CASA EX74/24 – Part 121 – Single Pilot Aeroplane (MOPSC 10-13) Operations – Exemptions and Directions Instrument 2024

CASA EX74/24 is a legislative instrument that exempts operators and pilots in command of certain single-pilot aeroplanes from compliance with Part 121 of the Civil Aviation Safety Regulations 1998 (CASR) and the Part 121 Manual of Standards (MOS). The exemption is conditional: the operator and pilot must instead comply with Part 135 of CASR (air transport operations - smaller aircraft) as modified by a companion instrument, CASA EX71/24, plus additional equipment and operating conditions set out in Schedule 1. The instrument applies only to aeroplanes with a maximum operational passenger seat configuration (MOPSC) of 10 to 13, a maximum take-off weight of no more than 8,618 kg, that are type-certificated for single-pilot operation, and whose flight manual permits a single pilot crew. In practical terms, this allows operators of small regional turboprops and piston twins (e.g., King Air 350, Beech 1900, Cessna 404) to fly under Part 135 rules rather than the more stringent Part 121 framework, which is designed for larger aircraft with higher passenger capacities. The instrument commences on 2 December 2024 and is automatically repealed on 1 December 2027, giving it a three-year life. It replaces an earlier instrument, CASA EX97/22, with largely identical effect.

The exemption is not a blanket relief from all safety obligations. The operator and pilot remain subject to Part 135 (as modified by EX71/24) and must meet enhanced equipment requirements that intentionally exceed Part 135 minimums. These include mandatory airborne weather radar for all flights, terrain awareness warning systems (TAWS) graded by aircraft type and weight, and tight restrictions on inoperative autopilots. A notification direction under section 10 requires the operator to tell CASA, using the appropriate form, which similar types of aeroplanes they intend to operate under the exemption, before starting those operations. This is a registration-like step but not an approval process; it functions as a filing obligation. Importantly, the operator and pilot cannot take the benefit of this instrument while also relying on CASA EX69/24, another supplementary exemptions instrument. So this is a standalone pathway, not additive to other relief.

Mechanically, the instrument replaces the regulatory regime for a defined class of operations. Instead of complying with Part 121 (which covers air transport operations by aeroplanes with a MOPSC of more than 9), the operator complies with Part 135 (which covers a lower rung of air transport operations) plus the extra Schedule 1 conditions. The effect is to lower the compliance burden for small single-pilot operations, but with strings attached that are meant to address specific risks of single-pilot IFR and night flying. The instrument represents a regulatory carve-out, not a relaxation of all standards, and it is temporary, forcing a review or remake before December 2027.

MOPSC (maximum operational passenger seat configuration) is a term defined in the CASR Dictionary. It refers to the highest number of passenger seats the aeroplane is configured to carry, excluding crew seats. The instrument applies only to aeroplanes with a MOPSC of at least 10 but not more than 13. This is the key scope parameter: if the aeroplane has 9 or fewer passenger seats, Part 121 does not apply anyway (that is Part 135 territory), and if it has 14 or more, the exemption is unavailable.

Relevant aeroplane is the defined class of aircraft eligible for the exemption. It must meet five cumulative conditions: (a) would otherwise be subject to Part 121; (b) MOPSC 10-13; (c) MTOW ≤ 8,618 kg; (d) type-certificated for single-pilot operation; and (e) flight manual permits single-pilot crew. The 8,618 kg MTOW cap limits the exemption to smaller turboprops and piston twins - larger aircraft like regional jets are excluded.

Part 121 vs Part 135 is the central regulatory trade-off. Part 121 is the CASR rule set for higher-capacity air transport operations (more than 9 passenger seats) and imposes more prescriptive requirements on crew composition, fatigue management, maintenance programs, and operational control. Part 135 covers lower-capacity air transport and is generally considered less burdensome. The instrument allows eligible operators to be treated as if they were Part 135 operators, but with the extra Schedule 1 conditions.

