Enter the twin-aisle narrowbody

A320 cabin - Muller.JPG

Airbus and Boeing remain under pressure from airlines to define their narrowbody replacement plans. But with strong backlogs for the Airbus A320 and Boeing 737, neither airframer appears too terribly worried about would-be successors. Instead they have been developing their current programmes to improve efficiency. Airbus may even opt to re-engine the A320.

That is all fine and dandy but what about the cabin? With narrowbody replacement appearing to be pushed out beyond the next decade, doesn’t the six-abreast cabin deserve a revamp too? (Sorry Boeing, the new ‘Sky Interior’ for the 737 is sweet but it is far from game-changing).

Might there be a way for current A320/737 operators to improve ground rotation capability (a major concern), satisfy passengers (by providing more comfort) and make in-flight service easier?

One chap with a possible answer is Morten Müller, an aircraft engineer who says he is a former member of the Airbus sales squad.

Müller has developed a cabin concept that would turn your average A320 or 737 into something decidedly more appealing than the traditional single-aisle (3+3) layout and yes, as the headline suggests, it involves a twin-aisle configuration.

In a paper prepared for the Crystal Cabin Awards Competition held at the Hamburg Aircraft Interiors Expo in April, Müller made the following argument for his design:

“Iconoclastic perhaps, but not exaggerated, A320/737 six-abreast single-aisle (3+3) cabins are user-unfriendly; unattractive to passengers; dreaded by cabin attendants; [and] a pain-in-the-neck to cabin cleaners!

“Quoting [former SAS Group chief executive] Jan Carlzon (“Moments of Truth”, 1985) : ‘How would I explain to our passengers that SAS shall invest hundreds of millions in the purchase of new 737 or A320 aircraft, if the only new feature is a line down the full length of the cabin only with middle seats in a triple, where nobody wants to sit?’

“Use the A320 trim-to-trim 146.4″ cabin width to install something closer to Jan Carlzon’s (2+2+2) “Passenger Pleasing Plane”, e.g. five-abreast twin aisle HP3 (1+2+2) or HQR (1+3+1) seating? Amazingly, it works! (“QuickRotation” HQR (1+3+1) cabins may also be fitted in the 737).”

The picture directly above and below shows the A320 in (1+2+2) configuration, while the cross-section (far bottom of blog) shows the 737 (1+3+1) concept.

A320 five-abreast.JPG
Quite obviously, in order to accomplish either new arrangement, a carrier would have to sacrifice some capacity (something the likes of Spring Airlines and Ryanair, which claim to be seriously studying stand-up seats, probably wouldn’t get excited about).

But it would allow carriers that care todifferentiate their product (yes, there are still some out there!) todo so in an innovative, crowd-pleasing way while waiting until 2020or beyond for next-gen narrowbodies.

“Ticket yield leveraging is powerful: customers are informed, educated, selective; they will check, compare and vote, with assurance and autonomy, for the best product [and] making profit will be easier with [these designs],” says Müller.

That’s a BIG claim. But I wonder if Müller isn’t onto something here.

As a matter of interest, ILFC in 2008 notably advocated the development of twin-aisle narrowbody aircraft with seven-abreast seating (let’s not talk about what ILFC might be advocating right now, ahem).

But has the time come to really do something about the interior of current-generation narrowbodies?

737 cross section proposal.JPG

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29 Responses to Enter the twin-aisle narrowbody

  1. KDR December 23, 2009 at 9:44 am #

    New and Great ideas should never be shot down. They are the backbone of a changing industry. However at times we have to take a realistic view of things. The thought of making a narrow body airplane more passenger and cabin cleaner friendly is great (especially for people at well over 100K miles per year in the back, like me). This is not the case in real airline life. They don’t care about cabin cleaning or the happiness of passengers. They care about fuel burn and weight. Take the idea of a 2-2-2 configuration, same pax as in a standard 3-3. The draw backs are as follows; 8-12 lbs per row of seats because your adding an extra set of seat legs for each row, more seat track in the floor, more seat to seat cabling for IFE, Etc.. and more floor beams with which to attach everything. Thus a minimum of 500lbs (being conservative) of weight added to the aircraft. No one in todays market will carry the extra weight just to make it easier for passengers and cleaning crew. Don’t get me wrong. Sign me up I would love to fly on a twin isle narrow body. Easy in easy out.

