Indigo – the Indian airline known to religiously adopt best low cost carrier practices, thanks to its founders who brought with them unequalled relevant airline experience, has taken yet another step to lower costs, and in part increase passenger comfort.
IndiGo flies one aircraft type- The A320-232, with some of the newer ones featuring fuel saving wingtip modifications known as ‘Sharklets’. As of date, the A320 can seat a maximum of 180 passengers in an all-economy cabin layout. With such a configuration, all seats, with the exception of those at row 1, 12 and 13-the later two being emergency exit row seats- feature a 29 inch seat pitch.
Of the 29 inches in seat pitch, around 4 inches may be subtracted due to the thickness of the seat, leaving an effective room of about 25 inches, or 2′ 1″. For an average Indian with a height of around 171cm and a Body Mass Index (BMI) of 24, this leaves between two to three inches between the knee and the seat pocket in front. Magazine thickness in the seat pocket affects how much ‘knee’ room is finally available.
With SpiceJet talking about its latest cabin product SpiceMAX, where the first five rows of most of its Boeing 737-800 & -900 aircraft feature a generous 35 inches of seat-pitch, or about 31 inches from the backrest to the seat pocket in front – or half a foot more than IndiGo’s offering, IndiGo may have felt threatened by its inability to match such a product for its passengers. The Flying Engineer learns that the airline has recently changed its passenger seats to the Dragonfly from SICMA Aero, which manufactures and sells aircraft seats under ZODIAC Aerospace group. The airline previously flew the model ‘5600’ seats from Weber seats – the company which in 2012 became Zodiac Seats U.S. LLC, which is now a subsidiary of Zodiac Aerospace of France, and is one of the largest manufacturers of airline seats in the world.
The new ‘Dragonfly’ seats offer a double advantage and a disadvantage.
The new seats are thinner, and lighter. Thinner seats free up more legroom. The seats offer between and inch and two of extra legroom. The lighter seats shave off 700kgs from the airline’s aircraft’s operating empty weight. 700kgs on a Bangalore-Delhi sector of 1000NM translates to a saving of about 50kgs of fuel per such flight. The savings are as low as 0.6% for a short (200NM), full flight, and 0.8% for a long (1000NM), full flight, and can touch 1% when load factors are lower. With savings between 10kg and 50kg of fuel, dependant on the flight, an assumed 20kg of saving per flight, on average, translates to a saving of 3.65 million kg of fuel per year, assuming 500 daily flights. This translates to INR 34 Crore per year, with an average fuel price of INR 74.69 per litre.
The disadvantage, as reported by a recent flyer on board IndiGo, is the discomfort associated with such seats. The manufacturer describes, “With its ergonomic stamped backrest, the Dragonfly offers tremendous operational savings, fewer parts and increased cabin density – all the while adapting to finicky passengers’ growing desire for improved living space”. However, comfort isn’t stressed upon as much as the 5600’s, and the thinner cushioning has been reported as relatively uncomfortable.
Further, unlike the model 5600, the Dragonfly seats may not be IFE capable.
The seats on board IndiGo’s A320s are 18 inches wide, inner armrest to inner armrest. Airbus offers customers an option of 17 inches seat width with a 25 inch wide aisle – a configuration designed for quick turnaround times, or 18 inches seat width and a 20 inch wide aisle – a configuration designed for enhanced passenger comfort.
To be fair, the seats on SpiceJet’s 737s – as are all 737s, world over- are only 17 inches wide. Barring the first five rows of ‘SpiceMAX’ seats, and seats on the emergency exit rows, most other seats on SpiceJet’s 737s feature a 29 inches seat pitch, which offer a passenger 25 inches from the backrest to the seat pocket, and 17 inches in seat width. IndiGo’s seats, however, offer one to two inch more legroom, and one inch more seat width, catering to the ever increasing population of those with above-normal BMIs. The new seats allow the airline to offer more space uniformly across the cabin, while saving money, too.
