Aviation safety issues and actions

Requirements for upper torso restraints in small aircraft

Issue number: AO-2017-005-SI-06
Who it affects: All aircraft owners, operators, pilots and passengers of small aircraft without upper torso restraints for all passenger seats.
Issue owner: Civil Aviation Safety Authority
Transport function: Aviation: Air transport
Background: Investigation Report AO-2017-005
Issue release date: 17 October 2019
Current issue status: Not addressed
Issue status justification:

No changes in mandatory requirements for upper torso restraints have occurred, even for air transport operations involving small aircraft for which mandatory service bulletins exist.

Safety issue description

Upper torso restraints (UTRs) were not required for all passenger seats for small aeroplanes manufactured before December 1986 and helicopters manufactured before September 1992, including for passenger transport operations. Although options for retrofitting UTRs are available for many models of small aircraft, many of these aircraft manufactured before the applicable dates that are being used for passenger transport have not yet been retrofitted.

Response by the Civil Aviation Safety Authority:

In August 2019, in response to the draft ATSB report, the Civil Aviation Safety Authority stated:

CASA agrees with the ATSB’s observations regarding UTR’s for small aircraft in general terms and that some of pre 1986 small aircraft used in passenger transport or aerial work have not been retrofitted. Without accurate data CASA could not confirm that ‘most’ aircraft used in passenger transport have not been retrofitted with UTR’s nor can CASA verify the percentage of the fleet of these aircraft used in passenger transport…

CASA notes that retrofitting is available at the discretion of the aircraft owner.

Operators with a robust Safety Management System would be expected to critically analyse the hazards presented by impact forces and provide appropriate mitigators which may include the fitment of UTRs, or other appropriate modifications and detailed briefings on brace positions. Moreover, CASA observes that while Australia has an aging fleet, the number of aircraft predating the fitment of UTR’s will decrease over time. For the absence of ambiguity, CASA (like many other regulators globally) does not intend to mandate the retro fitment of UTR’s in small aircraft. The ATSB has mechanisms such as Safety Advisory Notices to put forward its views on the efficacy of UTRs including, if it desires, affirmative advice to CASA that the ATSB recommend that CASA mandate their fitment.

ATSB comment:

The ATSB notes that:

  • CASA has stated that it will not be mandating the retrofitting of UTRs in non-front row seats of small aeroplanes manufactured before December 1986 and helicopters manufactured before September 1992.
  • CASA’s response is consistent with other regulatory agencies around the world, despite the substantial evidence to demonstrate the benefits of UTRs and many previous recommendations made by investigation agencies.
  • CASA will be mandating that operators of air transport flights in small aeroplanes will be required to provide briefings to passengers about the brace position (see the safety action for safety issue AO-2017-005-SI-07). However, although such action is necessary and of significant benefit, it will not be as effective as UTRs for minimising the risk of injury during an impact.
  • The proportion of the Australian fleet of small aircraft that was manufactured with UTRs for all seats is gradually increasing. However, there are still many aircraft in use that were manufactured before the applicable dates.
  • Aircraft manufacturers have issued mandatory services bulletins for retrofitting UTRs in many models of small aeroplanes and helicopters, but aircraft owner's and operators are generally not required to comply with such bulletins.
  • Most of the older aircraft have not been retrofitted with UTRs. In addition, there has been no safety education activity in Australia in many years to encourage aircraft operators and owners to fit their older aircraft with UTRs, even though they are available and relatively inexpensive to fit for many models of small aircraft.

The ATSB believes that fitting UTRs (where they are not already installed) is an important safety enhancement for any operator or owner of a small aircraft. However, this is particularly important for operators of passenger transport aircraft. 

Accordingly, the ATSB has issued the following safety recommendation to CASA, and has issued a safety advisory notice to all small aircraft owners and operators.

Safety advisory notice

Action number: AO-2017-005-SAN-028
Action status: Closed

ATSB safety advisory notice to all operators of small aeroplanes and helicopters

Action number:  AO-2017-005-SAN-028

The Australian Transport Safety Bureau strongly encourages operators and owners of small aeroplanes manufactured before December 1986 and helicopters manufactured before September 1992 to fit upper torso restraints to all seats in their aircraft (if they are not already fitted).

Recommendation

Action number: AO-2017-005-SR-027
Action organisation: Civil Aviation Safety Authority
Date: 17 October 2019
Action status: Closed

The Australian Transport Safety Bureau recommends that the Civil Aviation Safety Authority consider mandating the fitment of upper torso restraints (UTRs) for all seats in small aeroplanes and helicopters, particularly for those aircraft (a) being used for air transport operations and/or (b) for those aircraft where the aircraft manufacturer has issued a mandatory service bulletin to fit UTRs for all seats (or such restraints are readily available and relatively easy to install).

