WOT chock to chock!
Full throttle?
"Drive it like a rented mule"
Wet,throttle to the wall.
Nothing flies like a rental
Yup.
Once you buy your own plane and start paying maintenance and fuel, that tactic will change - but if you're renting wet, full rental power is the only option that makes sense.
Guys... Reading comprehension, seriously! A) It's not a rental, B) it's
TACH time.
I believe the tach hour meter is driven off of oil pressure, so it only registers time when above idle at some preset RPM, and that RPM is well below anything that will keep you airborne. So, all the smart ass answers should still be correct.
Depends on the tach... But there are no tachs that I know of that are driven off oil pressure. Most Hobbs meters are driven off an oil pressure switch, but not tachs.
Also, if you're in an equity club - Fly it like you own it, because you do. If you fly at "full rental power" your club will incur higher fuel and maintenance costs, and rates will need to increase. If everyone is nice to their planes, rates can remain the same for longer or in some cases, even go down.
I am in a flying club with a 172N. We pay a wet rate to to the club of $99 per tach hour. I'm trying to calculate what the ideal Cruising speed/power setting is to get the most nautical miles per tach hour.
I know max range is achieved at max lift/drag (vg) which in this case would be 65kts indicated. But is it the same with tach time.
First of all, congrats! Club flying is an excellent way to fly nice planes for less money (compared to renting) and for WAY less money than owning.
Second - As I mentioned above, it depends on the tach:
1) If you have a
Horizon P-1000 digital tach - Fuhgeddaboutit, it's almost as bad as a Hobbs. In fact, it'll usually be equal to a Hobbs, the only time it *might* not be counting time is if you're at the lowest possible idle setting on the ground, but it's likely counting most of that time as well. Once you're up to maybe 800 RPM, it functions pretty much like a Hobbs, and sadly that means that the short-term cost per mile will be lowest with full rental power as everyone says.
2) If you have another digital tach such as the
popular EI ones, they generally count time 1-to-1 above a certain RPM such that they won't count ground time at all but they'll count all time at any power setting that'll sustain flight just like a Hobbs. Better than the Horizon because you don't have to feel rushed on the ground, but still unfortunately encourages full rental power. However, again, if you and other club members abuse it, your rates will have to go up to cover increased maintenance, so please be nice to your airplane!
3) If you have the original mechanical tach, lower power settings = less time, on a fairly proportional basis. Flying around at Vg is probably not the answer, but the best (and most fun!) way to figure this out is to just go out in YOUR plane and fly it! Climb up to a normal cruising altitude (probably 4500-5500), take note of conditions (temp, etc) so you can calculate true airspeed, and then set up in stable straight-and-level flight at 2400 RPM, wait for speed to stabilize and mark it down, then reduce to 2300, wait for speed to stabilize and mark it down, down to maybe 1700-1800 RPM at which point you might be down to Vg. Then, raise it 100 RPM at a time and mark the speeds down again, just in case you didn't wait long enough for speed to truly stabilize! After the flight, you should be able to calculate true airspeed for each power setting as well as cost per air mile. If you plot it, you'll likely see that it's shaped like a curve and that flying as low as Vg might cost the least, but you might be able to fly significantly faster for not much more money per mile.
Armed with that knowledge, you can choose the power setting that strikes the right balance for you. Be aware that on each particular flight, a headwind will result in a higher power setting to get the optimum cost per mile, while a tailwind will result in a lower power setting. If this doesn't make sense, think of it like this: If your optimum cost per mile is at your Vg of 65 knots, and you're going on a $100 burger flight straight into a headwind of 50 knots, your groundspeed would be only 15 knots at your "optimum" power setting, but setting it a couple hundred RPM higher would likely double your groundspeed and thus halve the amount of time spent in that headwind. The opposite happens on the return flight - As long as you're at or slightly above Vg, you'll be feeling the benefit of the tailwind for the most time possible.
Hope this helps!
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