  2. Wandering Aramean December 23, 2009 at 11:33 am #

    Of course it fits physically. Giving up one seat in exchange for an aisle is an easy thing to do.

    But any airline looking to cut 16% of its capacity is going to do it by increasing legroom rather than adding a second aisle on a narrow-body plane. Extra pitch sells quite well.

  3. Uwe December 23, 2009 at 4:05 pm #

    inflight entertainment will now include
    service trolley races.

    Ryan Air will have “Bookie Pursers” for
    taking the passengers betts and
    some added revenue for the carrier.

    MOL will be happy to announce that betting
    revenue compensates the losses induced via
    reduced seatcount nicely.

    Air India reports …

  4. Blue Cloud December 23, 2009 at 4:33 pm #

    I believe the new 737 will be completely new from the ground up and of maximum composite construction. It will be a larger diameter with double isles and a main cabin 2-3-2 seat configuration.

    The design will incorporate all of the experience gained from the 787.

    A new plant will be built to better accommodate the new construction requirements while maintaining the current Renton Washington plant operational as long as there is demand for the current style. There could be an overlap of several years.

    My guess is that Boeing will try to deliver the plane by 2016 if possible. This will be about the same time Airbus and China want to deliver their new aircraft in the 737 size category.

    If things go well for Boeing in SC, the new 737 may be built there since I’m sure there will be parts and skills needed for it, similar to the 787.

  5. Vijay December 23, 2009 at 5:37 pm #

    ….Air India reports that there will be twice as many aisles for their domestic passengers to sit in

  6. Bruce December 24, 2009 at 4:04 am #

    Interesting…very interesting. I suspect the greater interest of airlines may come from increasing the premium cabin capacity whilst creating a true point of difference from the economy product.

  7. Singcloud December 24, 2009 at 5:03 am #

    I think the mindset of having a six abreast narrow-body has to change. Airlines wanting to improve on their existing fleets of 150 passenger aircraft would probably be looking at 180 or 200 seat aircraft. An advantage would be to have a twin aisle, maybe a 2-3-2 configuration, that would increase capacity without having too long an aircraft.
    I suspect we would see something like the A310 of old resurrected.

  8. Uwe December 24, 2009 at 9:33 am #

    OK…. Air India:
    My mind was more set on the “restraining” notices placed
    on certain elements of the workforce which would easily
    be overcome by the fitness aspect of trolley races.

    To Singcloud on December 24, 2009 5:03 AM

    If Stand Up “Seating” will ever become a certifyable
    arrangement I could envision single row seating along
    the windows and SUS with a tight row pitch and 3/4 across
    as a “value” PAX Bagger down the middle.

    seasonal greetings all around!

  9. Frequent Traveller December 25, 2009 at 4:28 am #

    American Airlines experimented with extra seat pitch, and failed to attract additional traffic, loosing out revenue; SAS’ analysts surveyed this issue and found that passengers are highly sensitive to lateral freedom of space, plus to differentiated cabin service quality but only vaguely to extra seat pitch. SAS restrained selling the middle seat in their DC9/MD-80 triples, leaving it available for laptops and newspapers : with these ingredients plus more direct city-pairs (serving their network with smaller modules) Jan Carlzon’s “Businessman’s Airline” was a winner ! This to put a shade on Wandering Aramean’s comment about the attraction of extra pitch ?

  10. Frequent Traveller December 25, 2009 at 5:06 am #

    Agreed, Bruce : very interesting indeed ! And food for thought for Flight Attendant unions worldwide, not forgetting the Federal Airworthiness Authority : without any reasonable cabin installation alternative on offer, operators and FAA certification agents are not confronted when extending beyond reason the already 50 years long life of a dating sardine-box (3+3) cabin installation concept, although unergonomic for Cabin Attendants and possibly a safety hazard for the outer passenger in a triple seat squeezed against the wall. Singing in duo with Runway Girl, isn’t it time to vamp up the cabin offer on SMR Feeder services ? : “Time has come”, the Hatter said…

  11. Andy December 26, 2009 at 5:50 pm #

    2-2-2 will work on a A320 with Thompson staggered seats. Delta is installing those seats on their 767′s. This increased the seating from 7 abreast to 8 abreast. The 767 cabin is 15’6″ wide and the A320 is 12’2″ wide. The staggered seats on the 767 are 18″ wide. Deleating two of them would fit into 12’6″. Reducing the seat width from 18″ to 17.25″ gets you down to 12’2″.