TAWS-Class A, TAWS-Class B, TAWS-Class B+ are terrain awareness warning system standards. TAWS-Class A is the most capable, with full terrain display and predictive warning. TAWS-Class B is a lower standard. The instrument creates a new hybrid category, TAWS-Class B+, which is TAWS-Class B with a colour terrain display meeting specific depiction and orientation requirements. Schedule 1 mandates different TAWS levels depending on engine type, MTOW, and flight rules.

Automatic pilot is defined by reference to Part 135 of CASR. Schedule 1 imposes strict rules: for VFR day flights, the aeroplane must comply with subsection 11.10(2) of the Part 135 MOS (which mandates an autopilot with certain capabilities). For any flight, subsection 11.10(3) (which would allow inoperative autopilot under conditions) is disapplied. An autopilot may be inoperative at the start of a day VFR or day IFR VMC flight only if departing an aerodrome without repair facilities and within 24 hours of discovery. The effect is that an inoperative autopilot cannot remain unrepaired for more than 24 hours, essentially requiring operators to have a spare or rapid maintenance capability.

The instrument directly affects two categories of person: the operator of a relevant aeroplane, and the pilot in command of the operator of a relevant aeroplane. The operator is the entity holding the air operator's certificate (AOC) that conducts the flights. The pilot in command is the individual responsible for the flight. Both are granted exemptions from Part 121, and both are subject to the conditions in sections 5 and 6, the additional conditions in Schedule 1, and the notification direction.

Indirectly, the instrument affects a range of stakeholders. Small regional airlines and charter operators that fly single-pilot aeroplanes seating 10-13 passengers are the primary beneficiaries. These operators typically fly turboprops like Beechcraft King Air 200/350, Beech 1900, Cessna 208 Caravan (though Caravan is single-engine and may not meet class rating requirements for some pairings), Piper Cheyenne, and piston twins such as Cessna 404 or Piper Navajo. Without this exemption, these operators would need to comply with Part 121, which may require two pilots (in some circumstances), more rigorous maintenance schedules, and additional operational control staff. The exemption allows them to continue operating under the less intensive Part 135 framework, which is closer to what many of them already used under the old CAR 1988 system.

Pilots in command of these operations are affected because they must comply with Part 135 duties as modified, plus the Schedule 1 conditions. This includes ensuring that the aeroplane's autopilot, TAWS, and weather radar are serviceable within the strict timelines. The prohibition on subsection 11.10(3) of the Part 135 MOS means that the pilot cannot simply defer an inoperative autopilot under general inoperative equipment procedures for day VFR flights; the autopilot must be working or within the 24-hour ferry-like window.

Maintenance providers and engineers will be affected because the equipment requirements are mandatory and the autopilot repair window is tight. Having an autopilot unserviceable for more than 24 hours grounds the aeroplane unless the operator also has another exemption. This may increase demand for mobile maintenance or rapid parts supply at outlying aerodromes.

CASA itself is affected as the regulator. The notification direction under section 10 requires CASA to process filings (likely via the existing AOC amendment or non-significant change forms). CASA must also monitor compliance and enforce the conditions. The instrument reduces CASA's workload in one sense (fewer operators needing Part 121 approvals) but increases monitoring of Part 135 compliance with the extra conditions.

Exemption right: The operator and pilot in command have a right to be exempt from compliance with Part 121 and the Part 121 MOS, provided they comply with all conditions. This is a right, not a duty, though exercising it triggers duties.

Primary duty - comply with Part 135 as modified: The operator and pilot must comply with Part 135 of CASR, but as if CASA EX71/24 also applied. EX71/24 is a companion instrument that provides its own exemptions and directions for Part 135 operations. So the operator must read both instruments together. The duties under Part 135 include, among others: holding an AOC appropriate for the operations, ensuring the aeroplane meets airworthiness requirements, complying with flight time limitations, having an operations manual, and ensuring the pilot is appropriately qualified. The Part 135 MOS adds requirements for standard operating procedures, checklists, and equipment.

