| N941WR |
01-06-2012 03:06 PM |
Quote:
Originally Posted by longranger
(Post 614267)
But that same O-320 on a -7 (or an (I)O-360 at 55%;)) will get you another 45-minutes in the air (6 gallons at 8 gph). Even using 75% of 180hp on both airplanes, it's 30 minutes or more. Yes, if you're limited to 3-hour VFR legs, it won't make much difference, but if your mission is 600nm or more, or IFR, that extra 6 gallons might save you a stop, assuming you have the "personal range" for it. I'm not a big acro guy (yet?), so fuel capacity put me over the edge toward the -7.
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What numbers are you using?
36 gallons divided by 8 GPH gives you 4.5 hour range. Call it 4 hours with a half hour VFR reserve. If you get that low, you can power back even more and stretch that half an hour even longer.
Using Van's numbers you can pull back to 55% power and still fly at over 140 knots for 730 Nautical miles. That is plenty long enough. If you power up to 75%, then the range is 600 Nautical miles (710 statute miles) until dry tanks.
Truth is, very few people fly their RV?s at 75% power, most throttle back smile at the lower fuel burn.
Either way, everyone will have some reason to justify their choice and they are all valid reasons for the decision maker to drop some major coin on the aircraft of THEIR choice.
If you are still undecided in your 7 vs 9 choice, ask Van?s to hold your order until you can arrange a ride in both. I?m not going to tell you the -9 or the -7 is better because it is all about YOUR mission. They are both fine aircraft.
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