Diesel Numbers
I just read the article in the March 2003 Aviation Consumer regarding the SMA diesel. I help manage a flying co-op named the Flying Country Club, Inc. We are a for-profit corporation owned by its members.
Weve been in operation since 1961 and have six airplanes including a Cessna 152, Cessna 172M, Piper PA28-180, PA28-181, Cessna 177RG and a 210L. Our member/owners pay both monthly dues and for flight time tach hours when they fly. We are located in the heart of the Midwest at Moline, Illinois.
A few things come to mind as I read the article. Id like to put them on the table as concerns I didnt see discussed in the article. The first one is that with increased cost and equity, youll also have increased cost of insurance.
If you ding a prop or land gear up, Id bet the manufacturer will still require a complete teardown and that will cost a bundle more than our current engines do.
Another thing is that in our climate, we need excellent starting systems. I also happen to own a late-model diesel truck and a 13-year-old diesel tractor. Both use glo-plugs to get them started and to fire up during stabilization.
My truck has a man-sized electrical system with two batteries and a 100-amp alternator. The tractor is similarly equipped. I didnt see any debit against the SMA diesel system for the additional weight of bigger batteries.
Also, a diesel engine is very different than a jet engine in the way it produces power. There are more heavily loaded parts in the diesel and also a fuel injector.
This is more of a question than a point, but has the EPA taken the lubricity out of the Jet-A due to sulfur reduction as it has to our diesel fuels for ground-based equipment? If they have, conditioners must also be added to the fuel, otherwise theres a severe penalty in the life of the injectors and the pump.
I didnt see the heavier weight of the Jet-A taken into account during the amortization of the extra 50 pounds. As I recall, Jet-A weighs 1.5 pounds per gallon more than 100LL.
This means that on the hypothetical four-hour flight, the SMA engine will burn 240 pounds of fuel and the Lycoming will burn 265 pounds of fuel. Thats 24 pounds difference and so we still have a 26 pound penalty.
I think what those in GA are looking for are cheaper engines, not more expensive ones. Were putting a factory remanufactured IO-520 in our Cessna 210 this month. With a decent core credit and all else involved in the exchange, it will cost us $30,000.
Weve gotten over 2200 hours on the three IO-520 engines weve had in the 210 since it was new. So how much will SMAs 300 HP diesel cost? Also, the biggest hurdle for any GA innovation is the FAA certification. Before I start shouting hurray, I think Ill wait for that to happen.
-Dennis J. English,
Secretary, Flying Country Club
Moline, Illinois
At this point, the engines effect on insurance rates is unknown and, given the variables, we hesitate to even speculate. However, there is no evidence that a teardown/overhaul of the SMA Diesel will be any more or less expensive than its gasoline equivalent, thus we dont see any change in insurance numbers for the prop-strike case.
The question regarding lubricity as a result of sulfur reduction is a good one and I dont have a ready answer except to say that such issues, if any, will be shared with turbine engine fuel pumps as well as over-the-road vehicles. The trend in the industry appears to be a substitute of a small amount of biofuel (2 percent) which is both a much better lubricatorand far less polluting than sulfur.
Fixing fuel lubricity (if it needs to be fixed) for Jet-A/diesel is easier than fixing the lead issue in gasoline. We havent heard anything regarding battery replacement and a new battery/batteries isntpart of the STC kit.
The article factored in the different weights of Jet-A vs. gasoline in its calculations.
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XL-2 Sport Pilot?
I am interested in airplanes meeting the Sport Pilot category requirements. From your article on the Liberty XL-2 in the March 2003 issue, it seems that it, the Eagle 150 and Katana Eclipse might satisfy those specifications.
However, you did not mention stall speed, which is one of the prime requirements. You also did not say much about the Eagle 150. Have you covered that in a previous article or do you plan to in the future?
-William Brin
Via e-mail
The Liberty stalls at 45 knots with flaps, 52 knots clean. Handling in the stall is conventional in all respects. Since the article was prepared, the company has agreed with our assessment that a wing step should be added to the trailing edge of the wing rather than the leading edge and we are told they plan to include that in the certified version.
While were at it, a correction: We reported that Liberty was considering farming out construction of the fuselage halves to Romania. Actually, its the metal work for the wings and chassis that will be done out of house.We reviewed the Eagle 150 in the April 2000 issue of Aviation Consumer.
Current information on the Eagle 150B can be found at http://www.hglaero.com/. The company has been quiet recently, but a check of FAA registration records shows they are still delivering airplanes, with two being registered in February to HGL Aero, the U.S. distributor. Total shipments of Eagles to date has been 29 since introduction in 2000.
