Admin :
Merci de ne pas répondre ici au message (ci-dessous) de Corvus Hungary.
Continuer ce sujet là où il a été recopié : Avis de CORVUS HUNGARY sur UL POWER
I'm Sandor from Corvus Hungary, the manufacturer of the Corvus Fusion, which we have designed and built as an UL /LSA aircraft but also for aerobatics. For this goal, we have tested the UL Power 260 iSA engine, with very sad results. Please find my notes in the mail I have sent to UL Power right after we decided not to work with them.
Just for Your info, Corvus Hungary might be known for many of You, now we are relocating our production to China, with assembly in Italy and plan to build some 40-70 aircraft in 2013. I have shared this also with UL Power management, but they did not take us seriously..Well, bad luck for them, but better not sell a good aircraft with an unreliable, untested engine..
"UL Power issues
Since we started the cooperation with UL Power we experienced couple of problems, which led now to a situation, which has a very serious effect related to our aircraft normal production process and productivity, and herewith we announce to finish our cooperation with Ul Power.
First, as we ordered our first engine though we paid it as agreed, the delivery was delayed with at least two, also the second shipment of 3 UL Power 260iSA was in delay of 3 weeks.
Right after we installed the engine into our prototype, and started to test couple of propellers, we experienced that there are not too many options, and we need to use a constant speed prop, but for those there is only a few options, without any good controller..The only prop worked more or less okay, was the Woodcomp 3000 BJ, electric constant speed. Without variable pith prop, the engine delivers much less power and has very high consumption.
The performance of the engine was not really what we expected, right after we had the comparison with the Rotax 912 ULS conventional aspirated engine, we experienced that the Rotax has far better consumption, performance and first of all much better after sales service.
Just for comparison: straight and level flight at 75% power with:
UL Power 260 iSA: 123 kts, consumption 19 ltrs/hour
Rotax 912 ULS: 134 kts, consumption 17 ltrs/hour
No comment…
After the first problems with electric system, fuel system were experienced during flight we have sent couple of emails requesting company support, but in more than 6 months nobody visited us or gave any useful support.
The first plane which we have sold to our Romanian dealer was also a fiasco. Right after the first handover the client’s chief pilot had to make an emergency landing on an agricultural field, luckily neither pilot nor plane was damaged.
After the inspection of the engine, plane and systems we found the problem caused by the fuel pump, more exactly the lightweight fuel pumps, which were never tested by UL Power in any flight condition. They are proven as for NOT appropriate to pump out any air from the system and this leads to collapse of the fuel supply and the engine quits.
With the bigger pumps this problem could be eliminated. But also this was only clear after our experiments, without any company support from UL Power.
We do not understand why UL Power sells fuel pumps, which can not be used for aerobatic in an aerobatic engine?
Now, the second emergency is also happened, luckily without any damages again, now due to the regulator failure.
The reason: small regulator which cannot be cooled enough, the capacity of regulator (small size) is insufficient.
Another very disappointing feature the low rpm or idle run of the engine. With a modern fuel injected engine it is unacceptable to run on idle with too much rich fuel also it is not safe. The piston heads, sparks get black due to coal surplus which can decrease performance and in an emergency it can be also dangerous. A modern new built engine must be able to handle a constant speed, eg. Variable pitch prop electric and/or hydraulic. However electric controlled props are not allowed and designated for aerobatics, but there are no sufficient controllers for such props due to lack of pick up ports, the Hall sensor or even injector based pick up is not reliable. Vibration of the engine is also a question mark from the side of the prop manufacturers. Huge forces are on the prop due to the pistons movements of the relatively big engine. There were only a few fix pitch props which were tested on this engines, which is also unacceptable. We bought something that cannot be sold and we do not get the advantages UL Power promised. Some of the parts are changed without any prior notice, alternator fans get loose and we have also lost one in flight, and it could have led to a tragedy if the fan’s sharpe edge cuts the oil and fuel lines!! This is also just due to lack of testing of the engine.
We have requested Dyno data to recheck those, but never got. There are no references for the engines.
Corvus Hungary has spent more than 6 months for test the UL Power engines, has spent more roughly 120,000 Euros for engines and repairs, travel costs, experiments, tests with different props and controllers without any success. We wanted to send those engines back to You as manufacturer which we got with huge delay, but even You do not trust Your engines, and did not want to take them back,.,.
Due to the total lack of support from the side of UL Power, herewith we announce to stop every and any kind of cooperation with You."
Admin :
Merci de ne pas répondre ici au message (ci-dessus) de Corvus Hungary.
Continuer ce sujet là où il a été recopié : Avis de CORVUS HUNGARY sur UL POWER