To maintain altitude you’ve got to generate lift equal to weight. The only way to generate more lift is more AOA or more speed or both. At the limit you find yourself at max continuous power at L/D[sub]max[/sub] = V[sub]Y[/sub] at your 0 rate of climb service ceiling of 6" above the highest nearby wave.
For the weights I ballparked above, you’ll be over published max gross for ~90% of the flight. You’ll get down to published gross with about 4 hours fuel on board, 2 of which are your intended reserve.
My WAG is 55% is what you’ll need to carry on short final. Not in cruise. For much of that you’ll be at max continuous power while mushing along not too far above V[sub]Y[/sub].
As you burn off weight the AOA will drop, so will the induced drag, and the speed will go up. At some point the speed will get up to where you can back off from MCP. But IMO it’s gonna be a long time into the flight before that happens.
I am probably overcautious when leaning, but I never got close to the published fuel burn rates. I’m pretty sure that I’d be really overcautious if leaning an engine on a transoceanic flight. I’d figure 9.5 gph at least Johnny.
What about oil consumption for a 17+ hour flight? New engine a must?
Easy, just rig up a mini-JATO setup that will get you to near cruising altitude. Maybe some kind of wacky 3-stage arrangement that will give you a low-power extended burn.
If you’re running too rich you’re not helping the engine; you’re just loading up the plugs with gunk and pissing away fuel you might need if the enroute winds or arrival weather are worse than forecast.
With a modern engine analyser that can give you every cylinder’s individual EGT there’s no legit reason to “Add 75F rich of peak for Mom & the kids” on top of the e.g. 50F rich of peak the manual calls for. It might have been good advice in 1960. Not now. IMO.
I’d be reluctant to take a low time engine across an ocean. Bathtub curve and all that. My Twin Comanche’s IO-320s did real well on oil burn. I’d not be worried about 17 hours with no top-off. I’d certainly start full plus a smidgen for tolerances.
Other Lycs are more … flaky. I bet folks have jury-rigged top-off arrangement for long ferries.
Turns out the guy who discovered the Canada-to-Canada line figures as long as it’s a circular arc, it counts as straight. It isn’t a great circle, so it’s not the shortest surface route between two points on it, so it’s not a “straight line” by any definition.
“Great Circle” means the path lies in a plane that contains the centerpoint of the Earth. If that applies to the path shown, it hs a great circle – that is, if the path across Canada from the ending point to the starting point is a great circle, so it the path from the starting point to the ending point.
If you get in your plane and fly at a constant heading, you will be following a great circle. That is what “straight line on the Earth” means. The problem that arises is that the Earth is an imperfect sphere (c. 27 miles wider than it is tall, or 0.35%), so a straight line that crosses the equator will be ever so slightly different from the mathematical great circle path. It seems likely that the deviation may be enough to invalidate the presented result, because I seriously doubt oblateness was accounted for.
Not true. That’ll be a straight line on a Mercator projection (that’s the reason for the existence of the Mercator projection), but it’ll make a spiral path on the Earth.
Consider: A great circle path must eventually (if you continue long enough) come back to its starting point. Which means that if you’re ever going at all north, there must also be some point on the circle where you’re going south. But no northerly path would ever have the same heading as a southerly path.
Since I believe the factual question has been answered, I’ll add that I believe often these sort of ferry flights will take the long way around – something like Alaska - Russia - Japan - Guam - Wake Island - Midway Island - Hawaii. Particularly when ferrying something like a regional jet without the range to make it from the US mainland, but enough to make all those legs without the need for additional fuel tanks.
The Pakistan-to-Kamchatka line is the longest all-water “straight line”, on a perfect sphere or an imperfect one. Easy to show that a “straight line” Canada to Canada will hit Antarctica on a spherical Earth; it’s more work on a WGS84 Earth. (Truth to tell, I haven’t done the work. Want me to?)
