Weigh more, pay more on flights?

January 15th, 2012 at 1:47 pm by David Farrar

Travelmole reports:

A former Qantas group chief economist says people who weigh more should pay more to fly on planes.

Writing for Business Day in Fairfax newspapers, Tony Webber, now managing director of Webber Quantitative Consulting and Associate Professor at the University of Sydney Business School, claims fuel burnt by planes depends on many things “but the most important is the weight of the aircraft. The more a plane weighs, the more fuel it must burn”.

Webber said if passengers on the aircraft weigh more, the aircraft consumes more fuel and the airline’s costs go up.

In turn, the airline would need to lift airfares to recover the additional costs. And when they did, the burden of the higher fees should not be lumbered “on those who are shedding a few kilos or keeping their weight stable”.

Webber said airline fuel costs have increased since 2000 not just because of higher oil and jet fuel prices…”but also because the average adult passenger is carrying a bit more heft”.

Between 1926 and 2008, the average weight of an Aussie female adult increased from 59 kilograms to 71 kilos and the average weight of an Aussie male adult increased from 72 to 85 kilos, according to Webber.

I agree. If you pay more for extra weight in your baggage, you should pay more for extra weight on your person. It will also provide a good extra incentive to lose weight.

There would be some practicalities, but if you just get people to select a weight group upon booking most would do so honestly. I don’t think you need to weigh people upon check in.

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98 Responses to “Weigh more, pay more on flights?”

  1. infused (646 comments) says:

    +1. btw, how is your weight loss going David?

    [DPF: Held steady over Africa which was amazing. Now aiming to be at 95 by end of March]

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  2. MajorBloodnok (361 comments) says:

    As an airline passenger you are paying for a service. That service is to lift your body and your luggage off the ground to 30,000 feet, and put you down again at your chosen destination. The service cost is largely a factor of the weight required to lift. Every gram counts (which is why airlines consider carefully their choice of cutlery, or how much paint is on the fuselage).

    It is only fair that air passengers pay for their combined person + baggage + carry-on luggage weight. And if all 3 components are weighed together, it does not reveal a person’s weight (unless they have no luggage).

    Until then, ordinary people are subsidising the obese.

    (And if the obese complain, point out those who are much taller than normal cannot fit in the economy seat spacing and have to pay extra to even get on a plane.)

    Bring it on. It’s long past time it was introduced.

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  3. tvb (4,254 comments) says:

    Some grossly obese people get on planes, squash into economy seats and provide a very uncomfortable flight for any person who is unlucky to be seated next to them. Hopefully the airline can make a seating adjustment. The extra charge for such people should mean this can be allowed to happen.

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  4. Other_Andy (2,513 comments) says:

    Absolutely agree! Price should by total weight (luggage and person).
    Here I am, an 85 kg person with 25 kg of luggage and I have to pay a $50 overweight fee.
    Behind me a 180 kg person with 23 kg of luggage doesn’t pay anything extra.

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  5. tristanb (1,133 comments) says:

    There’s plenty of examples of people subsidising others in business. If you rush through a museum after paying entry, you’re less of an expense than the guy who stays there all day – but it’d be silly for the museum to charge by the minute.

    Anyway, it’d be publicity-suicide for a large airline to “discriminate” against the overweight.

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  6. Pauleastbay (5,035 comments) says:

    Can you imagine the extra burden on the NZ taxpayer factoring in Gerry , Parakura etc

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  7. hmmokrightitis (1,571 comments) says:

    And every single woman on the planet would be a size 8. Tui ad. :)

    How far do you go with this? Im 6 foot, just under 100kgs, ultra marathon runner, resting heart rate of 44 BPM. Im classed as obese, but can run 100 km. Im far less likely to die from a heart attack than some scrawny prick smoker, and thereby create less fuss than them – do I get recognition for better fitter and more healthy?

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  8. CJPhoto (218 comments) says:

    Agree in part but also remember:

    Only a portion of the ticket price is referable to fuel. the majority would be use of plane, staff, food, corporate overheads, profit.

    re fuel, Divide the weight of an empty plane by the maximum number of passangers (say 180,000kg divided by 524 = 324kg). That is each persons share of the weight of a plane (you would also need to add their share of the weigth of the fuel etc). So just because a person is twice as heavy as you, doesn’t mean they use twice as much fuel.

    My guess is the difference is price would not be that great and therefore not worth while.

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  9. Other_Andy (2,513 comments) says:

    @tristanb

    Interesting comparison. However, not quite right. You are looking at it from the customer’s side.
    It doesn’t cost the museum anything extra for people who stay longer, the airline however does pay more for the heavier person. And as for consistency, why pay more for extra luggage?
    Why can’t the heavier person subsidise my overweight luggage?

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  10. Manolo (13,517 comments) says:

    Hang on. This is grossly unfair to Parakura Horomia and his ilk.
    Expect Waitangi Tribunal and Human Rights Commission complaints.

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  11. JC (933 comments) says:

    It might have been MacDoctor, but anyway, someone recently pointed out that before any persons or groups are banned or charged extra there has to be a process of demonisation of those people and/or groups.. and that this process is underway for the obese.

    However, lets look at the obese in terms of flying..

    A pregnant woman is obese and unless she can produce a certificate that she is pregnant as a result of rape, she must be charged extra.

    Most All Blacks are obese.. even the halfbacks!

    Most Maori and Pacific Islanders are obese and must be charged extra.

    The cite shows an adult Aussie male is on average 85kgs. Now the average is not the median but its probably close enough to say that half are 85kg and under, and the other half are over.. so half the adult male population is obese in terms of flying whether they have a big gut and wide hips, or not.

    So why dont we agree that the problem is not with so called obese people but that the airlines have simply not adjusted to the size and weight of passengers over time and have used all the improvements in flying for their own benefit and not the passengers?

    Personally I think runty people should be put in the hold and allow the adults a bit more room upstairs.

    JC

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  12. Other_Andy (2,513 comments) says:

    CJPhoto

    “So just because a person is twice as heavy as you, doesn’t mean they use twice as much fuel.”

    Yes it does.

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  13. Other_Andy (2,513 comments) says:

    @JC

    Discrimination is a fact of life.
    You have to be 15 to get a restricted license.
    You have to have a license if you want to drive.
    You have to be a man to become an All Black.

    Only beautiful women become top models.
    Only fit men can be All Blacks

    If you are sick you have to pay for a doctor while healthy people don’t.
    Very tall people pay extra for clothes.

    It has nothing to do with demonisation, it is plain economics.

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  14. seanmaitland (472 comments) says:

    @OtherAndy:

    “So just because a person is twice as heavy as you, doesn’t mean they use twice as much fuel.”

    “Yes it does.”

    Lol – looks like you left your brain behind today. Going on your math, if I drove my car from Wellington to Auckland and had my girlfriend who weighs roughly the same as me in the car it would cost twice as much in petrol……

    You realise that the weight of the plane is orders of magnitude more than the passengers on it, and it flies at up to 900-odd km/hr?

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  15. Peter (1,664 comments) says:

    @ tristanb “Anyway, it’d be publicity-suicide for a large airline to “discriminate” against the overweight.”

    On the contrary, many people would flock to such an airline, as there is less chance of being jammed in next to a lard-arse in economy.

    The horror.

