Aviation safety issues and actions

Regulatory requirements and guidance for in-flight fuel management

Issue number: AO-2014-190-SI-11
Who it affects: All operators and flight crew, particularly those who conduct flights to remote or isolated aerodromes
Issue owner: Civil Aviation Safety Authority
Transport function: Aviation: Air transport
Background: Investigation Report AO-2009-072
Issue release date: 23 November 2017
Current issue status: Adequately addressed
Issue status justification:

The ATSB is satisfied that CASA has introduced requirements and guidance for in-flight fuel planning that, together with changes to fuel planning requirements, have reduced the risk associated with the safety issue.

Safety issue description

The available regulatory guidance on in-flight fuel management and on seeking and applying en route weather updates was too general and increased the risk of inconsistent in-flight fuel management and decisions to divert.

Proactive Action

Action number: AO-2014-190-NSA-036
Action organisation: Civil Aviation Safety Authority
Date: 23 November 2017
Action status: Closed

As outlined in the safety action for AO-2014-190-SI-10, since 2009 CASA has conducted or initiated a number of actions to improve requirements and guidance for fuel planning and fuel management. These activities also addressed in-flight fuel management aspects.

In August 2012, the following text was added to AIP ENR 1.1 (based on requirements in ICAO Annex 6, see Additional safety action regarding fuel planning and management):

8.10.4 In-Flight Fuel Management The pilot in command shall continually ensure that the amount of usable fuel remaining on board is not less than the fuel required to proceed to an aerodrome where a safe landing can be made with the planned fixed fuel reserve remaining upon landing. The pilot in command shall request delay information from ATC when unanticipated circumstances may result in landing at the destination aerodrome with less than the fixed fuel reserve plus any fuel required to proceed to an alternate aerodrome or the fuel required to operate to an isolated aerodrome.

In August 2012, CASA published a new version of CAAP 215-1(1) – Guide to preparation of operations manuals. Annex B of the CAAP provided guidance on information to include in an operations manual regarding the calculation of a critical point (CP) and a point of no return (PNR). However, the guidance was applicable to situations where the destination aerodrome and alternate aerodrome were on the same track as the flight path from the departure aerodrome to the destination aerodrome.

In December 2014, CASA amended the fuel planning requirements in CAO 82.0 for operations to remote islands so that these requirements applied to RPT operations and aerial work operations involving air ambulance functions (regardless of whether a patient was carried) in addition to passenger-carrying charter flights (see Safety action AO-2014-190-NSA-035). In addition, the requirements included:

…during the flight, the pilot in command carries out in-flight fuel management to ensure that the aeroplane is always carrying sufficient fuel to enable it to reach its destination aerodrome as planned, or its nominated alternate aerodrome if necessary, with the required minimum fuel reserves intact.

In January 2016, CASA issued Consultation Draft (CD) 1508OS – Fuel and oil quantity requirements. The CD included proposed amendments to CAR 234 and CAAP 234. The proposed instrument included specific requirements for in-flight fuel management. More specifically, section 5 included:

In-flight fuel quantity checks

(2) The pilot in command must ensure that fuel quantity checks are carried out in-flight at regular intervals and the usable fuel remaining is evaluated to:

(a) compare planned fuel consumption with actual fuel consumption; and

(b) determine that the usable fuel remaining is sufficient to complete the planned flight in accordance with subsection 4 (3) (if applicable) and subsection 4 (4); and

(c) determine the expected usable fuel remaining on arrival at the destination aerodrome.

(3) The relevant fuel quantity data evaluated in accordance with subsection 5 (2) must be recorded after each fuel quantity check.

Section 6 of the instrument included specific procedures to be used in the event a fuel quantity check identified the fuel quantity was below the required level.

The proposed version of CAAP 234-1(2) associated with the instrument included additional guidance on in-flight fuel quantity checks and in-flight fuel management. This proposed guidance included:

6.4.1 After a flight has commenced, in-flight fuel management is the practical means by which the pilot-in-command ensures that fuel is used in the manner intended during pre-flight planning, or in-flight re-planning.

6.4.2 In-fight fuel management does not replace pre-flight planning or in-flight re-planning activities, rather it acts to ensure continual validation of planning assumptions that influence fuel usage and required fuel reserves. Such validation serves as a trigger for re-analysis and adjustment activities that ultimately ensure that each flight is safely completed with the planned fixed fuel reserve on board at an aerodrome where a safe landing can be made.

6.4.3 The pilot-in-command should ensure that a critical point of last diversion to the final en-route alternate is identified during the pre-flight planning stage. This is particularly important when operating to a remote island. During the course of the flight, the critical point should be assessed and, if necessary, revised based upon actual fuel consumption and in-flight conditions.

6.4.4 The revised critical point then becomes the last point by which the pilot-in-command should obtain and assess updated destination information (i.e. meteorological conditions, traffic and other operational conditions at the destination aerodrome) in order to validate the destination planning assumptions and allow timely diversion to occur if necessary (i.e. the revised critical point is the final opportunity to assess options for preserving the required fuel reserves should the destination aerodrome no longer be available).

In August 2017 (after receiving the draft ATSB report for the reopened investigation), CASA advised the ATSB:

Since the accident, ICAO published in 2015 a comprehensive guidance document in relation to in-flight fuel management - Doc 9976 Flight Planning and Fuel Management Manual.

CASA intends to update CAAP 234-1 (1) to incorporate similar concepts to those outlined in the ICAO Manual but on a more limited scale and scope as part of Project OS 09/13 (Fuel and Oil Quantity Requirements).

