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When will a diesel be available for my aircraft? |
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News, facts, and comments on the coming revolution for piston-engine aircraft.News of May 18, 2005We flew the Cessna 182 SMA during the Discovery Event on May 16 at PDK …On May 16, The DieselAir Newsletter (Publisher Yours Truly) and Atlanta PDK Airport’s Wings & Things pilot supplies shop (Proprietor Leonard Harris) organized a series of discovery flights with FlyJetA’s demo Cessna 182Q N 200ER converted with the SMA 305-230 diesel engine. Fly Jet A LLC, CEO Patrick Canivet, is the Florida distributor and service center licensed to execute the conversion, and operates two 182 SMA’s. Patrick came himself with pilot Bob Ohlinger. SMA was represented by Thierry Saint-Loup, Senior Field Support engineer. 20 visitors came to see the plane, and 6 discovery flights took place with local pilots owning a 182 and considering their options at next TBO. We learned a lot about SMA during this event, see next paper. N200ER has been completely refurbished, looks and feels like a new plane (no, there are no oily diesel smells). The nose is very different from a standard model, with 4 air intakes positioned like eyes and gills of a shark. So is the massive 3-blade propeller. When you open the hood, one notices that the 4-cyl. engine is very small (it has only 305 c. u.), and positioned in front, the space available behind being used for the heat exchangers, and the turbo being located where the carburetor used to be. The dashboard displays a full IFR equipment with the now classical Garmin 430-530 combination, but the 3 usual throttle-propeller-mixture controls are replaced by a single throttle controlling power. The propeller pitch is automatically maintained at 2,200 rpm, and the small manual pitch control is used only during the run-up check. The manifold pressure is in the green up to 85 PSI, which explains clearly why such a small engine can generate 230HP at only 2,200 rpm, and will soon generate 300 HP at 2,400 rpm. The engine starts at the very first solicitation, like any diesel, and one notices at once that it is less noisy than my good old O-470. Before leaving the tie-down we conducted a noise comparison test with my own 182, running each engine at 1,000 then 1,700 then 2,300 rpm. Absolute decibel figures would be meaningless since we were not in conditions to control environment, but we can state as certainty that at all speeds the diesel was 2 decibels less noisy than the O-470, which is a very significant difference. During taxiing one notices the accuracy of the throttle which I will discuss later. Run up, clearance, take off. During take off, acceleration demonstrates the strong torque. So do the rotating and initial climb. Again the torque gets your attention: more right rudder than usual, and the climb rate is very good. I can confirm that a diesel of identical nominal power has more kick to accelerate and climb than a gasoline engine, which is by the way well known of European car drivers. (Diesel automobile represent today some 40% of car production in Europe). I established a cruise, then a slow speed flight to give my passenger time to look at the Stone Mountain’s famous bas-relief sculptures, then a maximal rate climb at 80 knots and got at once to a stable 1,200 ft/mn. We refueled the plane, for the sheer fun of surprising the Jetfuel truck driver, not at all used to refill a high wing Cessna. Patrick showed us the plane logbook: The 49 gallons we put in (N200ER is a Q model with 92 gallons tanks) corresponded to a bit more than 6 hours of flight, including the six discovery flights meaning take offs, climbs and play arounds. So we were witnessing a bit more than 8 gallons/hour. Patrick said to count on 9 gallons at maximal cruise. This means savings of at least 4 gallons/hour. But the picture of a small piston engine plane being refueled with Jet A sends another signal: Now we don’t need Avgas anymore… This is the future. The 182 SMA keeps all its promises so far. I want to insist on what impressed me the most: On final approach I crossed the usual turbulence before runway 2L touchdown, well known of student pilots and so good for training. I controlled sink with the throttle. Again the accuracy is amazing and the feel is completely new. Coming back to my 182, suddenly the throttle felt mushy, gargly, and uncertain. When you move the throttle of a diesel to a position, it gives you an exact power. You move it backwards just one bit and get another slightly lower power. And you forget leaning the mixture, squaring the prop and manifold, pulling the carb heat, or checking the CHT (CHT monitoring during initial climb with 10º flaps at full load is a fascinating skill in our hot, muggy climate). This power control is so accurate that you envision at once how easy it will be for ATC, in an emergency, to override the A/P and take full control of a plane when the pilot had a malaise, including lowering the speed to 4 gallons/hour and establishing the exact approach speed for an automatic landing. I will prefer that to any parachute. “Ah! But if you lose your engine?” Will you ask. I answer: how? There is no ignition, you can turn off the contact and the master switch, lose your battery, and it keeps running, only 450 moving parts instead of 2,500… When you open the engine after 2,000 hours the parts are so clean that you still see the honing marks in the cylinders; it runs on synthetic oil in which it is hard to find a trace of metal… Jet fuel use sets you free of any practical fire hazard… I am ready to cross the Atlantic with such a plane. posted at 12:50 PM |
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