Logging SIC Time in a Single-Pilot Aircraft: FAA Evidence

Executive Summary

Logging SIC time in a single-pilot aircraft is possible under United States rules, but the seat, company title and aircraft's single-pilot capability do not decide eligibility. The relevant routes are service as a required second in command (SIC), supported by the aircraft or operating requirements, and qualifying optional-SIC service under an authorized Part 135 SIC professional development program (PDP). Title 14 of the Code of Federal Regulations (CFR), §61.51(f), treats these as different bases for an entry. ^{[1] [2]} An insurer's request for another pilot does not itself establish a regulatory logging basis. ^[3]

For a personal logbook, the useful question is: what evidence supports this leg on this date? Required-SIC entries need the applicable crew requirement and qualification evidence. PDP entries need the certificate holder's authorization, applicable program conditions, employment and assignment, qualifications, and the pilot in command's (PIC's) certification in the pilot's logbook. ^{[4] [5] [6]} The National Business Aviation Association's (NBAA's) explanation identifies OpSpec A062, an operations specification, as the program authorization. ^{[7] [6]} An attached roster or flight plan can help identify a flight; neither substitutes for the authorization or certification.

Logging, airline transport pilot (ATP) experience credit and an airline application's requested breakdown are separate decisions. PDP time can contribute to eligible ATP experience categories, but it cannot be logged as PIC, including when the SIC is the sole manipulator of the controls, or satisfy §61.159(a)(5). ^{[6] [5] [8]} Using that time toward ATP experience also engages the International Civil Aviation Organization (ICAO) PIC-experience limitation described by §61.159(e). ^{[5] [6]} A pilot should preserve the PDP subset even when an application includes it within an overall SIC total.

The hypothetical six-leg reconciliation below produces 2.5 hours of documented required-SIC time, 3.1 hours of eligible, certified PDP time, and 2.1 hours awaiting evidence. Thus, the supported SIC subtotal is 5.6 hours, with the PDP subset still identifiable. These are invented teaching inputs, not measured pilot outcomes or an assessment of any operator. The recommended evidence packet links each entry to its governing source, applicable dates and certification. Software can organize that packet, but its export deserves inspection: ForeFlight documents that its comma-separated values (CSV) export excludes signatures and endorsements. ^[9] The recordkeeping objective is an explainable entry and a reproducible total.

Introduction and Background

A professional pilot reviewing right-seat hours often starts with a roster labeled “first officer.” That label answers a personnel question. It does not identify which United States logging provision supports the flight time. Section 61.51(f) instead refers to aircraft certification, the rules governing the flight, or a qualifying program route. ^[2] The distinction matters particularly when an aircraft can be flown with a single pilot but the actual operation may require another pilot.

Aircraft capability and required crew are different facts. United States §135.99(a) connects crew composition to the aircraft operating limitations or Aircraft Flight Manual (AFM) and the requirements of the operation. ^[10] For example, §135.101 addresses carrying passengers under instrument flight rules (IFR), subject to the exception in §135.105. ^[4] This report examines the records needed to establish the applicable basis; it does not prescribe how to dispatch or operate a flight.

Older discussions also need a date check. The AskACFI PC-12 question describes a proposed second pilot who would not be on the charter certificate, a materially specific set of facts. ^[11] The Federal Aviation Administration (FAA) later made the relevant PDP amendments effective November 26, 2018. ^[6] Historical answers cannot settle a different pilot's current program eligibility.

The analysis is anchored to sources retrieved on October 29, 2026. Where the official annual CFR edition is cited, it is the January 1, 2026 edition; the relevant wording was compared with the current electronic Code of Federal Regulations (eCFR) during this research. ^[4] It distinguishes controlling United States regulations, FAA advisory guidance, association explanations and suggested audit practices. An airline form's own instructions remain a separate input; no universal airline definition is assumed. The deliverable is a personal evidence file for first officers, captains certifying PDP entries and pilots reconciling ATP experience. Public-aircraft logging and safety-pilot arrangements have distinct conditions and are kept outside the main commercial-SIC decision path.

Key Changes: The Routes Behind an SIC Entry

Required SIC remains a separate route

United States §61.51(f)(1) addresses qualifying service in a multiple-pilot type-certificated aircraft, while paragraph (f)(2) addresses appropriate qualifications and a second pilot required by type certification or the regulations governing the flight. ^[12] A statement that the aircraft model is “single-pilot” does not resolve the operating-rule branch.