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  16. beautox (436 comments) says:

    hmmokrightitis – you seem to be misinformed. Your risk of having a heart attack is quite high actually.

    http://www.pponline.co.uk/encyc/heart-attack-risks-are-greater-for-athletes-who-compete-in-endurance-sports-263

    Quote:
    The truth is that marathon runners, ironman triathletes and long-distance cyclists, swimmers, rowers and cross-country skiers are all in the same boat. In fact, any athlete who participates in a strenuous test of endurance lasting about three hours or more has an increased chance of dying during – and for 24 hours following – the exertion, even when the athlete’s chance of a death-door knock is compared with the risk incurred by a cigarette-smoking, sedentary layabout who spends the same 24 hours drinking beer and watching TV.

    Otherwise, what your post had to do about the topic is beyond me. Or were you just bragging?

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  17. Bullitt (138 comments) says:

    I fully agree. I think there should be a limit on total weight and beyond that people pay. For example give people an allowance of say 80kg + 20kg luggage + 7kg carry on and if your total weight is below 107kg then you can fly for the standard price. If you’re slightly over 80kg you make sure you have less luggage to compensate. If you’ll never get below that threshold you have to pay more…seems fair to me.

    Why should I be limited to 65kg + 20kg luggage when a large number passengers weigh more than that before they pick up a suitcase. Yet we both pay the same.

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  18. B A W (98 comments) says:

    In actual fact it would be safer to weigh passengers. Planes have maximum take off weights and while they weigh the baggage in the hold (which is why they are more lenient with excess baggage if you check in early) they do not weigh the passengers or their carry on luggage.

    In once case a plane was full of passengers from a coin fair. Not wanting to lose any coins they carried them on-board with themselves. There was about an extra ton of weight on the plane and while there was no crash it turned out the plane found it harder to take off.

    9 times out of 10 people choose to be obese through their life style choices etc. We have a obesity epidemic and we need to make being obese as socially unacceptable as smoking.

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  19. Pauleastbay (5,035 comments) says:

    Taken to the nth degree.

    I don’t drink so take that off my fare
    I dont eat airline food take that off my fare
    I’m deaf, take the movies off my fare.

    What about when the plane is only half full , do they increase everyones fare until it makes up a plane load?

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  20. hmmokrightitis (1,571 comments) says:

    @beautox – how was I bragging – Im 100kg FFS, every single other runner weighs around 50kg. Im always in the rear of the field. How could that possible be “showing off”. Did I mention that I was good at it? No. Dick.

    Use what little brain you have to determine the comparison I was drawing you numpty, instead of picking fights on the interweb.

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  21. Elaycee (4,332 comments) says:

    @pauleastbay: Air NZ already charges extra for meals and movies on trans tasman sectors anyway. Doesn’t matter even if you’re Gold Elite – the rule and charges apply to all. So much for loyalty – I’ve been Koru for over 20 years, but I’m still asked when I book online to select whether I want a meal / a movie on the flight (and I’m charged accordingly). And I don’t travel in Business Class on trans Tasman – the sectors are short / no sleeping necessary.

    Thats why many travellers are shifting to other airlines now – Emirates / Qantas don’t have these charges and the fare is similar to Air NZ’s anyway. Air NZ does many good things, but they’re treating long standing Koru members, like crap.

    But Emirates is good. :)

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  22. LeftPilot (63 comments) says:

    I decry the western obesity epidemic but plenty of supposedly healthy ‘fit’ people drop dead before their time.

    It is entirely possible for airlines to weigh all of their passengers at check-in and to do so with minimal fuss and almost no extra time used in the check-in process. What is stopping it from happening? The fact that many it would become all to readily apparent just how many flights routinely take-off overweight. Leading to the very real need for a large number of seats to remain empty on flights. All aircraft by design are capable of maintaining flight past their certified maximum weights that is why there is a certification process, those limits represent a buffer on the ultimate capability of the aircraft. However, there have been numerous cases over the years where catastrophic accidents have nearly taken place because aircraft have been unknowingly overweight.

    My own company suffered a fatal accident last year where weight was a contributory factor (cargo flight) and it has certainly brought the issue of passenger and cargo weight and correct documentation of that to the forefront of everybody’s minds.

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  23. Pauleastbay (5,035 comments) says:

    With you Elaycee, I was pointing out that this tread was starting to sound like one run by the wharfies.

    ” Its not fair, he’s a fat bastard and we paid the same”.

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  24. MT_Tinman (3,044 comments) says:

    You skinny, humourless little pricks make me cry. Poor, poor you.

    I weighed 125 – 130 kg when I was a wool presser (That’s serious fitness folks), 135 now I’m an old fat bastard so don’t give me this “It’s for the obese’s sake”crap, you’re just too fucking tight to allow the non-skinny, non-wrinkly good guys and guy-esses to share your space.

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  25. davidp (3,557 comments) says:

    A 777-300ER has a maximum take off weight of around 350,000 kilos. That’s about 1000kg per passenger, most of which is aircraft and fuel. Being 20kg overweight therefore adds 2% to a person’s total aircraft weight, but not 2% to total fuel burn since fuel burn isn’t proportional to weight.

    It would be a brave airline that started penalising heavy customers on the basis of such a tiny marginal cost factor. Especially since it would mean penalising middle-aged males, who are likely to be their most regular customers. Airlines go to a lot of trouble to keep these frequent fliers onboard with all sorts of incentives. It would be perverse to reward them on one hand, and then to insult and penalise them on the other.

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  26. LeftPilot (63 comments) says:

    Interesting though as Elaycee has stated Air New Zealand seem to be less and less looking after their HVC/Frequent Flyers with the changes they have been making. They have also confused their brand quite considerably with Seats to Suit ala Low Cost carriers with itemised charges and add-ons despite maintaining premium products on long-haul. Even then on the 777-300ER Air New Zealand has degraded the economy experience for which they used to be renowned.

    What Tony Webber wrote was more to be provocative than anything, something he has acknowledged but this kind of ‘innovation’ isn’t entirely out of left field.

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  27. Scott Chris (5,974 comments) says:

    Hmm, some rough calculations based on an A380 with 800 people aboard.

    Fully laden plane is around 550,000 kg

    10,000km trip to LA uses 240,000 litres of avgas which costs around a buck a litre so that’s $240,000.

    So that’s a raw cost of around 43c per kilo in pure fuel costs. (weighing in at 64 tonnes, passengers only make up 11% of gross weight excluding luggage)

    So if an airline were to introduce a passenger’s weight component to the ticket, a 100 kg person would be charged $43, whereas a 70 kg person would be charged $30.

    Seems fair to me.

    Of course the volume issue is a different kettle of fish, but as long as airlines use a one size fits all policy in economy class, they can’t really do much about that.

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  28. adze (2,002 comments) says:

    Not sure about charging by personal weight, just as long as I don’t have to share my seat with the lipid tissue (or other emissions) of other passengers.

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  29. Other_Andy (2,513 comments) says:

    @seanmaitland

    “Lol – looks like you left your brain behind today. Going on your math, if I drove my car from Wellington to Auckland and had my girlfriend who weighs roughly the same as me in the car it would cost twice as much in petrol……
    You realise that the weight of the plane is orders of magnitude more than the passengers on it, and it flies at up to 900-odd km/hr?”

