The Future of FlightBlogger

Sun	Mon	Tue	Wed	Thu	Fri	Sat
					1	2
3	4	5	6	7	8	9
10	11	12	13	14	15	16
17	18	19	20	21	22	23
24	25	26	27	28	29	30
31

Stuart Clarke

on March 27, 2013 7:03 AM | Permalink | Comments () | TrackBacks (0)

My name is Stuart Clarke and i'm the new editor of flightglobal.com. We know that many of you have been waiting patiently for an update on the status of this blog. We apologise for any frustration caused while we took the time to carefully consider what to do with FlightBlogger before making any formal decision.

As most of you know, Jon Ostrower no longer works for Flightglobal, and has taken up a position at the Wall Street Journal. You can follow him now and as proud alumni of flightglobal.com we wish him the best and follow his career with interest.

Obviously continuing this blog without Jon was always going be a difficult task, so we've taken the decision to keep this blog and its records as an archive and resource, but we will not be publishing any new content.

We will also be switching off commenting on this blog shortly but please contact me with any of your further questions.

Instead we will soon start a new blog from one of our most experienced journalists that will cover the world of air transport so stay tuned, and of course we also have many excellent blogs written by our other expert journalists - which you can check out on our dedicated blogs homepage.

No split over similar-looking wingtips

Stephen Trimble

on August 9, 2012 6:51 AM | Permalink | Comments () | TrackBacks (0)

In a remarkable coincidence, the split-tip winglet that went out of fashion with the demise of the MD-12 concept in the early 1990s has suddenly re-appeared in in two applications -- Boeing's straight-edged Advanced Technology (AT) winglet for the 737 Max (above) and Aviation Partners' scimitar-edged split-tip blended winglet on the 737 Next Generation series.

Aviation Partners is jealous about guarding what it considers proprietary information (ask Airbus), but founder Joe Clark says he has no suspicions that Boeing copied the Aviation Partners design. Robb Gregg, Boeing's chief aerodynamicist on the 737 Max, agrees that both companies came to a similar conclusion from different directions. But the joint venture partners remain divided on the potential benefits of applying a more efficient split-tip design on the 737NG as a retrofit. We explore the history and opinions on both designs in next week's issue of Flight International, but here is a sneak-peek.

Aviation Partners poised to offer split-tip winglet for 737NG, but Boeing not convinced

Aviation Partners has started showing airlines a split-tip winglet with blended, "scimitar"-edged feathers as a retrofit option that the joint venture estimates can reduce fuel consumption by 2.5 to 3% on next-generation 737s.

The move precedes a launch decision by the board of directors of the joint venture, but that approval should come "shortly", says Joe Clark, founder of Aviation Partners, the Seattle-based firm that designed the standard blended winglet ordered on more than 4,600 737NGs.

Aviation Partners unveiled the scimitar-edged winglet last October and launched flight tests on a 737 Boeing Business Jet in April, which confirmed the estimates of computational fluid dynamics models to within one-tenth of a percentage point, Clark says.

"We are very pleased with what we've achieved," he adds. While Aviation Partners prepares to offer a scimitar-edged split-tip winglet on the 737NG, Boeing is readying a straight-edged split-tip winglet on the 737 Max.

Both companies claim to have arrived on the split-tip configuration for the 737 at nearly the same time by coincidence. Aviation Partners had no prior knowledge of Boeing's "dual-feather" split-tip winglet for the 737 Max, and has received no information on the design from its joint venture partner, Clark says.

For its part, Boeing also was unaware of the Aviation Partners design when it began working on the Advanced Technology (AT) winglet around June 2011, says Robb Gregg, a chief aerodynamicist for the 737 Max. "As I was looking at the configuration, we needed to get more performance out of it and really the only place we hadn't spent a lot of time was looking at the [wing]-tip," Gregg says.

Boeing completed trade studies between August and September last year, he says, then fabricated a set of optimal shapes for testing in a wind tunnel. Although the split-tip design appears to be a new innovation, it traces back to Robb's previous work as a chief aerodynamicist at McDonnell Douglas.