For personal documentation, request the precise AFM limitation, configuration or operating-rule reference relied on by the operator. Where the basis involves passenger IFR requirements, retain an explanation of why the applicable exception does or does not apply to that leg. Section 135.105's autopilot provision involves appropriate operations-specification authorization; possession of an autopilot alone does not settle the record. ^[4] This is an evidence request, not an invitation to make an independent operational determination after the event.

Qualifications also require the right framework. Section 61.55 contains SIC qualifications and exceptions, including distinctions involving domestic operations. ^[13] United States §135.245 generally requires at least a commercial pilot certificate, appropriate category and class ratings, and an instrument rating for Part 135 SIC service. ^[4] A generic qualification checklist should therefore not stop at the baseline certificate language in §61.55.

The PDP route addresses an otherwise optional SIC

The FAA's rulemaking created a route for qualifying pilots to record SIC experience where another pilot was not required. ^[6] Current §61.51(f)(3) connects that route to operations under §135.99(c) and the conditions in §61.159(c). ^[12] Its existence does not make every optional right-seat assignment loggable.

Under §135.99(c)-(d), eligibility includes employment, authorization, applicable duty/rest, training and testing requirements, and compliance with the program's operations specifications. Certificate holders using only one pilot in their operations, and holders approved for the specified manual, training or management deviations, are excluded. ^[4] NBAA's explanation likewise links the assigned SIC to A062 authorization and the operator's training program. ^[7] For the pilot's file, retain a dated authorization reference.

The authorization must also fit the flight. Qualifying Part 91 repositioning operations can be included, but the FAA's rulemaking discusses conditions involving standard operating procedures, operational control and recordkeeping. ^[6] Merely finding “Part 91” in a roster export does not establish those conditions.

Updated guidance highlights a downstream limitation

FAA lists Advisory Circular (AC) 135-43 with Change 1 as active guidance. ^[14] The consolidated Change 1 is advisory rather than independently binding law. ^[8] Its program and endorsement examples help explain the documentation process; they should not be turned into additional statutory logbook fields.

The distinction between logging and licensing credit is particularly important for PDP time. The original amendment expressly excluded PIC logging even during sole manipulation. ^[15] Current §61.159(c)(4) retains that exclusion and the separate paragraph (a)(5) restriction. ^[5] The pilot flying (PF) therefore does not acquire PIC credit merely by handling the controls during a PDP leg. ^[8]

Implementation Considerations and Process Changes

The recommended process starts with a leg-level classification, before hours enter an application subtotal. The following sequence is an audit method, not an additional FAA-mandated form:

• Identify the flight: Match date, aircraft identification, departure, arrival and recorded duration to the personal entry.
• Identify the crew basis: Record the aircraft limitation or operating requirement, rather than relying on the seat occupied.
• Test program applicability: Where the second pilot was optional, identify the operator authorization and program conditions covering that flight.
• Check qualification dates: Connect assignment, training and checking evidence to the date flown.
• Confirm certification: For a PDP entry, locate the PIC's certification covering the identified flight.
• Classify the result: Separate supported required-SIC time, supported PDP time and entries awaiting evidence.

The information normally recorded in the logbook is a starting point. United States §61.51(b) addresses general entry information, experience classification and flight conditions. ^[2] The additional evidence references recommended here help explain the classification. They are not all statutory columns.

Program applicability is date-specific. An authorization obtained later cannot, merely by existing now, establish that an earlier flight was covered. Request the applicable authorization or a reliable operator reference identifying its effective period, scope and amendments. The controlling question remains compliance with the authorized program for the flight being claimed. ^[4] If a particular document cannot be shared, record the unresolved question and seek an operator or FAA determination rather than treating its absence as proof either way.

The evidence must cover the participating pilots as well as the aircraft. NBAA emphasizes that participating SICs must be current and qualified under the operator's training program, and participating captains complete mentoring training. ^[7] A pilot need not demand a captain's entire personnel file to ask for confirmation of program eligibility on a specified date.

