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Dual-point restraints

Issue number: AO-2014-053-SI-03
Who it affects: Australian parachuting industry
Issue owner: Civil Aviation Safety Authority
Operation affected: Aviation: General aviation
Background: Investigation Report AO-2014-053
Date: 23 June 2017

Safety issue description

Research has identified that rear‑facing occupants of parachuting aircraft have a higher chance of survival when secured by dual-point restraints, rather than the standard single-point restraints that were generally fitted to Australian parachuting aircraft.

Response to safety issue by the Civil Aviation Safety Authority

The immediate survivability in a number of specific crash scenarios may be increased by the use of dual-point restraints. However, other possible scenarios requiring rapid emergency egress from an aircraft should also be taken into account. Survivability in possible scenarios, such as an emergency landing or crash into a body of water (e.g., ATSB Aviation Occurrence Investigation 200600001, Collision with terrain, Cessna U206, VH-UYB, Willowbank, Qld, 2 January 2006), post-crash fire (AO‑2014-053, Collision with terrain involving Cessna U206G, VH-FRT, Caboolture Airfield, Qld, 22 March 2014) or the immediate emergency evacuation of passengers who are in an injured or non‑conscious state should also be examined. The usage of dual-point restraints in these post-crash scenarios may impede the rate that the emergency evacuation may be completed thus presenting additional risks as identified in the survival aspects section of this report.

The differing aircraft types utilised in parachuting operations in Australia also needs to be taken into account when examining the possible usage of dual-point restraints. With reference to Sport Parachuting, United States Federal Aviation Administration (FAA) Advisory Circular AC105-2E Appendix 3 (Seats and Restraint Systems) depicts an aircraft equipped with quick release track fittings. This type of floor mounted fitting, although standard in many large, turbine-powered aircraft such as the Cessna Caravan and Twin Otter, are not fitted to all aircraft. Smaller piston-powered aircraft in use for parachute operations, such as the Cessna 182 or 206, do not have these floor mounted fittings. In these types of aircraft the restraints need to be fitted to suitable anchor points, which may or may not be located at convenient loading points for the operation.

The anchor points used to secure the restraints in these smaller aircraft types are generally those approved by the aircraft manufacturer as the original seatbelt or seat mounting points. An STC [supplemental type certificate] owned by the APF [Australian Parachute Federation] allows certain models of Cessna 182 aircraft to operate with a total of 6 POB providing the MTOW is not exceeded. To allow this the STC requires an appropriate number of single-point restraints (SPRs) to be fitted to specific attachment points in the aircraft cabin. Any additional requirement to use dual-point restraints would double the number of attachment points required which would increase the compliance costs. CASA is required to take all relevant considerations, including cost, into account.

The research conducted into the use of dual-point restraints stems from a Twin Otter Skydiving Aircraft accident in the USA on 29 July 2006 (NTSB/AAR-08/03/SUM). The NTSB Aircraft Accident Summary Report contained the following safety recommendations:

Recommendations

The National Transportation Safety Board recommends that the Federal Aviation Administration:

Conduct research, in conjunction with the United States Parachute Association, to determine the most effective dual-point restraint systems for parachutists that reflects the various aircraft and seating configurations used in parachute operations. (A-08-71)

Once the most effective dual-point restraint systems for parachutists are determined, as requested in Safety Recommendation A-08-71, revise Advisory Circular 105-2C, Sport Parachute Jumping, to include guidance information about these systems. (A-08-72)

The National Transportation Safety Board recommends that the United States Parachute Association:

Work with the Federal Aviation Administration to conduct research to determine the most effective dual-point restraint systems for parachutists that reflects the various aircraft and seating configurations used in parachute operations. (A-08-73)

Once the most effective dual-point restraint systems for parachutists are determined, as requested in Safety Recommendation A-08-71, educate your members on the findings and encourage (edited to add emphasis) them to use the most effective dual-point restraint systems. (A-08-74)

ATSB comment/action in response

The ATSB acknowledges the concerns of CASA and the APF regarding egress following an accident. However, occupants of an aircraft must first survive the accident and remain conscious in order to extricate themselves and/or others. Research shows that this is more likely to occur if dual‑point restraints are used for rear facing parachutists.

The Federal Aviation Administration (FAA) provided educational material to those engaged in parachuting in the form of advisory circular AC 105-2E (appendix B). That document has reference material which can and has been used by the industry in an effort to enhance safety. It provides guidance:

…to improve sport parachuting safety and disseminates information to assist all parties associated with sport parachuting to be conducted in compliance with Title 14 of the Code of Federal Regulations (14 CFR) part 105…

Appendix 3 to that circular states:

(3) Single point, single tether restraints are not recommended.[emphasis added]

(4) Dual point, dual tether restraints offer superior restraint compared to single point, single tether restraints. This restraint method consists of two straps, each connecting the parachute harness to the aircraft floor on both sides of the parachutist…

While the FAA have not made the use of dual‑point restraints mandatory, they have provided guidance to industry that clearly shows that single point restraints are an inferior restraint option. As a result, the ATSB has issued the following safety recommendation to the Civil Aviation Safety Authority.

