I thought it would be documented in the POH.
Thank you for your answers
Holy Moses, what have I been doing? Should have flown with one engine!
If your numbers are really correct (better test them, the asymmetric flight should cause massive drag, I would think it is much worse), then yes. Just make sure you alternate between the engines so that when you sell the airplane, you don’t have to present this hardly credible explanation as to why the engine hours differ 
The DA42 has both engines turning in the same direction, i.e. a critical engine. This means asymmetric flight characteristics depend on which engine is off, doesn’t it?
A few DA42 comments………engines…….
A year or two back I did attended the DA24 & Austro engine maintenance course at the factory ( followed a week later by the Thielert course).
It is clear that the decision by Diamond to change away from the Thielert engine was largely political following the problems that resulted from the interfacing of the Thielert engine and Diamond airframe.
Austro engines have used the Thielert experience to built what I would consider to be a very reliable product but at the cost of a considerable weight increase over the Thielert engine.
Being the first engine of its type on the market Thielert suffered from the inevitable teething problems and these were seized by the aviation Luddites to criticise the engine………… Mostly because they failed to understand it ! Thielert have come a long way and the 2.0 is a far better product than the 1.7 and I’m sure that it will match the Austro in terms of reliability.
Airframes………..
Unfortunately there are very few real experts in the maintenance and repair of composite structures resulting in some very bad advice given to owners, a lot of parts are getting replaced with new items that could have been repaired at an attractive cost and when ever a composite aircraft has an accident it is a race between the Luddites who want to cut it up because they think it is scrap and the insurance company who know that in the right hands the aircraft can be repaired, I know of one maintenance company that was found sawing through the spar pin retaining fittings of an aircraft that they considered a write off….. The aircraft is now flying following the repair by one of the few company’s with a major repair approval.
It is for the owner to decide who he takes his aircraft to for maintenance but you should know that there are very few Diamond ( or Cirrus) service centers that are capable of all but the most basic airframe repair so if you are unfortunate enough to need a composite part repairing call Diamond UK ( or Cirrus UK ) and they will put you in touch with people who can repair composite parts and release them under EASA 145.
Austro engines have used the Thielert experience to built what I would consider to be a very reliable product but at the cost of a considerable weight increase over the Thielert engine.
I would say that they have basically undone most of the weight saving improvements to the Mercedes design that Thielert did. In addition, they eliminated the clutch for a torsional dampener. It is a much less sophisticated engine and it’s sad they had this political fallout. Thielert 2.0 and 2.0s appear to be fine aero engines which is a miracle given that they are under stress the original Mercedes engine was never designed for (Mercedes-Benz A class, driven once a week at max 40kph by 70 year old).
I think that if I was building planes, and due to the engine maker’s bankrupcy I had a factory full if airframes which could not be sold and which had the potential to bankrupt me, I too would be making some big move to get independent of that engine maker – regardless of how good their current product is.
In both business and private life you normally avoid being bent over a barrel – even if it costs you money
Also it is far better for the gross profit on the engine building to be going back to one’s own pocket, than feeding an outside company.
More so if that outside company is known for some interesting but childish accounting “practices” which everybody who has been in business for more than 5 minutes will know will eventually come to light.
I too would be making some big move to get independent of that engine maker – regardless of how good their current product is.
Or maybe use a small percentage of the cash sunk in your own development of the same engine in a less sophisticated version and buy the insolvent company?
Or maybe use a small percentage of the cash sunk in your own development of the same engine in a less sophisticated version and buy the insolvent company?
I am sure Dries thought about that. It would be fun to be a fly on the wall
Also you can’t buy a private company unless the owner wants to sell. There is no way you could buy my company for example. Well, you could spend say a million on lawyers to start a purely frivolous fabricated “harrassment” lawsuit and after running this for a year I would probably sell up (that is how the UK tax people collect 10k-50k from small businesses – running a mostly baseless “enquiry” for a year).
I can imagine Thielert not being for sale anyway, because any prospective buyer doing due diligence would have found the creative accounting in the few minutes it takes to open the ring binder labelled Unpaid Sales Invoices. And once they were in administration, the administrator presumably had other ideas…
I am sure Dries thought about that.
From what one reads, both are similar characters. This was probably a case of warfare between the two men. When I saw Dries, I never had the impression he suffered from low blood pressure…
Also you can’t buy a private company unless the owner wants to sell. […] And once they were in administration, the administrator presumably had other ideas…
You can when the company is under insolvency proceedings. A court appointed insolvency administrator has the complete say over all things, the existing management and owners are mere spectators. Generally, a quick sale which keeps the business and workforce is what everyone is aiming for. Thielert was a very long procedure, not normal in Germany for a company of that size.
An insolvency also means that all contractual obligations of the company can be nulled so the administrator can make turn it into an attractive package.
I know first hand that Kübler tried to pitch Thielert to just about everybody remotely involved in aviation and engines. The problem was that there weren’t a lot of interested parties with Dries starting his nonsensical “let’s do the same engine again but worse” project. In the beginning Kübler had unrealistic ideas about the price I heard (but I was told by a prospective buyer so he would always say that, wouldn’t he?).
There is no way you could buy my company for example.
Check the trade register documents. It might already be mine. After all, I know a bit about computer systems and their flaws
If your numbers are really correct (better test them, the asymmetric flight should cause massive drag, I would think it is much worse), then yes. Just make sure you alternate between the engines so that when you sell the airplane, you don’t have to present this hardly credible explanation as to why the engine hours differ The DA42 has both engines turning in the same direction, i.e. a critical engine. This means asymmetric flight characteristics depend on which engine is off, doesn’t it?
Yes, left engine is critical. Before I go to sleep will re-read how to minimize drag. IIRC, rudder and a bit of bank into the working engine, but maybe I should leave the work to George, the GFC700 that does it all so well. Will report back. Only if the results are favourable of course.. But most important let me first try and convince my wife that I have a valid excuse to go fly tomorrow. I treated her well for Valentine’s so maybe I get a green light.
Some single engine testing today.
ISA conditions, at MTOM: simulated a stopped engine by putting it at 10% power (accurately simulates a feathered engine), working engine at 80%. 107 KIAS.
So 17.2 NM/gal (vs. 11.8 NM/gal on two engines).
A bit counterintuitive, like Achim said. But all tested in stable flight, on autopilot. But then again, the difference between 135 KIAS and 107 KIAS corresponds to a lot of power/drag.
No difference between right and left engine shutdown.
Any other twin flyers here have similar results?