The aircraft branch also deserves an explicit reference. Section 135.99(c)(2) limits PDP aircraft eligibility to multiengine airplanes or single-engine turbine-powered airplanes, with specified independent controls, equipment and instrumentation; a throwover control wheel does not satisfy the controls condition. ^[4] Keep an aircraft eligibility reference in the packet instead of copying a fleet-wide assumption into every flight.

Finally, distinguish missing documentation from a settled legal conclusion. “Awaiting authorization evidence” is a useful audit status. It does not mean that the pilot has been found ineligible, and it does not authorize adding the hours to a supported total. A neutral unresolved category keeps the question visible while protecting the reconciliation from assumptions.

Evidence to Request and Keep With Each Entry

Table 1, split into four case-specific checklists, maps the evidence questions to the proposed classification. Its document references and unresolved-status fields are recommended audit practices. The underlying logging and certification rules remain those in §61.51 and §61.159. ^{[1] [5]}

Type-required SIC

Operation-required SIC in a single-pilot aircraft

Optional SIC under an authorized PDP

Optional seat without an established logging route

The case checklists separate what must be established from how the pilot organizes proof. A required-SIC entry and a PDP entry can both contribute to an SIC subtotal, but they reach it by different routes. The PDP subset has additional licensing consequences that should survive any later export or summary. ^{[6] [16]}

A useful personal packet contains:

• Entry identifier: A stable reference connecting the flight row, attachments and any later correction.
• Governing source: The aircraft limitation, regulatory paragraph or program reference used to classify the leg.
• Effective period: The dates covered by the authorization, assignment or qualification record.
• Operator reference: A document title, revision, page or written response precise enough to retrieve again.
• Qualification records: Applicable certificates, ratings, training and checking references.
• Certification source: The original signed logbook entry or preserved certification covering the flight.
• Export check: Confirmation that the copy retained actually contains the certification and relevant attachments.
• Open question: The missing item, contact and resolution status.

Operator records provide important supporting evidence. United States §135.63(a)(4) addresses individual pilot records, including checking and training completion information. ^[4] For PDP participants, the requested copies specified by §135.99(c)(1)(ii) concern §135.63(a)(4)(vi) and (x). FAA guidance discusses supplying those requested records generally within 20 calendar days, while the regulation uses a reasonable-time standard. ^[8] Treat that distinction accurately when requesting documents.

A file attachment is evidence of its contents, not automatic proof of legal sufficiency. A roster can corroborate assignment; it does not establish that the operator held the applicable authorization. A flight plan can identify the aircraft and route; it does not establish the SIC's qualifications. Link the document to the proposition it actually supports.

Captain Certification and the Retained Source

For the PDP route, United States §61.159(c)(3) requires the PIC of the operation to certify in the pilot's logbook that the SIC time was accomplished under that section. ^{[5] [8]} Cornell's accessible republication expresses the same requirement. ^[16] This certification is a distinct piece of evidence, not simply a captain's name imported from a roster.

FAA's AC offers an endorsement example to certify each flight. The example identifies the participating pilots, regulatory basis, flight identification, date, PIC signature and airman certificate number. ^[8] The example is useful as a completeness check. It should not be described as the only permitted wording, or as a regulation establishing a particular signature deadline.

The following retention checks are recommendations:

• Flight coverage: Confirm which individual flight or clearly identified flights the certification covers.
• Certifying person: Preserve the identity and signature of the PIC who made the certification.
• Regulatory statement: Retain the statement addressing the applicable PDP provision.
• Original context: Preserve the surrounding entry, not just an isolated signature image.
• Copy quality: Open the saved or printed version and check that the statement remains readable.
• Change history: Keep a record of later amendments affecting a certified entry.

A generic electronic signature capability should not be assumed to implement this precise certification. For example, LogTen documents signed entries and signatures appearing in reports. ^[17] That is evidence of a software capability, not proof that a particular statement was made by the required PIC for an eligible flight.

Edits also deserve attention. MyFlightbook's documentation distinguishes valid signatures from signatures invalidated by an edited flight. ^[18] The practical implication is to inspect the signed result after a correction or migration. Do not assume that the presence of a signature symbol in an old view establishes the status of a changed entry.

Where a certification is missing, preserve the actual record and ask the operator and relevant captain how to resolve it through the applicable process. Do not invent an earlier approval, reproduce another person's signature, or date a statement as though it existed when it did not. Acceptance of a later clarification depends on the actual facts and applicable examination process.