An eye on costs is what the airline is known for: the airline has a very strict fuel policy, wherein the airline, and not the captain, decides on how much extra fuel must be uplifted. This has been possible due to a strong analysis of historical fuel data. The airline also incurs a cost of between INR 4 and 5 for every kg of potable water that is uplifted. The capacity of the potable water tank is 200 litres, but the airline monitored water consumption for every sector, and now only fills between 40 litres and 120 litres, depending on the sector. As a result, the airline saves between INR 320 and INR 640 per sector. Assuming a very conservative saving of INR 300 per sector – the airline saves, over 500 flights a day and over a year, almost INR 5.5 Cr.
Savings – possible through constant innovation, quick adoption of fuel saving technologies, constant analysis, great strategies, and strict implementation.
This piece clears the air over a possibly misleading media report in Business Today (BT), “DGCA plans to shut doors on low fuel landings”. The DGCA is right.
Delhi International Airport Limited (DIAL) is known to witness severe fog in winter, which is responsible for a significant number of flight diversions. In the winter of 2011, there were 57 diversions, which steadily grew to 89 in 2012, and 143 in 2013: a 60% yearly growth over the last three years.
To address these now unacceptable number of diversions in winter, the DGCA setup a committee in January 2014 to study the ways in which Delhi may be made a “zero diversionary airport”. The committee concluded the study with a report that included 27 recommendations, one of which was not well understood. Recommendation number 13 states, “AIP shall be amended to indicate that the term fuel emergency would not be recognised at Indian aerodromes.” That recommendation is valid, but was misunderstood by a section of the media.
Further, the BT report stated “DGCA justifies move by saying that airlines are expected to carry at least 1.5 times more fuel than what it actually requires during a flight but they generally carry less fuel.” This too shall be clarified.
An airplane is always expected to land with an amount of fuel in the tanks that is above a minimum quantity commonly referred to as “final reserve fuel”. When in flight, if the fuel quantity in the tanks dips below the reserve fuel quantity, the airplane is deemed to be in an emergency. This reserve fuel is the fuel required to fly at 1,500ft above the destination airport, for 30 minutes. For the Boeing 737-800, at typical loads, this is around 1,200kg. Larger airplanes, which consume more fuel in 30 minutes, consequently have a larger weight of fuel as reserve.
Until recently, there was no recommended standard phraseology to be used when the flight crew determined that the aircraft will infringe upon its final fuel reserves before landing. There were two widely used phrases: “Minimum Fuel”, and “Emergency Fuel”. Minimum fuel is an advisory to Air Traffic Control that should there be further delay for landing, the airplane will start eating into the reserve fuel. “Emergency Fuel” was a declaration of emergency, that the airplane has started eating into the reserve fuel. However, the interpretation of this term has been varied, with the FAA recognizing it as “The point at which, in the judgment of the pilot-in-command, it is necessary to proceed directly to the airport of intended landing due to low fuel.” Low fuel does not necessarily mean the final reserve fuel, and is a very subjective quantity.
Unfortunately, a declaration of “Emergency Fuel” would require Air Traffic Control to award the airplane priority. Priority is defined as no further delay into getting the airplane to land. This was reportedly abused by some airlines, including India’s only consistently profitable airline, to ensure that the airplane lands without burning further fuel. That is money saved.
India is a member of the United Nations (UN). The International Civil Aviation Organisation (ICAO) is a UN Agency. ICAO works with member states, and industries and aviation organizations to develop international Standards and Recommended Practices (SARPs) which are then used by states when they develop their legally-binding national civil aviation regulations (CARs). The SARPs ensure uniform best practices, and safe, efficient , and secure flights through commonly understood standards.
Effective 15th November 2012, ICAO has amended ICAO Annex 6 Part I, to include:
“The pilot-in-command shall advise ATC of a minimum fuel state by declaring MINIMUM FUEL when, having committed to land at a specific aerodrome, the pilot calculates that any change to the existing clearance to that aerodrome may result in landing with less than planned final reserve fuel.”