    Now 17.25″ is standard seat width on Boeing narrow bodies. So Airbus could offer a twin aisle with standard seats. That would be a kick in the teeth for Boeing. The A320 and the 737 run neck and neck now. This would give the A320 a clear advantage.

  12. pundit December 28, 2009 at 1:53 pm #

    FWIW, Boeing has long had patents covering a small twin-aisle concept that would embrace 737 (and almost 757) capacity dating from the early 2000s (and possibly the source for the 737H QR cross-section above?). ‘Twould make interesting competition against the new generation of 70- to 130-pax single-aisle designs if Boeing chooses to stay in that capacity bracket. Considerations include drag/weight/fuel-burn/DOC versus perceived pax comfort/space.
    Boeing could try to achieve commonality with claimed 787 cabin advantages in a narrower guage that, in turn, could be stretched to match the market for the smallest 787 (as the 757 did with the shortest 767 – some payload/range combinations essentially being addressed by both designs, with markets/routes defining which aircraft was used).

  13. Andy December 28, 2009 at 10:15 pm #

    Reading Boeing’s patent (www.freepatentsonline.com/6834833.html), one sees the patent is for a certain type of airplane. In this case, the airplane already exists. Boeing would have no claim against Airbus for rearranging their seating.

  14. Frequent Traveller December 30, 2009 at 8:19 am #

    Five abreast twin aisle seating was already installed historically in the Lockheed Superconstellation cabin, hence the concept is not new and cannot be protected by patents, the question is not here, but whether it will fit or not fit, dimensionally. HQR seating (1+3+1) fits in A320 AND 737, obviously at an advantage for A320 Series (with 7.2″ wider cabin at arm-rest height vs 737), but HP3 seating (1+2+2) will probably NOT fit in the 737 Series (due to head clearance problems vs overhead hatracks), giving better flexibility to Airbus to play such a twin aisle narrow-body strategy…

  15. Frequent Traveller December 30, 2009 at 8:46 am #

    I believe there is more in this new concept than “drag, fuel consumption, etc” vs “passenger acceptance”… The Twin Aisle Narrowbody SMR Feeder aircraft option drives primarily at shorter Ground Turnaround time, possibly 15 to 22 minutes less per each Ground Rotation pending which ground handling scenario and time-of-day departure one looks at… Multiply by five or six and you have enough extra time available per each period of 24H to add on an extra leg out, or a return leg, boosting aircraft PRODUCTIVITY/24H, draining more revenue/24H : you earn back with additional productivity/24H what you loose out with less seats per each flight : aircraft do not produce revenue when on ground ! With better Cabin Factors (smaller module, better passenger acceptance, better last-minute pax accomodation,…) and better ticket yields (better passenger acceptance), the higher Break-Even cabin factor (from higher seat-mile cost) may be balanced or even outbalanced?

  16. Andy January 2, 2010 at 12:01 am #

    When done on the A320 there is no trade-off of higher passenger acceptance vs. higher productivity. With the Thompson Cozy-Suite, you get all the benefits with out having to make any sacrafice in seating capacity. This would be a HUGE plus for A320 operators. If anything, since every row of six seats has four aisle seats, you might be able shorten the pitch a bit and increase the seating capacity.

    I wonder if anyone at Thompson or Airbus has thought of this.

  17. Frequent Traveller January 3, 2010 at 4:48 am #

    The weight issue (going Twin Aisle Five Abreast) mentioned by KDR is pertinent but may be tackled : if we agree once and for all that the days of (3+3) seating are counted, preferring the Twin Aisle alternative(s), let’s go ALL THE WAY ! I mean, let’s take the NO-RETURN alley ! By processing the full set of aircraft STRUCTURAL and DYNAMIC stress equations through the number-crunchers at Boeing or Airbus, starting out with a design mission payload reduced by – say – up to 35 pax or 3.6 metric tons less, the reduced structural weight including second-loop and third-loop repercussions will bring forth a “Light Weight” A320H or 737H. I mean, let’s process these aircraft through a “no-concessions” liposuction, in the way the Low-Cost Carriers have stripped themselves systematically from every bit of organisational fat not directly linked with business operations, and : KDR, you’ll not need to worry ?!