The airframer that merged with Boeing in 1997 had pioneered the installation of winglets on airliners in the mid-1980s. The MD-11 entered service with an up/down winglet, with a shortened lower surface forward of the upper surface. The lower surface was shaped to improve stall characteristics at low-speed, Gregg says. McDonnell Douglas also proposed a split-tip winglet for the short-lived MD-12, a late-1980s concept for a four-engined double-decker. As the chief aerodynamicist of the MD-12 concept, Gregg says, he proposed the split-tip to optimize lift of a wingspan artificially constrained to a length of 64.9m (213ft) to fit into existing airport gates.

Likewise, the 737 Max also demanded more performance than a blended winglet could produce. "Because we needed more performance to satisfy the customers we felt we needed to push the technology a bit further," Gregg says.

A split-tip winglet has never been tested in flight test, and Boeing currently has no plans to test the 737 Max AT Winglet on a surrogate platform. Boeing is confident that computational fluid dynamics models have predicted drag characteristics accurately, Gregg says.

At the same time, Boeing is not convinced a split-tip winglet will produce performance improvements as a retrofit option on the 737NG, although it has not conducted an analysis yet.

Holding Boeing back is the knowledge that the AT Winglet increases the aerodynamic loads on the outboard wing section. "The better the winglet the more load it's going to drive outboard. Otherwise it didn't do anything for you," Michael Teal, chief project engineer on the 737 Max, said in a July interview. "The question is how difficult it would be to retrofit," he added. "You're getting out there on the end of a wing; it's not that thick. It's not something that's easy to take apart and add gauge to."

Despite being joint venture partners, Boeing and Aviation Partners also have different views on the margin of benefit provided by a split-tip winglet. Boeing predicts the straight-edged split-tip on the 737 Max will contribute 1.5% to fuel burn reduction. Aviation Partners, on the other hand, is proposing a 2.5% to 3% benefit from installing the scimitar-edged winglet on the 737NG, which shares the same airfoil as the 737 Max. Even so, Aviation Partners is optimistic that scimitar-edged split wing-tips will be retrofitted on as much as 60% of the 737NG fleet, Clark says.

Superjet honeymoon over with launch customer

Stephen Trimble

on August 6, 2012 2:35 PM | Permalink | Comments () | TrackBacks (0)

The relationship between Sukhoi Superjet and launch customer Armavia continues to unravel, as new reports indicate the Armenian flag carrier has returned its only delivered SSJ100 jet.

Armavia's enthusiasm for the Superjet has waned ever since it took delivery. That much was apparent last November. Armavia had operated the 94-seater for seven months, and Sukhoi hosted a joint press conference. The intent of such events is for both parties to exchange warm platitudes, and smile for the cameras. Armavia could not quite follow the script. Aeroflot had already complained about air conditioning malfunctions and false alarms on the health monitoring system. Armavia said the Superjet needed to be "optimised" before it could meet its potential. Armavia was expected to take its second aircraft in April, but the jet is still sitting on Sukhoi's ramp.

Sukhoi isn't exactly on the best of terms with its launch customer either. Armavia has been accused by Russian authorities of running up unpaid debts, with Moscow's Vnukovo airport reportedly banning refueling services and civil aviation agency Rosaviatsia suspending Armavia's rights to enter the airspace for 10 days in March.

But the Superjet programme can ill-afford more bad press. Mechanical error has been ruled out as a cause of the 9 May crash of a demonstration flight in Indonesia. But Sukhoi's plans for mass production have proved wildly optimistic. Six Superjets were delivered to two customers last year, nine less than planned. Twenty-three SSJ100s are supposed to be delivered this year, but so far only four have been handed over to one customer -- Russian flag carrier Aeroflot. Last week, Flightglobal staff writer Kristin Majcher reported that delivery to North America launch customer Interjet will be delayed five months to March. Interjet blamed the delay on its own training pipeline, but Sukhoi's ability to deliver the aircraft on time remains the biggest question about the programme.

PICTURE: Alaska apologises for MX message on 737

Stephen Trimble

on August 3, 2012 5:50 AM | Permalink | Comments () | TrackBacks (0)

Photo: Reddit

Alaska Airlines says on Twitter this perhaps unfortunate maintenance message, which went viral on reddit this week, was "inappropriate", and, more ominously, "we have followed up w/ the team". (Uh-oh.)

But there may have been good reasons why the maintenance team wrote a message that some passengers clearly interpreted as unintentionally funny and/or scary.

In the reddit discussion forum, where the picture was originally posted, a self-identified Delta Air Lines employee, says such a message does wonders to reduce paperwork. "Marking apparent damage prevents reports from being filed at each station at which the aircraft arrives," he says.

