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Fitment of bladder-type fuel tanks to R44 helicopters (US)

Issue number: AO-2013-055-SI-02
Who it affects: All owners and operators of R44 helicopters
Issue owner: United States Federal Aviation Administration
Operation affected: Aviation: General aviation
Background: Investigation Report AO-2013-055
Date: 04 June 2015

Safety issue description

Accidents involving Robinson R44 helicopters without bladder-type tanks fitted result in a significantly higher proportion of post-impact fires than for other similar helicopter types. In addition, the existing United States regulatory arrangements are not sufficient to ensure all R44 operators and owners comply with the manufacturer's Service Bulletin SB-78B and fit these tanks to improve resistance to post-impact fuel leaks.

Response to the safety issue by the United States Federal Aviation Administration
The Federal Aviation Administration (FAA) advised that, based on the results of their own analysis, and a belief that the ATSB’s analysis methodology was invalid, they fundamentally disagreed with the ATSB’s conclusion that accidents involving R44 helicopters without bladder-type tanks resulted in a significantly higher proportion of post-impact fires (PIF) than for other similar helicopter types. As such, no advice of safety action was provided by the FAA in response to this safety issue.

ATSB action in response
Following receipt of this advice from the FAA, the ATSB reviewed its PIF analysis methodology. The review concluded that the method used by the ATSB to analyse PIF occurrences, and the resulting conclusion that R44 helicopters without bladder-type tanks fitted result in a significantly higher proportion of PIF than for other similar helicopter types, were valid.

Recommendation

Action organisation: United States Federal Aviation Administration
Action number: AO-2013-055-SR-025
Date: 04 June 2015
Action status: Released

The ATSB recommends that the United States Federal Aviation Administration take action to ensure that owners and operators of Robinson R44 helicopters comply with the manufacturer’s service bulletin SB-78B to replace all-aluminium fuel tanks with bladder-type tanks on Robinson R44 helicopters.

Proactive Action

Action organisation: International civil aviation regulators
Date: 04 June 2015
Action status: Closed

On 17 May 2013 the South African Civil Aviation Authority issued emergency AD 2013-001 re R44 Bladder Fuel Tanks, which mandated compliance with SB-78B.

On 27 June 2013 the Civil Aviation Authority of New Zealand issued AD DCA/R44/30 Bladder Fuel Tanks – Retrofit requiring replacement of the all-aluminium fuel tanks by the next helicopter overhaul, or by 27 December 2013, whichever occurred first.

On 19 March 2014 the European Aviation Safety Agency (EASA) issued AD 2014-0070 Fuel-Tank-Replacement. That AD had an effective date of 2 April 2014 and mandated the incorporation of SB-78B into all affected R44 helicopters in the European Community, its Member States and any European third countries that participate in the activities of EASA under Article 66 of that Regulation.

   
Current issue status: Safety action pending
 
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Last update 04 June 2015