Additional duty - Schedule 1 equipment: The operator must ensure the aeroplane is fitted with the following:

• Automatic pilot meeting Part 135 MOS subsection 11.10(2) for VFR day flights (i.e., a capable autopilot must be installed and serviceable). For all flights, subsection 11.10(3) does not apply (no general inoperative autopilot relief). Autopilot may be inoperative only at start of a day VFR or day IFR VMC flight from an aerodrome without repair facilities, and only within 24 hours of the discovery of the inoperative condition.
• TAWS: turbine-engine aeroplanes >5,700 kg MTOW must have TAWS-Class A. Turbine-engine aeroplanes ≤5,700 kg MTOW must have TAWS-Class A or TAWS-Class B+. Piston-engine aeroplanes must have TAWS-Class A, B+, or B. For VFR day flights, any of those three TAWS types must be fitted and not inoperative.
• Airborne weather radar equipment must be fitted on all flights. Inoperative weather radar may be handled under Part 135 MOS section 11.28.
• The TAWS and weather radar must be not inoperative at the start of flight (unless inoperative equipment procedures under the MOS are followed, but the equipment must be installed).

Duty not to double-dip: The operator and pilot must not take the benefit of any exemption under CASA EX69/24 while taking benefit of this instrument. EX69/24 provides supplementary exemptions for Part 121 and Part 91. The operator must choose which exemption pathway to use for a given flight.

Duty to notify CASA: Before commencing operations under this instrument, the operator must notify CASA using the relevant approved form of the similar types of aeroplanes intended to be operated. This is a one-time notification per type or class rating. If the operator already notified under predecessor EX97/22, they do not need to re-notify. The notification is not an application for approval; it is a reporting duty. The form depends on whether the change is significant (use AOC and associated approvals form) or non-significant (use non-significant changes form). The operator must make this determination based on regulation 119.020 definition of significant change.

The instrument itself does not create penalty provisions. Penalties arise from the underlying regulations. If an operator or pilot fails to comply with the conditions of the exemption, they lose the benefit of the exemption and are therefore in breach of Part 121 (which would have applied absent the exemption). This is the enforcement mechanism: non-compliance with a condition means the exemption is no longer effective for that operation, and the operator and pilot become subject to the full force of Part 121.

The conditions are framed as "each exemption under section 5 is subject to the condition that…". Failure to comply with a condition is not itself a separate offence under this instrument, but it makes the operation non-exempt. CASA could then take enforcement action under Part 121 for operating without compliance. Part 121 contains its own penalty provisions, typically civil penalties under the Civil Aviation Act 1988 or administrative action such as suspension or cancellation of the AOC.

CASA could also enforce the notification direction under section 10. Section 10 is a direction, not a condition of exemption. Failure to notify before commencing operations could be dealt with as a breach of a direction under CASR. The direction likely falls within civil penalty provisions or can lead to a remedial direction.

Additionally, the instrument includes a note referencing "significant change" as defined in regulation 119.020. If the operator fails to correctly classify the operation and uses the wrong form (or fails to notify at all), this could affect the validity of their AOC. CASA may treat unapproved operations as unauthorised.

The practical enforcement risk is increased because the instrument requires operators to self-assess whether they meet the conditions. CASA does not pre-approve eligibility; the notification is just a filing. If an operator mistakenly relies on the exemption for an aeroplane that does not meet the MOPSC, MTOW, or certification criteria, they are operating outside Part 121 without a valid exemption. The civil penalty for that could be significant.

There is no private right of action under this instrument. Enforcement is solely by CASA.

The instrument is repealed automatically on 1 December 2027. After repeal, the exemption ends, and operators must either comply with Part 121 or have a replacement instrument in place. Operating after repeal without a new exemption would be unlawful.

Primary interaction: Part 121 vs Part 135. This instrument sits at the intersection of two regulatory regimes. Part 121 applies to aeroplanes with a MOPSC of more than 9 (subject to some transitional arrangements). Part 135 applies to aeroplanes with a MOPSC of 9 or fewer, plus certain small turbine operations. The instrument carves out a category of aeroplanes (MOPSC 10-13) that would otherwise fall under Part 121 and moves them into a modified Part 135 regime. This is a legislative override of the default boundary.