“The pilot-in-command shall declare a situation of fuel emergency by broadcasting MAYDAY, MAYDAY, MAYDAY,FUEL, when the calculated usable fuel predicted to be available upon landing at the nearest aerodrome where a safe landing can be made is less than the planned final reserve fuel.”
As a result, henceforth, ’Fuel Emergency’ or ‘fuel priority’ are not recognised terms. India not recognizing these two terms only aligns the country with ICAO standards, helping the country get out of safety audit downgrades.
Further, “Minimum Fuel” is only an advice to ATC, requiring no action by ATC, but “ MAYDAY, MAYDAY, MAYDAY,FUEL” is a declaration of an emergency, in which the ATC must assist the airplane in landing as soon as possible.
DGCA, in its Civil Aviation Regulation (CAR) that covers “Operation of Commercial Air Transport Aeroplanes”, states:
“A flight shall not be commenced unless, taking into account both the meteorological conditions and any delays that are expected in flight, the aeroplane carries sufficient fuel and oil to ensure that it can safely complete the flight. In addition, a reserve shall be carried to provide for contingencies.”
In accordance with the CAR, the airplane must at minimum carry the following fuel, for a flight from Bangalore to Delhi (1000NM), with 180 passengers on a Boeing 737-800W, with an assumption of no cargo. Quantities are derived from the airplane flight manuals and typical airline practices.
The fuel required to taxi from the gate to the runway.
The required fuel quantity from initiating take-off to the landing at the destination airport.
Typically 5% of the Trip fuel, but can be as high as 10%. caters to unforeseen circumstances or prediction errors.
The fuel required to execute a missed approach at Delhi and fly to an alternate airport (Jaipur in this case), in case landing at Delhi is not possible, due to issues like visibility.
Final Reserve Fuel
The final reserve fuel is the minimum fuel required to fly for 30 minutes at 1,500 feet above the alternate airport.
Based on statistically derived data at the airline, and also at the discretion of the Captain (based on his judgement and reports of a congested airport, or bad weather, or the like.) Assumed Zero for this example.
The sum of the fuels 1 – 6, which must be uplifted at the departure airport.
If the flight goes as planned, the aircraft should consume only the trip fuel, which amounts to 6,000kg. But the aircraft is filled with 9,000 kg of fuel, which is 1.5 times that of the trip fuel.
One of longest domestic flights into Delhi is from Bangalore, the others being from Chennai and Cochin. As flights get longer, the total fuel will fall below 1.5 times the trip fuel. As flights get shorter, the total fuel will amount to greater than 1.5 times the trip fuel. Since the Bangalore – Delhi flight is one of the longest domestic flights into Delhi, BT’s “DGCA officials” were not off the mark with a ballpark 1.5 figure, but that is a number that is written nowhere, must never be used for planning, and should not have been quoted in the first place. The Mumbai-Delhi sector (which is shorter) will consume only 4,000kg of fuel, but will need to legally carry a minimum of 6,900kg of fuel, which is 1.7 times the trip fuel.
1. The DGCA’s recommendation is not “highly controversial”, as reported by BT. The ambiguous term “fuel emergency” is not recognized and is replaced by standard phraseologies as described above. Flight safety is not compromised but rather improved.
2. DGCA cannot “shut doors” on low fuel landings, as reported. That means you can’t land if you’re low on fuel. What DGCA is doing is to ensure certain standard terminologies are used, doing away with old ones.
2. The laws are not ” draconian”, but progressive to keep up with ICAO standards.
3. A “1.5” figure is not justified, as it depends on many factors. However, if the DGCA official used it to throw a ball park ratio, he’s not off the mark. But later in the BT article is probably a typo which is misleading, “expected to carry at least 1.5 times more fuel“. It must read 1.5 times the trip fuel.
Edit: Added Cochin & Chennai to Delhi as other long flights into Delhi. Thanks to Cyril.
