Dec 26 2011

Rules Governing the Use of Aeronautical Apparatus

1. The aeronaut should seat himself in the apparatus, and secure himself firmly to the chair by means of the strap provided. On the attendant crying: “Contact,” the aeronaut should close the switch which supplies electric current to the motor, thus enabling the attendant to set the same in motion.

2. Opening the control valve of the motor, the aeronaut should at the same time grasp the vertical stick or control pole which is to be found directly in front of the chair. The power from the motor will cause the device to roll gently forward and the aeronaut should govern its direction of motion by use of the rudder bars.

3. When the mechanism is facing into the wind, the aeronaut should open the control valve of the motor to its fullest extent, at the same time pulling the control pole toward his (the aeronaut’s) middle anatomy.

4. When sufficient speed has been attained, the device will leave the ground, and assume the position of aeronautical ascent.

5. Should the aeronaut decide to return to terra firma, he should close the control valve of the motor. This will cause the apparatus to assume what is known as the “gliding position,” except in the case of those flying machines which are inherently unstable. These latter will assume the position known as “involuntary spin,” and will return to earth with no further action of the part of the aeronaut.

6. On approaching closely to the chosen field or terrain, the aeronaut should move the control pole gently toward himself, thus causing the mechanism to alight more or less gently on terra firma.

© 1911 Curtiss Pusher Instruction Sheet

Dec 5 2011

Wallet Pressure: Cross-Country Economy

Good cross-country airplanes are expensive. Tremendously expensive, but they do go places, real fast. Old clunkers can also go places, but it takes them a lot of time and effort. They are way cheaper though, and burn much less fuel… So which way of cross-country flying is the most economic, in the long run? Let’s do some math.

I’ve picked a range of fairly common (and some not so common, for the sake of comparison) General Aviation airplanes, and listed their fundamental cross-country characteristics – cruise speed, engine power and associated fuel burn. Let’s imagine us venturing into a thousand-mile cross-country journey – how much time would it take to fly that distance with a given cruise speed?

Aeronca C-3 36 3 50 20
Taylorcraft B 65 4.4 80 12.5
Ercoupe 415 85 5.4 90 11.1
Jodel D11 100 6.1 100 10
Globe Swift 125 6.5 120 8.3
Piper Pacer 135 7.2 105 9.5
Cessna 170 145 8.1 105 9.5
Bellanca Cruisair 150 9 130 7.7
Stinson 108 165 9.3 105 9.5
Piper Cherokee 180 9.8 120 8.3
Mooney 20 200 10.5 170 5.9
Cessna 182 230 12.5 160 6.3
Rockwell Commander 260 14 180 5.6
Bonanza V35 285 15 200 5
Corvalis TT 310 17 260 3.8

First of all, let me clarify that I have used pretty conservative numbers for the fuel consumption and especially the cruise speed. I know it’s possible to find much prettier numbers in Internet, or even in the respective airplane POH, but let’s be realistic – very few machines and engines in the real life are rigged and tuned to the factory prototype standards. Even less of them are flown perfectly coordinated, and in a standard atmosphere conditions.

Aerodynamically clean planes are cutting through the headwinds much better – and newer planes are generally in a more decent shape than old machines. Turbocharged airplanes can also climb higher and take advantage of the strong high level winds and faster true airspeed – good for them!

So let’s treat those cruise speed numbers as a reasonably fair approximation to the real life true airspeed on the average calm day. We will also imagine that our airplanes have an infinite fuel supply, allowing them to fly the whole distance without intermediate landings (we’ll review this condition further). And off we go to our thousand-mile cross-country – distance by airspeed gives us time, time gives us fuel burn, gallons to litres, litres to dollars, dollars per hour… How much are we going to spend?

Name HRS Cost Time Δ Price Δ
Aeronca C-3 20 $328.86 100.00% 100.00%
Taylorcraft B 12.5 $301.46 62.50% 91.67%
Ercoupe 415 11.1 $328.86 55.56% 100.00%
Jodel D11 10 $334.34 50.00% 101.67%
Globe Swift 8.3 $296.89 41.67% 90.28%
Piper Pacer 9.5 $375.84 47.62% 114.29%
Cessna 170 9.5 $422.82 47.62% 128.57%
Bellanca Cruisair 7.7 $379.45 38.46% 115.38%
Stinson 108 9.5 $485.46 47.62% 147.62%
Piper Cherokee 8.3 $447.62 41.67% 136.11%
Mooney 20 5.9 $338.53 29.41% 102.94%
Cessna 182 6.3 $428.20 31.25% 130.21%
Rockwell Commander 5.6 $426.30 27.78% 129.63%
Bonanza V35 5 $411.08 25.00% 125.00%
Corvalis TT 3.8 $358.37 19.23% 108.97%

(In this calculations, 1G=3.78LTR and 1LTR=$1.45)

An obvious expectation was that the more money you pump in, the faster you make it to your destination. And this is true for what the numbers tell us in most of the cases. But interestingly, we never spend more than 20-30% of the base value for the whole trip – more powerful planes simply shrink the space and arrive so fast, they don’t waste much more money than the slowest clunkers. Just look at the grand champion, Corvalis – spending barely thirty dollars more it finishes the distance five times faster than cute Aeronca C-3!

Taylorcraft, Globe Swift, Cruisair and Mooney with their clean and efficient airframes bolted to a relatively small engines, shine bright demonstrating how to make lots of miles fast and efficiently. Try adding some struts, slats, fat airfoil, and get rid of the retractable gear, constant speed prop, or tiny cockpit for the sake of utility and simplicity – and you will have to pay money for slowing your ship down. That’s ok if you are making a sacrifice for another advantages – such as heavy hauling capacity, additional passenger seats or advanced STOL capabilities – but we are only talking the cross-country here.

Typically not seen as cross-country vehicles, 85-100 HP machines are still able to make a distance significantly faster than the lowest common denominator, and remain soundly economical. Popular all-around airplanes, such as the “midsize” Cherokees or Cessnas, are well within the tendency “spend a bit more, get there a bit faster” – nothing to admire or be surprised with.

And now let’s review the artificial condition with infinite fuel. This won’t happen in the real life – our lowly little clunkers with small tanks should land for refuel quite frequently. Keeping in mind the amount of time required to make the distance – at least one of those refuel landings will have to be an overnight stay. Good chance to spend all that money you’ve saved on fuel, in bed and breakfast charges! Probably even more, if you are with the passenger – and that’s besides being tired as hell after bobbing through the turbulent low-altitude air for hours and hours…

So what is the best cross-country ship? Is it a Corvalis or Cruisair, Swift or Mooney? I guess the answer depends on how much one is going to pay for a toy, so the sky is the limit. However, if we’ll think economy once again, the choice becomes smarter. Besides the price tag for the airplane itself, one complete overhaul of Cirrus may buy you a couple of beautifully restored Taylorcrafts. Add to that amount the insurance, maintenance and other expenses – and humble “family cruisers” from the middle of the list, such as Piper Pacer, suddenly start looking quite attractively.

On the other side of the spectre, how about imagining a Beech Baron or a Cessna twin compared to the numbers above? Result will be shocking – spending 2-3 times more those planes barely go any faster! How do they manage to stay afloat in the economical sense, then? Payload, baby – but that’s a totally different story…

Resuming, one can enjoy an easy to fly and relatively cheap to maintain airplane, bring a bunch of friends and some stuff – and make that thousand miles trip within a reasonable timeframe. You just have to leave with the fact that there will be a couple of hot rods leaving you behind in a race – but not by a really big margin, considering the price their owners have to pay to remain “first”. And that, I guess, is what something like Cessna 182 is all about?