ATSB comment:

The ATSB acknowledges CASA has undertaken work since 2009 to revise and improve requirements and guidance for in-flight fuel management. However, the ATSB is concerned that, as yet, this work has not resulted in many actual changes to the requirements and guidance. Accordingly, the ATSB issues the following recommendation.


Action number: AO-2014-190-SR-043
Action organisation: Civil Aviation Safety Authority
Date: 23 November 2017
Action status: Closed

The Australian Transport Safety Bureau recommends that the Civil Aviation Safety Authority continue its work to address the limitations associated with the requirements and guidance for in-flight fuel management.

Additional correspondence

Response date: 21 February 2018
Response from: Civil Aviation Safety Authority
Action status: Closed
Response text:

CASA has finalised the revisions and improvements to the requirements to conduct in-flight fuel management and the development and provision of significantly detailed guidance material in relation to in-flight fuel management practices and procedures. This material is part of the OS project 09/13 - Phase 4 - implementation. The enhanced guidance material will be published immediately following the making of the CAR 234 regulation amendment and the Fuel Requirements Instrument and sufficiently prior to the regulation commencement date mentioned above.

[Further background information regarding CASA's safety action regarding inflight fuel management requirements and guidance is provided in CASA's response to ATSB recommendation AO-2014-190-SR-142.]

ATSB comment date: 22 February 2018
ATSB comment:

The ATSB notes the CASA response and will continue to monitor CASA's development and delivery of changes to relevant requirements and guidance.

Response date: 05 July 2019
Response from: CASA
Action status: Closed
Response text:

On 5 July 2019, CASA provided the following additional information.

In relation to ATSB Safety Recommendations AO-2014-190-SR-042 and AO-2014-190-SR-043 regarding Fuel Planning and In flight Fuel Management CASA provides the following.

Civil Aviation Regulations, 1988 Compilation 98 (the version in force currently) was registered on 4 April 2019 and included an amended CAR 234 establishing the mechanism to prescribe Fuel and Oil requirements for operations.

CAR 234 provides that CASA may issue a legislative instrument prescribing the requirements relating to fuel for aircraft. Instrument 29/18 is that instrument.

In addition to, and in support of, the regulatory provisions relating to fuel requirements noted above CASA updated CAAP 234. The Latest version is version 2.1 (June 2019) and provides additional guidance on fuel management and requirements.

CASA has publicised and promoted these changes with a comprehensive advice page recently updated 23 June 2019 and can be accessed via the CASA website www.casa.gov.au/aircraft/fuel.

CASA seeks ATSB’s acknowledgement of CASA actions in this regard and views the safety findings as fully addressed and therefore be formally closed.

ATSB comment date: 25 July 2019
ATSB comment:

On 25 July 2019, the ATSB responded to CASA and advised it had reviewed CASR 121, CASR 135 and the CASA 29/18 instrument.

The instrument 29/18 certainly formalised in-flight fuel management requirements that had been proposed. We also note that there are potentially related requirements in 121.225/235 and 135.205/215 (relying on expositions and MOSs). CASR 135.190 also contained related requirements. Although there are new and useful requirements and guidance in all these documents, the requirements are distributed and we would like to confirm our understanding of the situation.

Can CASA please outline to what extent, amongst all these new in-flight fuel management requirements, a flight crew and/or operator of a 121 or 135 flight where alternate fuel has not been required and uploaded prior to flight is required to:

  • calculate the decision point
  • conduct in-flight checks of the aircraft’s fuel quantity (at regular intervals and prior to the decision point)
  • check the calculation of the decision point prior to reaching the decision point
  • obtain updated weather information for the destination aerodrome prior to reaching the decision point?
Response date: 31 October 2019
Response from: CASA
Action status: Closed
Response text:

On 31 October 2019, CASA provided the following response to the ATSB question and some additional information.

CASA Instrument 29/18 will be deleted upon the commencement of the future flight operational CASR Parts in March 2021. Its requirements will be appropriately transcribed into relevant Manuals of Standards.

These [in-flight fuel management] requirements are best explained in the context of the existing CASA Instrument 29/18, the contents and requirements of which are being moved to all Manuals of Standards although minor modifications will be made to the content transferred into the Part 121 MOS to accommodate the introduction of an ICAO based isolated aerodromes (and wider alternate aerodromes requirements) policy.

  1. In-flight checks of aircraft fuel quantity, at regular intervals, is required by subsection 6(2) of CASA 29/18.
  2. For the other 3 matters raised, these requirements are not specifically stated, and do not need to be, as they are inherent in the application of the stated legal requirements of CASA Instrument 29/18. The requirement to conduct regular in-flight fuel checks is phrased to require the PIC to determine whether the usable fuel remaining is sufficient to complete the planned flight. If this flight was planned to involve the use of a decision point, then by necessity the decision point would have to have been calculated and, noting the requirements of section 4 of the instrument in relation to the matters that must be taken into account to calculate usable fuel, meteorological reports and forecasts must be incorporated into any such calculation. Additionally, the requirements of paragraph 7(1)(b) of the instrument for procedures in the event that an in-flight fuel check results in a determination that there is insufficient fuel to complete the flight to the destination aerodrome means that the PIC must calculate a decision point. Additionally, the nature of the legal definition of the term decision point is such that the PIC cannot rely on a pre-flight calculation of where the exact location of the decision point is due to the fact that the definition of the term does not incorporate a time-based component, i.e. the term is not expressed to be a “pre-flight” calculation.
Last update 17 March 2020