Paper, Electronic Logbooks and Application Breakdowns

The legal classification should remain understandable in whichever medium the pilot uses. NGPA's association guide notes that electronic logbooks can still contain entry errors. ^[19] An automatic total therefore needs a classification check before it becomes an application answer.

Table 2 compares recordkeeping approaches through the narrow question of preserving an explainable SIC total. Vendor statements describe documented capabilities, not an independent finding that any product approves FAA flight time.

The comparison is about record preservation, not a ranking. A readable PDF, an imported flight or an attractive authority-style layout does not itself decide eligibility. The FAA logging rule still requires experience to be recorded in a manner acceptable to the Administrator. ^[1]

Automation has a specific scope. LogTen's Typical Roles documentation says fields such as SIC can autofill according to the selected role. ^[24] The pilot should therefore compare those populated fields with the actual logging basis. A role setting can implement a chosen workflow; it cannot supply missing authorization evidence.

Exports also serve different purposes. ForeFlight describes its PDF option as including entries, endorsements, certificates and licence information. ^[9] LogTen expressly distinguishes its spreadsheet export from a complete backup. ^[22] Keep a machine-readable hours file and the source certification record where both are needed, then open the saved copies to verify their contents.

For an airline or licensing submission, use a documented mapping rather than changing the source history to fit the form:

• Source classification: Preserve required SIC and PDP SIC as distinguishable categories.
• Form definition: Read the actual requested category and any accompanying instructions.
• Included subset: Show PDP within, rather than added again to, an inclusive SIC total.
• Excluded entries: Keep unresolved hours outside the supported answer pending resolution.
• Reconciliation note: Save the filter, calculation and date used to produce the submitted figure.

This mapping is a recommended personal-record practice. No specific airline's acceptance policy was established by the research, and no universal airline treatment of PDP hours is asserted.

Data Analysis and Evidence

The regulatory numbers are eligibility conditions

This subject does not need invented error rates or claims about how many pilots keep inadequate records. The useful numbers are the applicable rule thresholds and the arithmetic of a transparent example.

Under United States §135.99(c)(4), a participating PDP captain must have been fully qualified as the operator's PIC for at least the preceding 6 calendar months, and have completed mentoring training within the preceding 36 calendar months. ^[10] These are qualification checks against the flight date, not additional hours the SIC can claim.

United States §135.63(b) specifies at least 12 months of operator retention for individual pilot records. ^[4] That is a different question from how long a pilot should preserve evidence for a later application. The recommended personal archive should be designed around the pilot's future need to explain the entry, rather than assuming that an operator retention minimum is an ideal personal deletion schedule.

For a conventional airplane ATP path, §61.159(a) begins with 1,500 total pilot hours, with specified experience components; §61.159(a)(5) separately addresses 250 airplane hours of the qualifying PIC or supervised-SIC experience described there. ^[5] Restricted-ATP alternatives require their own analysis. The key point here is that PDP hours do not satisfy paragraph (a)(5), even where they contribute elsewhere. ^{[16] [15]}

Six-leg reconciliation (Hypothetical Example)

The following fictional legs assume a pilot assigned to the same Part 135 certificate holder and an aircraft capable of single-pilot operation. For legs A and B, the records establish that the actual passenger IFR operations required an SIC under §135.101, with no applicable §135.105 exception. ^[4] For C and D, the second pilot was optional, but all applicable PDP conditions and PIC certification are assumed documented. E and F remain unresolved.

Table 3 contains invented durations solely to demonstrate classification and arithmetic. It is not an operator case study or an entitlement decision.

The supported SIC total is 2.5 + 3.1 = 5.6 hours. The physical-flight dataset contains 7.7 hours, while 2.1 hours remain outside the supported total. The PDP subset is 3.1 hours within 5.6, not an additional amount to add again. Leg D contributes no PIC through sole manipulation under the PDP rule. ^[15]

Other overlapping dimensions need separate evidence. Qualifying cross-country, night or instrument experience is not established merely by placing a duration in the SIC column. The FAA's rulemaking explains that PDP experience can contribute to qualifying ATP component categories, subject to their conditions. ^[6] If a form requests a different definition, preserve the supported logbook record and document how the requested answer was derived.