Airbus’ first A320NEO, MSN 6101 (A320-271N) has entered the final assembly line (FAL) at Toulouse, marking yet another milestone in the A320NEO program. The forward fuselage, which arrived from St. Nazaire in France, and the aft fuselage, which arrived from Hamburg in Germany, were mated at the FAL, marking the start of the final assembly.
The next stage is the joining of the wing to the fuselage. Overall, it takes about one month to complete the final assembly of an A320 Family aircraft.
The A320 program crossed a major milestone in November 2013, when the assembly of the first major component- the engine pylon- took place.
First flight is expected in the Autumn of 2014, almost 4 years after the program was launched in December 2010. Airbus took the landmark decision of re-engining the A320 Family after sensing imminent competition from Bombardier’s C-Series airplanes.
Airbus will retain 95% airframe commonality with the present A320, offering the benefit of high dispatch reliability associated with a mature airframe. Airbus has also effected incremental changes to its traditional Airbus A320, thereby eliminating the risks associated with too many modifications in one shot.
In the November of 2011, Airbus flew the first A320 with the version of the sharklets that are now seen on all new production Airbus A320 airplanes, first sharklet-equipped A320 being MSN 5428 delivered in December 2012. The sharklets, which will feature on the A320NEO as well, introduce fuel savings of upto 4% on long flights. Preliminary wing strengthening to handle the aerodynamic loads introduced by the sharklets, and airplane-wide weight reduction to offset the weight due to the strengthening have already been effected.
NEO’s difference from today’s in-production A320 aircraft is the further strengthening of the wing and fuselage to handle the loads associated with the heavier and larger New Engine Option (NEO): The Pratt and Whitney PW1100G and the CFM LEAP-1A. The new more efficient engine together with the sharklets realize a 15% fuel savings on 800nm route lengths, and up to 16%+ on the longer routes, compared to non-sharklet fitted Airbus A320 aircraft.
The Pratt and Whitney Geared Turbofan Engine PW1100G series for the A320, took to the skies in May 2013, on a Pratt and Whitney Boeing 747SP flying test bed.
Changes to the A320 are minimal and the least among other airplanes which are being re-engined and modified to a larger extent, such as the Boeing 737MAX and the Embraer Second Generation E-Jets E2. Historically, all new airplane programs have been met with significant dispatch reliability issues related to technical or maintenance issues associated with an immature airframe. The A320NEO program has the least changes, followed by the MAX and E2 program. The all-new Bombardier C-Series introduces many firsts for Bombardier, making it the program that may likely have the most number of issues, initially atleast: a reason which explains the low number of firm orders: 201, despite having 3 flying airplanes in the test campaign.
In contrast, the Embraer E-Jet E2 program, which airplanes are still “paper” (conceptual), has 200 firm orders. The Boeing 737MAX has 1,807 firm orders and the Airbus A320NEO program has firm orders for 2,667 airplanes.
Least changes with benefits where it matters to an already proven and mature airframe, incremental modifications, early introduction into service (Q4 2015), a dual engine source (all other new/re-engine programs have only one engine supplier), keeping up program development schedule, and the smallest training impact have contributed in large to the sales success of the program.
IndiGo has an order for 180 Airbus A320NEO Family aircraft, which include the A320NEO and A321 NEO. Go Air has 72 airplanes on order, and Air Asia 264 A320NEOs on order. Both IndiGo and GoAir’s A320NEOs will be powered by the Pratt & Whitney PW1100G. IndiGo operates the IAE engines, of which Pratt and Whitney is a part. Go Air which flies CFM powered A320 aircraft, has switched engine suppliers, to Pratt and Whitney. The PW1100G engines offer two advantages: Room for growth, and availability sooner than the CFM LEAP-1A Engines. Air Asia, which flies CFM powered A320s, has opted for the CFM LEAP-1A to power its NEOs.
