Bell Helicopter did not reach first flight with its V-280 Valor on 30 September as originally announced and instead projects the tiltrotor aircraft will meet that milestone in November, V-280’s programme manager tells FlightGlobal this week.

In August, Bell finished building its V-280 prototype but only referred to its first flight date as this fall. Bell started ground tests on 20 September, beginning with checks of the GE Aviation T64 engines and later electromagnetic interference checks on the Lockheed Martin-supplied avionics. Bell didn’t add test points to its ground test regimen, but is taking those tests more slowly, V-280 programme manager Chris Gehler says.

“We’re being very cautious and methodical,” Gehler says. “So it’s maybe taking a little bit longer but we’re not pushing the aircraft beyond what we think is safe. We had a couple of items we wanted to investigate.”

Weather also played a role in pushing first flight later into the fall, with even drops of rain threatening to erode instrumentation on the rotor blades.

“I wish I would have installed a carport over my ground run facility so I could run during the rain,” he says. “With all the instrumentation that we have on the blades and everywhere else, we’re really limited to being able to operate when it’s not raining.”

Bell remains well ahead of Sikorsky-Boeing’s SB-1 Defiant, lagging months behind its first flight date for US Army’s Joint Multi-Role Technology Demonstration (JMR-TD). Defiant was scheduled to fly this fall, but Boeing announced in April the milestone would be pushed to early 2018.

Programme managers did not report a significant issue that caused the delay, though Boeing was still procuring Defiant’s fuselage even as the programme was undergoing wind tunnel tests.

The JMR-TD flight demonstration is intended by the army to evaluate technologies that could be used for a family of high-speed, Future Vertical Lift (FVL) aircraft. Such designs, with speeds well above the limit of about 170kt for most conventional helicopters, would replace the army's fleet of Boeing AH-64 attack, Sikorsky UH-60 utility and Boeing CH-47 cargo helicopters.