Part 5 SMS for Part 135 operators: what the four pillars actually require

14 CFR Part 5 made Safety Management Systems mandatory for Part 121 air carriers and Part 135 commuter operations. For unscheduled Part 135 charter operators — the bulk of the on-demand charter market — Part 5 is recommended practice, not a mandate. That distinction matters less than it used to.

Aviation insurance underwriters increasingly treat Part 5 compliance posture as a rating factor. FSDO oversight programs use SMS maturity as a criterion for surveillance targeting. And operators who can demonstrate a functioning SMS — even a minimal one — consistently report smoother renewal conversations than those who cannot. "Recommended" is becoming the market expectation.

The four pillars

Part 5 is built on four pillars. Each has concrete operational requirements.

1. Safety Policy

A written safety policy signed by the accountable manager, stating the organization's safety objectives and the manager's commitment to them. It does not need to be long — two pages is sufficient — but it must be current, distributed to all personnel, and visibly supported by leadership.

The policy should name a Safety Manager (even if that is the DO or the chief pilot at a small operation), define reporting channels, and commit to a just culture — the principle that personnel who report hazards in good faith will not be penalized.

2. Safety Risk Management

Systematic hazard identification and risk assessment before changes to operations, routes, or procedures. For an on-demand charter operator, this pillar is most visibly represented by the FRAT — Flight Risk Assessment Tool — applied to each trip before dispatch.

The FRAT scores relevant risk factors (weather, crew experience on route, time of day, passenger complexity) and produces a risk band: GREEN (proceed), AMBER (mitigated), or RED (DO sign-off required). The score and the outcome must be logged. An AMBER or RED trip that was dispatched without documented mitigation is an SMS finding.

Risk management also includes the pre-dispatch compliance gate — the 135.267 duty/rest check, the 135.247 currency check, the MEL and airworthiness review. These checks do not just protect the operator legally; they are the operational execution of SRM.

3. Safety Assurance

Ongoing monitoring of safety performance against the objectives in the safety policy. In practice, this means:

• A hazard and incident reporting system with a documented response process.
• A corrective-action register tracking every hazard report from open to closed.
• Periodic safety meetings (quarterly at minimum; monthly for larger operations).
• Periodic audits or self-assessments against the SMS program.

Safety assurance is where most SMS programs stall. A hazard register that collects reports but never closes them is worse than not having one — it shows the system exists but is not functioning. Closure rate and time-to-close are the metrics auditors look at.

4. Safety Promotion

Training and communication that builds safety competency and a safety culture throughout the organization. At minimum: initial SMS training for all personnel, recurrent awareness communications (safety bulletins, incident summaries), and documented evidence that the safety policy has been communicated — not just posted.

What an SMS audit actually checks

An FSDO SMS audit — or the self-assessment an operator runs before an insurance renewal — works through each pillar and asks three questions:

1. Does the program exist? Written policy, defined roles, documented procedures.
2. Is it being followed? Records of FRAT scores, hazard reports, corrective actions, safety meetings.
3. Is it working? Closure rates, trend data, evidence that hazards identified are actually being resolved.

An auditor who finds a well-written SMS manual and no supporting records concludes the program exists on paper. An auditor who finds a sparse manual and a complete corrective-action register with documented closures concludes the program is functioning. The second outcome is better.

The minimum viable SMS for an on-demand charter operator

For a single-certificate, 2–5 aircraft operation, a functioning SMS does not require a dedicated safety manager or a compliance management platform. It requires:

• A signed safety policy (2 pages, updated annually).
• A FRAT applied to every trip, with the score logged.
• A hazard reporting channel — even an email address — with a documented response process.
• A corrective-action register (a spreadsheet works; the closure rate matters more than the format).
• Quarterly safety meetings with attendance documented.
• A pre-dispatch compliance log demonstrating that duty, rest, currency, and airworthiness checks are happening before dispatch — not after.

That is the foundation. It is not a heavy lift. It is documentation of what a well-run operation is already doing. The gap for most operators is not the practice — it is the record.