Operating under multiple appendices

Operating under multiple appendices means:

• combining multiple appendices within a single flight duty period, and/or
• switching from one appendix to another on consecutive flight duty periods.

The limits vary between some of the appendices. As a result, transitioning between appendices can sometimes produce inconsistencies in duty, flight, standby and off-duty requirements, which can result in increased fatigue risk.

How the new fatigue rules work when operating under multiple appendices

If an operator chooses to operate under multiple appendices, the fatigue rules address this risk by requiring operators to have procedures in place:

• that ensure their pilots are within the limits of the new appendix prior to transitioning, and
• to determine the limits that will apply to the proposed flight duty period when pilots transition between appendices in a single flight duty period.

Before pilots can change from one appendix to another, their operator must:

• identify the hazards associated with the pilot transitioning between the appendices
• develop a risk management procedure, to ensure that the transition does not result in increased risk to aviation safety
• document the procedure in the operations manual.

Operating under two or more appendices in a single flight duty period (FDP)

If two or more appendices apply to a single flight duty period, the operations manual must contain procedures that ensure:

• The maximum flight duty period (FDP) that an operator and a pilot must comply with is:
  • the FDP limit contained in the appendix under which the operation is being conducted at that particular time, and
  • based on the original start time of the FDP (not on the start time of operations under each appendix).
• The maximum flight time that an operator and a pilot must comply with is:
  • the flight time limit contained in the appendix under which the operation is being conducted at that particular time (based on the assumption that the entire FDP was conducted under that appendix), and
  • based on the original start time of the FDP, and not on the start time of operations under each appendix.
• The off-duty period (ODP) that must be applied following the flight duty period is the greater of the minimum ODPs. This is calculated by assuming the entire FDP was conducted under each appendix. For example, the procedure should require that:
  • the operator works out the minimum ODPs required (if the entire FDP was conducted under each appendix), and
  • the longest minimum ODP that was calculated is then the minimum ODP, which must be completed before the pilot can commence another FDP under any appendix.

Example: Operating under two or more appendices in a single flight duty period

Emilia is a pilot who often conducts both charter flights and aerial work within a given flight duty period. When this happens Emilia’s operator has chosen to operate under two appendices within the flight duty period—Appendix 4 when she conducts charter operations, and Appendix 5 when she conducts aerial work.

On this occasion, Emilia starts her flight duty period at 7 am.

Because Appendix 5 has a maximum flight duty period limit of 12 hours, and Appendix 4 has a maximum flight duty period limit of 10 hours, Emilia can only conduct charter within the first 10 hours of her flight duty period—but she can conduct aerial work any time in the 12 hour flight duty period.

Her combined flight duty period started at 7 am and finished at 7 pm.

The minimum off-duty period for Appendix 5 is 10 hours (if the off-duty period had included the hours between 11 pm and 5.29 am, the off-duty period could also have been 8 hours).

The minimum off-duty period for Appendix 4 is 12 hours at home base (the off-duty period is 10 hours away from home base).

The longest off-duty period of these two appendices is 12 hours. Therefore Emilia must complete an off-duty period of 12 hours before she can start another flight duty period under any appendix.

Switching from one appendix to another on consecutive flight duty periods

If an operator intends for a pilot to conduct operations under different appendices from one duty period to the next, their operations manual must contain procedures that ensure:

• the pilot’s off-duty period (ODP) following the first flight duty period is at least that of the minimum ODP required under the first appendix,
• the sleep opportunity requirements of the second appendix (if any) are met prior to commencing the flight duty period, and
• the pilot’s cumulative duty and flight time limits of the second appendix are met.

Transitions from Appendix 4B, 5 and 5A to other appendices

The different off-duty requirements for Appendix 4B, 5 and 5A must be taken into account when transitioning to other appendices.

Unlike other appendices, Appendix 4B, 5 and 5A do not require a specific number of off-duty days to be completed across an 84 day period. As a result, a pilot may not meet the minimum number of days off-duty required to commence a flight duty period under another appendix (such as Appendix 4 or 6).

Rather than require the pilots to complete an extended number of consecutive days off-duty before they can transition from Appendix 4B, 5 or 5A to another appendix, subsection 13A of CAO 48.1 sets out specific requirements for operators when transitioning from Appendix 4B, 5 and 5A to other appendices.

For example, if a pilot is transitioning from Appendix 4B, 5 or 5A to Appendix 4, they must first meet all the requirements of the new appendix other than the requirement for 24 off-duty days in 84 consecutive days. The off-duty requirement is met by the prescribed number of days off specified in subsection 13A of CAO 48.1, specifically:

• the pilot must have had at least 7 days off-duty in the 28 consecutive days before commencing the flight duty period or standby, and
• the pilot must have had either:
  • at least 24 days off-duty in the 84 consecutive days before commencing the flight duty period or standby, or
  • the minimum number of off-duty days equal to half as many days as would otherwise be required for that pilot to meet the requirement for 24 off-duty days in the preceding 84 days (rounded up to the nearest whole number).

If the pilot commences operating in the new appendix with less than 24 off-duty days within 84 days, they have 28 days (from the commencement of operating under the new appendix) in which to achieve sufficient off-duty days to meet the requirements set out in subsection 13A. At all times they are conducting the charter operation they must meet the requirement for 7 off-duty days in 28 days. If the pilot later transitions back to Appendix 4B, 5 or 5A, then the whole procedure is reset and commences again when the pilot next transitions from Appendix 4B, 5 or 5A to another appendix.

Example 1:

If the pilot had 5 off-duty days in the preceding 28 days and 16 off-duty days in the preceding 84 days then they would need to complete a period of 4 consecutive off-duty days (i.e. 24-16 = 8; half of 8 equals 4 off-duty days). In this case, completing the 4 off-duty days means that the pilot then also meets the requirement for 7 off-duty days in a 28 day period and is clear to transition.

Example 2:

If the pilot had 2 off-duty days in the preceding 28 days and 16 off-duty days in the preceding 84 days then they would need to complete a period of 4 consecutive off-duty days (i.e. 24-16 = 8; half of 8 equals 4 off-duty days). In this case, completing the 4 off-duty days means that the pilot then still requires an additional day to meet the requirement for 7 off-duty days in a 28 day period and is clear to transition once all 5 days off-duty are completed.

Aside from the specified days off, if there is any question regarding the suitability of this minimum period when employed in the operator’s context, the operator should monitor the fatigue levels of pilots and increase this minimum period if required. For example, the operator could use surveys or regular meetings to discuss fatigue with the pilots involved (the effectiveness of this approach would depend on the safety culture evident in the organisation at the time).

Further information

• Duty time, flight time and flight duty period
• What steps do I need to take?
• CAAP 48-01 Fatigue Management for Flight Crew Members