CASA EX71/24: The instrument requires that the operator and pilot comply with Part 135 "as if CASA EX71/24 also applied". EX71/24 is a companion exemption instrument that provides its own exemptions and directions for Part 135 operations. The effect is that the operator must read this instrument (EX74/24) together with EX71/24 to determine the full set of applicable rules. EX71/24 might, for example, modify Part 135's requirements for certain turbine operations or provide relief for inoperative equipment. The operator cannot simply comply with raw Part 135; they must apply EX71/24's modifications as well.

CASA EX69/24: This instrument provides supplementary exemptions for Part 121 and Part 91. The operator under EX74/24 is prohibited from also taking the benefit of EX69/24 in respect of a relevant aeroplane. So the two exemption pathways are mutually exclusive for a given aeroplane.

Part 91 of CASR: Part 91 sets out general operating and flight rules. While the operator is exempt from Part 121, they remain subject to Part 91 (unless otherwise exempted). The instrument does not grant any exemption from Part 91. Operators must still comply with airspace, flight planning, fuel, and other general rules. The Schedule 1 conditions (TAWS, weather radar, autopilot) are additional to Part 91 requirements.

Part 119 of CASR: Part 119 deals with AOC certification and management. The operator must hold an AOC that permits operations under Part 135. The notification direction under section 10 contemplates that the operator may need to use the "Air operator's certificate and associated approvals form" if the change to operate under this instrument is a significant change. If it is not a significant change, a lesser form is used. The operator must self-assess under regulation 119.020.

Part 61 of CASR: The definition of "class" in relation to an aeroplane is given by Part 61. This matters for the definition of "similar type" in the notification direction. The operator must know what class ratings apply to their aeroplane types to correctly determine which similar types need to be notified.

The instrument is made on 29 November 2024 and commences 2 December 2024. It is a new instrument, so no amendments have been made to it. However, it replaces an earlier instrument, CASA EX97/22 - Part 121 - Single Pilot Aeroplane (MOPSC 10-13) Operations - Exemptions Repeal, Remake, and Direction Instrument 2022. The repeal clause in section 2 of EX74/24 refers to repeal at the end of 1 December 2027, but the predecessor EX97/22 was also a three-year instrument. The current instrument is a re-make of that earlier exemption, presumably with refinements. The most notable change is the introduction of the TAWS-Class B+ category, which did not exist in EX97/22 (which referenced only TAWS-Class A or B). Additionally, the notification direction now includes an exemption for operators who notified under EX97/22, indicating continuity.

The accompanying instrument CASA EX71/24 is also new and modifies Part 135 for these operators. The system of instruments (EX74/24 and EX71/24) together form a regulatory package that replaces the previous single instrument approach.

There have been no other amendments since commencement. The instrument will be repealed automatically on 1 December 2027 unless earlier repealed by CASA. Given CASA's practice, a new instrument will likely be made before that date, possibly with further adjustments.

As at the date of this instrument (December 2024), there is no reported litigation concerning CASA EX74/24. It is too recent. There is also no known litigation concerning its predecessor EX97/22. These are narrow exemption instruments of limited application; they are unlikely to attract litigation unless a dispute arises about CASA's power to impose conditions, or about the validity of a notification direction, or about enforcement action taken against an operator who failed to comply with conditions. Because the instrument is a legislative instrument made under delegated powers, it could be challenged on administrative law grounds (e.g., unreasonableness, ultra vires, failure to consider relevant matters) but no such challenge is on record. The instrument was made by a delegate of CASA under regulations 11.160, 11.205, and 11.245 of CASR, which confer broad power to grant exemptions and impose conditions. Any challenge would likely focus on whether the conditions are reasonably proportionate to the risks of single-pilot operations.

Given the narrow scope and the non-controversial nature of this exemption (it allows continued operations rather than imposing new restrictions), litigation is improbable. Operators who are aggrieved by enforcement action might challenge the interpretation of conditions, such as whether a particular TAWS qualifies as TAWS-Class B+ or whether the 24-hour autopilot repair window is triggered.