  18. Frequent Traveller January 5, 2010 at 5:08 am #

    Andy’s proposal for a Thompson-type staggered (2+2+2) solution for the A320 Series is interesting, yet I wonder what kind of “open, free, unhindered, unobstrued” (in the uncompromising FAA/JAA understanding and interpretation thereof) aisle width one would get with such a zig-zagging twin aisle geometry ? In particular, I’m concerned whether this proposal would meet the Airworthiness Authorities’ demanding criterion for Emergency Evacuations, or whether the same actually could be demonstrated to be met without too many broken legs ?!

  19. Andy January 8, 2010 at 3:08 pm #

    If my calculations are correct, the aisle width will be the same as the 767 configured with the Thompson stagger seats. Insofar as the A320 is 3’4″ narrower than the 767, that difference is made up by the two fewer seats per row (which gets you 3′) and a reduction of seat width from the 18″ on the 767 to 17.25″ (which gets you the remaining 4″). The aisle width would remain the same.

  20. Frequent Traveller January 11, 2010 at 7:47 am #

    The A320 trim-to-trim cabin width is 146″.4 or (with 3+3 seating) 0.7″ x 2 (RHS+LHS clearances from wall panel) + 63″ each triple seat (= 2″+18″+2.5″+18″+2.5″ +18″+2″) x 2 + 19″ (aisle)… Reducing the seat width from 18″ to 17.25″ will yield 6 times .75″ or total 4.5″… If using three A320-type double seats to offer 2+2+2 seating, you’d get 2+18+2.5+18+2 = 42.5″ per double seat, ie a total 2 x 0.7″ + 3 x 42.5″ = 128.9″ for the seating, leaving 17.5″ for splitting between the two aisles ? Even with 737-type double seats the width of the two aisles would be less than 15″, not airworthy @ FAA current standards ?!

  21. Andy January 11, 2010 at 7:51 pm #

    With the Thompson seats, the staggering lets you overlap the armrests and eliminate the space between the seats while at the same time avoid having to rub shoulders and elbows with the person next to you. So, each double seat is 2″+17.25+0+17.25+2=38.5. Now all six require 2×0.7″+3×38.5″=116.9. So, 146.4-116.9=29.5. We are 0.5″ short. Lets shave 0.1″ off each of the outer arm rests. The gains us 0.6″. We squeezed them in with 0.1″ to spare. You are cleared for take off Frequent Traveler!

  22. Frequent Traveller January 12, 2010 at 6:17 am #

    Good point you made here, Andy… yet you’d get two aisles of about 15″ each, whereas airlines (or their travelling Customers and Cabin Attendants) are getting accustomed to aisles in excess of 18″ (some airlines even chose to install 737-type (59″ wide) triple seats in the A320 (3+3), going for a single WIDER AISLE option @ eg 25″ or more), this to say that aisles of only 15″ are not in the blowing of the wind these days, not to talk of the hindrances contra free trolley circulation, ie contra smooth cabin service, or contra easy getting around a trolley in-flight on the way out or back to/from lavatory, not to mention Uwe’s IFE trolley races, where the risk of abrazing any legs sticking out in the aisle would increase to a point where it cannot be ignored anymore, hein Uwe ?

  23. Frequent Traveller January 18, 2010 at 10:37 am #

    In SMR feeder markets there are as many needs for varying module sizes (95 ? 150 ? 185 seaters ? …) as there are airlines out there. To catch a better portion of the Frequent Travellers on leg A-B, there is inly one strategy : increase the frequencies offered on this leg, ie, at equal total traffic on any leg A-B, reduce module size ! or if total traffic increases, stay with same module and offer better frequencies … By the way, I don’t know about any possibility to stretch the 737 beyond the -900 ??, but for the A320 Series there is still room for a stretch beyond A321, say, to an A322, which would offer up to 185 seats twin aisle five abreast, why not ? Suits you, Singcloud ? But a stretched A322 with sardine (3+3) seating would just repeat the “757 syndrome”, with its string of in-service and ground rotation inefficiencies ! So beyond 200-220 seats, give them thirty+ rows of (2+3+2), agreed, Singcloud !