    I will try to keep it simple for you seanmaitland.
    The plane\car isn’t included, it is a constant (All things being equal).
    We are talking about the extra weight (transporting a person) it carries and the cost of transporting a person.

    Read the statement again: “So just because a person is twice as heavy as you, doesn’t mean they use twice as much fuel.”

    Yes, is does. They use twice as much fuel to to transport a person that is twice as heavy.
    To keep it very simple, if they use a 1000 litres to move the plane, and 10 litre for you.
    They will need to use another 20 litres, twice as much, for the person that is twice the weight.
    So it will cost them twice as much to transport that person.
    The fact that we also pay for the plane, the total cost, doesn’t change the fact that the energy (Fuel) needed to move an object of 2 kilos is twice that for an object of 1 kilo.
    Simple enough?

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  30. Viking2 (11,275 comments) says:

    hmmokrightitis (252) Says:
    January 15th, 2012 at 2:37 pm

    And every single woman on the planet would be a size 8. Tui ad. :)

    How far do you go with this? Im 6 foot, just under 100kgs, ultra marathon runner, resting heart rate of 44 BPM. Im classed as obese, but can run 100 km. Im far less likely to die from a heart attack than some scrawny prick smoker, and thereby create less fuss than them – do I get recognition for better fitter and more healthy?

    As someone else pointed out your risk is actually a lot more than you think. Particularly if your mineral and vitamin intake is too low. These are the things that keep you ticking. Plenty “fit” people drop dead in the middle of their runs etc. One on the weekend in the swim at Taupo.

    Think about it.

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  31. Steve (4,522 comments) says:

    Passengers should be weighed just before boarding and charged accordingly.
    Don’t drink before boarding and make sure you have a good shit first. User pays. There are no discounts for sending parcels, so why should a light person subsidise a fat obese prick?

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  32. Sean (299 comments) says:

    Its a crazy and unworkable idea, as noted here:

    http://blogs.crikey.com.au/planetalking/2012/01/12/silly-season-finale-a-fat-tax-on-pax/

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  33. labours a joke (442 comments) says:

    scottchris fyi son , A380 carries 525 maximum in standard configuration , A380′s dont run on avagas , they run on JetA1.
    Jet A1 is around 1.50 a litre.
    Stick to your knitting.

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  34. NX (603 comments) says:

    Well, I kinda agreed.

    I’m currently overseas at the mo… trekking about. And even with my giant twenty kilogram backpack I still weigh less than DPF (no offense David). Yet I pay extra if my bag breaches the 20kg theshold by only 1kg.

    However the policy would be very difficult to implement. For one it might need to be based on BMI, or body fat percentage.. rather than raw weight.

    And, on another note – if you want to loss weight – backpacking is the way to go.

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  35. gravedodger (1,528 comments) says:

    @ sean Maitland 03 43 Basic laws of physics suggests to me the energy required to move the weight component of a skinny little bugger will easily be doubled for a big mate
    Pity the guy promoting this idea is a “FORMER” senior Quantas exec.
    Freight by air is weight dictated with volume secondary.
    Freight by road or sea is more unit based.
    I have wondered for years why heavier people travelling by air, have the same Luggage weight as lighter people when overweight luggage penalties are quite severe.

    An airline that adopts weight aggregation rates will gain my support promptly.

    I weigh around 85 Kgs and carry very little luggage.

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  36. Falafulu Fisi (2,177 comments) says:

    OA …

    doesn’t change the fact that the energy (Fuel) needed to move an object of 2 kilos is twice that for an object of 1 kilo.

    The total weight of the aircraft during flight decreases either linearly or exponentially decay since the fuel is being used up by the engine. I haven’t thoroughly investigated its effect in commercial airlines (whether it is a major or minor) but engineers do take this fact into consideration in their design.

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  37. Falafulu Fisi (2,177 comments) says:

    The scenario that I described in my previous post above, is briefly covered in the following link. See Figure-1.2a and Figure-1.2b.

    ROCKET PROPULSION

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  38. fatnuts (164 comments) says:

    Calculation of cost is complex, probably goverened more by route planning / hold times than overweight passengers. An interesting graph is at:

    http://www.airways.co.nz/ASPIRE/_content/cost_index.asp

    Air New Zealand used to weight passenegers boarding in Samoa (or was it Tonga?) – rumor has it one 737 had some issues getting off the ground, with the calculated weight being somewhat different from the actual.

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  39. Falafulu Fisi (2,177 comments) says:

    I came across the following , which is not about passengers’ weights but I think that it may be relevant here.

    Baggage Fees : A Game Theory Perspective

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  40. gump (1,553 comments) says:

    Other_Andy said:

    Yes, is does. They use twice as much fuel to to transport a person that is twice as heavy.

    ——————–

    The fuel consumption on a jet airliner isn’t linear.

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  41. Other_Andy (2,513 comments) says:

    @FF

    No dispute there but I still maintain that the total amount of fuel needed to move 2 kg is twice as much compared to moving 1 kg.

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  42. Other_Andy (2,513 comments) says:

    “The fuel consumption on a jet airliner isn’t linear.”

    No it isn’t, but that isn’t the argument.

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  43. Nostalgia-NZ (5,044 comments) says:

    Okay, so what about a discount for being under weight? A family of 5, 4 paying an adult fare (2 teenagers) and coming in underweight, or even 15 kgs under the ‘limit’ for an individual? In the case of the family of 5 they’re actually paying the fare of a phantom customer because the combined minus weight for the teens, or a skinny granny and a teen equals the weight of an ‘adult’ fare.

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  44. seanmaitland (472 comments) says:

    @Other_Andy – your simple case is not relevant -it still doesn’t change the fact that fuel usage is not linear.

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  45. hmmokrightitis (1,571 comments) says:

    @viking2: huge assumption that the person who died at Taupo was “fit” – you know this how? Because they rocked up to a start line? Meh, not even.

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  46. Scott Chris (5,974 comments) says:

    labours aj you moron, the only thing I got wrong was falling into old habit and calling kerosene avgas in the manner of my father.

    1) Jet fuel is US$3.17 a US gallon:

    http://www.indexmundi.com/commodities/?commodity=jet-fuel

    2) The A380 can take up to 853 passengers depending on class:

    http://www.airbus.com/aircraftfamilies/passengeraircraft/a380family/a380-800/specifications/

    But that is beside the point. You do know the meaning of the phrase “rough calculations” don’t you? Even with 500 passengers, they only make up around 10% of the gross laden weight.

    Dickhead.

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  47. Other_Andy (2,513 comments) says:

    @seanmaitland

    “Your simple case is not relevant.”

    Sorry, but it is, simple physics (work of the force).
    No, fuel consumption is not linear but that has no effect on the total fuel consumption.
    It doesn’t matter that the first 100 KM of the trip you use more fuel (as you need to carry the fuel as well) as the last 100 km.
    The total amount of fuel to move 2 kg 200 km compared to total amount of fuel to move 1 kg 200 is still twice as much.
    So it still cost twice as much to move 2 kg compared to 1 kg.
    As compared to the total cost it would cost only a fraction more.

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  48. seanmaitland (472 comments) says:

    @Other_Andy:

    “So just because a person is twice as heavy as you, doesn’t mean they use twice as much fuel.”

    “Yes it does.”

    ——-

    “The fuel consumption on a jet airliner isn’t linear.”

    “No it isn’t, but that isn’t the argument.”

