Scimitar split: a new generation of winglets.

Image: Southwest Airlines.

The search for improved aerodynamics that maximise lift, and minimise its ugly sister drag, is as old as powered flight. Winglets provide a very effective way of reducing one of the biggest contributors to drag on an aircraft the vortex drag from the wingtips. And there’s a new tip in town – Scimitar.

Why winglets?

Aerodynamics 101 says that the pressure imbalance – high pressure below the wing, low above – creates a problem at the wing tips. The high pressure air below spills over the end of wingtip into the low pressure air above. This is most pronounced at the wingtips. The wing’s forward motion spins this upward spill of air into a long spiral, that trails behind as wing tip vortices or vortex drag.

Winglets reduce the aircraft’s drag by partial recovery of the energy that is lost to vortices. They smooth the flow of high pressure air, reducing its spill to the top of the wing. The Smithsonian Air & Space magazine has a brief, but excellent history of the winglet.

Boeing’s sleek blended winglets on the 737 deliver a a better climb to cruise that eliminated the need to step climb at full payload; steeper climb rates; derated takeoff and climb thrust settings; and, they reduce fuel burn by approximately 3.5 to 4 per cent on 737s.

They also add another efficiency dimension: reducing interference drag. The smooth curve instead of a sharp interior angle as on the A330 or 747 reduces interaction of the boundary layer – smooth air attached to the wing - at the wing/winglet junction which if disrupted causes vortexes.

Enter the scimitar.

First seen on the MD-11, the new 737 scimitar or feathered winglet is a more pronounced design that will deliver a further 2 per cent reduction in fuel burn.

Shaped slightly differently to Boeing’s patent design on the 737 MAX, Aviation Partners Boeing new winglets increase the -800’s wingspan about 15cm, with the lower ventral strake adding approximately one metre (three feet) below the wing. A bigger increase in span delivers a further increase in aspect ratio without materially increasing the wingspan, the extra wingspan lowering lift-induced drag.

The new winglet balances this increase in effective span between the upper and lower parts. It  makes the system more efficient without adding more weight.

On the ground.

Airline research has also shown winglets also have a known psychological impact on customers who believe they makes the aircraft seem bigger, more technologically advanced and reliable.

The downward strake is more vulnerable to damage, requiring increased training, with United writing “scimitar” on the nose of its 737s to alert ground crew. This presents a new risk, but its one that doesn’t phase United Airlines Fleet Vice President Ron Baur “the fuel saving is so great, we’ll take that risk.”

Image: United Airlines.

Bold and beautiful in monochrome.

Air New Zealand’s first Boeing 787-9 registered ZK-NZE. Image: Boeing/Air New Zealand.

ANA retires the B747.

Yesterday ANA ended 35 years of continuous B747 operations, Boeing 747-400D JA8961 operating the final service from Okinawa’s Naha Airport to Tokyo-Haneda where it greased the tarmac for the last time at 15:13 local time.

It also marks the end of passenger 747 operations in Japan, during which ANA and JAL operated every variant of the B747 produced including the -SR and -400D produced specifically to service the high density Japanese market. The 747′s capacity and reliability created a unique niche facilitated by the growing Japanese economy and tourism during the 80s and 90s.

I thought it was a wonderful aircraft. There is no comparison” – ANA’s CEO, Osamu Shinobe.

Farewell to the Lockheed L-1011 TriStar

Squadron 216′s last two Tristars taxi out on their final sortie at RAF Brize Norton. Image: Allan Huse.

As aviation continues its twin engine march, yesterday marked the end of an era for another Trijet with the RAF formally retiring its final two L-1011-500 series TriStars after 30 years of service.

Departing RAF Brize Norton  for a refuelling sortie over the North Sea before one aircraft conducted ceremonial fly pasts to mark the disbandment of the RAF’s 216 Squadron, formed in 1917 and in operation continuously for 97 years. Only 250 TriStars were manufactured by Lockheed, with the nine L1011s that saw service with 216 Squadron previously operated by British Airways and Pan Am joining the RAF in 1984.

Lockheed L-1011 TriStar prototype during its first flight on November 16, 1970. Image: Air Pictorial magazine, January 1971.