  24. Frequent Traveller February 16, 2010 at 5:20 am #

    Hi folks ! I’m back here just to try keep the discussion going, I think the subject is worth the while, isn’t it ?! :
    Many other advantages would stem from the Twin Aisle Five Abreat HQR or HP3 concepts : with +/-26 less pax to carry, some of the containers in e.g. the A319H underbelly would become available for other uses than luggage. One such use is for ACTs : Auxiliary Container Tanks, ie additional fuel capacity for extended range operations, whereby eg transatlantic direct operations become within reach for this aircraft, picking up – expanding on – the British Airways “sleeperette” concept.

  25. RobertR March 18, 2010 at 6:11 am #

    The twin aisle narrowbody is a nice idea, but since you lose capacity it is not very likely to take to the air.
    Fares the travelling public is willing to pay simply do nor allow for less seats, quite the contrary is happening.
    More likely would be a successor to the shorthaul widebodys A300 and B767.

  26. Frequent Traveller March 19, 2010 at 8:09 am #

    On hub-to-hub city-pairs, certainly “small feeder” aircraft are not appropriate. But any “Frequent Traveller” will prefer to enter a start-city-to-stop-city direct offer, from transiting through an intermediate hub-and-spoke center, spending his precious time in boarding areas. The type 737/A320 vectors, which today offer proper response to the SMR Feeder problematic, are not likely soon to quit the Air Transport arena. With 32″ pitch, an A322HQR or A322HP3 would accomodate 185-190 passengers. Airbus is not offering to stretch the A321 with 6-abreast seating, because of the need to revise the aerodynamic surfaces with the extra stress, and because of the “757 syndrome” (string of in-flight service and ground rotation inefficiencies) but a stretched five abreast twin aisle aircraft would make full technical and commercial sense. Do you consider 185/190 seats to be too small ?

  27. Frequent Traveller March 24, 2010 at 4:56 am #

    Airline and manufacturer planners alike need to reckon with the emergent countdown for a BAN BY FAA/JAA(EASA) against installing triple seats squeezed against a wall panel in aircraft cabins. It is only a matter of time until FAA Rulemakers will say BASTA! : Gentlemen, from (deadline) onwards, triples/quadruples must be accessible from both ends, no seat shall be more than one off from an aisle ! When this happens, the HQR (1+3+1) concept is retrofittable, HP3 (1+2+2) probably not, or at a much higher cost. Planners need to anticipate or they’ll get caught the pants down ! The armwrestling between the Producer Lobby (Manufacturers-Operators) and the User Lobby (you and me, AFA, Airport Worker Unions and Safety Advisors) has started!

  28. office cleaning July 20, 2010 at 5:53 am #

    Great post!

  29. Frequent Traveller December 23, 2010 at 5:26 am #

    Coming back on a comment by Singcloud, also echoed by RobertR, that to lose out module size is swimming upstream to current market trends, let me suggest that with the Lufthansa-Recaro idea of “butt-cushion” seats, where the knee feeling is unchanged vs 32″ standard cushion seating yet with actually two inches less pitch at the seat-tracks whereby you gain two rows of extra seats in any average size SMR Feeder cabin, cf http://www.flightglobal.com/blogs/runway-girl/2010/12/photos-will-i-need-a-butt-cush.html, with a (longer) type A322H module the gain is THREE more rows, raising capacity from 36/37 rows 5-abreast (180-185 seats) “standard cushion” to 39/40 rows (195-200 seats) “skinny cushion”. Result : we haven’t given anything away in terms of module capacity, plus we now have a much better cabin product boosting yields, we’re rotating on ground in 30′ planned block time boosting productivity/24h, and we have greatly boosted our freight revenue capability : we have a WINNER ! Merry Christmas with A322H aircraft, to all Operators, LCC and Majors alike !