1. Welcome to Recreational Flying, the Home of Recreational and GA Pilots, Aircraft and Aviation. Please register, it's FREE to use ALL our great features. Hi

How much per seat mile?

Discussion in 'General Discussion' started by old man emu, Jun 7, 2013.

  1. old man emu

    old man emu Well-Known Member

    Joined:
    Feb 1, 2007
    Messages:
    1,326
    Likes:
    609
    What is your plane's "cost per seat mile"?

    This is a simple calculation based solely on fuel and oil usage, cruising speed and number of seats. We are not interested in fixed costs etc.

    The equation is:
    [{( litres per hour x cost of fuel per litre) +(litres of oil per hour x cost of oil per litre)} /cruise speed)]/number of seats.

    For the purposes of comparison over the whole of Australia, set the price of fuel at $2.00 per litre and oil at $10 per litre.

    If you reply to this post, please indicate the type of plane, number of seats, cruise speed and fuel burn rate.

    Old Man Emu
     
  2. motzartmerv

    motzartmerv Student Mentor First Class Member

    Joined:
    Nov 30, 2007
    Messages:
    3,933
    Likes:
    2,794
    Cost depends on if its been maintained at camden:)....
     
    • Funny Funny x 1
  3. Gentreau

    Gentreau Active Member

    Joined:
    Aug 27, 2012
    Messages:
    435
    Likes:
    256
    Doing this calculation for lightweight 2 seaters will give false results as the impact of adding a passenger is a significant percentage increase in weight.
    Should the fuel burn and cruise speed used be solo or two-up?
    If you calculate for solo and two-up, you will get very different results....
     
  4. kgwilson

    kgwilson Well-Known Member

    Joined:
    Jan 17, 2010
    Messages:
    932
    Likes:
    1,032
    Mine has cost about $75,000 & has only done 45km or 24.3 nautical miles all be road to my hangar so on that basis it has cost $3,086.42 per mile or $1,543.21 per seat mile. I haven't calculated fuel and oil as they are insignificant. The good thing is all the future miles are free plus fuel & oil. The theory, Cruise 130 knots @ 75% power, fuel burn 25 lph, 2 seats which equals ah, er, quite a lot. I think I'll just keep building it.
     
    • Funny Funny x 2
  5. rgmwa

    rgmwa First Class Member First Class Member

    Joined:
    Mar 2, 2009
    Messages:
    1,152
    Likes:
    711
    Mine is much more economical. Cost so far is about $92k but the distance covered to get to my place is 14,800km or 7992 nautical miles, so the cost works out at a mere $5.76 per seat mile. Call it $6 even after paint. No contest! Flying cost at cruising speed should be about 18 cents per seat mile.
    rgmwa
     
  6. frank marriott

    frank marriott Well-Known Member

    Joined:
    Nov 19, 2008
    Messages:
    1,032
    Likes:
    695
    Old Man Emu
    Never looked at it in this light before, but FYI this is mine.

    J230 / Avgas 25ltrs/hr / oil 30mls/hr / 2 seats / 120+kts (TAS) = 36c per seat nm. using your numbers of $2 and $10 per Ltr. [empty or MTOW]
     
    • Creative Creative x 1
  7. old man emu

    old man emu Well-Known Member

    Joined:
    Feb 1, 2007
    Messages:
    1,326
    Likes:
    609
    OK. We've got a J230. What about the J160 and 170?

    OME
     
  8. Aldo

    Aldo Active Member

    Joined:
    Mar 28, 2011
    Messages:
    142
    Likes:
    119
    Frank

    Not sure that I will get you to do my costing's but be happy to have you do my invoicing (haha)
    I fly a Jab 230, plan 26 lts/hr same oil consumption (30 cents/hr) and 120 kts
    (26*2)+(0.30) = $52.30/2 (seats) = $26.15/120 kts = $0.2179/nm or approx. 22 cents/nm
     
  9. Eric McCandless

    Eric McCandless Active Member

    Joined:
    Sep 7, 2011
    Messages:
    118
    Likes:
    110
    Jabiru J170
    Fuel Consumption 15 Ltr/Hr
    Oil Consumption 50 ml/hr
    Cruise Speed 95 knots
    Fuel Cost $2.00 /ltr
    Oil Cost $10.00 /ltr

    cost per mile $0.32 per NM
    cost per seat mile $0.16 per seat NM

    I have attached a spreadsheet for others to use to calculate if they wish.

    However I don't think these figures mean anything in the real world as ownership and maintenance costs should be also considered which would change the outcome considerably.

    P.S. I wish I could buy Avgas for $2.00 per litre and oil for $10 per litre.

    Eric
     

    Attached Files:

  10. Eric McCandless

    Eric McCandless Active Member

    Joined:
    Sep 7, 2011
    Messages:
    118
    Likes:
    110
    This is probably more representative of my J170 aircraft ownership costs and cost per seat mile (too scary to think about too much).

    Of course the costs would be different for hiring (a lot cheaper in my case).


