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Requirements for visual flight rule flights in dark night conditions

Issue number: AO-2011-102-SI-02
Who it affects: All aircraft operating under the night visual flight rules (VFR)
Issue owner: Civil Aviation Safety Authority
Operation affected: Aviation: General aviation
Background: Investigation Report AO-2011-102
Date: 08 November 2013

Safety issue description

Aerial work and private flights were permitted under the visual flight rules in dark night conditions, which are effectively the same as instrument meteorological conditions, but without sufficient requirements for proficiency checks and recent experience to enable flight solely by reference to the flight instruments.

Response to safety issue by: the Civil Aviation Safety Authority

On 18 October 2013, the Civil Aviation Safety Authority (CASA) stated that as part of the new pilot licencing rules (in development prior to August 2011), Civil Aviation Safety Regulation 61.970 will require pilots to demonstrate competency during biennial night visual flight rules assessments, which become effective in December 2013. As noted in Minimum requirements for night operations, this will certainly help maintain some pilots’ ability to a higher level than previously, but it will not ensure that the pilots are able to maintain their skills at an instrument rating standard.

CASA also advised of the following actions:

  • CASA will implement a regulatory change project to study the feasibility of rule changes that provide enhanced guidance on NVFR [night VFR] flight planning and other considerations, addressing all categories of operation.
  • CASA will clarify the definition of visibility as outlined in CAR [Civil Aviation Regulation] 2 to ensure the primary coincident safety issue above is dealt with. CAR 2 defines visibility as the “ability, as determined by atmospheric conditions and expressed in units of distance, to see and identify prominent unlighted objects by day and prominent lighted objects by night”. CASA will, via regulatory change project, explore the potential to add the requirement that for night visual flight rules the determination of visibility must also include the ability to see a defined natural horizon. This will in effect address the root cause of the matters outlined in the … [safety issues], as pilots will need to have a discernible horizon throughout their flight.
  • CASA will provide additional guidance material and advisory notes in Civil Aviation Advisory Publication (CAAP) 5.13-2:
    - distinguishing the difference between NVFR / IFR and instrument conditions;
    - including Certification standards for instrument and non-instrument rotorcraft; and
    - emphasising the authority given by a NVFR rating.

The proposed changes project will be subject to CASA’s normal consultation requirements.

ATSB comment/action in response:

The ATSB welcomes the intent of the action proposed by CASA in response to this safety issue. In particular, the ATSB agrees that expanding what is meant by the term ‘visibility’ at night to include the requirement for a visual horizon will help ensure that pilots operating under the night VFR will have sufficient visual cues. However, given the importance of the safety issue, the ATSB is concerned about the indefinite nature of the proposed evaluation and other exploratory activities.

As a result, the ATSB has issued the following safety recommendation.

Recommendation

Action organisation: Civil Aviation Safety Authority
Action number: AO-2011-102-SR-059
Date: 08 November 2013
Action status: Monitor

The Australian Transport Safety Bureau recommends that the Civil Aviation Safety Authority prioritise its efforts to address the safety risk associated with aerial work and private flights as permitted under the visual flight rules in dark night conditions, which are effectively the same as instrument meteorological conditions, but without sufficient requirements for proficiency checks and recent experience to enable flight solely by reference to the flight instruments.

Correspondence

Date received: 07 February 2014
Response from: Civil Aviation Safety Authority
Action status: Monitor
Response text:

CASA partially accepts the recommendation in as much as regulation 61.970 of the Civil Aviation Safety Regulations 1998 (CASR) requires pilots to demonstrate competency during biennial night visual flight rules assessments. The regulation was made in February 2013 and commences in September 2014.

In addition, CASA also commenced a project on 16 December 2013, OS 14/01 Night Visual Flight Rules. This will consider whether to require a discernible external horizon during flights under Night Visual Flight Rules (NVFR). CASA proposes to clarify the definition of visibility in regulation 2 of the Civil Aviation Regulations 1988 (CAR) to ensure the primary coincident safety issue above is dealt with. CAR 2 defines visibility as the "ability, as determined by atmospheric conditions and expressed in units of distance, to see and identify prominent unlighted objects by day and prominent lighted objects by night". Project OS 14/01 CASA will consider whether to seek an amendment to this definition by adding to it the requirement that for NVFR, the determination of visibility must also include the ability to see a defined natural horizon. This will in effect address the root cause of the matters outlined in the safety issue as pilots will need to have a discernible horizon throughout their flight. If a discernable horizon is not present then the flight should be conducted under the Instrument Flight Rules (IFR) and all associated regulations for IFR flight will apply.

The project will also review the current NVFR regulatory requirements and CASR definitions to ensure it limits the visual environment to that in which a defined external horizon is available for aircraft attitude control. The project will examine the night VMC requirements for both rotorcraft and aeroplanes. However the outcome of the project may limit the change to the night VMC requirements to rotorcraft only in recognition of the difference in certification requirements between the categories. The project will also amend the guidance provided in CAAP 5.13-2 to emphasise the importance of maintaining a discernible external horizon at night particularly in light of the certification basis for NVFR rotorcraft.

   
Current issue status: Safety action pending
Status justification:

The ATSB recognises CASA’s ongoing efforts to address this safety issue.

 
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Last update 19 May 2014