ClosedMedium impactAI Generated

AW139 Tail Rotor Duplex Bearing Failure at Norwich Prompts AAIB Safety Recommendations

Occurred 13 Jun 2022·Detected 22 May 2026·
🇬🇧 Norwich Airport, Norfolk, United Kingdom1 reportEnded 29 May 2026
AviationAviation

A collapsed tail rotor duplex bearing was discovered during post-flight maintenance on a Bristow Helicopters AW139 (G-CIMU) at Norwich Airport on 13 June 2022. The AAIB determined that a loss of tail rotor control would likely have occurred had the helicopter continued operating, drawing parallels to the fatal 2018 Leicester City AW169 crash. The investigation revealed the bearing had been improperly refitted contrary to maintenance manual instructions. The AAIB has issued safety recommendations to Leonardo Helicopters for enhanced inspection regimes and HUMS upgrades, facing opposition from Italy's ANSV regulator.

AI-generated from linked source reports. See our correction policy.

Impact verdict

Medium impact. The incident directly affects the AW139 fleet globally, particularly offshore oil rig operations where tail rotor control loss in hover is high risk; while no hull loss occurred, the safety recommendations and regulatory dispute could drive significant airworthiness compliance costs and affect insurability of the broader fleet.

View assessment methodology

How we grade what we know -- Known · Reported · Uncertain. Methodology →

Intelligence ledger

Each line expands in place to its underlying sourced claim.

Known6 lines

Collapsed tail rotor duplex bearing discovered on Bristow Helicopters AW139 (G-CIMU) during post-flight maintenance at Norwich Airport on 13 June 2022
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No separate sourced-claim record is available for this line yet.
AAIB confirmed loss of tail rotor control would likely have occurred had the aircraft continued operating
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No separate sourced-claim record is available for this line yet.
Bearing had been improperly refitted contrary to approved maintenance manual instructions, accumulating 1,007h before refitting and a further 1,743h before failure was identified
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No separate sourced-claim record is available for this line yet.
HUMS failed to flag real-time warning signs, though retrospective analysis showed a changing relationship between airspeed and pedal position from approximately 7 June 2022
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No separate sourced-claim record is available for this line yet.
AAIB has issued recommendations to Leonardo Helicopters for comprehensive inspection programme and HUMS enhancements
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No separate sourced-claim record is available for this line yet.
The AW139 fleet did not receive safety measures introduced for AW169 and AW189 following the 2018 Leicester City crash
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No separate sourced-claim record is available for this line yet.

Reported2 lines

Pilots noted foot pedals 'felt a bit strange' on preceding flights but did not consider it a serious concern
structured linereported
No separate sourced-claim record is available for this line yet.
Italy's ANSV civil aviation regulator disputes both the safety recommendations and the classification of the event as a 'serious incident'
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No separate sourced-claim record is available for this line yet.

Uncertain2 lines

Whether the failure mechanism on the AW139 is the same as that which caused the AW169 Leicester City crash has not been proven
structured lineuncertain
No separate sourced-claim record is available for this line yet.
Whether existing mitigation actions for the AW139 fleet are adequate to address the airworthiness risk remains disputed between AAIB, Leonardo, and EASA/ANSV
structured lineuncertain
No separate sourced-claim record is available for this line yet.

Affected countries

🇬🇧 United Kingdom🇮🇹 Italy

Timeline

Status Change2 Jun 2026, 13:05

Lifecycle changed

monitoring → closed

Closure2 Jun 2026, 13:05

Event Closed

auto_closed_monitoring_timeout

Status Change29 May 2026, 05:30

Status changed to monitoring

Auto-transitioned: no updates for 6 hours

active → monitoring

Status Change28 May 2026, 22:36

Status changed to active

remediation: existing authoritative signal

signal → active

Initial Detection22 May 2026, 14:24

Initial Detection

A collapsed tail rotor duplex bearing was discovered during post-flight maintenance on a Bristow Helicopters AW139 (G-CIMU) at Norwich Airport on 13 June 2022. The AAIB determined that a loss of tail rotor control would likely have occurred had the helicopter continued operating, drawing parallels to the fatal 2018 Leicester City AW169 crash. The investigation revealed the bearing had been improperly refitted contrary to maintenance manual instructions. The AAIB has issued safety recommendations to Leonardo Helicopters for enhanced inspection regimes and HUMS upgrades, facing opposition from Italy's ANSV regulator.

The extent of the damage to the bearing confirmed that a loss of tail rotor control event would likely have occurred had the helicopter continued to operate with the bearing fitted.

Source: FlightGlobal (Trade Media) · View source

Lloyd's classifications

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