On August 20, 2007, a Boeing 737-800 registered B18616 (Boeing MSN 30175) operating as China Airlines Flight 120 departed from Taiwan, Taoyuan International Airport on a scheduled flight to Naha Airport, Okinawa, Japan. The aircraft caught fire, and exploded after taxiing and parking at the gate at Naha Airport.
While initially it appeared as a freak case of a spontaneous Boeing 737NG’s combustion, investigation has reveled the true cause of the incident which is very, very interesting. While there can be a textual description of the findings, it is best explained through this very clear animation, and will be best appreciated by maintenance engineers and technicians. Not a single screw, or washer must be left behind. After all, the manufacturer spends years researching and bettering the airplane, and the combined experience that goes into designing the airplane far outweighs the combined experience of all technical staff in any single airline.
Air Berlin’s focus on reducing its carbon footprint, and its fuel bills, is inspirational. Airberlin, despite having achieved a new record with its average fuel consumption of 3.4 liters per passenger kilometer flown, is continuing to extend its pioneering role through constant innovative developments. It has so far had three approaches to reducing fuel bills: through operational techniques, which involves pilots; through drag reduction techniques, which involves maintenance of the aircraft skin paint, and now through weight reduction programs. Weight, Drag, and Flying techniques: all three impact fuel burn.
In 2012, the Fuel Efficiency Training program was introduced in which 60 pilots served as “Fuel Coaches" to pass on their knowledge to around 280 pilots, on “Fuel Efficiency Flights". These flights placed emphasis on the use of the GPU instead of the APU, when parked at the gate; Continuous Descent Approaches, and Single Engine Taxi. These save not only fuel, but cut maintenance related bills due to reduced system wear.
Airberlin also became the first airline to develop new software for aerodynamic optimization, using a in-house developed measuring tool aimed at optimizing air flow over the aircraft exterior. This new software calculates the additional fuel consumption due to the increased air resistance and allows Airberlin to repair these specific flaws in the course of the next maintenance event.
In its latest drive, “Mission Clear Out", Air Berlin removed all non-fixed items from an Airbus A330: D-ALPC, to weigh and identify those that were essential, non-essential, and those that could be replaced with something lighter. For example, the Quick Reference handbook is essential, but a hard copy of the manual does not need to be carried since it is already available in digital form on the computer in the cockpit.
With this exercise, Air Berlin was able to save 17kg, which, over a year, translates to significant savings. The longest route flown by Air Berlin is to Los Angeles, from Berlin, which is around 5,000NM. An Airbus A330-200 burns, over this distance, approximately 200kg of fuel for every 1000kg of additional load. If even 17kg is knocked off an airplane, it translates to a saving of 3.5kg per aircraft, and at least 7 kg per aircraft per day. Over a year, this amounts to 2,555kg per aircraft per year, or 3,200 litres per aircraft per year. With their fleet of 14 A330-200 (as of 30th of June 2013), this can result in a saving of as much as 44,712 liters of ATF per year, and this is huge: enough to fuel an A330 for a 4,000NM trip!
“This project has demonstrated that Airberlin is already very well positioned in terms of eco-efficient flying, since only a few items were found that were non-essential. Nonetheless, the expense has paid dividends and reduced annual CO2 emissions per aircraft on long-haul routes by about eight tonnes, which is equivalent to 2.5 tonnes of fuel," said Christian Bodemann, Head of Cabin Maintenance at Airberlin technik and the project manager of Clear Out.
The mission has had a further positive outcome: during the detailed analysis carried out on the aircraft’s non-fixed furnishings, it was possible to identify several follow-on projects, which Airberlin will now continue to pursue as part of its efficiency drive.
Recently, Airberlin received the “Silver Eco-Airline of the Year" award, given as part of the Eco-Aviation awards, by the American aviation magazine Air Transport World, in recognition of its commitment in the area of eco-efficiency.
What makes an airline like Air Berlin stand out from the crowd? Innovation.