The TriStar began as a request from American Airlines for a widebody aircraft that was smaller than the 747, but offered equivalent range and capacity to the recently retired DC-10. The TriStar was a technical marvel in many areas incorporating aerodynamic, avionics, engine technology and a cabin design that surpassed the market offerings of Boeing and McDonnell Douglas.

Mounted into the rear fuselage, the middle engine was fed by an S-duct (similar to the B727) rather than adopting the DC-10′s separated vertical stabiliser mounted engine. The design reduced airframe drag and improved stability.

In the cockpit the L1011 pioneered a number of important technological advances, being the first widebody to incorporate:

  • an Inertial Navigation System which aligned the aircraft’s navigation system using current latitude and longitude;
  • an advanced autopilot system with truly independent autoland capability, fully certified to FAA CAT-IIIC zero visibility conditions;
  • automated descent control or Direct Lift Control (DLC), allowing the aircraft to maintain a consistent pitch without the need for pilot input by using four redundant hydraulic systems to automatically deploy spoiler panels to maintain the selected angle.

The sole engine choice was Rolls Royce’s groundbreaking triple-spool RB211 turbofans offering an unprecedented advance in engine technology. It was the first engine to incorporate carbon-fibre fan blades that delivered fuel efficiency and a power-to-weight ratio better than any competing design. Ironically the turbofan that launched RR into a global leader in aircraft engines was also the L1011′s downfall – design issues delayed the engines entry into service (EIS) by two years to 1972. The delay gave GE an advantage, it delivered its higher-thrust CF6 engine facilitating an earlier EIS of the intercontinental DC-10-30, highlighting the inherent inflexibilities in the L1011 design, which also suffered from a higher than expected MTOW and centre of gravity issues limiting its payload.

Image: Allan Huse

Teething issues overcome, the L1011 demonstrated reliability and redundancy in an era of that saw an increasing number of challenging aircraft accidents. Eastern, and later Delta were the largest US operators, while Cathay Pacific operated the largest L1011 fleet outside the US with 21 aircraft flying across its pan-Asian network.

But Lockheed needed to sell 500 aircraft to break-even. Great engineering wasn’t enough to save it from dwindling orders and a failed attempt by Jimmy Carter to sell production licensing Soviets. L1011 production ended prematurely in 1984. A victim of poor product differentiation and Rolls Royce.

#AvGenY: Aviation’s next generation

For years Australia’s aviation industry, indeed the industry worldwide, has tepidly danced around the issue of what to do about the falling number of young people attracted to aviation. It’s not a new issue. But it’s an issue following a repetitive script, with an incomprehensible lack of engagement of the young people walking away to more lucrative careers in other industries.

For an industry that prides itself on innovation and renewal, why are the hangar doors so firmly closed to young people?

My new #AvGenY series launched in March Australian Aviation is about bringing recognition to this incredibly important issue – written from a young perspective. It’s an issue that has been revisited again and again, but never by anyone young – at least that I’ve come across. Every time it’s by a generation seemingly disconnected from the next, believing they know better, but delivering the same conclusions.

I’m part of a generation that is full of ideas, and I believe there’s an amazing opportunity to develop a conversation incorporating as many of these as I can.

The industry is flying through promising times. If it is to grow at the levels IATA and ICAO predict there needs to be serious debate and recognition of the people who will carry it forward.

As the series progresses we want to hear from you by commenting here, on Facebook or Twitter using #AvGenY.

  • What makes it hard to enter the industry?
  • Can we encourage a change in thinking?
  • Do you think young talent is recognised?
  • Is help readily available?
  • Would age quotas help?
  • What role can social media play to attract you?



9M-MRO captured at Singapore. Photo: wikicommons.

*this post will continue to be updated as official information is released.

Latest update Sunday, March 9 AEST18:00.

SAR operation continues across the Gulf of Thailand and the South China Sea in an unprecedented operation involving the deployment of 22 aircraft and 40 ships from six countries. Today, Malaysia’s DCA also confirmed there is no reason to ground the country’s Boeing 777-200 fleet following the disappearance of the aircraft yesterday.

Latest update at AEST18:25.