Passengers sitting over the wing, of course, have no way of knowing that.

PREVIEW: Big earnings day for Boeing Commercial Airplanes

Stephen Trimble

on July 25, 2012 7:32 AM | Permalink | Comments () | TrackBacks (2)

Boeing Commercial Airplanes (BCA) expects later this morning to post a good second quarter, and we'll wait for the final tally to decide if we should further modify 'good' with 'very'. It's the first time that's possible to say without any major caveats since 2007. With the 787 and 747-8 finally certified amidst swelling demand for commercial aircraft, BCA can have a nice quarter for once.

The numbers don't lie. Operating earnings for the BCA segment have plunged even as revenues have stabilized. Aircraft deliveries hit a five-year low in what was already a down-cycle in 2010, and then barely improved in 2011. This year, BCA already has reported delivering 150 aircraft in the second quarter, including 13 total 787s and 747-8s.

Although that's a huge improvement, BCA will have to work hard to meet its full-year delivery guidance of between 35 and 42 787s. The airframer has delivered only 11 787s in the first half of the year. Meeting that delivery target is essential for BCA to begin unwinding its mountainous stockpile of 787 inventories.

BCA ($m)	2008	2009	2010	2011	2012
Revenues	8567	8431	7433	8843	11843
Operating Earnings	777	817	920	920	1211
R&D expense	770	659	693	771	560
Assets	18893	20497	28341	33379
Liabilities	16556	17141	19663	21018

Aircraft deliveries	126	125	114	118	150
737	100	99	95	94	109
747	5	2			7
767	3	3	3	5	6
777	18	21	16	19	22
787					6

Total inventories		18568	26550	32592
787 work in progress, including deferred production		3885	9461	12684
787 Supplier advances		2187	1956	1852
Tooling & non-recurring		1231	1447	1677

ANA 787 grounding spotlights Hamilton Sundstrand gearbox

Stephen Trimble

on July 23, 2012 9:14 AM | Permalink | Comments () | TrackBacks (0)

Photo: Rolls-Royce

All Nippon Airways has grounded five Boeing 787s powered by Rolls-Royce Trent 1000 engine. Ground endurance tests by R-R showed the engine could be damaged by crown gears that corroded faster than expected. (Click here to read the full story posted earlier this morning by Flightglobal's Singapore office.)

R-R selected Hamilton Sundstrand nearly eight years ago to provide the Trent 1000 gearbox system, which was the supplier's first such placement on an R-R engine. On the rival General Electric GEnx-1B, which is not affected by the ANA grounding, Italy's Avio supplies the gearbox.

The 787 gearbox is a unique specimen. Boeing chose a "more electric aircraft" architecture, replacing bleed air-sourced pneumatic power for cabin air conditioning and wing de-icing with electric power. The same generator is also integrated with the gearbox and is used to start the engine. A recent Hamilton Sundstrand patent application for an integrated gearbox and air turbine starter illustrates the concept.

The ANA grounding appears to be unrelated to the more-electric aspects of the gearbox that are unique to the 787. R-R has instead pointed the finger at Hamilton Sundstrand's manufacturing process. Hamilton Sundstrand has confirmed it is "of course aware of the issue", and is working with R-R and Boeing to resolve it.

Why would Boeing design a mid-wing, twinjet, double-decker 747?

Stephen Trimble

on July 19, 2012 8:52 AM | Permalink | Comments () | TrackBacks (0)

Breguet's range equation is a cruel tyrant. The fuel-efficiency conscious airframe designer has only three levers -- weight, thrust and aerodynamics -- to pull, and yanking one often complicates things for the other two. At the concept stage, however, it still helps to tug upon one of Breguet's levers, just to see what happens.

So it appears with the Boeing design concept named "mid-wing aircraft", which is revealed as a patent application published on 28 June.

Boeing obviously set a challenge for itself: How to incorporate an ultra-high bypass ratio turbofan engine -- either a geared direct drive system or an open rotor -- into the 747's classic airframe, augmented by a full stretch of the upper-deck. In Breguet-speak, this is about tugging as hard as possible on the thrust lever, at the expense of weight and aerodynamics.

Ultra-high bypass ratios are achieved by significantly enlarging the fan diameter, but that adds considerable weight and more drag. Perhaps to counter the effect, Boeing in this concept reduces the 747's traditional four engines to a twin-jet.

