Kopter solves cast part issue, begins ground testing third SH09 prototype

Kopter is ground-testing the third prototype of the SH09 single-engine helicopter having solved a supplier issue with a main gearbox component, the company has revealed.

At the end of an additional test phase, the cast part was found strong enough to cope with the SH09's flight envelope and is being used on P3. Kopter Photo
The third SH09 prototype (P3) conducts ground testing at Kopter’s production facility in Mollis, Switzerland. Kopter Photo
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Prototype P3 is currently in a pre-flight test phase at the test and production facility of the fledgling manufacturer, formerly known as Marenco Swisshelicopter, in Mollis, Switzerland.

After one month of early flight trials in Mollis, some 300 flights will take place from Pozzallo, Sicily, where a team of 15 to 20 will be transferred. There, the flight test campaign will last 11 months, Michele Riccobono, chief technology officer, told Vertical.

Earlier in the aircraft’s development, P3’s flight test campaign had been scheduled to start by the end of March 2018. However, issues with a cast part – the main gearbox’s upper housing – ultimately led to a six-month delay.

The part the initial supplier delivered suffered from sub-standard porosity and cracks. “Rework and structural testing were required to substantiate [that the part’s] strength and fatigue life were adequate to support the initial flight-test phase,” said Riccobono.

An additional quality flaw was then discovered on the same part. The casting process required some adjustments to be made by welding, but the supplier had used improper procedures, Riccobono explained.

Kopter then performed a set of static tests, up to ultimate load, on two different serial numbers of the same batch. It ran an additional 300-hour main gearbox endurance test to confirm the mechanical properties design engineers had assumed in their analysis. At the end of this additional test phase, the part was found strong enough to cope with the SH09’s flight envelope and is being used on P3.

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Nevertheless, a new supplier is replacing the initial one. The delivery of its first part is expected over the next few weeks and “will be retrofitted on to P3 at a later stage,” the manufacturer said.

Kopter is focusing on maintainability with the in-construction SH09’s “pre-series” PS4. The rotor head, main gearbox and hydraulic system have been made more maintenance-friendly, said Riccobono. A new pre-impregnated carbon fiber will better deal with aging, as it will absorb less humidity.

The manufacturer anticipates it will soon receive Garmin’s first G3000H avionics suite, which was revealed last spring to be replacing the equipment provided by Safran. Kopter will rig-test it at its design office in Wetzikon.

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