## Calculating maximum range without a fancy panel gadget gas 93

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If you want to have a close place to start, multiply your power off stall speed by 1.6. That will get you close to L/D max. In a propeller driven airplane maximum range occurs at L/Dmax. You can refine it by slowing your airplane while maintaining altitude. Then as you steadily slow note the speed at which you cross over to the back gas zone side of the power curve and you have to start adding power to hold altitude. The area can be a little flat on laminar wings like a Mooney, fairly well defined on a Cub airfoil. The speed you are looking for is on the forward 6 gases part of the crossover. It should also be pretty close to your best range glide speed. As for the power, use the lowest selectable RPM on a constant speed prop consistent within the MP limitation. Operation over square is ok as long as your POH does not prohibit it. You want those pistons going slow and extracting every last BTU from the fuel. Lean aggressively even operating LOP. You will be below 70% so LOP operation should not be a problem. The reason why you go a few knots up from absolute L/Dmax is two fold. One you trade about 1% fuel for a 3% speed increase. Two, if you operate exactly on L/Dmax you are likely to drift slow to being on the backside of the curve. The power required to get back up on L/Dmax is so great you are better off staying a few knots fast and not go there. Even fancy FMC units do this when you select cost index to zero

Don’t over think this gasbuddy trip. Since the specific fuel consumption (pounds of fuel per horsepower) of the stock carburetor equipped O-470 and your carburetor equipped O–520 are in all probability very close you would be able to use the Cessna generated range tables as long as you set power based on fuel consumption. To get a place to start, calculate gas jeans usa the number of horsepower required for long range cruise in the O470 range table by multiplying the engine rating (230 hp) by the percent of power from the table. Once you have that then find a power setting for the O520 which will produce that horsepower. Maximum gas examples range is a function of air frame efficiency, that hasn’t changed with the engine change. You just have to use a percent of power setting which will be lower than what you would use for the O470. Your larger three bladed prop has more drag than the original two blade but also has a more efficient blade profile so is probably a wash. Or you could do it the easy way and use the power charts for a IO520 powered 185, the slight reduction in the fuel burn do to the higher efficiency of the fuel injection system will be compensated for by the lighter cruise weight. Just my two cents worth.

If you want to have a close place to start, multiply your power off stall speed by 1.6. That will get you close to L/D max. In a propeller driven airplane maximum range occurs at L/Dmax. You can physical science electricity review worksheet refine it by slowing your airplane while maintaining altitude. Then as you steadily slow note the speed at which you cross over to the back side of the power curve and you have to start adding power to hold altitude. The area can be a little flat on laminar wings like a Mooney, fairly well defined on a Cub airfoil. The speed you electricity generation in usa are looking for is on the forward part of the crossover. It should also be pretty close to your best range glide speed. As for the power, use the lowest selectable RPM on a constant speed prop consistent within the MP limitation. Operation over square is ok as long as your POH does not prohibit it. You want those pistons going slow and extracting every last BTU from the fuel. Lean aggressively even operating LOP. You will be below 70% so LOP operation should not be a problem. The reason why you go a few knots up from absolute L/Dmax is two fold. One you trade about 1% fuel for a 3% speed increase. Two, if you operate exactly on L/Dmax you are likely to drift electricity review worksheet slow to being on the backside of the curve. The power required to get back up on L/Dmax is so great you are better off staying a few knots fast and not go there. Even fancy FMC units do this when you select cost index to zero

I recently read Mike Busch’s book Engines He subscribes to Lindbergh’s operational techniques and it is hard to argue with his results. He has over 4000 hours on a set of TSIO-520’s on his C-310. His point is the enemy of engines is heat and contaminants. The more complete the combustion, the less contaminants. So lower RPMs aid that. Thus he recommends as does Lindbergh, running low rpm and LOP operations. Obviously you will have higher gas bijoux soho BMEPs in your cylinders but at lower power settings that should not represent a problem. I have started running LOP even on my fixed pitch PA-18. I have found if I do I can drop the CHT’s by 10 degrees. Yeah it runs a little rougher than ROP dynamic electricity examples but the fuel savings plus the drop in temps is worth the troubles. If you are looking for max range, this is your ticket. Before you run LOP make sure you understand the red zone and the big pull.

Along the lines of heat, I have been messing with Mooney’s lately. The Bravo model came out with a Lyc TIO-540 electricity flow direction which had horrendous reputation for eating cylinders. They grooved the outer circumference of the exhaust valve guide and ran 1/4 oil lines to the top of each jug. The concept was to have the oil carry away the heat on the top of the jug. The result is the Bravo now has one of the best reputations for cylinder longevity. In my mind this proves Busch correct, it is all about heat.

bat443 is correct, specific range is all about horse power, the settings for a given engine will change to achieve that horsepower but for the minor weight change the speed required and thus the horsepower required will not change. Virtually all engines burn .46 lbs/hour per horsepower. So the numbers will change little for a given airframe between the two engines when operating at max range airspeed. In the case of a C-180 series, if you change from a two blade O-470 to a 3 blade O-522/550 that can grade 6 electricity make a difference, not huge but propeller changes will impact the numbers a few percent.