Malaysia’s Defence Minister and deputy Transport Minister have confirmed that multiple SAR assets have been deployed in search of missing aircraft 9M-MRO. The assets include Malaysian Navy ships, ships from other Vietnam and China, as well as a Malaysian Air Force Lockheed Martin C-130 and Airbus EC725 helicopters - equipped for combat SAR with electro optical/infrared sensors.

Original post. Latest update at AEST16:25.
There has been a considerable amount of unverified speculation driven by Twitter this morning generating a myriad of conflicting  reports on the whereabouts of Malaysian Airlines flight MH370 that disappeared from radar while operating MH370 from Kuala Lumpur (KUL/WMKK) to Beijing (PEK/ZBAA).

The aircraft remains missing and there is no official confirmation that the aircraft has crashed.

Malaysian and Malaysian Airline Systems (MAS) officials as well as China’s Civil Aviation Authority and Chinese state media agency Xinhua have now confirmed that  the aircraft has disappeared enroute and that a coordinated search and rescue (SAR) operation has been launched by China, Malaysia, and Vietnam. The aircraft was due to land in Beijing at 06:30 local.

The Boeing 777-200ER registered 9M-MRO departed with 227 passengers and 12 crew members at 12:41am, disappearing from radar around 02:40 while transiting Subang Air Traffic Control in Malaysia at approximately 35,000 feet, 30 minutes after departure from Kuala Lumpur International Airport.

Airspace over the Gulf of Thailand/South China Sea where 9M-MRO went missing, and which is now the focus of an ongoing SAR operation.

There is now confirmation that the last point of contact of MH370 was 120 nautical miles off Kota Bharu over the South China Sea near a waypoint named BITOD. Vietnam and China have now deployed SAR ships toward the area.

The aircraft did not transmit a distress signal, and no flight plan would be available unless it is officially released by MAS or authorities through whose airspace jurisdictions MH370 would pass.

There are unconfirmed reports the aircraft made contact with Vietnamese ATC and that the aircraft was identified Vietnamese radar before it disappeared. Civil Aviation Authority Vietnam Flight Control Department manager Bui Van Vo said the aircraft failed to check-in at GMT17:21 “it’s code didn’t appear in our system”. Vietnam’s ADS-B coverage is known to be excellent along the country’s eastern seaboard; further, the majority of airports throughout SE Asia have primary radar coverage from 50-100 nautical miles, so a radar return would only appear if the aircraft was in range of the radar head.

The captain has logged 18,365 flying hours after starting with the airline 1981, the first officer has logged 2,763 hours having joined the airline in 2007. According to aviation reference databases 9M-MRO was built in 2002 and is powered by Rolls-Royce Trent 800 engines.

Boeing and the NTSB continue to monitor the situation and have yet to provide official statements.

Those who may have relatives travelling on this service are advised to call Malaysian Airlines on +603 7884 1234.

RAAF Centenary Airshow

Got my #avgeek on last weekend at the RAAF’s Centenary Airshow, and thought I’d share some photos of the incredible flying programme and static display that celebrated a centenary of military aviation in Australia. The airshow was held to mark the anniversary of the first Australian military aviation flight undertaken by Lt Eric Hudson of the Central Flying School who took off in a Bristol Boxkite on March 1, 1914.

1H/FY14 Results Day 2: Qantas transforms.

This is a post that will be updated throughout the day as information develops.

The Qantas Group has announced a record half-year PBT loss of $252 million broken down as follows:

  • Domestic a $57 million profit
  • International $262 million loss
  • Loyalty – a record $146 million profit
  • Freight $11 million profit
  • Jetstar Group airlines a $16 million loss
There will be a reduction in headcount of 5,000 staff approximately 16% of the workforce – equivalent to the reductions American Airlines and British Airways made in their transformations.
Qantas will return and lease back its Brisbane terminal resulting in a net gain of $112 million for the business.

There will be a reduction in domestic capacity with A330s redeployed to international services to accelerate B747-400 retiement.

Brisbane and Sydney-Singapore services will be downgraded to A330 aircraft. Melbourne – London services will be permanently re-timed.

B767 retirement will be accelerated with the fleet to be retired by the second half of FY15.