The 24-hour autopilot clock starts from discovery, not from failure. The instrument says the autopilot may be inoperative at the beginning of a day VFR or day IFR VMC flight only if the flight begins "within 24 hours of the time the automatic pilot was found to be inoperative." The critical moment is when the inoperative condition is found, not when it occurred. If a defect is discovered during a pre-flight check at 0600, the operator has until 0600 the next day to depart from an aerodrome without repair facilities. The clock cannot be reset by leaving the aeroplane unflown for a day. If the defect is not found until a later inspection, the operator may inadvertently breach the 24-hour limit if they had constructive knowledge earlier. Operators must have robust defect recording and tracking to avoid exceeding the limit.

Weather radar is mandatory on all flights, even day VFR in clear weather. Condition 8 of Schedule 1 requires the aeroplane be fitted with airborne weather radar equipment for a flight in a relevant aeroplane, with no exception for flight rules or conditions. The only relief is the option to apply inoperative equipment procedures under section 11.28 of the Part 135 MOS. This means the radar must be installed and serviceable at the start of every flight. A day VFR local flight in clear conditions cannot be operated without weather radar installed. This requirement exceeds what Part 135 normally mandates, and operators switching from older CAR operations may find this surprising. The cost of retrofitting weather radar to an older aeroplane that does not have it could be significant.

TAWS-Class B+ is a new category with strict display requirements. The instrument defines TAWS-Class B+ in detail. It is not simply a COTS product; it must meet specific requirements for colour terrain display, orientation, elevation depiction, and alert display. Operators cannot assume any TAWS-Class B unit qualifies; it must have the extra capabilities. The CASA note to Schedule 1 says "The equipment fitment requirements under this Schedule intentionally exceed those under Part 135 of CASR." This is a deliberate raise of the bar.

No simultaneous relief under EX69/24. If an operator has another exemption that provides relief for Part 121 requirements (e.g., for two-crew or maintenance), they cannot use both. They must pick one pathway. This could be a problem for operators who have tailored exemptions covering specific routes or aeroplanes. They should review their existing exemptions before relying on this instrument.

Step 1: Confirm eligibility. Before taking the benefit, the operator must verify that each aeroplane intended to be operated meets all five criteria in the definition of "relevant aeroplane": MOPSC 10-13, MTOW ≤ 8,618 kg, type-certificated for single-pilot, flight manual permits single-pilot crew, and would otherwise be subject to Part 121. This involves checking the aircraft type certificate data sheet, the flight manual, and the current configuration (passenger seats installed). It also requires confirming that the aeroplane is not subject to a two-pilot requirement under its type certificate or operating rules.

Step 2: Ensure equipment fitment. The aeroplane must be fitted with:

• Automatic pilot meeting Part 135 MOS subsection 11.10(2) capability (for all flights, except the 24-hour ferry window).
• TAWS: for turbine >5,700 kg: TAWS-Class A. For turbine ≤5,700 kg: TAWS-Class A or TAWS-Class B+. For piston: TAWS-Class A, B+, or B. For VFR day flights: any of the three, but must be not inoperative. For IFR or night VFR: must meet the higher thresholds as specified.
• Airborne weather radar equipment: fitted and serviceable for all flights. All equipment must be installed in accordance with applicable airworthiness requirements (supplemental type certificate or approved modification). Operators should document the TAWS-Class B+ compliance by obtaining a statement from the manufacturer or CASA confirming the unit meets the detailed display requirements in the definition.

Step 3: Review Part 135 and CASA EX71/24. The operator and pilot must understand the Part 135 requirements as modified by EX71/24. This includes AOC holding, operational control, flight time limits, check pilot programs, and maintenance procedures. The operator must ensure their AOC covers the operations they intend to conduct. If the operations under this exemption represent a significant change under regulation 119.020, they must apply for an AOC amendment.

Step 4: Notify CASA. The operator must complete the relevant form:

• If the change is significant: use the "Air operator's certificate and associated approvals form" from CASA's website.
• If the change is non-significant: use the "non-significant changes form". The operator must identify the similar types of aeroplanes intended to be operated, defined as either the same type or another type within the same class rating. The instrument provides examples: operating a King Air 350 (type rating) and a Beech 1900 (also requires a King Air type rating) can be notified together. But a multi-engine twin and a single-engine type are different class ratings and must be notified separately. The notification must be made before commencing operations under the exemption. If the operator previously notified under EX97/22, re-notification is not required.