Posted on: 10 July 2016 by Mark Howells
The day before the official start of the Farnborough Airshow, Boeing gave members of the press a tour of the fourth 737 MAX flight test vehicle – equipped with 32” seats designed by B/E Aerospace – which will eventually be delivered to Southwest Airlines.
Keith Leverkuhn, VP and general manager of the 737 MAX programme at Boeing Commercial Airplanes, averred that the type has already clocked over 800 hours of flight tests and that the fifth, sixth and seventh 737 MAXs are already waiting on the ramp at the OEM’s Renton facility.
The fourth flight test vehicle is set to complete the “mundane” tasks, remarked Leverkuhn, “So we know how the aeroplane’s going to act in a degraded condition when it has to do an ETOPS diversion,” as well as conducting ‘Fly-turn-fly’ testing to see how quickly the aircraft can turn.
Leverkuhn noted the latter isn’t a typical part of the certification programme, and when asked whether it was to become standard, he answered that the company is now doing these tests (and others) across multiple aircraft types in order to share best practices.
Standing outside the 737 MAX aircraft, Leverkuhn stated, “The AT (Advanced Technology) winglet is an integral two-blade design with natural laminar flow benefits. The biggest benefit is in terms of fuel burn, where we’re seeing a 1.5% improvement.” Leverkuhn confirmed that some 737NG aircraft have been fitted with an AT-type winglet, but the process is different as it consists of bolting on a lower blade.
While an improvement in range wasn’t one of the main objectives with the 737MAX, Leverkuhn said as a result of better efficiency the aircraft type has an increased range of about 500 nautical miles in comparison to its predecessor.
“The LEAP-1B engine provided by CFM is really tailor-made for this aircraft both in terms of size and in terms of thrust,” continued Leverkuhn. “These engines are significantly larger from a fan diameter standpoint than the engines on our 737NGs, but what you can’t see is that the nose gear has been raised up by about eight inches to enable us to have that engine tucked up under the wing to get the same kind of ground clearance that the NG has.
“Another unique thing is that the inlet on this engine is now made by Boeing by our team down in South Carolina,” Leverkuhn added. “Several years ago we decided we wanted to vertically integrate in the area of nacelles and this inlet was the first step towards that.
“A further difference you can see is that we’ve sculpted the tail to improve the aerodynamics. It looks much more like a 787 tail than the blunt tail we had on the NG,” Leverkuhn divulged. “Elsewhere, our spoilers are now fly-by-wire (digitally controlled by a new spoiler control electronics unit) and we did that to make sure we could meet all the most recent regulatory requirements.
“On the flight deck, we now have four large displays instead of the six that the NG has. What that’s allowed us to do is port a lot of the maintenance information that currently resides down in the electronics bay in the NG and it’s now able to be shown on a front display in the 737 MAX. That’s part of our change with the onboard network system,” Leverkuhn concluded.
With the engineering and build of the LEAP-1B engine on schedule, Boeing’s 737 MAX is scheduled to enter into service during the third quarter of 2017.
Stephanie Taylor, assistant editor, Low-Fare & Regional Airlines / LARAnews.net