    -> It certainly is the argument I was making – you tried to change it to a simple highschool physics example.

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  49. Nostalgia-NZ (5,044 comments) says:

    If they were to pay more for more weight (and therefore space) wouldn’t they be entitled to a ‘fatties’ seat rather than one they needed to be squeezed into from all sides and towed out from?

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  50. tvb (4,254 comments) says:

    It should be simple to have a total weight allowance of say 120kg for person plus luggage including hand luggage. Any thing over that costs. Too bad for the grossly obese who may also have to purchase an extra seat for some flights. Perhaps even have a special seat for the grossly obese to be available on some flights.

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  51. JC (933 comments) says:

    “If they were to pay more for more weight (and therefore space) wouldn’t they be entitled to a ‘fatties’ seat rather than one they needed to be squeezed into from all sides and towed out from?”

    Thats the way I see it. But then watch all the skinny buggers put lead weights in their pockets and rush to grab them!

    JC

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  52. tas (596 comments) says:

    (i) An empty plane still needs fuel to fly. I’m told that the figure is around 70% of the amount it would need when fully loaded. And, given that fuel is only a fraction of the overall cost of air travel, a fair weight surcharge would be so minimal that it probably wouldn’t be worth it.

    (ii) Surcharges just piss me off as a customer. I like to know the cost of something up front. I know it can make economic sense to charge for everything extra, but I prefer a flat fee. That way I can fully assess the price before purchasing and I don’t have to keep fishing out my wallet while I’m half-asleep on the plane.

    (iii) Since when have airline prices made sense?

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  53. dime (9,664 comments) says:

    fuck that! i get pinged everywhere else, i aint paying extra cause im naturally a big mofo.

    my best weight is 110kg. built like a brick shit house.

    comparing my “extra” 35kg to extra baggage is bullshit – the extra baggage takes up extra room. i fit in a seat quite well thanks.

    some people dont have a grasp of weight. they see over 100kg and think fat. whats richie mccaw at the moment? 108kg? 6’3?

    also, not sure why people are keen to see extra charges. its not like skinny weeds are gonna get a discount.

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  54. bhudson (4,736 comments) says:

    dime,

    …its not like skinny weeds are gonna get a discount.

    Now there’s a fine point. What chance the ex-QANTAS exec and Quantitative Consultant has been consulting on how to increase margins while being seen to be ‘fair’?

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  55. dime (9,664 comments) says:

    and if you believe they will reduce tickets for weeds then you are thick enough to believe taking gst off fruit n veg will reduce prices too

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  56. Mr Nobody NZ (397 comments) says:

    As has been suggested above discrimination is simply a part of life and as a plus 100kg guy I’m happy to pay a bit extra as long as airlines are going to start a similar policy in all the other areas that specific groups have caused additional costs for example perhaps:
    - Muslim passengers should be charged an additional fee due to cover the extra security costs that Airlines have had to implement post 9/11.
    - Elderly or Disabled passengers with who may require more attention than more “normal” passengers should be charged extra as they are likely to tie up staff more frequently or often.
    - Instead of infants being charged less than an adult they should be charged triple due to the likely hood of them crying and making the flight uncomfortable for the rest.
    - Those with BO, bad breath, too strong a perfume or smoke should also be charged due as I’m sure that their smells cause the air filters in the air con units to need replacing more frequently (may be the sick as well due to their germs).
    - People who listen to ipods etc so loudly that despite them wearing headphones I can still hear their music to rows away.
    - People who insist of trying to use laptops etc in economy should be charged extra as well due as they nearly always end up encroaching into their neighbor’s space.

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  57. Jmac (16 comments) says:

    6’5, 150kg.

    Please, no.

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  58. dime (9,664 comments) says:

    mr nobody lol yep.

    how bout offensive asians who like to cough and spit all the way to fucking HK.

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  59. gump (1,553 comments) says:

    Other_Andy said:

    “The fuel consumption on a jet airliner isn’t linear.”

    No it isn’t, but that isn’t the argument.

    —————————-

    Sorry if I wasn’t clear. I meant that the marginal fuel consumption on a jet airliner isn’t linear.

    The principal determinant of fuel consumption in an airliner is the drag (which must be opposed by engine thrust). The drag is proportional to the lift required for flight, and the lift is of course equal to the weight of the airliner.

    The problem is that aircraft drag is non-linear. This means that the marginal fuel consumption is non-linear also.

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  60. gump (1,553 comments) says:

    Oh. Before I forget:

    http://i.imgur.com/Ts8K3.jpg

    This is not my photo but it seems appropriate.

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  61. Kimble (4,410 comments) says:

    Story behind that photo, gump, he actually booked a window seat.

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  62. bhudson (4,736 comments) says:

    gump,

    The problem is that aircraft drag is non-linear. This means that the marginal fuel consumption is non-linear also.

    Yes. IIRC there is something of a tipping point quite early in the graph of power to speed where drag leads to 4x power to achieve 1x increase in speed. [My reading was for automotive aerodynamics.]

    In that case, weight would not be as much of a factor as the weather ( and pre-flight delays), as the pilot adjusts power (burning more fuel) to provide speed to stay on schedule.

    Perhaps we will have a case of “the airline that sued god” before weight-based fares?

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  63. UpandComer (523 comments) says:

    I’m 6’4 and 105 kgs, but I look pretty skinny and have narrow hips. I play basketballl, and this is about as light as I can get without seriously sub optimal calorie dieting. I think this would be pretty unfair. I have lots of mates who are pretty heavy but also pretty tall and are very very far from being fat or obese. Given men are heavier then women this would hurt men. My mate tomasi is 6’6 and weighs honestly about 160kg, but he can play full court basketball at nbl level for a full one hour scrimmage. It seems pretty discriminatory to charge people like me much more based on something I can’t change. People are getting heavier and taller every generation. Someone who is actually obese and fat because they don’t know how to/won’t look after themselves is different to an athlete, but how do you discriminate? and realistically there is only so much floor space an aeroplane can have. Regardless of people’s weight, you can still only fit a certain number of people into the cabin. I think people who have a waist width too great for a person to comfortably sit along side should have to pay more, because that is effecting other passengers who would otherwise be able to fly.

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  64. ben (2,414 comments) says:

    Since when was marginal cost the determinant of anything in airlines? Its all price discrimination unrelated to actual incremental passenger cost. By all means charge more for the obese. It will amount to about $0 if done at actual cost. Red herring, all of it.

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  65. dime (9,664 comments) says:

    maybe they could do fat tests :) the check in person has calipers etc

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  66. Pharmachick (229 comments) says:

    Wow,
    there’s a lot of nonsense on this thread, some of it masquerading as physics… but most not very accurate.

    FWIW the original question has nothing to do with freight, “marginal cost determinants” etc … Rather the original post was about large people only paying for ONE seat. Personally, I travel a lot by myself for business. Sine I am a ‘lone traveller’ and not a “child” or other “special” case… when I’m not traveling in business or 1st Class, I’m always the person that gets sat next to these awful excuses for “the general public”… apparently, as I am a “non-married, corporate woman traveling alone” the companies think that “surely she will be nice in this negative circumstance” …

    Answer: come on you guys, that’s just bigoted and misogynist, so **please** don’t try that sh*t with me and expect me to be nice about it. Either I or my company paid for my seat *fair and square** … there is NO place on long haul flights for the oozers that take up 1.5 seats (at best) nor for those miserable people that make it hard for other travelers!!

