 24 calendar months — an FAA inspector is one option, not a requirement. Per §135.340(b), the observation is considered completed in the month required if completed in the calendar month before, or the calendar month after, the month in which it is due — the same one-month grace window that applies to check pilots. The 24-calendar-month observation requirement is the recurring obligation that keeps a flight instructor authorization valid; like the check pilot observation, it is a date that must be tracked per individual instructor and per authorization.
Where is a check pilot or flight instructor authorization documented in the records?
Two places. First, the completion of the qualification requirements is entered in the individual's training record maintained by the certificate holder — §135.337(c) requires completion of the §135.337(b)(2), (3), and (4) items to be entered in the check pilot's training record, and §135.338(c) imposes the parallel requirement for flight instructors. Second, the authorization itself appears in the individual pilot record required by 14 CFR §135.63(a)(4), which must include "the pilot's check pilot authorization, if any." So an FAA inspector verifying a check pilot pulls both the training record (showing the §135.339 training and the observed check were completed and current) and the individual pilot record (showing the authorization exists and what it covers). A gap in either record is a finding.
Can a check pilot be approved only for a simulator (FSTD)?
Yes. 14 CFR §135.337(a) distinguishes a check pilot (aircraft) — qualified to conduct flight checks in an aircraft for a particular type — from a check pilot (FSTD) — qualified to conduct flight checks only in a Flight Simulation Training Device for a particular type. The same aircraft/FSTD split exists for flight instructors under §135.338(a). A check pilot (FSTD) carries an additional recency requirement: per §135.337(d), to serve in the FSTD that person must, within the 12-month period preceding, either fly at least two flight segments as a required crewmember for the type, class, or category aircraft involved, or satisfactorily complete an approved line-observation program. §135.338(d) imposes the identical FSTD recency requirement on flight instructors. These FSTD recency dates are separate, additional records to track beyond the 24-calendar-month observation.
What records prove a check pilot or flight instructor is currently qualified?
A complete, audit-ready file for each check pilot and flight instructor contains: (1) the pilot certificate and ratings establishing they meet the PIC-eligibility baseline under §135.337(b)(1)/§135.338(b)(1); (2) records of the completed PIC training phases and recurrent training (b)(2); (3) records of the satisfactory proficiency or competency checks (b)(3); (4) the §135.339 (check pilot) or §135.340 (flight instructor) initial/transition training completion (b)(4); (5) the FAA letter of authorization or OpSpec/training-program approval evidencing Administrator approval under §135.337(b)(5); (6) the date of the most recent observed check or instruction — by an FAA inspector or other authorized observer (the rolling 24-calendar-month item); and (7) for FSTD authorizations, the §135.337(d)/§135.338(d) two-flight-segment or line-observation recency record. Miss any one and the authorization is incomplete on its face.
Does a lapsed check pilot observation invalidate the checks they administered?
It creates serious exposure. A check pilot whose 24-calendar-month observed check (by an FAA inspector or aircrew designated examiner) has lapsed no longer meets §135.339(a) and is not qualified to serve. Checks administered by an unqualified check pilot can be challenged, and the pilots who received those checks may not have valid currency as a result — meaning the carrier may have flown crewmembers who were not properly checked. This cascading effect is why check pilot currency is treated as a high-severity recordkeeping item: a single lapsed date on one check pilot can put the currency of many line pilots in question. The defense is structural date tracking — knowing the observation expiration for every check pilot and scheduling the re-observation well before it lapses.
Related Aviation Compliance Reading
Part 135 Maintenance Recordkeeping + CAMP Requirements
How the airworthiness records side of Part 135 is structured
Part 135 Helicopter Air Ambulance (HEMS) Records
Subpart L training and currency records for HAA operations
Part 91K Fractional Ownership Compliance Records
Where 91K and 135 training requirements overlap and diverge
Inspection Authorization (IA) Renewal Requirements
The maintenance-side parallel to recurring authorization currency
What Is Operational Control in Part 135
The §1.1 definition and why it anchors the certificate
How to Prepare for a Part 135 FAA Surveillance Audit
What inspectors ask for and how to have it ready
Keep every check pilot and instructor authorization audit-ready
FileFlo is a compliance document intelligence platform. It classifies Part 135 check pilot and flight instructor records against the governing CFR — §135.337/§135.338 qualification elements, §135.339/§135.340 training, the 24-calendar-month observation clock, the FSTD recency rule, and the §135.63 individual pilot record — tracks every expiration, and generates an inspector-format audit binder on demand. It is the proof layer for your records; it does not run your training program, replace your POI, or function as your operational control system. Starter $89/month · Professional $299/month · 5-day free trial, no credit card required.