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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 October 26, 2008A subscriber asks us to publish the story of his nightmare with his Diamond DA42…David Akel, retired FedEx Airbus Captain (30 years) in Memphis, TN, reports: Over 150 DA-42 (Diamond Twinstar) Owners in the United States are now grounded due to fraudulent concealment and what appears to be corruption on FAA certification of this Daimler Chrysler diesel automotive engine for aircraft use. Some engines did not even last 190 hours on a $600,000 aircraft, with warranty canceled by Thielert and Diamond refusing assistance on the aircraft that they manufactured and sold, and were solely responsible for selecting the defective Thielert 1.7 engines. I signed a purchase order with Premier Aircraft Sales in Ft. Lauderdale for a 2006 Diamond DA-42 on May 14, 2007. Purchase price was $560,000. At the time I was an A-300 Captain for FedEx and was planning on using the DA-42 to supplement my retirement at age 60 in October 2007 by leasing the aircraft to a flight school in Atlanta. Before accepting delivery of a Premier DA-42 demonstrator with 140 hrs, I requested in writing to cancel my purchase due to defective Thielert engines, as evidenced by double flame out and crash, multiple mandatory service bulletins, as well as engine seizures. The request was denied and as per contract I would lose my $56,000 down payment. The first 6 months I averaged a monthly gross of $10,600. Then in April, after performing a service bulletin, a broken piston cooling nozzle was discovered, requiring a replacement engine and grounding the aircraft. A replacement engine was promised to be shipped May 6 2008. However Thielert, the engine manufacturer, declared bankruptcy. Diamond Aircraft Industries executives would not even acknowledge my multiple Fedex requests for help in asking what my options were to get my DA-42 airworthy and back in flight school service, as the bank note, insurance, etc. was $5000/month. This Thielert engine (Centurion 1.7) was certified by the FAA in November of 2004. The engine is a 4 cylinder 135 hp diesel automotive engine made by Daimler Chrysler which Thielert converts for airplane use by adding a gearbox and other aviation specific parts. The FAA approval surprised many industry observers because it entailed producing an engine with parts that the manufacturer (Daimler Chrysler) would not verify. Another FAA first is certification of this engine with 1000 hrs. TBR (To Be Replaced). Diamond quietly started production in late 2005 to replace these defective Thielert 1.7. I also paid $63,000 for the TKS known icing option, which Diamond published as certified for known ice, but it was not certified until March 2008 and only then after performing a Diamond Service Bulletin. Diamond also supplied me with a break even analysis for consideration before purchase showing Thielert 1.7 engine as 2400 hrs TBO with no mention of engine replacement at 1000 hrs. There are 150 DA-42 in USA and most if not all are AOG due to either broken cooling nozzles or cracked cylinder heads. The 2 year warranty on the engines is gone, and any replacement parts or engines are now cost prohibitive as the insolvent Thielert has jacked up the prices 3 to 4 times and will not honor warranty. The dealer has offered nothing but mediation and arbitration as per their contract, and Diamond has offered a customer assistance program with conditions to their ‘valued customers’. If an owner will sign a liability release, then Diamond will put you in the queue for one of their Austro Engines, when it becomes certified. Certification in the US will not be until late 2009, and will require a retrofit STC certification. This will require gutting the aircraft from firewall forward and beefing up the landing gear as the Austro Engine is 84 lbs heavier than Thielert 1.7. Production limitations may push the conversion option to 2010 while your DA-42 sits AOG. However, in return for signing the liability release, Diamond will reimburse their ‘valued customers’ up to 30% of the price of their Austro Engine. DA-42 owners purchased their aircraft from Diamond, and Diamond selected the defective Thielert 1.7 engines for their DA-42. Diamond cannot abdicate responsibility and must cover loss of use as well as the cost of new engines for their DA-42's either out of franchise integrity or by court order. Comment from DieselAir: We are ready to publish answers from Diamond and Thielert… posted at 4:32 AM News of October 12, 2008Thielert bids receivedA savior for diesel propulsion manufacturer Thielert Aircraft Engines may be about to emerge. A spokesman for the German company's administrator says ‘several’ prospective bidders have submitted letters of intent, with "purchase prices within the range the administrator is expecting" a statement on the sale is expected ‘shortly’. A total of 24 potential investors had by late July signed a confidentiality agreement to receive financial details on the company. However, Diamond Aircraft, Thielert's biggest customer and the only general aviation manufacturer to fit its Centurion engine as original equipment, rules out taking over its former supplier. It comes as Austro Engine, the engine maker set up by Diamond, prepares to deliver its two-liter Jet A1-powered AE 300, an alternative to the Centurion. The Austrian company's marketing and sales director Markus Hergeth expects European Aviation Safety Agency certification this month. There are 2,000 Thielert engines powering Diamond s DA40 and DA42 aircraft, retrofitted Pipers and Cessnas, and versions of General Atomics Predator unmanned air vehicle. (By Murdo Morrison, Flight International 9/08) posted at 11:36 AM The forgotten secret of the superb German diesel flying boats.
