Flight Time Limitations (FTL): Maximum Flight Duty Period (FDP)

Maximum Flight Duty Period (FDP)

2.1 Determine Status of Acclimatization

“Acclimatized” means a state in which a crew member’s biological clock is synchronized to the time zone where the crew member is. A crew member is considered to be acclimatized to a 2-hour wide time zone surrounding the local time at the point of departure. When the local time at the place where a duty commences differs by more than 2 hours from the local time at the place where the next duty starts, the crew member, for the calculation of the maximum daily flight duty period, is considered to be acclimatized in accordance with the values in the table below:

Typical Implementation of Subpart Q:

Some operators are not concerned by Acclimatization issues. The feature can be neutralized by setting all values in the table to “B”.*if acclimatization is not relevant, set all values to “B” = Acclimatized to Home Base. (below is how the AOC of the system is displayed)

2.2 Maximum FDP for Acclimatized Crew

2.2.1 Basic Maximum FDP

The Basic Maximum FDP is 13h*

2.2.2 Reduction by number of legs

The Basic Maximum FDP is reduced by 30min* for each sector from the third* sector onwards with a maximum total reduction of 2h*

2.2.3 Reduction by Encroachment with Window of Circadian Low (WOCL)

2.2.3.1 Calculate WOCL

• IF current airport = within 3 time zones from home base: WOCL = 02:00 - 05:59 home base times
• IF current airport = more than 3 time zones away from Homebase: WOCL = 02:00 - 05:59 home base time for the first 48h after departure from the home base time zone
• OR Local Time of current airport thereafter

2.2.3.2 Calculate WOCL Encroachment

• IF Report Time is within WOCL, calculate the overlap (= Encroachment at FDP-start)
• IF FDP ends in OR fully encompasses the WOCL, calculate the overlap (= Encroachment at FDP-end)

2.2.3.3 Calculate WOCL Reduction
The Reduced Maximum FDP resulting from 2.2.2 is further reduced by WOCL encroachment as follows:

• Encroachment at FDP-start reduces Maximum FDP by 100% of encroachment; the maximum reduction is 2h*
• Encroachment at the FDP-end reduces FDP by 50% of encroachment

=> Reduced Maximum FDP

* All rules and values are implemented in FL3XX by interpolation between values from the table below. They can be customized to fit the operator’s Operations Manual. The table below shows the default EASA Subpart Q rules.

2.3 Maximum FDP for Crew with Unknown State of Acclimatization (No FRM)

The Maximum FDP for Crew Members in the Unknown State of Acclimatization shall be in accordance with the following table if no Fatigue Risk Management (FRM) is implemented. No Reduction for WOCL encroachment is considered.

=> Reduced Maximum FDP

2.4 Maximum FDP for Crew with Unknown State of Acclimatization (FRM Implemented)

The Maximum FDP for Crew Members in the Unknown State of Acclimatization shall be in accordance with the following table if a Fatigue Risk Management (FRM) is implemented. No Reduction for WOCL encroachment is considered.

=> Reduced Maximum FDP

2.5 Extensions

2.5.1 Standard Extension

The Reduced Maximum FDP can be extended by up to 1h with the following restrictions:

• Maximum two such Extensions in any 7 consecutive days
• # of legs < 6 ⭙
• IF WOCL encroachment
• ≤ 2h: # of legs < 5 ⭙
• > 2h: # of legs < 3 ⭙
• IF Extension is used
• EITHER increase pre-flight AND post-flight Rest by 2h
• OR increase post-flight Rest by 4h
• IF Extension is used, no Split Duty is possible
• IF FDP with Extension starts between 22:00 and 04:59 THEN FDP is limited to 11:45h ⭙

* All rules and values are implemented in FL3XX by interpolation between values from the table “Maximum daily FDP - With Extension”. They can be customized to fit the operator’s Operations Manual.

2.5.2 Split Duty

Split Duty is a break on the ground time between block-on and block-off, free of all duties, but less than the Minimum Rest Time

2.5.2.1 Check Applicability

In FL3XX, Crew Control has to enter whether and when a Split Duty should be applied.

2.5.2.2 Calculate the Amount of Extension

FL3XX offers two ways to calculate Split Duties:

1. Split Duty increases Maximum FDP by 50% of the Break; the Break itself is fully considered as FDP. In order to use this implementation you need to Check the relevant Checkbox:
   
2. A part of the Break counts as FDP, Maximum FDP is not affected by Split Duty. 
   In this case, the first 90 minutes of the Break shall count in full while the time in excess of 90 minutes until block-off, shall count as 50% for the purpose of calculating FDP. In order to use this implementation you need to leave the relevant Checkbox unchecked.

There are optional parameters that may or may not apply to your OM. Please discuss those with FL3XX during the implementation process:

• OPTIONAL: Any time of the Break that encroaches the WOCL does not count for the Extension of the FDP
• OPTIONAL: Maximum Extension of the FDP through Split Duty = 3h
• OPTIONAL: The total length of the FDP as increased shall not be longer than 20h including the break

2.5.3 Augmented Crew - In-Flight Rest

• Applicable only if all flights in one FDP have Augmented Crew
• No WOCL reduction is applied in this case
• Max FDP = 18h for all Crew Members if Aircraft has "Crew Bunk"
• Max FDP = 15h for all Crew Members if Aircraft does not have Crew Bunk

 2.6 Extension of FDP by Split Duty (CAR OPS 1.1127)
* UK and UAE operators.