Charter dispatch software: comparing the options for Part 135 operators

Charter dispatch software is a fragmented market. The established players were built around scheduling and quote management — trip sheets, crew rosters, aircraft availability. Compliance was an afterthought, layered on after the core was built. The result is systems that are good at moving trips through a workflow but require manual intervention for the regulatory checks that determine whether a proposed flight is legal.

This comparison covers the tools most commonly used by Part 135 on-demand charter operators in the US market: Leon Software, Q5 Systems (formerly Quantum 5), FOS (Flight Operations System), Avinode Ops, and Clearspar. The comparison focuses on pre-dispatch compliance — not trip accounting, quoting aesthetics, or CRM features, because those are not where the legal risk lives.

What to actually evaluate

Before comparing products, define what you are comparing. Charter dispatch software typically covers some combination of:

• Trip and scheduling management — quote-to-trip workflow, aircraft scheduling, crew assignment
• Crew management — roster, currency tracking, training records
• Pre-dispatch compliance — duty/rest checks, currency checks, MEL review, FRAT, flight release
• Documents and reporting — trip sheets, flight release records, audit trails
• Integrations — weather, NOTAMs, accounting, maintenance systems

Most operators evaluate on the first category and discover the third category matters during an FSDO visit or an insurance renewal. The right time to evaluate pre-dispatch compliance is before selecting a system, not after.

Leon Software

Leon is a European-built flight operations platform widely used by business aviation operators globally. It is strong on scheduling, crew rostering, and trip management — the core workflow from quote to invoice is well-developed. Leon has a large operator base, good documentation, and active development.

For Part 135 pre-dispatch compliance specifically: Leon tracks crew currency and will flag expiring qualifications, but its duty time calculations are calibrated primarily to EU-OPS (EASA) limits rather than 14 CFR 135.267. US operators using Leon for Part 135 compliance frequently configure custom duty rules — which works, but requires setup expertise and periodic audit to confirm the rules are correct. Leon does not include a native FRAT module; most operators using Leon for FRAT use a separate paper or spreadsheet system.

Best fit: mid-size to large US charter operators, particularly those with international operations under EASA rules, who prioritize scheduling depth and are willing to configure compliance rules manually.

Q5 Systems (Quantum 5)

Q5 is a US-built platform focused on Part 135 and Part 91 business aviation. It covers scheduling, crew management, maintenance tracking, and has US-specific duty rule configurations. The crew currency tracking is generally regarded as reliable for 135.267 duty limits and 135.293 currency windows.

The gap in Q5 is the pre-dispatch gate itself — Q5 tracks currency as a roster function, but the connection between currency status and a dispatch decision (preventing a release when a crew member is out of currency) requires manual process on the dispatch side. Q5 does not generate a tamper-evident compliance log that captures the decision and the timestamp — the trip is released through the scheduling workflow, and currency status is visible, but the decision record is not the same as a hash-chained compliance ledger.

Best fit: US operators who want solid crew scheduling and currency tracking and are willing to maintain separate documentation for the actual dispatch compliance decision.

FOS (Flight Operations System)

FOS is a legacy platform with a long history in US regional and charter operations. It handles the breadth of flight operations — scheduling, dispatch, crew, maintenance, finance — and has configurations for Part 135 duty rules. The interface is dated by modern standards, and the platform is in a maintenance-mode development cycle rather than active feature expansion.

FOS is common in operators who have been using it for 10+ years and have built their workflows around it. The pre-dispatch compliance functionality is present but implemented as a checklist process rather than an automated gate — the dispatcher verifies items against the system's crew currency display, but the system does not block a release on a failing check.

Best fit: Established operators with existing FOS infrastructure and a trained dispatch team who are not looking to change platforms in the near term.

Avinode Ops (formerly AVIOBOOK / Schedule Master)

Avinode is primarily known as a charter marketplace — the dominant platform for connecting operators and brokers on trip requests. Avinode Ops (their flight operations product) handles scheduling and some crew management for operators who want their marketplace and operations in one ecosystem.

For Part 135 compliance specifically, Avinode Ops is not the tool. The product is optimized for the quoting and sales workflow in the Avinode marketplace ecosystem. Compliance checks are not a core feature. Operators using Avinode for marketplace access typically pair it with a separate tool for compliance tracking.

Best fit: Operators for whom Avinode marketplace access is the primary goal and who have separate compliance tooling.

Clearspar

Clearspar is built compliance-first — the pre-dispatch gate is the product, not a feature layered onto scheduling. Every quote triggers a 14 CFR 135.267 duty/rest check, a 135.297 instrument currency check, a 135.293 recurrent training check, a medical currency check, a MEL/airworthiness review, and a FRAT score before the release is issued. Each check cites the specific regulation. UNABLE findings block the release and require a documented override by a named person in the OpSpecs.

Every dispatch decision — CLEAR or UNABLE — is written to a hash-chained, append-only ledger. The ledger can be exported at any time as a loss-control summary PDF suitable for an insurance submission or an FSDO records request. The compliance methodology can be reviewed and signed off by a Director of Operations, after which every audit report and compliance finding cites that DO by name and credential.

What Clearspar does not do (currently): full trip accounting, invoice generation, maintenance tracking, or integration with aircraft maintenance systems. It is a compliance gate and a compliance record — not a full operations platform. Operators who need the breadth of Leon or Q5 alongside the compliance depth of Clearspar typically run both.

Best fit: Part 135 on-demand charter operators for whom the pre-dispatch compliance record is the primary operational and legal risk, particularly operators with insurance renewals, FSDO relationships, or enterprise clients who ask compliance questions.

The compliance gap that most products share

The common thread across most charter dispatch tools is the treatment of compliance as a display function rather than a gate function. The system shows you that a crew member is out of currency; the dispatcher is expected to act on that information. The dispatch action and the compliance status are separate.

The legal consequence of that architecture is that the certificate holder's compliance record is the dispatcher's memory and the trip notes — not a system-generated, tamper-evident log of what was checked and when. That distinction matters when an FSDO investigator requests records after an incident, when an underwriter asks for a loss-control summary, or when a passenger's attorney asks what the pre-dispatch check looked like for the flight in question.

The right question when evaluating any charter dispatch tool for Part 135 compliance is not "does it show me currency status?" It is "what does my flight release record look like, and can I produce it on demand?"