AW139 faces FAA scrutiny over main rotor tension link cracks

Regulator says concern stems from recent flurry of reports from a US repair station flagging the issue.

US regulators are attempting to ascertain the scale of a potential safety issue affecting the main rotor assembly on the Leonardo Helicopters AW139 intermediate-twin.

Detailing its inquiries in an ‘airworthiness concern sheet’ issued on 22 April, the Federal Aviation Administration (FAA) says the problem is focused on cracking of main rotor tension links on the helicopter.

Each AW139 has five tension links, joining the rotor hub to the main rotor blade.

The FAA says its probe was sparked by three recent ‘service difficulty reports’ filed by a US repair station.

Additional data provided by the same repair station showed 34 additional instances of main rotor link cracking had been discovered over the past six years, says the FAA.

Those cracks occurred on 15 different AW139s from 15 different operators, it says, and involved multiple different use cases.

“The data revealed that some AW139s had a single cracked tension link, while others had four out of five tension links cracked on the same rotorcraft,” the document states.

Of those AW139s where a cracked link was discovered, 50% had accumulated less than 400 flight hours, 71% had under 900h and “the lowest-time rotorcraft” had just 103h, the FAA says.

Additionally, of the 34 cracked links found by the repair station since April 2020, 50% had been detected in the 13 months from March 2025.

The European Union Aviation Safety Agency (EASA) – the primary regulator for the AW139 – was already aware of in-service tension link cracking, says the FAA, but its counterpart’s investigation “determined the cracks were not critical” or an unsafe condition.

Although the latest cracks appear to be in a “similar location to cracks previously investigated by EASA”, the FAA says it “is unknown” whether they are “of the same severity”.

It is now working with the European regulator to determine if the recently reported tension link cracks are “consistent” with those previously investigated by EASA.

The FAA says its “current concern” stems from the “critical” nature of the component.

As such, it is seeking feedback from US-based AW139 operators to ascertain whether the issue is occurring consistently throughout the fleet, whether the rate of cracking is accelerating, or “now consistently occurring to rotorcraft with minimal time in service.”

Leonardo Helicopters already requires a “detailed inspection” of the tension link after every 50 flight hours and mandates that the component is replaced if “similar findings are detected”.

“Findings reported by the relevant aviation authorities had been thoroughly assessed over the past years and do not represent any major damage subject to critical failure,” the manufacturer adds.