Implications and Future Directions

The most useful improvement is a record that can answer a later question without relying solely on memory. In this context, that means preserving the basis for the entry, the dates of applicability, and the certification source, alongside the flight data.

There is also an application-stage document requirement worth planning for. Current United States §61.39(a)(3)(i) requires a practical-test applicant relying on §61.159(c) experience to present copies of the records specified in §135.63(a)(4)(vi) and (x). ^[25] The original rulemaking included that record-presentation requirement. ^[15] A captain's logbook certification and those training/checking records serve different evidentiary functions.

When information is missing, a targeted request is more useful than asking whether all right-seat hours count:

• Operator authorization: Which issued program authorization covered these listed flights and dates?
• Individual eligibility: Which assignment, training and checking records establish participation?
• Aircraft applicability: Which aircraft record supports eligibility for the flights listed?
• Captain certification: Where is the certification covering each claimed PDP flight?
• Application treatment: Which category should receive the supported time under the actual form's instructions?

Corrections should preserve their context. NGPA recommends a visible single-line correction and an explanation of what changed in paper records. ^[19] That is association advice, not a universal statutory correction format. For a digital record, the analogous recommendation is to preserve the prior value, explanation and supporting source, then check any affected certification.

AOPA identifies aircraft records, receipts and operator statements as possible supporting material when a logbook must be reconstructed. ^[20] Such material may help recover flight facts; it should not be treated as creating a program authorization or certification that never existed. Where the remaining issue concerns legal eligibility or administrative acceptance, obtain a case-specific answer from the operator, FAA or relevant examiner and retain the response with its factual assumptions.

Frequently Asked Questions

Can a company first-officer title make optional right-seat time loggable?

The title alone does not establish a §61.51(f) route. The current regulation distinguishes required-crew and qualifying program service. ^[2] An insurance requirement likewise does not itself change the regulatory logging basis, as AOPA explains. ^[3]

Is a Part 91 positioning flight automatically a PDP flight?

No. The FAA's explanation permits qualifying Part 91 operations for the certificate holder subject to program conditions. ^[6] Identify the authorization and applicable conditions for the actual flight. A roster label is insufficient evidence by itself.

Can a safety pilot log SIC in a single-pilot aircraft?

Potentially, under a separate factual and regulatory analysis. United States §91.109(c) addresses the safety pilot required for simulated instrument flight. ^[26] AOPA explains an example in which the safety pilot logs SIC while the manipulating pilot acts as PIC. ^[3] An Experimental Aircraft Association (EAA) chapter handout emphasizes the simulated-instrument segment rather than the entire flight. ^[27] This should not be merged into a blanket PDP rule. Shackelford's explanation also distinguishes safety-pilot service from acting as an assigned SIC. (Source: shackelford.law)

Does using PDP time for ATP experience have a limitation?

Yes. Section 61.159(e) addresses the ICAO PIC-experience limitation, and paragraph (f) describes issuance without it upon satisfactory evidence of meeting the relevant requirements. ^{[5] [6]} PDP time does not become PIC or paragraph (a)(5) experience through sole manipulation. ^[16]

Conclusion

The recordkeeping answer to logging SIC time in a single-pilot aircraft starts with the route supported by the actual leg. A type-required SIC, an operation-required SIC and an optional SIC participating in an authorized PDP are different cases. A company title is useful context, but the evidentiary work lies in the aircraft or operation requirement, applicable authorization, pilot qualifications and, for PDP entries, the captain's logbook certification.

The recommended personal record keeps that explanation close to the flight. A document index can identify the source and effective period without turning every supporting fact into a mandatory logbook column. An unresolved status can preserve a question without moving the hours into a supported subtotal. A retained signed record can preserve information that an hours spreadsheet may omit.

The hypothetical reconciliation demonstrates the practical result: required-SIC time and eligible PDP time can be added into an inclusive SIC subtotal while the PDP subset remains visible. Unresolved optional-seat hours stay outside that supported answer until the evidence and applicable acceptance process resolve them. Neither PF status nor an imported roster should silently change the category.

For an ATP submission or an airline form, produce a reproducible answer from that source record and the destination's actual definitions. Preserve the calculation, certification and supporting documents together. The objective is a personal logbook that explains both the hours claimed and the evidence supporting their classification.