UL/LSA Annex II Advice

aart wrote:

But maybe I’m wrong. What’s your experience on such ‘failures’ on the iS on the Atec?

Nothing so far of sensors etc on the engine.

Thanks LeSving, always good to get info from the field. I need to test fly an iS then, always interested in an (even) more smooth engine. But I suppose sounds levels clearly also depend on how the engine is installed, sound dampening materials or not, position of a parachute to serve as an isolation between engine and cabin and metal or composite or wooden airframe to name a few.

Having flown behind ‘Thielert’ Diesels I must admit that sometimes I got a little annoyed at the (mostly false) electronic & sensor failures so I am reluctant to get back to the gadget world, even if means a little more gas. But maybe I’m wrong. What’s your experience on such ‘failures’ on the iS on the Atec?

Btw I agree on the CS prop advantage. Not really in cruise, just a matter of convenience for short fields and some more flexibility to pick an rpm that is smooth.

aart wrote:

The engine is an ULS and not the modern ‘iS’. Minuses: More fuel consumption, more prone to carb icing (although usually not a real issue in Rotax engines). Pluses: simpler, very reliable and proven. The iS is more modern, electronic ignition, ECU’s and stuff but sometimes that extra complexity means more failures (or false failure warnings). You won’t fall out of the sky, but still could be a nuisance. So, an ULS is fine..

7. a RG brings more speed, but also extra maintenance and introduces another failure mode. I guess that UL aircraft designers have a very tight weight budget, so the gear may not be all that sturdy? In combination with rough fields that may be a problem? I have no experience, others may want to chime in.

the iS Sport is a much better engine than the ULS. Runs much smoother, use less fuel. On the glider towing aircraft we have had a bunch of problems with the carbs. That one is now converted to EFI (not by Rotax). The iS Sport in the Atec is a real iS. Obviously much more electronic gadgets, but I don’t think electronic gadgets are more unreliable than carbs. Then again the ULS on the other Atec runs just fine with carbs. never had any problems, except the iS is much smoother.

The Atec with the iS, also came with a variable pitch. That is changed to fixed pitch. Partly because it is used for training, but mostly because the variable pitch mechanism was already worn at 200h. Compared with a Lycoming/Continental CS it really is “light weight” and seemingly much too “light weight”. But there are different manufacturers here, with different designs. These panes have a stall speed of 35 kts and max cruse of 110-120. That is more than 4 times the stall speed, which will benefit a CS prop (or variable pitch as some are). Optimal cruise is probably the same though.

Changing the registry of an aircraft is potentially an open ended process, which at worst could leave it in a legal limbo from which there is no economically viable escape.

This is because the accepting registry’s CAA inspects it carefully, and usually finds stuff he doesn’t like.

When I went G to N a number of issues were found. It is fashionable to say that going EASA-EASA (e.g. PH to F) it is just a paper exercise but, for example, in one case I know about, the accepting CAA found that a very expensive avionics item was installed with the wrong STC; this was eventually resolved with some subterfuge but a proper fix would have cost well into 5 figures and comprehensively devalued the aircraft, as well as possibly resulting in litigation against the avionics firm which did the installation. The accepting CAA never saw the aircraft and found the cockup simply by looking at the paperwork!

Normally, with certified aircraft, you can park them anywhere within Europe… with some exceptions. But with uncertified aircraft there has been a gradual tightening of this – example – whose aim appears to be to force the owners to be on the registry of the country they are based in. France and the UK appear to have done this concurrently and therefore my guess is that there is an informal policy agreed among some CAAs to keep a lid on the size of the GA fleet which exists outside the “Part M oversight” sphere. So with one hand they give you some great privileges but with the other hand they take some away to make sure you stay where they can see you

This thread has tended to drift away from the “UL” subject to uncertified generally, but the issues are similar.

Peter wrote:

This comes up fairly frequently in aircraft sales.

The seller will (and should) always walk away from such a condition, because it can be totally open-ended.

Why would a seller be against a buyer reregistering? I’m looking at planes to buy in Europe and haven’t come across this yet. Just curious.

aart wrote:

4. The DUC prop is unusual to be used on the Bristell. Check what the advantages are. Maybe weight. May also have to do with better characteristics for glider towing?

Having looked into buying a new Bristell, the DUC propeller is just one of the factory-offered prop options. The options list says it is 5.5 kg additional weight. I’ve spoken to the broker for this particular aircraft and IIRC it was never used for glider towing.

you may want to make sure that the deal includes a guarantee that you’d be able to re-reg it.

This comes up fairly frequently in aircraft sales.

The seller will (and should) always walk away from such a condition, because it can be totally open-ended.

The only way it might work is if the seller wants to move the reg anyway to sell it. For example it is much easier to sell an EASA-reg than an N-reg nowadays.

I can’t comment on the Breezer other than it’s an LSA which may not be able to be downgraded to an UL in Austria (see item 2 below)?

The Bristell is indeed a very well equipped aircraft. Some comments:

1. It is almost certainly the ‘HD’ version, with a stronger wingspar and therefore suitable for 600 kg MTOM. The parachute more than covers that weight. Do check though.

2. Assuming you would want to re-reg it to Austria, do check whether your country goes for the increase in MTOM to 600 kg. If not, from a legal point of view you will have a severe payload limitation as this aircraft will have a empty weight of approx 350 kg (you may want to check that weight with the seller anyway). Also check if Austria may have other limitations imposed on UL aircraft equipment, like in the area of avionics. The other parameters changes that go along with the MTOM increase 600 kg (empty weight, take-off distance, stall speeds) should not be a problem for the Bristell. Basically, what I’m saying is that you may want to make sure that the deal includes a guarantee that you’d be able to re-reg it.. Same goes for the Breezer.

3. It has a rear view mirror. Assuming that is not meant to spot aircraft behind desiring to shoot it down, it was used for glider towing. Maybe a thorough check on any adverse structural consequences?

4. The DUC prop is unusual to be used on the Bristell. Check what the advantages are. Maybe weight. May also have to do with better characteristics for glider towing?

5. The in-flight pic indeed shows close to 115 KTAS. I’m a little puzzled though by the power setting and fuel flow. Power setting in the pic corresponds to about 65%, and the fuel flow I see in my Bristell would be around 18-19 lt/hr. The picture shows a quite high FF of 22.7. It also shows a green annunciation of ‘Fuel Pump’ in the PFD, maybe that has to do with it. Anyway, the seller claims a FF of 15 (which is obviously at a low power setting/speed ). Assuming you would increase the power setting from the one in the pic to something like 75% you may get 10 KTAS more..

6. The engine is an ULS and not the modern ‘iS’. Minuses: More fuel consumption, more prone to carb icing (although usually not a real issue in Rotax engines). Pluses: simpler, very reliable and proven. The iS is more modern, electronic ignition, ECU’s and stuff but sometimes that extra complexity means more failures (or false failure warnings). You won’t fall out of the sky, but still could be a nuisance. So, an ULS is fine..

7. a RG brings more speed, but also extra maintenance and introduces another failure mode. I guess that UL aircraft designers have a very tight weight budget, so the gear may not be all that sturdy? In combination with rough fields that may be a problem? I have no experience, others may want to chime in.

Go and test fly it!

Hope this helps.