While Jetstar experienced a 2 per cent improvement in unit costs, Jetstar Asia has experienced significant yield, as well as fuel price and foreign exchange pressure in its Asian operations. Growth across its Asian operations will be frozen and the current A320 order book will be renegotiated with Airbus.

The last three of 14 Boeing 787-8 orders for Jetstar will be deferred.

1H/FY14 Results Day 1: REX and Sydney Airport.

REX Regional Express

First cab off the rank, and in line with its guidance released earlier in February REX has issued a Profit Before Tax for the six-months to December 31 of AUD$5 million – a 60 per cent decline on 1H FY2013.

Announcing the results in a report entitled “aviation is crisis”, COO Gary Filmer says “the Abbott government needs to take immediate steps to fulfil their election promises to regional aviation outlined in the Coalition’s Policy for Aviation before the irreversible collapse of regional aviation occurs.” Filmer also made it clear that any Federal Government debt guarantee extended to Qantas should be available to the regional airline.

REX attributes its weak performance to the “continuing weak Australian economy”. The airline saw revenue decline 5 per cent to $130.1 million dollars on a load factor decline of 2.7 per cent to an average 54.1 per cent.

REX’s passenger Cost/ASK increased by 0.5 per cent, with the airline also experiencing an increase in the proportion of total cost attributed to fuel. However, overall the airline’s cost control programme saw a decline in total cost by $200,000 to $ 103.1 million.

Sydney Airport

Sydney Airport today released its 2013 full year results to December 31, announcing a Profit Before Tax of $126 million on the back of a small increase in revenue to $1.139 billion.

Aeronautical revenue grew delivering 49 per cent or $548 million of total revenue after a 4.1 per cent increase in international passengers drove capacity additions by more than half of the 36 international airlines serving Sydney. Retail revenue was also strong, following increases in retail space in T1 and T2.

The airport reiterated its potential to handle capacity growth and its ongoing airport investment programme as the airport fights an impending, but again delayed decision, on a second Sydney Airport.

Now we all wait with baited breath for Air New Zealand’s expected profit and Qantas’ half-year catastrophe. Friday it’s Virgin Australia’s turn. In the meantime here is a reminder of last year’s full year performance.

ETOPS in action: Perth – Mauritius

I thought a recent flight from Perth to Mauritius provided a great basis to highlight the impact of ETOPS restrictions on airline operations in the Southern Hemisphere.

There is no trans-polar or oceanic route in the Northern Hemisphere that requires more than ETOPS 240 approval (four hours from flying time from a suitable airfield), and more than 90% of routes require no more than ETOPS 180.

ETOPS speed schedules are designed assuming a MTOW at departure with highest gross weight and enroute weather conditions at critical points enroute determining diversion speed and endurance. Speeds vary by operator, and other factors including carriage of additional passenger oxygen allowing operations at an intermediate level above FL140 are also taken into account.

Down south ETOPS restrictions have arguably a much greater operational impact as this Perth – Mauritius sector highlights.

Air Mauritius’ previous A340 operation to Australia tracked along a flight path relatively close to the great circle routing (see map below). Now operated by its A330-200 fleet – approved for ETOPS 180 (for arguments sake roughly 1,000nm) – the aircraft must track significantly to the north of the great circle route. Flying north-west after departing Perth to remain within diversion flying time of Learmonth, the Cocos Islands and then Diego Garcia, before tracking to the south-west for Mauritius.

The result is a longer flight time – the previous 8:30 minute block time westbound, is now an 8:30 minute flight time – approximately 45 minutes to one hour longer airborne.

The associated impact on flight economics is substantial as Virgin Australia learnt the hard way in its brief foray into Boeing 777-300ER operations between Melbourne and Johannesburg. To remain with ETOPS 180 restrictions the 777 operated a more northerly, inefficient routing – maps of westbound and eastbound flights – resulting in a flight time 1:15 longer than Qantas’ 14 hour Sydney – Johannesburg service.

The lightest grey shade on the map indicates ETOPS 180 limits. If Air Mauritius were to gain approval for ETOPS 207 or even 240 it would allow a more efficient southerly routing. But would you really be comfortable knowing you are that far from land on the off chance your Royce stops Rolling?




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