Additional correspondence

Response date: 21 January 2020
Response from: Civil Aviation Safety Authority
Action status: Closed
Response text:

Overview

CASA acknowledges fitting upper torso restraints (UTR) has merit and encourages operators to do so. CASA intends to address this recommendation by issuing an Airworthiness Bulletin for the relevant aircraft that will outline the safety benefits of fitting these types of UTR. It will be the responsibility of owners and operators to decide the merits of fitment.

CASA does not support mandating the fitment of UTR for small aircraft based on the currently available safety evidence and given the associated costs this involves.

Current State

An airworthiness directive issued by the state of design is the only way of effectively mandating the fitment of UTRs. For aircraft certified in the United States (such as the accident aircraft) the Federal Aviation Administration (FAA) is the relevant authority and has not issued such an airworthiness directive. The FAA in responding to a similar recommendation made by the NTSB stated;

Mandating the retrofit of aircraft manufactured before December 12, 1986, with a two-point inflatable restraint or a shoulder harness would require the determination that an unsafe condition exists and issuance of an airworthiness directive. The cost of retrofitting the fleet would be substantial. The economic burden levied on the GA fleet with such a mandate would outweigh any potential benefit. Therefore, the FAA does not intend to mandate the installation of a two-point inflatable restraint system or a shoulder harness on the existing fleet.”

CASA’s approach in considering additional safety improvements for small aircraft is to consider a wide range of feasible options for safety improvement and to actively pursue those options that provide the greatest safety benefit for the investment made by owners/operators.

While older aircraft are not unsafe, there are potentially many features of modern aircraft that provide a superior level of safety given the changes in design standards and technology over time.

Any upgrade to the safety standard of older aircraft should therefore focus on the best safety outcome per resource input.

To inform our approach in improving safety particularly in small air transport operations, CASA recently undertook a sector risk profile for the small aeroplane air transport sector. The sector risk profile considered a wide range of information, including the accident and incident data for these types of aircraft, to develop the most critical ‘risks’ or safety issues for this sector. The types of restraints used for rear seat passengers was not identified as a ‘risk’ or safety issue.

As a result of the sector risk profile, and other considerations, CASA is proposing to adopt the following safety enhancements to Part 135 operations (small air transport): new

  • training and checking requirements
  • safety management systems,
  • consideration of human factors in operations and maintenance.

Furthermore, in addressing an outstanding ATSB safety recommendation, AO-2011-115-SR-050, CASA is removing the option of a generic maintenance schedule (CAR ‘Schedule 5’) for aircraft in air transport operations. This is currently the subject of a policy making proposal.

CASA is of the view some of these safety enhancements are a more appropriate focus of mandatory action.

Summary

CASA acknowledges fitting upper torso restraints (UTR) has merit and encourages operators to do so. CASA intends to address this recommendation by issuing an Airworthiness Bulletin for the relevant aircraft that will outline the safety benefits of fitting these types of UTR. It will be the responsibility of owners and operators to decide the merits of fitment.

CASA is of the view it is better to take a systems approach to making safety enhancements when issuing mandatory action, unless clear safety deficiencies exist. CASA is not convinced that these aircraft are unsafe without UTR restraints. CASA intends to mandate a number of other safety enhancements to small air transport operations.

ATSB comment:

The ATSB welcomes CASA’s safety enhancements in areas such as training and checking, safety management systems and considerations of human factors. The ATSB also welcomes CASA’s proposed action to encourage aircraft owners and operators to install upper-torso restraints (UTRs) for rear seats, which will complement ATSB’s safety advisory notice on the same topic.

Nevertheless, the ATSB still believes there is an unnecessary risk to passenger safety that, particularly for air transport operations in many small aircraft, would be relatively easy to address.

The ATSB recognises that a recent recommendation by the US National Transportation Safety Board (NTSB) for retrofitting UTRs on all general aviation aircraft (A-11-4) resulted in no change in mandatory requirements by the Federal Aviation Administration (FAA), and in December 2016 the NTSB closed the recommendation and classified the FAA response as ‘unacceptable action.

The ATSB also recognises that a recent recommendation by the Canadian Transportation Safety Board (TSB) to require all small seaplanes in commercial service to be fitted with UTRs for all passenger seats (A13-03) has, to date, resulted in no change in regulatory requirements, and the TSB have classified the response to date by Transport Canada as unsatisfactory.

Last update 06 April 2020