Recommendation R20040052

Recommendation issued to: Civil Aviation Safety Authority

Recommendation details
Output No: R20040052
Date issued: 12 May 2004
Safety action status:

There are currently no regulatory requirements for a non-Instrument Flight Rules (IFR) equipped helicopter, involved in flight under the Night Visual Flight Rules (NVFR), to be equipped with a standby attitude indicator (artificial horizon) flight instrument. Helicopters engaged in single-pilot commercial or aerial work NVFR operations do not have the same level of system redundancy as IFR equipped helicopters, to safely cope with equipment failures and emergency situations.

Attitude Indicators

Loss of the functionality of a normally electrically operated primary attitude indicator, on a helicopter not equipped with a standby attitude indicator during flight under the NVFR would result in limited or partial panel flying by the pilot. Limited or partial panel flying is defined as flight with key instruments obliterated or inoperative and external cues absent. Partial panel flying is very demanding and previous accident investigations indicate that even highly experienced IFR rated pilots may have difficulty safely operating a helicopter or aircraft under such circumstances.

Australian Civil Aviation Safety Authority Civil Aviation Order (CAO) Part 95.7.3 currently provides specific requirements for helicopters engaged in charter marine pilot transfers. These requirements include meeting the requirements of Appendix VIII of CAO Part 20, section 20.18, 'Instruments Required for Night VFR Flight in Helicopters Except While Engaged in Agricultural Operations'. This Appendix includes a requirement for '(1) a primary attitude indicator and (2) a standby attitude indicator or turn indicator.'

CAO Part 20, section 20.18, Appendix VII 'Instruments Required for Instrument Flight Rules Operation in Helicopters (Except Night VFR)' includes a requirement for a standby attitude indicator for both one and two pilot operations.

The Helicopter Association of Australia recently drafted a paper called 'Night Operations Risk Reduction Checklist'. This checklist is being developed to allow operators to evaluate the risk related to night operations. The checklist provides an allocation of points to each item that contributes to the safety of operations (out of a maximum of ten points per item). The checklist allocates four points to an operator whose helicopter was fitted with a standby attitude indicator with an independent power source.


Under certain conditions, external visual reference may not be available while flying a helicopter under the NVFR. These conditions include operating over remote areas, in moonless or near moonless conditions, over water, and at times when the celestial horizon is obscured by cloud.

Spatial disorientation refers to a failure by a pilot to sense correctly the position, motion, or attitude of the aircraft or of themselves within the fixed coordinate system provided by the surface of the earth and its gravitational force. For example, a pilot's inaccurate perception of their position, attitude, or motion with respect to the aircraft or their own aircraft relative to another aircraft, terrain, or other obstacle is considered spatial disorientation in flight.

When spatial disorientation occurs, pilots are unable to process, believe, see, or interpret the information on the flight instruments and they rely upon the erroneous information provided by their senses. In addition, the risk of spatial disorientation is high during instrument meteorological conditions (IMC) and night flying in either visual meteorological conditions (VMC) or IMC.

Partial panel flying by a pilot inexperienced in IFR flight and operating in low celestial or artificial lighting conditions, during flight under the NVFR, may impose a significant safety risk. The inclusion of a requirement for a standby attitude indicator, with an independent power source, in the event of the failure of the primary instrument during flights under the NVFR would mitigate the risk of the pilot incurring spatial disorientation by providing him a backup instrument in the case of a primary instrument failure.

Output text

Safety Recommendation

The Australian Transport Safety Bureau recommends that the Australian Civil Aviation Safety Authority assess the safety benefits of requiring a standby attitude indicator, with an independent power source, in all helicopters operating flights under the NVFR in the Charter and Aerial Work category, excluding dual pilot training.

Initial response
Date issued: 14 July 2004
Response from: Civil Aviation Safety Authority
Action status: Open
Response text:

Issues raised in the recommendations relate to Civil Aviation Safety Regulation (CASR) Part 133, which is currently under review. Therefore, until the review is complete, CASA is unable to provide the ATSB with any substantial comment.

Further correspondence
Date issued: 21 July 2004
Response from: Civil Aviation Safety Authority
Response status: Closed - Accepted
Response text:

As part of the consultation process associated with the development of Civil Aviation Safety Regulation (CASR) Part 133, CASA consulted with the Helicopter Association of Australia (HAA) and the general helicopter industry regarding the benefits of a standby attitude indicator.
On the basis of these consultations, CASA has assessed the safety benefits of requiring a standby attitude indicator with an independent power source, and determined that greater emphasis should be placed on training pilots carrying out NVFR flight. CASA considers this to be a more effective approach than introducing a mandatory requirement for the fitment of a secondary attitude reference instrument. Therefore, CASA has taken steps in CASR Part 133 to strengthen recurrent training and checking and operator proficiency checks for pilots undertaking NVFR flights in helicopters engaged in air transport operations. It will also apply to those engaged in Emergency Medical Service (EMS), Search and Rescue (SAR) and Marine Pilot Transfer operations as well as any other aerial work operations that CASA deems appropriate.

ATSB comment:

The Australian Transport Safety Bureau notes that the Civil Aviation Safety Authority issued Civil Aviation Advisory Publication (CAAP) 5.13-2(0) Night Visual Flight Ratings in December 2006. The CAAP was developed following a number of accidents involving flight at night under the VFR. The CAAP addresses typical threats and errors applicable to night flight and presents possible countermeasures or defences for pilots and operators conducting NVFR operations. Users are encouraged to incorporate these into both training and operations.

Last update 01 April 2011