skippydiesel

Sounds like a great aircraft Blue however the performance figures don't lie: My Zephyr, with a 912ULS, sub 30 knot stall, 300 kg empty weight, very comfy for two, with ergonomically laid out controls and large baggage space - 100 knot Cruise @ 5200 rpm, ground adjust able prop, advantage TO, consistently delivered an average fuel consumption a bit over 12L/hr (single pilot) Flight planned at 14L/hr- Topped out at 120 knots, 5500 rpm at sea level. My Sonex 912ULS, CS prop, 37 Knot stall, 340kg empty weight, squeezy for two, limited baggage volume - Crusie 130 knots @ 5000 rpm, 25" MAP, 14.25L/hr Flight plan at 15L/hr - tops out at 147 knots 5500 rpm. Check out 912ULS powered ATEC Faeta, Pipistrel Virus SW - there may be other low stall/high speed cruise light aircraft. The Fatea has particularly good luggage capacity. As far as I am concerned - anything that flies is wonderful and if it meets your wants thats all that matters. Personally I like economy (without it I could not afford to fly) so the combination of low fuel consumption, with good speed (low trip time) "ticks my box" 😈

Wow! That's one draggy aircraft 😈

Am I the only person who thinks the changes to the Virus SW performance figures (STALL/high speed Cruise) since Pipistrel was bought out by Textron are a tad strange? It would seem that the change of ownership has increased Stall from 30 Knots to 43 Knots and high speed Cruise from 135 Knots to 147 Knots. Under the previous ownership, this aircraft won several CAFE foundation competitions ie its performance was established by an independent third party.😈

Yes. There seemed to be a bit confusion, so I tuned out. Sorry!😈

It seems that Government departments (or is it just human behaviour) feel compelled to fix/change things/systems that aren't broken. The BOM has really gone insane on this change - how on Earth can they justify $96.5 million. The $4million, first figure, was crazy enough. The money must be coming from US THE TAX PAYER - would have been better spent on education/hospitals/ etc. Criminal charges should ensue (not holding my breath)😈

Thanks Rodgerc - Will look into it😈

Sad day. Baron/Bonanza are incredibly handsome aircraft. The replacement -Denali is somewhat lacking in the looks department and appear to be a much larger (Class) of aircraft to the B & B.😈

"Class C ".......... "typically transponders are referred to by mode, not class" Yes. My bad. Dont know what I was thinking of. While we are on the correct grammar /technical terminology; ".............there are ADS-B out transponders, and yes, there are ADS-B receivers,.." My understanding of the word "transponder" is that it is made up from transmit - respond. So transponder refers to a device for receiving a radio signal and automatically transmitting a diffrent signal in response. In aviation the same devise (if so capable/enabled) both receives & transmits -ADS-B IN/OUT. The SE2 does this. So your description, above is, when transponder & receivers is used, is incorrect, as receiver is redundant. That is unless you are referring to a seperate device/system altogether.😈

"..... the main purpose of turbocharged aircraft engines is to maintain manifold pressure and power at altitude ..." I think this is well understood by all. The thrust of my curiosity, is not the reasons for using a turbo charger or how it works but why was a simple wastegate was not used for the 914. Without anyone actually stating the reason, it seems likly that the (Rotax designers) desire for what is an extreme altitude (33,000ft) for the vast majority of recreational level aircraft, is that reason. Success in this venture, carried over into the production engine. I think it highly likly (speculation) that a mechanical wastegate system could have a Rotax 9 operating to 20,000 ft. Comparisons with Turbo LyCons & similar is questionable. Remember the Rotax 9's use an automatic diaphragm carburettor mixture control (no pilot input)- as far as I know, no legacy aircraft engine does this.😈

From the Rotax Owners Forum; "In 1993, the Rotax 912 engine was modified and equipped with a turbocharger for an altitude flight test. The airplane (HK36 Super Dimona model) reached an altitude of 33,000 feet (approx. 11,000 m). The concept was successful. The company started the development of the turbocharged Rotax 914 engine with 115 hp, and serial production began in 1996." It would seem that the desire to achieve high altitude flight, may have been the reason for selecting a TCU, rather than a mechanical wastegate. I am assuming that a mechanical wastegate would not have the "range " to respond to sea level - 33,000ft changes in atmospheric pressure.😈

