Cost per pound per mile?

[201er]

Anyone ever contemplated what it costs to move stuff with your Mooney? What I mean is, if you are traveling some place and have a lot to bring, is it cheaper to ship it ahead rather than fly with it? Anyone ever looked into this and ended up shipping stuff that they could have taken on board? So given you're within weight and balance, how much extra fuel do you have to burn per extra pound you carry?

[Jamie]

Interesting question. But I'm guessing there's not much difference based on the poh performance tables. (See attached).

 

For example, at "Economy Cruise" (just because that's what my reader opened up to in my scans), at 8000ft, 75% power, range at 2740 lbs is 835 nm. Range at 2300lbs is 850. That's only (850 - 835) / 850 = 0.0176, or ~ 1.76% difference.

 

 

That's kind of surprising, but maybe gross weight is more about CG than induced drag. Dunno.

[1964-M20E]

I'm not really worried about it once I'm flying unless I run or of room or weight capacity.  Usually run out of room before weight.

[Jamie]

I think  where it would start to get interesting is if you wanted to go somewhere, take something and the math has you leaving fuel behind to do it. Then there's a much clearer relationship to every extra pound you carry and the cost. Especially if the fuel is even more expensive at the destination (like, say, a dive trip to an island off the coast).

[201er]

That is where that diet topic really comes into play!

[Jamie]

I haven't been diving in a while. It's entirely possible I'd need *ahem* somewhat more weight to get neutral than a decade ago.

[Piloto]

I have done this comparison several times on shipping computer hardware stuff vs flying it on my own from KFXE to TJIG (900nm)

on my M20J.

 

Mooney full gross: Total fuel consumed 60 gallons or $400, same day delivery

FEDEX internatinal priority for 100 pounds of $300 value = $1400.00, next day delivery

 

It is a no brainer

[1964-M20E]

I have done this comparison several times on shipping computer hardware stuff vs flying it on my own from KFXE to TJIG (900nm)

on my M20J.

 

Mooney full gross: Total fuel consumed 60 gallons or $400, same day delivery

FEDEX internatinal priority for 100 pounds of $300 value = $1400.00, next day delivery

 

It is a no brainer

Well if you look at it that way.  60 gallons to get there 60 gallons to get back averaging 10GPH that is 12 hours of flying.   I think most of us can agree that the true full cost per hour of flying our beloved machines is somewhere between $100 to $150 per hour depending on how economical you are with maintenance and other items so that gives you $1200 to $1800.  You also have pilot time as well to figure in there even if you cannot charge for your time.

 

  It only makes sense if you are already going somewhere or you are trying to help out someone.  A couple of years ago a friend of mine was flying in a 172 with his girlfriend and they lost a mag.  It was only a 1.4hour flight in the Mooney and I flew up there with the mag so they could get back moving again the next morning of course I was looking for an excuse to fly.

[AlanA]

This is a good question because it also applies to how much extra gas to put in the tank if gas happens to be cheaper at one airport verses another.  In other words what is the cost of filling up your tanks to save 50 cents a gallon and flying that extra weight (say 30 gallons) to your destination?  Does the cost of the extra weight eat up the savings of cheaper gas?

[Flymu2]

This is a good question because it also applies to how much extra gas to put in the tank if gas happens to be cheaper at one airport verses another.  In other words what is the cost of filling up your tanks to save 50 cents a gallon and flying that extra weight (say 30 gallons) to your destination?  Does the cost of the extra weight eat up the savings of cheaper gas?

I don't have exact numbers, but the cost of tankering fuel is maybe 2% of the amount tankered. So, everything else being equal (which it rarely is) and $7/gal fuel, let's say one tankers 30 gal., 2% of that is 0.6 gal, or about $4.20. $0.50/gal saved on 30 gal is $15, so it's a net positive.

 

Stepping back and looking at the big picture, though, it probably doesn't make sense. Even at $7/gal, the differences are so small compared to the total amounts we spend on aviation as to be trivial. Also, we don't value the time, wear and tear on the airplane, and the additional risk of a heavy takeoff. It's almost never a good deal to stop or go out of the way for cheap gas (ok, maybe for the $1/gal deal in Texas right now).

 

For some perspective, I used to own an MU2. In that class of airplane, burning on average 80-90 gph, it was *never* favorable to go out of the way for less expensive gas. In addition to the down and up, it was 10 gal just to taxi in and out. It was, however, very worthwhile to consider landing at an airport a little further from the destination (another 20 min of driving time) for a large (as much as $2/gal) difference in fuel price. I routinely went to Boca Raton for vacations. The fuel at FXE was at times as much as $2/gal less than at BCT, parking was free vs $35/night, and the rental car was routinely $10-20/night less. That was a no brainer.

 

The numbers in a Mooney are much less dramatic, but based on the same principles.