Aviation safety issues and actions

Fitment of rubber, bladder-type fuel tanks to R44 helicopters

Issue number: AO-2012-021-SI-01
Who it affects: All owners and operators of R44 helicopters
Issue owner: Robinson Helicopter Company
Transport function: Aviation: General aviation
Background: Investigation Report AO-2012-021
Issue release date: 03 May 2013
Current issue status: Adequately addressed
Issue status justification: Manufacturer has made a number of modifications to the helicopter to lessen the hazard and they have placed a time limit on the modifications in an attempt to ensure compliance. CASA has educated the owners of R44 helicopters via Airworthiness Bulletin (AWB) 28-012, titled Robinson R44 Fuel Tanks, issued 26 June 2012.

Safety issue description

A significant number of R44 helicopters, including VH-COK, were not fitted with bladder-type fuel tanks and the other modifications detailed in the manufacturer's Service Bulletin, SB-78 to improve resistance to post?impact fuel leaks and fire.

Proactive Action

Action number: AO-2012-021-NSA-005
Action organisation: Robinson Helicopter Company
Date: 03 May 2013
Action status: Closed

The manufacturer had initially issued SB-78 on 20 December 2010. On 21 February 2012, following this and the R44 accident at Cessnock, New South Wales (NSW) on 4 February 2011 involving VH-HFH, the manufacturer issued a revision to SB-78, numbered SB-78A. That revision reduced the time frame for compliance with the bladder-type tank fitment from 31 December 2014 to 31 December 2013.

On 15 June 2012, the manufacturer forwarded a letter of offer to all R44 Dealers, Service Centres and Owners, advising them of a financial incentive for them to install the SB-78A fuel tank kits ‘on or before 31 December 2012’.

Subsequently, on 28 September 2012 the manufacturer again revised the compliance date with the issue of SB-78B. That revision further reduced the date for compliance to 30 April 2013.

In addition to the manufacturer’s bulletins in respect of the requirement to install bladder-type fuel tanks, on 21 February 2012, the manufacturer issued SB-82 relating to the fitment of a ‘more rugged, environmentally sealed[sic]’ type rotor brake activation switch. The manufacturer indicated that the new switch was less likely to cause a spark in the event of an accident. SB‑82 had a compliance date of 31 May 2012. Owners of R44 helicopters should give consideration to incorporation of this SB.

In conjunction with the United States Federal Aviation Administration, the manufacturer is also examining other methods to ensure greater compliance with the bladder-type fuel tank upgrade.


Proactive Action

Action number: AO-2012-021-NSA-006
Action organisation: Civil Aviation Safety Authority
Date: 03 May 2013
Action status: Closed

ASA websiteOn 26 June 2012, following this accident and the R44 accident at Cessnock, NSW involving VH‑HFH, the Civil Aviation Safety Authority (CASA) introduced Airworthiness Bulletin AWB 28‑012 titled Robinson R44 Fuel Tanks.[1] That AWB highlighted the improvement in the 'post-crash survivability' of R44 helicopters that had been fitted with bladder-type fuel tanks.

The AWB referred to Robinson Helicopter Company Service Bulletin SB-78 that, depending on the System of Maintenance affecting the individual helicopter, required the fitment of bladder-type tanks to all R44 helicopters in lieu of the all‑aluminium fuel tanks. The AWB also strongly recommended that all operators of R44 helicopters incorporate the additional service bulletins SB67, SB68, SB69 and SB82.

On 19 December 2012, in response to a question from the ATSB, CASA advised that:

CASA has drafted a Notice of Proposed Rule Making(NPRM) relating to a unique Australian Airworthiness Directive (AD) that will mandate the Robinson Helicopters R 44 SB 78B Bladder Fuel Tank Retrofit. Release of this NPRM, expected in early in 2013, is subject to confirmation from the FAA as to their intended actions, which will follow their current investigation.

On 15 March 2013, in response to the draft report into this accident, CASA advised that:

CASA has been liaising with the Federal Aviation Administration (FAA) certification office regarding the subject of mandating the R44 Service Bulletin (SB) SB-78B. The FAA advised CASA that, after analysis of the data, the R44 fuel system crashworthiness does not appear inconsistent with that of other similar helicopters and they will be taking no corrective action.

Robinson Helicopters advised that they brought forward the compliance date for SB-78B for all affected R44 rotorcraft to April 2013. Given this reduced compliance time, CASA issued a letter to all R44 operators recommending the installation of the bladder tanks and highlighting their responsibilities under Civil Aviation Regulation 42A (4). CASA is also taking steps to determine the SB-78B industry take-up rate.