Proactive Action

Action organisation: CASA
Action number: AO-2014-053-NSA-02
Date: 23 June 2017
Action status: Released

Response to safety issue by the Civil Aviation Safety Authority

The immediate survivability in a number of specific crash scenarios may be increased by the use of dual-point restraints. However, other possible scenarios requiring rapid emergency egress from an aircraft should also be taken into account. Survivability in possible scenarios, such as an emergency landing or crash into a body of water (e.g., ATSB Aviation Occurrence Investigation 200600001, Collision with terrain, Cessna U206, VH-UYB, Willowbank, Qld, 2 January 2006), post-crash fire (AO‑2014-053, Collision with terrain involving Cessna U206G, VH-FRT, Caboolture Airfield, Qld, 22 March 2014) or the immediate emergency evacuation of passengers who are in an injured or non‑conscious state should also be examined. The usage of dual-point restraints in these post-crash scenarios may impede the rate that the emergency evacuation may be completed thus presenting additional risks as identified in the survival aspects section of this report.

The differing aircraft types utilised in parachuting operations in Australia also needs to be taken into account when examining the possible usage of dual-point restraints. With reference to Sport Parachuting, United States Federal Aviation Administration (FAA) Advisory Circular AC105-2E Appendix 3 (Seats and Restraint Systems) depicts an aircraft equipped with quick release track fittings. This type of floor mounted fitting, although standard in many large, turbine-powered aircraft such as the Cessna Caravan and Twin Otter, are not fitted to all aircraft. Smaller piston-powered aircraft in use for parachute operations, such as the Cessna 182 or 206, do not have these floor mounted fittings. In these types of aircraft the restraints need to be fitted to suitable anchor points, which may or may not be located at convenient loading points for the operation.

The anchor points used to secure the restraints in these smaller aircraft types are generally those approved by the aircraft manufacturer as the original seatbelt or seat mounting points. An STC [supplemental type certificate] owned by the APF [Australian Parachute Federation] allows certain models of Cessna 182 aircraft to operate with a total of 6 POB providing the MTOW is not exceeded. To allow this the STC requires an appropriate number of single-point restraints (SPRs) to be fitted to specific attachment points in the aircraft cabin. Any additional requirement to use dual-point restraints would double the number of attachment points required which would increase the compliance costs. CASA is required to take all relevant considerations, including cost, into account.

The research conducted into the use of dual-point restraints stems from a Twin Otter Skydiving Aircraft accident in the USA on 29 July 2006 (NTSB/AAR-08/03/SUM). The NTSB Aircraft Accident Summary Report contained the following safety recommendations:

Recommendations

The National Transportation Safety Board recommends that the Federal Aviation Administration:

Conduct research, in conjunction with the United States Parachute Association, to determine the most effective dual-point restraint systems for parachutists that reflects the various aircraft and seating configurations used in parachute operations. (A-08-71)

Once the most effective dual-point restraint systems for parachutists are determined, as requested in Safety Recommendation A-08-71, revise Advisory Circular 105-2C, Sport Parachute Jumping, to include guidance information about these systems. (A-08-72)

The National Transportation Safety Board recommends that the United States Parachute Association:

Work with the Federal Aviation Administration to conduct research to determine the most effective dual-point restraint systems for parachutists that reflects the various aircraft and seating configurations used in parachute operations. (A-08-73)

Once the most effective dual-point restraint systems for parachutists are determined, as requested in Safety Recommendation A-08-71, educate your members on the findings and encourage (edited to add emphasis) them to use the most effective dual-point restraint systems. (A-08-74)

ATSB response:

The ATSB acknowledges the concerns of CASA and the APF regarding egress following an accident. However, occupants of an aircraft must first survive the accident and remain conscious in order to extricate themselves and/or others. Research shows that this is more likely to occur if dual‑point restraints are used for rear facing parachutists.

The Federal Aviation Administration (FAA) provided educational material to those engaged in parachuting in the form of advisory circular AC 105-2E (appendix B). That document has reference material which can and has been used by the industry in an effort to enhance safety. It provides guidance:

…to improve sport parachuting safety and disseminates information to assist all parties associated with sport parachuting to be conducted in compliance with Title 14 of the Code of Federal Regulations (14 CFR) part 105…

Appendix 3 to that circular states:

(3) Single point, single tether restraints are not recommended.[emphasis added]

(4) Dual point, dual tether restraints offer superior restraint compared to single point, single tether restraints. This restraint method consists of two straps, each connecting the parachute harness to the aircraft floor on both sides of the parachutist…

While the FAA have not made the use of dual‑point restraints mandatory, they have provided guidance to industry that clearly shows that single point restraints are an inferior restraint option. As a result, the ATSB has issued the following safety recommendation to the Civil Aviation Safety Authority.

Recommendation

Action organisation: Civil Aviation Safety Authority
Action number: AO-2014-053-SR-018
Date: 23 June 2017
Action status: Released

The ATSB recommends that the Civil Aviation Safety Authority, in conjunction with the Australian Parachute Federation, takes action to increase the usage of dual‑point restraints in parachuting aircraft that are configured for rear facing occupants

Proactive Action

Action organisation: Australian Parachute Federation
Action number: AO-2014-053-NSA-03
Date: 23 June 2017
Action status: Released

Regarding the use of dual‑point restraints, the Australian Parachute Federation (APF) stated:

…APF believes that the use of dual restraints will not result in a net improvement in safety due to additional complications. These include dealing with inexperienced or tandem parachutists in relation to in flight emergencies and the ability to disconnect them quickly and safely in reaction to an emergency…

ATSB response:

As detailed above, given the identified safety benefit offered by dual point restraints, the ATSB issues the following safety recommendation.

Recommendation

Action organisation: Australian Parachute Federation
Action number: AO-2014-053-SR-019
Date: 23 June 2017
Action status: Released

The ATSB recommends that the Australian Parachute Federation, in conjunction with the Civil Aviation Safety Authority, takes action to increase the usage of dual point restraints in parachuting aircraft that are configured for rear facing occupants.

   
Current issue status: Safety action pending
 
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Last update 02 August 2017