Understanding the Differences Between Part 121, Part 135, and Part 91 Training for Corporate Pilots

For pilots looking to advance their careers in corporate or commercial aviation, understanding the differences between Part 121, Part 135, and Part 91 operations and training is essential. Whether you’re transitioning from flight instructing, considering corporate flying, or aiming for the airlines, knowing how these regulations shape training, operations, and expectations will help you make the best career decision.

Let’s break down how training differs under each set of regulations and what pilots should expect when flying in these environments.

Part 121 – Airline Training and Operations

What is Part 121?

Part 121 applies to scheduled airline operations, including regional, national, and major airlines carrying passengers and cargo under strict FAA regulations. This category includes legacy carriers like Delta, United, and American, as well as regional airlines like SkyWest and Republic.

Training Under Part 121

Training under Part 121 is highly structured and standardized, designed to ensure consistency, compliance, and safety across large operations.

🔹 Indoctrination Training – Covers company policies, CRM (Crew Resource Management), and regulatory procedures.

🔹 Systems Training – Detailed classroom and computer-based training (CBT) on aircraft systems.

🔹 Procedures & Callouts – Standardized operating procedures (SOPs) for every phase of flight.

🔹 Simulator Training – Extensive full-motion simulator sessions covering normal and emergency operations.

🔹 Checkride (Type Rating) – Most Part 121 pilots earn a type rating in the jet they will operate.

🔹 Initial Operating Experience (IOE) – Supervised flying with a Line Check Airman before being released to the line.

🔹 Recurrent Training – Required every 6 to 12 months, including simulator sessions and check rides.

Pilot Expectations

✅ Highly regulated environment with strict SOPs

✅ Consistent and structured training cycle

✅ Crew-based operations (multi-crew cockpit)

✅ Requires an ATP certificate before upgrading to captain

Best For:

• Pilots looking for a structured career path toward major airlines.

• Those comfortable with highly standardized procedures and strict regulatory oversight.

Part 135 – Charter & Air Taxi Training

What is Part 135?

Part 135 covers charter, air taxi, and fractional ownership operations that involve carrying passengers or cargo for hire on an unscheduled basis. Examples include NetJets, Wheels Up, and MedEvac operators.

Training Under Part 135

Training for Part 135 varies depending on the operator’s size and aircraft type but generally follows these key areas:

🔹 Indoctrination Training – Covers FAA regulations, company procedures, and Part 135-specific rules.

🔹 Aircraft Systems Training – CBT or classroom instruction on the aircraft you’ll fly.

🔹 Simulator Training (If Required) – Larger operators use simulators for emergency and instrument training.

🔹 Checkride (135.293 & 135.297 Checks) – Covers instrument proficiency and company-specific procedures.

🔹 Line Check – Required for captains before flying revenue passengers.

🔹 Recurrent Training – Annual or semi-annual training, depending on company policy.

Pilot Expectations

✅ More flexibility in operations compared to Part 121

✅ Single-pilot or dual-pilot operations (depending on aircraft size)

✅ More diverse flying, often including high-end corporate clients or specialized missions (MedEvac, cargo, VIP charters, etc.)

✅ Varied work schedules, sometimes requiring on-call availability

Best For:

• Pilots who want corporate or charter flying experience.

• Those who prefer more variety in destinations and operational flexibility.

• Pilots aiming for business aviation but not necessarily the airlines.

  
  

Part 91 – Private & Corporate Aviation Training

What is Part 91?

Part 91 covers non-commercial operations, including corporate flight departments, private aircraft owners, and business jets used for company transportation. Unlike Part 121 or 135, there are fewer regulatory restrictions because no revenue is generated from passengers.

Training Under Part 91

Training under Part 91 varies significantly based on the company, aircraft type, and pilot experience level. Some common elements include:

🔹 Company-Specific Training – If part of a corporate flight department, expect tailored training based on company SOPs.

🔹 Aircraft Type-Specific Training – Many corporate pilots receive type ratings if flying jets (e.g., Gulfstream, Citation, or Falcon).

🔹 Manufacturer or Third-Party Training Centers – Many companies send pilots to FlightSafety International or CAE for simulator-based training.

🔹 Recurrent Training – While not FAA-mandated like Part 121/135, many corporate pilots train annually or semi-annually to maintain proficiency.

🔹 International Training – If operating globally, expect specialized training on oceanic procedures, ICAO regulations, and high-altitude operations.

Pilot Expectations

✅ More operational flexibility and less regulatory oversight compared to Part 121/135.

✅ High levels of customer service and professionalism required.

✅ Flying can range from routine domestic flights to long-haul international trips.

✅ More responsibility for flight planning, dispatch, and aircraft management.

Best For:

• Pilots who want corporate flying experience with high-net-worth individuals or business executives.

• Those who prefer a less structured training environment but still want high-level professional standards.

• Pilots who enjoy more operational autonomy and decision-making.

  
  

  Which Training Path is Best for You?

Training Aspect	Part 121 (Airlines)	Part 135 (Charter/On-Demand)	Part 91 (Corporate)
Structure	Highly regimented	Moderate flexibility	Varies by company
Simulator Training	Required	Often required	Common for jets
Regulatory Oversight	Very strict (FAA, TSA)	Strict (FAA)	Minimal compared to 121/135
Flight Operations	Scheduled	On-demand	Private/company
SOPs	Strict & standardized	Less standardized	Varies widely
Recurrent Training	Every 6-12 months	Annual/semi-annual	Company-dependent
Work Schedule	Fixed schedules	Irregular, on-call	More control but can vary
Best For	Pilots who want an airline career	Pilots who enjoy variety & flexibility	Pilots who want high-end corporate flying

Final Thoughts

The right path depends on your career goals, flying preferences, and lifestyle needs.

✈️ If you want structured, consistent schedules and a clear career progression, Part 121 is the way to go.✈️ If you prefer more variety, charter flexibility, and unique flying opportunities, Part 135 may be a great fit.✈️ If you’re looking for a high-end corporate flying career with less regulatory oversight but more responsibility, Part 91 is ideal.

Each path offers unique training experiences, so choose the one that aligns best with your professional aspirations!