    NO YOU ARE NOT “the general public” … when your “waist” and “thighs” significantly impinge upon my seat (by more than 50 cm of ooze). NEITHER is it normal to be constantly apologising to your seatmate about your oozing …

    My favourite airlines are the ones that **insist** on larger people paying for an extra seat when they’re wider than standard.

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  67. SHG (370 comments) says:

    One presumes that it works in the other direction – i.e., skinny people and children will now pay drastically reduced fares commensurate with their bodyweight. Paying full fare for a child who masses 20kg soaking wet has always annoyed me.

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  68. Scott B (23 comments) says:

    Weighing passengers would allow airlines to me more efficient than they currently are. Currently airlines have to use the expected weight of passengers (using average weights by gender i think) to calculate maximum loadings. This estimate has to be consultative just in case a couple of rugby teams or traveling Wrestling show end up on a plane. If passengers were weighed this safety margin could be cut.

    The economist proposes that heaver people pay more reflecting the increased cost to the airline. Those who suggest BMI testing miss the point. It costs just to same to transport a 100kg short fat person as a 100kg tall thin person.

    Every Kg of extra weight on the plane increases the amount of lift induced drag the aircraft experiences, and hence the amount of fuel burnt. However this change is not as large as some commentator’s make it out to be as parasitic drag (I.E. surface friction) is very significant, and significant amounts of lift induced drag are due to the weight of the plane not the cargo.

    @dime “extra baggage takes up extra room. i fit in a seat quite well thanks” Planes typically have ample baggage space but are limited by take off weight. This is why air freight / baggage is typically charged by weight not volume (unlike sea freight)

    It will be a brave airline that implements this policy. A massive angry media storm is sure to follow.

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  69. Mark (1,431 comments) says:

    Pretty easy to see who the skinny weakling types are on this blog. Insipid little bastards.

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  70. travellerev (149 comments) says:

    This is an inherently dishonest and unfair discussion. If you are a sdhort obese little git such as Yourself David you will most probably still be under the average weight and get a low airfair while an antire people such as the Dutch whose average length and therefore higher weight might be disadvantaged. The amount of people who are so overweight they are to big for their chairs are very far and few between and are used to impose price hikes on those unfortunate enought not to fall in the average length and weight.

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  71. Nostalgia-NZ (5,044 comments) says:

    Unfair discussion but it sure gave some people the opportunity to vent their predjudices even in this ‘enlightened’ time when people are a lot bigger and health and weight problems are treated with scorn by the ‘healthy’ minded.

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  72. Mary Rose (393 comments) says:

    >you will most probably still be under the average weight

    It should be by width, not weight, then. You have to show your hand luggage will fit into those metal basket things, they have barriers at theme parks to see if kids are tall enough to go on rides…

    Ok, I’m joking. A bit. But having had fat strangers squashing me into a small portion of my own seat on more than one flight, I’m with Pharmachick on how unpleasant it is.

    >Nostalgia-NZ
    I’ve no prejudice against anyone who can’t help something about themselves.
    But obesity is down in most cases to poor diet and lifestyle, and that’s a personal choice.

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  73. Nostalgia-NZ (5,044 comments) says:

    Mary Rose.

    I don’t know about the personal choice of obesity, but it seems more worthwhile targeting that than any type of assumption that big people have some kind of intention to annoy others on flights by making a ‘personal choice’ for which they. and others who are naturally big’ have somehow contrived. Seems to me it is the responsibility of the airlines to construct a plan to relieve this issue in a satisfactory way, that they’re not doing so, is to me’ their lack of personal responsibility to their customers. Not forgetting the airlines indifference to ‘weight saving’ on teens, the naturally small, or the elderly for example.
    When I first heard this one in a radio interview I also wondered about the mass weight of a group travelling together using 5 seats for instance and other obvious inbalances that favour the airlines and disadvantage their passengers – could be time for bigger seats and strategic seating for what might likely not be as a ‘big’ problem as the debate suggests.

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  74. Mary Rose (393 comments) says:

    >Seems to me it is the responsibility of the airlines to construct a plan to relieve this issue

    Sure. Charging people more won’t make them any thinner: the airline will just be making more money out of them, while the thin person next to them still gets squashed.

    Fewer, wider seats is the answer. Which will put the price up for everyone. But maybe not by as much as the gap between cattle class and business class, so still affordable for us types on a budget!

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  75. BeaB (2,082 comments) says:

    Wah wah. Life isn’t fair. Get over it. Some of you sound like those Treaty types, always looking for a grievance and someone who might be getting a bit more than you are.

    I prefer sitting next to the fatties to the guy with the nosehair and stinky suit that hasn’t been aired for a month. Or the nosepicker. Or the one with the leaky prostate who keeps stepping on your foot as he blunders past. Or the reeking, coughing smoker. Or the farter.

    The airlines could just give us all a bit more room.

    But what a lot of whingers. Perhaps you’d all be happier on Soviet Airlines.

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  76. AlphaKiwi (687 comments) says:

    Should we charge people in wheel chairs to cover the cost of building wheel chair accessible buildings?

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  77. Weihana (4,496 comments) says:

    “I don’t think you need to weigh people upon check in.”

    I don’t care about the cost (except when they’re so fat they spill into the next seat), but safety should prompt regulators to require passengers to be weighed. While aircraft do have safety buffers, the point is that we shouldn’t be using those buffers because if we do so routinely then we bring ourselves that much closer to potential disaster.

    http://en.wikipedia.org/wiki/Air_Midwest_Flight_5481

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  78. Ben Wilson (523 comments) says:

    Weight is not the only factor. If you take up a whole seat someone else can’t have it, no matter how much either of you weigh.

    But it certainly is a factor, and it does affect underlying cost substantially.

    Charging for it directly could produce highly perverse outcomes, though – the most obvious way for people to lose weight fast is to dehydrate themselves before a flight, which is extremely dangerous, considering how dehydrating the environment on an aircraft is, and how uncomfortable and cramped the quarters are. This would not only apply to fat people – every single person would be incentivized to doing something quite dangerous.

    I’d say there’s a good reason that weight is not charged for – airlines are one of the most likely businesses to fully model every possible outcome of policy decisions, it’s such an over engineered business. One of the most obvious outcomes would be that the first airline to start doing it would lose every heavy customer immediately to the other airlines. Considering that half of the population would feel picked on (the upper weight half), and that half is mostly likely to be men who do the most traveling, funneling the most money to the airlines, it’s a decision that doesn’t surprise me as never having been made, except by annoyed customers who notice that their entire suitcase weighs less than the weight difference between then and the fat guy who takes up their whole armrest.

    Essentially, it’s an idea that most people abstractly agree with to some extent (usually about everyone fatter than them), but it’s totally impractical which is why it’s never happened.

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  79. labours a joke (442 comments) says:

    “labours aj you moron, the only thing I got wrong was falling into old habit and calling kerosene avgas in the manner of my father”

    oh I see..the “only” thing you got wrong was calling kero avgas. Very flippant of you. Well scottyquis let me tell you something , in the aviation industry that is the absolute worst thing you can do…mistake jet a1 for avgas and vice versa.

    What happens when you mix the two scottquiss? Detonation. Plane stop working, fall from sky.
    Whos the moron scottquiss?