Air Berlin, based at Berlin, Germany, has always been a the forefront of implementing technology that has a business case. In May 2001 Air Berlin was the world’s first airline to take delivery of a Boeing 737-800 retrofitted with the Aviation Partners Incorporated (API) blended, fuel-saving winglets. Early 2013, Air Berlin received one of the first Airbus A320 equipped with fuel-saving sharklets at the Airbus factory in Hamburg. This airline, the second largest in Germany, will become one of the world’s first airlines to install an Electric Taxi system from WheelTug upon the latter’s certification, resulting in savings of over 80% fuel savings on ground. The largest shareholder in this tech-savvy company is Ethiad.
On 8th October, 2013, Air Berlin joined the ranks of none other, proclaiming itself to be the first airline to develop new software for aerodynamic optimisation. The tool is aimed at optimising airflow, with apparently no such software having hit the market, before.
Small blemishes, rough paintwork or even a one millimetre gap between the landing gear doors: any small irregularity on the surface of the aircraft affects its aerodynamics and leads to greater air resistance, which in turn means higher fuel consumption. This tool guides aircraft technicians through a standardised procedure, inspecting the entire surface of the aircraft and helping them measure and classify any imperfections. The software also calculates how much additional fuel consumption will result from that increased air resistance. It then generates a list of priorities for the maintenance schedule of each individual aircraft, so the areas concerned can be made good during subsequent maintenance.
According to Air Berlin, the additional fuel consumed in the course of a year due to the loss of paint from an area of 150 by 50 centimetres is sufficient for two 250NM flights from Berlin to Dusseldorf. The additional fuel consumed in the course of a year due to a slightly projecting seal on the movable doors for landing gear is sufficient for a 150NM flight from Nuremberg to Dresden. This tool will allow Airberlin to save that fuel in future.
Airberlin has used the new software to measure the surface irregularities on 15 of its 91 strong aircraft fleet. This inspection will gradually be extended to the entire fleet and will then be repeated periodically.
“In 2012 we set a record of just 3.4 litres of fuel per 100 passenger kilometres flown. But we are still not satisfied and we are constantly working on further potential ways of saving fuel. This new tool is another step towards our goal, which is the three-litre mark", says Felix Genze, airberlin’s Vice President Performance Improvement.
Indigo just became India’s first airline to operate a sharklet-equipped A320, with its VT-IFH registered Airbus A320 that it took delivery of, on 28th January, 2013. VT-IFH bears manufacturer serial number (MSN) 5437, and first took to the skies on the 15th of January, 2013, and herald a new chapter for Indigo with an operationally more economical airplane, that has the potential of saving the airline in excess of US$400,000 per year, per aircraft.
All future A320 aircraft to be delivered to IndiGo shall be fitted with the Sharklet wing tip devices.
This aircraft will be the 75th A320 that the airline has taken delivery of. Of the 75, 14 no longer fly for Indigo. Indigo sells every aircraft that it takes deliver of, leasing the airplane back from the lessor. The lease period is typically for six years: sufficient time for Indigo to make the most of a new airplane’s reliability and performance, while avoiding an expensive “D” check. Those that flew for Indigo, for the first six years of their life, now fly for Ethiad, SAS, BH Air, Myanmar Airways International, Kibris Turk Hava Yollari Charters, and Turkish Airlines.
MSN 5460 is the next sharklet equipped A320 slated to join the Indigo fleet as VT-IFI, while VT-INK will be the next A320 to leave the Indigo fleet.
Go Air will be the next Indian airline to receive Airbus A320 aircraft fitted with sharklets.
Air Asia recently received the world’s first “Sharklet”-equipped A320 for commercial operations. Indigo and Go air will very soon have VT-IFH and VT-GOL flying in the Indian skies; both equipped with “sharklets”. Ever wanted to know more about these “Sharklets” that are grabbing headlines today?
Here is a comprehensive article on Winglets, or what Airbus prefers to call them: “Sharklets”, which are “Hunting down fuel burn“.