On 3 April 2013, CASA issued AWB 02-044 Robinson R44 Helicopter Maintenance Requirements (Issue 1), which stated in part that:

Registered operators of Robinson R44 helicopters that are maintained using the manufacturer’s maintenance schedule are reminded that they must comply with Service Bulletins by their due date. The registered operator will be contravening regulation 41 of the CAR and the pilot and registered operator may also contravene regulation 47 of the CAR if they do not comply with Service Bulletins by their due date.

If the helicopter is maintained to an approved SOM then the SOM must have consideration for compliance with Robinson Helicopter Company Service Bulletins. With regards to Robinson Helicopter Company Service Bulletins mentioned in AWB 28-012, CASA would regard an SOM that does not include these Service Bulletins as deficient.

The full AWB is available on the CASA website: www.casa.gov.au


Proactive Action

Action organisation: US Federal Aviation Administration
Date: 03 May 2013
Action status: Closed

On 26 December 2012 the US Federal Aviation Administration issued a Special Airworthiness Bulletin (SAIB) alerting R44 owners and operators of the availability of a fuel tank bladder retrofit program for enhanced safety on R44 and R44 II helicopters.

That SAIB recommended that owners/operators of affected R44 helicopters incorporate SB-78B, Revision B, of 28 September 2012.


Safety Advisory Notice

Action number: AO-2012-021-SAN-001
Action organisation: Australian Transport Safety Bureau
Date: 09 March 2013
Action status: Closed

On 9 March 2012, following this and the R44 accident at Cessnock, NSW on 4 February 2011 involving VH‑HFH, the ATSB released safety advisory notice AO‑2012‑021‑SAN‑001.[1]

In that notice, the ATSB encouraged operators of R44 helicopters to actively consider the installation of bladder-type fuel tanks in their aircraft as follows:

The Australian Transport Safety Bureau encourages all operators and owners of R44 helicopters that are fitted with all-aluminium fuel tanks to note the circumstances of this accident as detailed in this preliminary report. It is suggested that those operators and owners actively consider replacing these tanks with bladder-type fuel tanks as detailed in the manufacturer’s Service Bulletin (SB) 78A as soon as possible.

Current status:

Residual risk:         Significant
Issue status:          Adequately addressed

Despite the availability of the bladder-type fuel tanks to replace the all‑aluminium tanks in R44 helicopters, the number of such helicopters yet to be installed represents a significant residual risk. The manufacturer’s emphasis on the safety benefits of the installation of these tanks, and encouragement for their installation by owners and operators of R44 helicopters is supported. Further emphasis on the enhanced survivability likely from the installation by operators of bladder-type tanks in their R44 helicopters has been provided by CASA and the ATSB.

The ATSB will monitor the progress of CASA’s NPRM concerning the development of a unique Australian airworthiness directive to mandate the incorporation in R44 helicopters of the SB-78B bladder-type fuel tank retrofit.

Further action by the Australian Transport Safety Bureau

Another low-impact energy accident that resulted in a fatal post-impact fire occurred at Bulli Tops near Wollongong, NSW on 21 March 2013 and involved R44 Raven helicopter VH‑HQH (ATSB investigation AO‑2013‑055, available at www.atsb.gov.au). As a result of this additional accident, and concerns that a significant number of Australian R44 owners and operators were very unlikely to be able to comply with the requirements of SB-78B by the required compliance date of 30 April 2013, the ATSB issued a safety recommendation to CASA on 5 April 2013. That recommendation sought further action by CASA to ensure that owners and operators of Robinson R44 helicopters were aware of the relevant regulatory requirements affecting compliance with manufacturer’s service bulletins, and complied with SB-78B to replace all-aluminium fuel tanks with bladder-type tanks on Robinson R44 helicopters.

Proactive Action

Action organisation: Robinson Helicopter Company
Date: 03 May 2013
Action status: Closed

Following this accident and the identification of a number of other issues by the manufacturer, the following proactive safety action has been advised by the manufacturer in response to the risk of pilots removing their hand(s) from the flight controls:

[The] Robinson Helicopter Company is currently drafting a Safety Notice to emphasize the importance of maintaining control of the helicopter especially in a simple unexpected event, for example; folding or unfolding charts, the sudden opening of an unlatched door or even programming communication/navigational equipment.


Last update 13 January 2014