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  80. Elaycee (4,332 comments) says:

    @Weihana: The cause of the crash (according to your link) was twofold: “During the investigation, it emerged that the… turnbuckles controlling tension on the cables to the elevators had been set incorrectly, resulting in insufficient elevator travel, leading to the pilots not having sufficient pitch control..” and second: ” ..the [weight] estimates were over 20 pounds (9 kg) lighter than the actual weight of an average passenger.” It concluded: “It was determined that neither problem alone would have caused the loss of control, which explains why it departed Huntington, West Virginia safely”.

    The 21 POB on the Beechcraft were ‘under assessed’ by a total of 189 kgs. That won’t bring a plane down by itself. But the fact that it was configured with a COG biased to the rear, would have been a greater factor to the accident than the passenger weight estimates.

    Indeed, the cause stated in your own link stated “Overweight to the back (baggage and fuel)” and the cause as stated by the NTSB was “LOSS OF PITCH CONTROL CAUSED FATAL AIRLINER CRASH IN CHARLOTTE, NORTH CAROLINA LAST YEAR”, NTSB SB-04-03, 26 February 2004

    So how about we stick to the facts?

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  81. Richard29 (377 comments) says:

    From my experience the larger passenger charge has nothing to do with larger passengers and everything to do with people who get upset with being charged for excess baggage.

    20kg for an international flight is heaps. It’s actually 30kg when you include the 10kg limit on the hand luggage and more than that when you include items like coats, carried personal effects etc.

    This limit should be more than enough for 99% of passengers – a lot of people just travel with a bunch of crap they don’t need and don’t plan for the weight allowances.

    I like the differential pricing whereby you can now buy a ticket on AirNZ with or without bag, meal etc. But if they ever went down the road of charging customers per kilo of weight then I’d expect to receive an equivalent rebate for every kilo my bags were under the maximum limit.

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  82. Weihana (4,496 comments) says:

    Elaycee,

    I haven’t strayed from the facts. I never said it was the sole cause of the crash and I didn’t comment specifically on the crash at all. I realize there were two contributing factors. But neither of them alone would have caused the crash and if the passengers had been weighed the aircraft would not likely have crashed.

    You may be able to get away with overloading a lot of the time, but when something else happens that also reduces pitch control then it’s just that more likely that the aircraft will become uncontrollable. Errors can add up. First the aircraft wasn’t serviced properly. Then the aircraft was overloaded. IIRC even this didn’t mean the plane couldn’t get off the ground and the aircraft only lost control when the front gear was raised which pushed the COG even further aft shortening the effective rudder arm and making it impossible for the aircraft to be saved.

    Point is, safety buffers are not supposed to be used. They exist to guard against things like wear and tear, human error etc. But regulation should surely proceed with the expectation that operators stay within the limits outlined in the flight manual and not permit operators to operate within limits they think they can get away with. This means they should weigh passengers before they get on the plane and not use estimates.

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  83. RRM (9,661 comments) says:

    Hmm, I wonder which costs the airline more, an extra kilo of luggage or an extra kilo of fat?

    In my experience even the fattest of passengers (unlike suitcases) make their own way onto the aeroplane without having to be picked up and handled by ground staff.

    (And ffs, we’re not talking about a little old Morrie Thou that is going to have it’s performance seriously compromised by fat old uncle Bill in the back seat. As a 747 rolls down the runway toward takeoff each engine is developing over 90 thousand compressor shaft horsepower. Each brake pad on one of those beasts probably weights more than fat old uncle Bill… )

    [PS: and we'll never see fat charges, because in order to introduce a "fat bastard" surcharge, they would be expected to start discounting childrens' tickets at the same per kilo rate, and they won't want to do that! ;-) ]

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  84. Weihana (4,496 comments) says:

    Elaycee,

    That should read “elevator arm” although the rudder arm was likewise reduced.

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  85. Paulus (2,562 comments) says:

    Once had a very uncomfortable flight Transtasman. A very large lady had got to our row early, and had ensconced herself over two seats with arm up. When asked to move closer into her seat and put the arm up, war was declared, and she would/could not do it. She had paid for her seat (probably WINZ had) and that was it. My wife and I asked her nicely but what was uttered (I do not speak Maori so I could not actually understand what she was saying) was not pleasant. The flight attendants avoided us. What a horrible flight all through being squashed up against this sweaty smelly blubbery object, being subject to unpleasantaness all through. The flight was full.
    Yes weight test, but how as it must be against some UN regulations.

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  86. Spoon (101 comments) says:

    What annoys me is the super-tight baggage restrictions (7kg? An empty case is 3kg!). I weigh ~80kg. I’d settle for them rounding the carry-on allowance up to, say, 10kg for everyone who weighs less than 100kg. There’s no “extra” cost for larger people, just a bonus for others.

    Of course Jetstar, Ryanair, etc already allow 10kg. Easyjet have no limit (as long as you can lift it over your head). AirNZ are just behind the 8 ball…

    As far as discrimination goes, I’m 6’5″ and all legs. Economy is uncomfortable. My knees routinely get crushed when the person in front feels the need to recline all the way. If I don’t want my knees crushed I need to pay for exit rows (ironically Jetstar seems to be the exception now). Cathay Pacific wanted $100US per person per leg last year. London and back is four legs, with my wife, so over $1000NZD.

    I have to pay extra for a “luxury” which would be standard in a fair world, isn’t it therefore equal to charge an overweight person for the “luxury” of a few kg extra baggage, which would be standard in a fair world? The difference is (most) overweight people can lose weight and re-gain their “luxury”. I can’t (easily) lose height to regain my “luxury”.

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  87. Ben Wilson (523 comments) says:

    The other reason they probably don’t do it is they don’t want people to know what the true connection is between weight and the cost of transport, because the current cost of luggage would turn out to be ridiculously unreasonable.

    A thread discussing that cost here: http://www.flyertalk.com/forum/travelbuzz/712294-anyone-know-average-cost-per-pound-fly-1-000-miles-3-gallon-fuel.html

    Most conveniently summarized answer was:
    >For the 737-900 (no winglets) I get 0.0155 gallons per pound per 1,000 statute miles.

    Which converted for metrics is 0.08037 liters per kg per 1000 km. I don’t really know the cost of jet fuel now, but even if it’s $5 per liter (that seems way high to me, I’d guess it’s not much different to petrol in reality), you could righteously charge (based on real costs) around 40c per kg per 1000km. So on a trip to Sydney, you could charge about 86c per extra kilo. Last time I was forced by circumstances to take overweight luggage they charged me $10 per kilo.

    If anyone knows the real cost (to the airline) of jet fuel we might be able to work out the real price at today’s rates. My gut feel is that it’s probably around $2/l, so divide my costs above by 2.5.

    This maths is probably the real reason they don’t charge. They’re not being PC, they’re actually shit scared they’ll look like rorting profiteers already.

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  88. Elaycee (4,332 comments) says:

    @Weihana” “if the passengers had been weighed the aircraft would not likely have crashed.”

    Whaaaat? Not at all. The aircraft took off OK – it was on the MTOW but wasn’t overweight. According to the CVR, it rolled beyond V1 and took off as normal. The initial trigger for the accident was that the COG was biased to the rear and when the pilot tried to correct it (when the gear retracted), she had less than half the amount of available control because the maintenance guy had buggered up the cable maintenance. In short, the pilot needed the full amount of elevator to recover the aircraft but could only get approx half that amount. The aircraft stalled. 26 seconds later, it hit the ground.