"I believe you will need a mode C transponder or higher (Skyecho will not cover it) and a VHF radio (but not a second radio)." Transponders I get a tad lost with transponder designations - Class C is on the way out ? and has been for yonks. If correct then its Class C that does not show up on ADSB IN/OUT transponders - so not on SE2 bluetoothed to an iPad. A safety issue that should concern every pilot transitioning/operating in, congested airspace. Transeviers/Radio You are correct in saying "....VHF radio (but not a second radio)" however it would be more correct to say not a second listening frequency. Again this should concerne all pilots operating in congested airspace - ALL pilots should be listening out on Area Frequency + their operating frequency. That the authorities accept single channel radios, in congested airspace, is an unnecessary risk to us all. NOTE: Its probable that the recent loss of three lives (2 aircraft) at The Oaks, could have been prevented, if the ancient C180 had an operating ASB OUT and/or a two channel radio (Area Frequency & The Oaks CTAF)😈

"Has that been confirmed, or is it just a CAsA wish-list item aired at the info session?" Confirmed? - a bit of yes and bit of no. Yes, verbally at the meeting and on the latest VTC maps - all Lanes have a red box with the words "Clearance Required". No, as in not yet implemented and who knows what may change between now and then. Note; Victor One looks to be unchanged , as does Richmond - the latter a bit unclear as I think Richmond Military ATC have always controlled this Lane. 😈

"Having to overfly Bankstown going north and south has also been known for a while." Yeh! But did you know the VFR Lanes of Entry will also require a Flight Plan???😈

I recently attended a meeting where the airspace changes to for the new airport, variously known as Western Sydney International (Nancy Bird Walton) Airport (IATA: WSI, ICAO: YSWS), also known as Badgerys Creek Airport or Western Sydney Airport, were discussed. Cant say I grasped all of the changes put forward however this is what I "took away"; For VFR aircraft wishing to transit north/south & visa versa through the Sydney Basin. There will be a new North & South Lane established, that will run from the vicinity of Campbelltown to Bankstown. Aircraft using the exiting N & S Lanes (Paramatta - Brooklyn Bridge) will access the above via Bankstown. Now for the killer - To use the new Lanes will require; The lodging of a flight plan The PIC holing a Controlled Airspace Endorsement Something Else; RAA approval to train and endorse Recreational Pilots, to enter Controlled Airspace, will be granted before Christmas (this year?). The existing Victor 1 rout is unchanged. The current Camden Inbound Reporting point, for aircraft coming from the West ,will be moved about 3 Nm north (Hayters Sawmill) to encourage aircraft away from The Oaks circuit area. 😈

Unlikly - ASIC is (at the moment) tied to Security Controlled Airfields, not Controlled Airspace. I have an idea that a similar/same system applies to certain Au ports. Practical problem - How would ATC determine that the pilot entering CTA has/or not an ASIC? Wave their card at the tower, as they pass overhead at 500ft (Min) above circuit height? 😈

Not necessarily -Home Affairs may be the senior organisation. As I pointed out before - aspiring (students) GA private pilots will be required to fly into a complex (controlled airspace) airport (as I was). It is almost certain that this complex airport will be a Security Controlled facility, which will require the pilot (if they alight their aircraft) to hold an ASIC. So its a condition of accessing a complex airport (a key part of their training) that requires an ASIC. Minor point, that shows you haw this ridiculous system has come to infect much more than just accessing a small regional Security Controlled Airfield. 😈

Recently, I had occasion to be in a meeting with several CASA staffers - turns out they are no fans of ASIC either. As you know, ASIC is a Department of Home Affairs cock up and it would seem aviation organisations have little influence in this bureaucracy.😈

"Spy -In-The- Sky" I have heard some use drones😈

Not at all. A turbocharges mechanical wastegate performs as I have described. I merely speculated that it may have a ceiling limit (I don't know what that night be). Knowing that the naturally aspirated 912 ,can (with the right airframe) get into the mid teen altitudes, I further speculate that a turbocharged varient, with a mechanical wastegate, may get to 20,000ft (again I don't know). I suspect that few small aircraft pilots are intersted in cruising at altitudes requiring O2 supplementation. This may change for plots wishing to cross the high mountain ranges of the World. So logical speculation; For pilots who are looking for enhanced (115hp) sea level performance up to at say 12,000ft - turbo with mechanical wastegate may be quite acceptable and attract a lower acquisition cost. For those few pilots who want to top Mt Everest etc the TCU may be an attractive proposition along with pressure suite & O2 -$$$$$$$$ I am not trying to "prove anyone wrong" just asking for an answer to a question - Why does the carburetted Rotax 914 have a sophisticated/complex TCU, when its highly likly a mechanical wastegate would have done the job - Yet to get an informed response 😈