As the fan diameter increases, the 747's classic low-wing attachment to fuselage becomes impossible. So Boeing attaches the wings into the middle of the fuselage, then carves out space for a full payload within the wingbox structure. It's hard to imagine how this works in practice, but as a thought experiment it's an interesting idea.

FARNBOROUGH: Orders 'race' winners and losers (w/CHART)

Stephen Trimble

on July 13, 2012 11:28 AM | Permalink | Comments () | TrackBacks (0)

It wasn't a banner year for the Farnborough air show in terms of orders, by any means. But that's probably to be expected. After all, how many new orders can Airbus claim for a product -- the A320neo family -- that does not enter service until 2016 and is practically sold out with more than 1,430 firm orders in the backlog already? Boeing also insists it has no intention of participating in an admittedly media-contrived "orders race" during show-week. There are also the macro-economic issues, which include a perpetual European debt crisis, anemic US economic growth and a worrisome slowdown in China.

Not that there weren't some at least eyebrow-raising announcements during the show. Perhaps the biggest surprise was the largest US regional carrier, SkyWest Inc., announcing an agreement in principle to buy 100 Mitsubishi MRJs. Of course, an agreement in principle and £3.50 buys you only an exploitatively-priced paper cup of coffee at the Farnborough concessions. But the announcement still represents a major threat to Bombardier and Embraer, who have both aggressively pursued the SkyWest regional jet order for more than a year. Mitsubishi still has to convert that agreement into a firm order.

Likewise, Airbus still has a long way to go satisfy certain customers about its decision-making on the A350-1000 configuration, but announcing a firm order by Cathay Pacific for 10 new A350-1000s, plus another 16 converted from a previous order for A350-900s, relieves some of the pressure and may cause some sleepless nights in Seattle over the airframer's newly-adopted, patient approach to reaching a launch decision on the 777X.

Boeing continued its assault on the A320neo's commanding backlog lead over the 737 Max, but the single-aisle scoreboard still reads: Sidesticks 1,438, Centresticks 649. Perhaps more surprising was the relative silence on the 747-8. Boeing has talked up its performance with more than 20 aircraft in service, but that still hasn't translated into backlog results. Whatever the airframer's marketing philosophy regarding air show announcements, Farnborough was an opportunity to show the world the 747-8 had raised its game with a new order, but it was an opportunity missed.

Type	Model	Firm	Option	Commitments
A350
	A350-1000	10
A330
	A330-300	5
A320
	A320			28
	A321	20		8
	A320neo	5	8	15
	A321neo	9
B737
	Max 8	60		135
	Max 9	115		20
	NG800			35
	NG900ER	50
CSeries
	Q400	6
	CRJ900	6	5
	CS100			5
	CS300	10		20
Mitsubishi Regional Jet
	MRJ70 or MRJ90			100
ATR
	ATR 42-600	1
	ATR 72-600	12	1
Aircraft Industries (LET)
	L410			13

FARNBOROUGH: Video tour inside Qatar 787

Stephen Trimble

on July 12, 2012 4:42 AM | Permalink | Comments () | TrackBacks (0)

Some of our colleagues here at the show get all the fun assignments. See Graham Dunn, Airline Business managing editor, and head of web content Michael Targett explore the Qatar Airways 787 interior.

FARNBOROUGH: Ground support vehicle sparks minor 787 incident

Stephen Trimble

on July 11, 2012 1:05 PM | Permalink | Comments () | TrackBacks (0)

A fuel problem in a ground support vehicle for the Qatar Airways 787 caused a minor scare on the flightline this evening, Boeing says. Emergency crews and vehicles around 17:30 swarmed the brand-new widebody, which was parked near the East Apron just aside the Farnborough runway. Emergency crews were seen removing blackened items lying on the apron near the 787's forward airstair. Boeing confirms the fuel problem did not cause any damage to the 787. Qatar Airways expects to receive the aircraft shortly after it is flown back to Seattle on 13 July. The aircraft has flown a total of seven flights since rolling off the change incorporation line on 1 July, including three flying displays during this week's air show.

UPDATE: Air show organisers have confirmed a ground power unit servicing the 787 started smoking and caught fire, triggering the emergency response. It happens sometimes. Ground power units can overheat if they run out of fuel.

Recent Entries

March 2013

Categories

Recent Comments