    Indeed, the NTSA confirmed: “The accident airplane’s elevator control system was incorrectly rigged during the detail six maintenance check, and the incorrect rigging restricted the airplane’s elevator travel to 7º airplane nose down, or about one-half of the downward travel specified by the airplane manufacturer”.

    http://www.ntsb.gov/doclib/reports/2004/AAR0401.pdf

    As I said, its best to keep to the facts…..

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  89. labours a joke (442 comments) says:

    Jet fuel, for the likes of say Singapore air, 1.50 per litre…less if you are a BIG user, Avgas , around 2 bucks.

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  90. Weihana (4,496 comments) says:

    Elaycee,


    The aircraft took off OK – it was on the MTOW but wasn’t overweight.

    Incorrect. The aircraft was overweight by 580 pounds. You seem to be under the impression that above max certified takeoff weight an aircraft can’t get off the ground. This is not the case. They often exist because excess weight will bring the aircraft’s centre of gravity out of limits and render the aircraft uncontrollable.

    This is what happened to this aircraft. The overloading brought the centre of gravity significantly aft of the aft limit meaning that greater than normal airplane-nose-down pitch control was required. This was not available due to the incorrect rigging of the elevator control system.

    But neither fault alone was sufficient to bring the plane down. Not only is this demonstrated by post-accident analysis, but by the fact that the airplane flew 10 times after the maintenance was completed and didn’t crash until its final flight.

    I suggest you read section 2.4 of the accident report and equip yourself with “the facts”. :)


    The airplane performance study for flight 5481 determined that the accident airplane’s actual weight was about 17,700 pounds and that its actual CG position was about 45.5 percent MAC. As a result, flight 5481 had exceeded the Beech 1900D certified weight limit of 17,120 pounds and the certified aft CG limit of 40 percent MAC.

    Of the accident airplane’s 10 flights after the D6 maintenance check, the accident flight was by far the most aft loaded.134 When an airplane is loaded so that the CG is aft of the aft limit, greater-than-normal AND pitch control is required.

    The Safety Board made several calculations to determine the conditions under which the accident airplane would have been flyable during different flight segments. The calculations showed that, with full elevator travel (14º to 15º AND) and the accident airplane loaded to the weight and balance of the accident flight, the airplane should have been able to maintain flight during the takeoff and climb (requiring 9º to 10º AND elevator), cruise and descent (requiring 5º to 6º AND elevator), and approach and land (requiring 8º to 9º AND elevator) segments. The calculations also showed that, with reduced elevator travel (7º to 8º AND) and the accident airplane loaded to, but not exceeding, the Beech 1900D weight and CG limits, the airplane might have been able to fly during the takeoff and climb (requiring 7º to 8º AND elevator), cruise and descent (requiring 4º to 5º AND elevator), and approach and land (requiring 7º to 8º AND elevator) segments. Even if the required AND elevator slightly exceeded the available AND elevator, the airplane would have been controllable. The airplane would have entered a climb before achieving cruise speed, but takeoff and climb, cruise and descent, and approach and land could have been controllable with the available elevator and changes in engine power.

    The restricted elevator travel alone and the aft CG alone would not have been sufficient to cause the uncontrolled pitchup that led to the flight 5481 accident. The Safety Board concludes that flight 5481 had an excessive aft CG, which, combined with the reduced downward elevator travel resulting from the incorrect elevator rigging, rendered the airplane uncontrollable in the pitch axis.

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  91. F E Smith (3,315 comments) says:

    Isn’t all of this discussion is fairly irrelevant to the issue? How much it costs an airline to run an aeroplane is not the point. It may be to their calculations, or they might make such a decision for completely non-commercial reasons.

    The relevant principle must surely be that the price that any airline charges is the business of the airline and nobody else? The market will decide whether such a move is commercially viable or not.

    If an airline wants to lose passengers who weigh more than their ‘normal’ limit, then that only concerns the airline and its shareholders.

    If anyone doesn’t like it, use another airline. So long as it doesn’t offend against the racial or gender discrimination laws, who cares?

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  92. Elaycee (4,332 comments) says:

    @Weihana: When you wrote: “if the passengers had been weighed the aircraft would not likely have crashed.” I said bullshit because the fact the passengers were not weighed, was not the reason it crashed.

    Indeed, weighing the passengers would not have affected anything unless someone plotted and calculated where in the seating config the individual passengers were sitting in deference to the COG. However, it is possible that, if all the ‘heavier’ passengers were sitting forward of the COG, the aircraft would not have gone nose up when the nose wheel was retracted during climb out and there would have been no accident.

    The fact this Beechcraft 1900D left the gate at 17120 (pilot calcs – ref the CVR) was not the reason for the crash because it rolled OK / it reached V1 OK and it took off OK. Indeed, both pilots agreed that it was OK to start and taxi at that weight. And the NTSB does not cite weight as a factor in the crash.

    But the quotation in your last paragraph is totally correct – its what I have maintained all along and it sets out the reason for the crash. And failing to weigh the passengers (as you suggested) was NOT a factor. And that’s a fact. :D

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  93. Weihana (4,496 comments) says:

    Elaycee,

    Indeed, weighing the passengers would not have affected anything unless someone plotted and calculated where in the seating config the individual passengers were sitting in deference to the COG.

    Yes that is the idea. Take their weights and with the seating config and the flight manual you can ensure the flight is within COG limits.

    But at the very least, taking their weights would have alerted the crew to the fact that they were 500 pounds over MTOW. If they then removed passengers and bags to come within MTOW the COG would have also been within limits as the report indicates.


    If the flight crew had, for example, off-loaded two passengers seated in the last row of the airplane and three bags from the AFT1 cargo compartment, a calculated weight of 17,106 pounds and CG position of 35.9 percent MAC would have resulted. Even though this calculated weight and CG position would have indicated that the airplane was within the Beech 1900D weight and CG envelope, the actual weight would have been almost 100 pounds more than the weight limit (17,233 pounds), and the actual CG position would have been slightly under the aft CG limit (39.9 percent MAC).


    However, it is possible that, if all the ‘heavier’ passengers were sitting forward of the COG, the aircraft would not have gone nose up when the nose wheel was retracted during climb out and there would have been no accident.

    Assuming the COG is forward of the centre of lift then most, if not all, passengers would be seated aft of the COG. Shifting passengers around would probably have had minimal effect on the COG position and so the aircraft would still have pitched up uncontrollably.


    The fact this Beechcraft 1900D left the gate at 17120 (pilot calcs – ref the CVR) was not the reason for the crash because it rolled OK / it reached V1 OK and it took off OK. Indeed, both pilots agreed that it was OK to start and taxi at that weight. And the NTSB does not cite weight as a factor in the crash.

    I have no idea why you are insisting that the plane left the gate at 17120. The pilot calcs were wrong and contrary to your assertion weight is cited as a factor in the report. When they talk of the COG being too far aft they are referring to weight because it is the extra weight which caused the COG to be out of limits.

    Why do you suppose that as a consequence of this crash the FAA has required changes to weight estimations if weight was not a factor?