"Think of the simple basic diaphragm type waste gate actuator in this way, on one side we have boost pressure, on the other there is a spring and ATMOSPHERIC pressure. I don't think this will work correctly at altitude." Simplicity does not necessarily equate with inefficiency or lack of precision. Humans have along history of overcomplicating solutions. No offence, you are clearly wrong - a mechanical wastegate will adjust inlet pressures, as atmospheric pressure reduces/increases. The question really comes down to the precision and range of the mechanical wastegate V TCU. It would seem that at least two of the 912 aftermarket turbo upgrade suppliers, use a mechanical wastegate. I assume that in this, their product is successful/reliable. If it isn't they would have gone out of business very quickly. "Recently I removed a turbocharged engine and all components from a Cessna 414. The wastegate is operated by regulated engine oil pressure. Why did they go with this complicated system and not a simple wastegate gate. It is called an absolute controller, designed to work at altitude. " Sorry cant comment - don't know what is meant by ".... wastegate is operated by regulated engine oil pressure" in this context. One would certainly hope that in going with "... this complicated system and not a simple wastegate gate. " they achieved some benefit over a mechanical system. It may be that an aircraft turbo system having to perform over such a large atmospheric pressure range, eg sea level to 35,000ft, the mechanical may not be able to equal the TCU In this speculation, I would still wonder why Rotax didnt offer a cheaper mechanical option, with say a 20,000ft ceiling.😈

Not so much "dismissed" as poked holes in Rotax doctrine. Detonation in diesel engines -Good question. Your first to articulate a possible problem with my argument. By definition the diesel compression ignition is a detonation - that is the principal reason why diesel are built to more rugged (heavy) specifications, than petrol spark ignition, lower compression engines. Diaphragm actuators - No expert but would expect that they only operate between certain parameters, in this context atmospheric pressure. Climb (function) to 16,000' - As above - I don't know. The naturally aspirated 912 carburettors (diaphragms) are, I have heard, operating at their efficient limit at about 8,000' - obviously they can go much higher however the air:fuel ratio may be increasingly outside optimum. Speculation - Given the ability of the naturally aspirated engine to get into the pilot O2 levels, I would expect the turbo varient with mechanical wastegate to achieve at least 16,000' Turbo charged engines without wastegates - In my experince such engines are operating at quite low boost pressures ie the turbo is small and the inlet/ignition pressures generated are within the structural capacity of the engine . Speculation - engines of this type are most often found in constant rpm service eg hydraulic pumps/ generators, etc where peak rpm/performance is a near constant. Wastegate The wastegates overriding function is to to prevent over boost, while maintaining sufficient inlet pressure for optimum (?) performance throughout the rpm range. Over boost is likly to cause severe fuel detonation, excessive heat and combustion pressures, which will destroy the engine. In an aircraft the wastegate also acts to maintain the ability of the turbo to deliver required "boost" as the atmosphere thins at altitude. This boost can be to maintain sea level air density to the combustion process (turbo normalised), and above sea level pressure (increased power/"Boosted", as in 80 hp delivering 115 hp. .

As I understand it the Rotax 914 is a 30 year old design - the ECU or in the case of the 914 a Turbo Control Unit (TCU) was in its infancy back then. Computer controlled electronic injected fuel delivery was still a long way from the every car/motorcycle/even ride on lawn mowers that we have today. What I don't understand is why a TCU, when mechanical wastegate turbo pressure control, was at the time, a mature technological concept.😈

"The benefits outweigh the negatives and any risk can be mitigated. " When you start to talk about fitting such gadgets as auto/electric trim, autopilot, to light aircraft ( 600kg MTO? ) navigation/landing lights to VFR only aircraft, etc. I think it fair to say that for the most part thats exactly what they are, gadgets/bling - they do little if anything to enhance the aircrafts flying characteristics or the skill of the pilot and may increase risk. So the "benefits " are really in the aspiration (mind) of the pilot/builder. The increased risk & cost, is overshadowed by the want, as there is clearly little, to no need. Who am I to stand in the way of their enjoyment/aspirations. All I ask - please do not fly your "enhanced" aircraft over my house 🥺. 😈

Further thoughts; My oil cooler is in the cowling exit air stream, so potential for delivering contaminated air, especially leaking exhaust CO, also leaking oil & fuel. Coolant radiator is front of cowling taking in fresh air - safer, possibly less noisy BUT longer ducting .😈