 (Dornier 26 - Doc: HistoricAircraft.org) Between 1930 and 1945, flying boats for transport were fashionable because the world was lacking runways, especially big runways for big planes. A flying boat doesn’t need a runway. So the jetset of the days was travelling in Boeing 314s, Martin 130, Sikorsky S-40, 42 and 44, Liore-Olivier 24 and 26, Short Calcuttas and Empires… Germany built many flying boats for various uses, most of them using the Junkers Jumo 205 diesel 2-stroke opposite pistons, with powers from 600 to 880 HP. Best knowns were the Do-18 twin, and the Blohm & Voss Ha 138 and 139. The most beautiful, and possibly the most beautiful flying boat ever made, was the Do-26 See Adler (Sea Eagle), which could carry 4 passengers plus crew of 4 and mail from Lisbon to New York, or during the war Bathurst to Natal, and back. During the battle of Narvik in early 1940 Do-26s were carrying 18 troops from Germany to northern Norway. The Do-26 weighed 25,000 Lbs empty and 50,000 Lbs at take off, therefore she could carry her own weight: So much for those who think that diesels are heavy… Top speed was 185 kts. Cruise economy speed was 135 kts and range was almost 4,000 NM. And this leads me to disclose the secret of these diesel flying boats. You certainly agree that the power a plane needs at best economy speed is much less than the power at take off. How much less depends on the design. The most economical plane would be the glider if it could glide for ever, which is why the most economical planes, and therefore the ones with the longest range, are the ones with a high aspect ratio (ratio of wing length to width) giving them a lower induced drag and a most efficient gliding ratio. A classical example was the Convair B36 strategic bomber of the fifties, which had an aspect ratio of 13 and could cruise at 230 kts for 9,000NM without bombs (ferry range). Its six R-4360 engines were delivering 1,000HP at cruise speed against 3,500 at take off. Therefore, to obtain a long range, basically you need a high aspect ratio, and an optimal cruise speed of some 1.3 to 1.5 times stalling speed clean. And here comes the problem with gasoline engines: at 1/3rd to 1/4th their nominal power, the specific fuel consumption (fuel consumed per HP-hour) becomes lousy because combustion is no more in optimal conditions. At same fractional power, the diesel is as efficient as at full power. So maintaining cruise speed may require down to 50% of the fuel flow needed with gasoline engines operating at same fractional power, meaning so much more range. The Germans therefore said: the future of air transportation is the diesel flying boat flying at some 1.3 to 1.5 Va with a high aspect ratio. And they demonstrated it. Then, in 1945, the secret was lost. Nobody was interested anymore in such planes when one could buy a surplus DC3 or DC4 for a song, and use all the runways built during WWII, and when the future so obviously was the turbojet. But today? A cargo diesel motor glider with a very high aspect ratio cruising around 100 kts could very well again be the most effective way to ship goods by air. Eventually, a very big one. Think about it while looking at the plane here under: Do you recognize it?  (Doc. www.ussr-airspace.com)
posted at 8:36 AM News of October 06, 2008Of diesel versus gasoline fuels...We answer here a question from a reader, question which we read quite regularly, and comes from incorrect information about what is a diesel engine: Q: I've been reading about the advantages that diesel will bring to general aviation. We can extract more energy from one gallon of diesel than one gallon of avgas, they are expected to be FADEC, turbo normalized, as well as a few other items. Lycoming just came out with the iE2 electronic engine which they say in the future will be able to burn Avgas, Auto fuel, and heavy fuels (diesel and Jet A I'm assuming). But I have two questions. A: You are right that diesel extracts more energy from one gallon of jetfuel than a gasoline engine from one gallon of Avgas. This is due to higher efficiency in terms of how much mechanical energy is extracted from thermochemical energy available. But this is not the sole advantage of diesel by far. I think that the first advantage is the almost constant specific fuel consumption (Lbs of fuel per HP-hour) which allows extending the range dramatically when reducing speed in an emergency. See our previous papers on this. I do not expect the new Lycoming to burn diesel fuel as well as gasoline. Q1. There are after market FADECs for my continental engine that can be installed by GAMI and Aerostance. Is that all that is needed to switch to Mogas or Diesel. A. Absolutely not. To switch from any kind of gasoline to diesel you need to replace your engine/engine mount/heat exchangers/propeller/engine instruments combine by a completely new one including a diesel engine. Q2: If the new engines can use Diesel or Jet A, but are not used in a diesel cycle engine, do you know if I can still get the extended range using Diesel fuel as oppose to Avgas. A. A diesel engine can only be used in a diesel cycle. It means: Compression ignition (no plugs, no magnetos...), very high compression ratio. And it can only use a diesel fuel such as motordiesel, JetA, or biodiesel fuel. posted at 3:58 AM |
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