    3.2 Probable Cause
    The National Transportation Safety Board determines that the probable cause of this accident was the airplane’s loss of pitch control during takeoff. The loss of pitch control resulted from the incorrect rigging of the elevator control system compounded by the airplane’s aft center of gravity, which was substantially aft of the certified aft limit.

    Contributing to the cause of the accident were (1) Air Midwest’s lack of oversight of the work being performed at the Huntington, West Virginia, maintenance station; (2) Air Midwest’s maintenance procedures and documentation; (3) Air Midwest’s weight and balance program at the time of the accident; (4) the Raytheon Aerospace quality
    assurance inspector’s failure to detect the incorrect rigging of the elevator control system; (5) the Federal Aviation Administration’s (FAA) average weight assumptions in its weight and balance program guidance at the time of the accident; and (6) the FAA’s lack of oversight of Air Midwest’s maintenance program and its weight and balance program.

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  94. Elaycee (4,332 comments) says:

    @Weihana – stop trying to flog a dead horse. You’ve already noted the cause of the crash. Weighing the passengers would not have prevented it.

    The first bit you highlighted (“if the flight crew..”) is irrelevant. And hypothetical. As previously (and painstakingly) pointed out to you, the NTSB did not cite weight (MCTOW) as a factor – only the aircraft’s COG and the inability of the pilot to correct the nose up because of maintenance failures.

    The FAA (following recommendations from the NTSB) usually looks at ways to avoid repeat events and sends out NOTAMs /Maintenance Updates etc if / when required. The one you highlighted was but one such recommendation and it referred to COG calcs.

    Unless you have something of value to add, best to move on.

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  95. Weihana (4,496 comments) says:

    Elaycee,

    COG and weight are not independent factors. One directly influences the other and the overloading, by 500 pounds, was the reason the aircraft was out of its COG limits. Of course the “if the flight crew” bit is hypothetical. But it is what would have happened IF THEY WEIGHED THE PASSENGERS. That is the point. If they weighed the passengers they would have known they were overweight in which case they would have had to unload passengers, baggage or both to come within limits. If they had done this then they would have been within limits and they would likely have had enough aircraft nose down pitch control to operate the aircraft despite the incorrect rigging. This is what happened on the previous 9 flights.

    The report states quite clearly that a contributing cause of the crash was the FAA’s average weight assumptions. They contributed to the crash because the average weight assumptions did not reflect the reality of people’s weights. It is why as a consequence of the crash the FAA increased the average weight assumptions and this has been done around the world, including NZ, where it has been realized that people are getting fatter. But, if they weighed people they wouldn’t need to use assumptions. They would know exactly how much people weigh and would be better able to ensure they are within the limits given in the aircraft flight manual.

    But yes I will move on. Trying to convince you of the obvious is very much like flogging a dead horse. Fortunately the FAA considered weight an issue and increased their average weight assumptions. I simply wish they would go further and require passengers to be weighed so assumptions are not necessary. As it is it’s only a matter of time before people get even fatter and the revised assumptions become inaccurate again and threaten our safety.

    In NZ we assume 190 pounds if not weighed. How many people do you know that weigh over that amount? Be careful the next time you get on a small plane full of All Blacks. :)

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  96. Elaycee (4,332 comments) says:

    Weihana: “COG and weight are not independent factors…”

    Actually, they are. Look up your Pilots Manual (if you have one). Or get the info from the CAA or even search for the FAA Publication ‘FAA-H-8083-1A’ and read Chapter 2. (I only have the hard copy version, but you can probably find it if you search for it). This clearly explains how weight and COG are totally different elements. Or do you want to differ with the FAA?

    Then you say: “One directly influences the other and the overloading, by 500 pounds, was the reason the aircraft was out of its COG limits.”
    At the risk of repeating myself, the weight of the aircraft didn’t bring it down! Remember, it took off and was climbing out OK. But as soon as the nose wheel was retracted the aircraft went nose up. That in itself, should not have brought the aircraft down either, but the pilot was unable to correct it because…. oh, I’ve already explained it several times. If you can’t grasp it now, you never will.

    But we certainly agree on something – trying to have a rational discussion with you, is totally frustrating. If something said doesn’t conform to your own blinkered thinking – then it must be wrong. Rather sad, really. But not uncommon for a lefty.

    So I’ll finish off with an example of an aircraft with correct weight (it had just landed and was unloading freight. Fuel tanks had not been refilled but it still tipped. Not because of the weight of the aircraft at all. But because of a poor COG. As I said, they are different elements):
    http://www.drive.com.au/editorial/articledetail.aspx?ArticleID=3001&vf=1

    Indeed, next time you board an Air NZ ATR72 and you wonder why there is a ‘tail stand’ hanging under the rear of the aircraft, think of this series of comments. The tail stand is there because because the rear can tip whether it is full of fuel or has empty tanks. Its all to do with the COG and an ATR72 ‘tipping’ is not unusual. That’s why they usually try to board ATR72s from the front rows to the back. The penny may then drop for you.

    Out. :)

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  97. Weihana (4,496 comments) says:

    Elaycee,

    The COG is determined by the distribution of weight. You can’t know how weight is distributed unless you know how much weight there is for each item you load onto the plane. Hence why balance calculations require knowing (or estimating) the weights of passengers and baggage. Hence why to be more accurate, and safe, I propose that people be weighed and we stop guessing.

    I have found a copy of the weight and balance handbook you just referred to. Section 2 does not contradict anything I have said and indeed explains what I just said above, that the COG depends on the distribution of weight.

    I have genuinely tried to understand what your point is because this is a subject which interests me. Alas I cannot determine what your point is except perhaps to suggest that a plane can be within MTOW but have a COG that is out of limits. Of course I wouldn’t disagree with that but it is irrelevant to the point I am making and the Air MidWest accident. The fact is that the overloading in that case did cause the COG to be aft of the aft limit and thereby contributed to the accident. Their COG calculations would have been more accurate had they known the actual weights of the passengers.

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  98. Elaycee (4,332 comments) says:

    @Weihana: AT LAST! We agree!

    COG is definitely about the *distribution* of weight. Not the *overall* weight. Now you can see why your original suggestion: “if the passengers had been weighed the aircraft would not likely have crashed” is just not correct. Neither is your comment: “…overloading in that case did cause the COG to be aft.. ” because it depends on *where* (in relation to the COG) the weight was added. Not whether it was added at all.

    Even if the passengers were half their estimated weight, this accident could still have happened – it depends on where they sat in the aircraft. In the case of this aircraft, the COG change when the nose wheel came up, could have / should have been corrected if the pilot had normal control of her elevators. But she didn’t – because of crap maintenance. THAT was the root cause – as stated by the NTSB.

    An ATR can tip when loading – whether it has full tanks or MT tanks. Nothing to do with overall weight. All about COG. Aircraft are trimmed in flight to maintain a constant altitude. If the aircraft is nose up, then the elevator tab wheel is used to push the nose down to maintain level flight. If the nose is down, the converse applies. Sometimes, (depending on the location of the fuel tanks in the aircraft), trim needs to be adjusted in flight as the fuel load reduces. All normal stuff. Nothing to do with overall weight, but rather the COG.

    Anyway, this has been debated to death. Rigor mortis is setting in. I’m giving up. Trying to explain stuff learned many moons ago to a leftie, is rather tiring. I’d sooner have a root canal or a digital prostate check.

    Elaycee Out. :D

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