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Interesting article on the Liberty in the March issue. I should point out a spec correction on the DA20-C1 Eclipse, however.
The usefull load for a typically equipped Eclipse is now averaging about 600 pounds since the gross weight was increased to 1764 pounds last fall. Usual equipped empty weights run about 1170 pounds.
-Jeff Owen
Diamond Aircraft
London, Ontario
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Missile Speed
I was surprised to read that you only got a 173 knot cruise out of the Missile, as reported in the March 2003 issue. They advertise 180-knot plus for the conversion. I was also surprised to read that you get 150 to 155 knots in a 201.
I have a 1994 MSE that I bought new. I have flown it to every state except Hawaii and to most of the Canadian provinces. As you know, the book speed is 168 KTAS. I constantly get around 163 knots at 8000 feet, even though the engine has 1700 hours on it.
I measured the speed a month ago after an annual. At 8000 feet, I flew north, east, south and west on the autopilot and averaged 164 knots at full throttle and 2600 RPM-around 22 inches MP.
I bought the airplane to go fast and far; I see no reason to throttle back in cruise. On long trips, I fly for four hours a leg and cover around 650 nautical miles in neutral wind conditions.
Eastbound, I take it up to 13,000 feet with a nasal cannula and get great range. I made it back to Chester non-stop from Peoria and landed with two hours of gas in the tanks. Thats 780 miles in five hours, burning a little over 8 GPH at altitude. It was a no-tailwind day so that worked out to around 156 KTAS.
The engine seems to like this way of flying. The annual recorded compressions are in the 78 to 80 PSI range. I have thought about the Missile conversion, but $90,000 for nine more knots would make no sense at all.
-Tappen Soper
Chester, Connecticut
Actually, note that we reported 183 knots TAS at low altitude for the Missile, at full throttle. The lower cruise value was at 65 percent power and 8500 feet. We also believe your 163 knots on a 1994 MSE, full throttle at a mid-altitude. Still, wed like to see a proper GPS-computed check of the airspeed indicator before accepting it without reservation.
Not many of the earlier J-models will deliver that kind of speed and we have tested quite a few. They are reliably in the 150 to 155-knot range, at typical 65 percent power settings. Some owners cruise a bit faster at higher power settings. We are skeptical of claimed cruise speeds faster that 160 knots at 65 percent power for the early J-models.
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Centurion Feedback
I enjoyed your coverage of the Cessna 210 series in the March issue. Our group operated a T210K for several years and I found it generally to be a very capable and pleasant airplane. A few things particularly stick in my mind, some good, some not.
We had small children at the time and the combination of its stable ride, high wing and low window sills made it ideal as a family hauler. Ride quality was simply superb. Visibility out and down was outstanding and the wing was well back so it didnt obstruct the pilots view as badly in turns as, say, the 172 does.
It was an excellent IFR platform and the turbo, while always a maintenance focus, gave it decent climb to get on top when icing was a concern. Cruise performance was good (we had a RAM engine conversion for 300 HP takeoffs) but it drank its share of fuel in doing so.
Control forces were significant and the CG envelope was wide. But toward the aft limit, the stick forces were light, quite out of character for the airplane. Conversely, with just myself aboard, I tossed a case of oil into the baggage area to avoid running out of nose-up trim during landing. Even though it was stable in cruise, I never felt comfortable operating into strips where approach airspeed was critical.
No matter how well we flew on final, nearing flare, the airspeed always wandered upward and the airplane tended to float rather unpredictably.By contrast, our Bonanza tracked right through touchdown as if it were on rails.
One downer not mentioned in the article was the frequent tendency for nosewheel shimmy. We constantly looked after the nosegear bushings, linkages and dampener with only limited success in controlling shimmy. It made operation into shorter fields undesirable because shimmy was so likely during serious braking.
Another problem was a walking tendency of the tubular main gear legs, which would shake back and forth during braking, especially on rougher fields, such as grass. The relatively small main tires made the ride worse on such surfaces. And, of course, the myriad switches and components in the gear demanded much more attention than the Beech gear I have worked with for many years.
I had at least three instances when the gear wouldnt retract, the power pack would not shut off or we couldnt get a locked indication during landing. We gave the gear plenty of attention.
The airplane served us well nonetheless until a partner suffered a dual mag failure within about five minutes, due to contamination of the Slick mags by the STCd pressurizing kit. (I believe an AD followed shortly thereafter addressing that issue.) Nobody was hurt but the airplane was history.
If I had to characterize the 210, I would say it was a great passengers airplane, while our Bonanza and Travel Air have been great pilots airplanes.
-Richard A. Lentz
Via e-mail