    Aircraft Operating Costs Units per year Cost per hour

    Flying Hours (per year) 50
    Cruise Speed (knots) 95
    Number of Seats 2

    Non-Cash Costs
    Aircraft Value $65,000
    Opportunity Cost of Money (% / year) 6.00% $3,900 $78
    Depreciation (per year) $3,000 $3,000 $60

    Cash Costs
    Registration $130 $130 $3
    Insurance $2,600 $2,600 $52
    Engine Overhaul Cost $10,000 $500 $10
    Engine overhaul Hours 1,000
    Engine top end overhaul cost $3,000 $300 $6
    Engine Top Overhaul Hours 500
    Propeller replacement cost $1,500 $75 $2
    Propeller replacement Hours 1,000
    25 hour Oil & Filter Change (L2) $100 $200 $4
    100 hourly (L2) $500 $250 $5
    Maintenance (ADs, tyres, Instruments, Misc) $500 $500 $10
    Hangar hire (month) $190 $2,280 $46
    Fuel consumption (litres / hr) 15 $1,500 $30
    Fuel cost (per litre) $2.00
    Oil consumption per hour (ml) 50 $25 $1
    Oil cost (per litre) $10.00
    Landing fees per year $800 $800 $16

    Total Cost $16,060 $321

    Cost per mile $3.38
    Cost per seat mile $1.69

    Eric
     

    Attached Files:

    • Informative Informative x 1
  11. frank marriott

    frank marriott Well-Known Member

    Joined:
    Nov 19, 2008
    Messages:
    1,032
    Likes:
    695
    Yep that's correct, have no idea what I did there, should have written it down to see what I actually divided.
     
  12. old man emu

    old man emu Well-Known Member

    Joined:
    Feb 1, 2007
    Messages:
    1,326
    Likes:
    609
    Nice work, Eric, but you didn't read the question.


    The point of the exercise was to show that the cost per seat-mile of all airplanes should be very similar. You've considered all the variable costs, but these vary from airplane to airplane, and where it is flown from. Also hours per year will affect costs. Do the calculation again using 100 hrs per year and see how you get economies of scale.

    OME
     
  13. Eric McCandless

    Eric McCandless Active Member

    Joined:
    Sep 7, 2011
    Messages:
    118
    Likes:
    110
    Hi OME, Thanks and I did understand your question which I think I responded to in my first post. The point of my second post was to demonstrate why I think the original calculation doesn't mean anything as I can't see how one cannot consider other costs as these are what comes out of our pockets to get from A to B. I think it would be more useful to do a comparison based on all costs. Each aircraft will have different operating and maintenance costs. However as aircraft owners each have different use and maintenance profiles, perhaps the best way would be not to base calculations on owners costs but on average wet hire rates. A J170 based on hire rates is shown below. If you have a specific purpose for not including these other costs, then sorry I have missed the point and I don't wish to hijack your thread. Thanks. Eric.

    Hire costs per Seat Mile.JPG
     

    Attached Files:

  14. Eric McCandless

    Eric McCandless Active Member

    Joined:
    Sep 7, 2011
    Messages:
    118
    Likes:
    110
    Yes agree, the breakeven point for owning vs hiring my J170 is about 140 hours per year. I did the sums before buying my aircraft to justify ownership vs hiring and decided that the spreadsheet must be wrong so I threw the spreadsheet out and went with my heart instead. Baked beans on toast for 3 meals a day so I can fund my habit ain't so bad. Eric
     
  15. rgmwa

    rgmwa First Class Member First Class Member

    Joined:
    Mar 2, 2009
    Messages:
    1,152
    Likes:
    711
    It helps if you put a (generous) dollar value on the satisfaction of owning your own aircraft and flying when you want to. A bit like the goodwill value of a business. It makes the real cost of ownership a little less depressing.
    rgmwa
     
  16. turboplanner

    turboplanner Well-Known Member

    Joined:
    Sep 16, 2007
    Messages:
    9,937
    Likes:
    3,322
    For the hirer, here is a cross section of hire costs wet, incl GST

    As you can see the fast aircraft start to save you money on a trip, where the key factor is how many Nm you wish to travel.
    That only applies when the aircraft is full, with full cost sharing of course.
     

    Attached Files:

    • Informative Informative x 1
  17. turboplanner

    turboplanner Well-Known Member

    Joined:
    Sep 16, 2007
    Messages:
    9,937
    Likes:
    3,322
    If you have different hire rates, you can use Eric's calculator to get your results.
     
  18. Gentreau

    Gentreau Active Member

    Joined:
    Aug 27, 2012
    Messages:
    435
    Likes:
    256
    The differences will show up the aerodynamic efficiency and the fuel consumption of the motor for each design.
     
  19. REastwood

    REastwood Member

    Joined:
    Oct 27, 2009
    Messages:
    81
    Likes:
    84
    Ok, as per formula with fuel @$2.00 and oil = Cessna 172 30l/hr 110knots & 4 seats = $0.14/nm/seat. My actual costs as per the formula (run on mogas) and 3 seats = $0.10/nm/seat.
     
  20. turboplanner

    turboplanner Well-Known Member

    Joined:
    Sep 16, 2007
    Messages:
    9,937
    Likes:
    3,322

    It would be worth working up a spreadsheet on that to.

    Hiring is cheap if you are just booking and hour to get currency up (or as one of my friends used to do, 15 minutes per week, and you can reschedule based on AC availability, weather etc.

    It's a lot more complicated when you get serious about touring though.

    (a) Most flying schools/clubs have a minimum flying time per day, so even medium trips with a couple of nights stay present a problem.
    (b) You commit friends to a specific date and someone takes the aircraft without filling out the booking sheet
    (c) The club sells the aircraft you spent your money getting endorsed on

    and so on.

    Hire rates have to cover premises, staff, company vehicles, power, non payments etc. so the differences when spread sheeted may not be so much.
     

Share This Page