Camel Posted February 5, 2018 Posted February 5, 2018 Nothing wrong with composites ! My fibreglass yacht is 40 years old. See, Composites: Airbus continues to shape the future. Airbus A350 vs the Dreamliner: Which new plane is best on a long haul? Composite - Airbus Helicopters
skippydiesel Posted February 5, 2018 Posted February 5, 2018 Who can say no to the opportunity of reply to someone who opens up with 'no offence intended'....So, with all due respect.... Performance claims are a general measuring stick, are you going to tell Rv9 owners their 140+ knots are simply a result of poorly calibrated instruments? That numerous Morgan owners are just liars? I don't have an entrenched view on composites, only my own experience, as I freely admitted. Nor do I think they've been making 'dodgy' Hilux canopies in Indo since the early 90's. Indeed the makers badge on the side is in the shape of Australia. Lets talk about those 'entrenched views' sometime, shall we. For those far too obtuse to see my challenge, it was to draw, real, evidenced comments which attest to the durability of composite craft, rather than biased and unvalidated vox-pop along the lines of "I have one therefore I am smarter than most and all the other materials are a bit crap".... To suggest that metal fabricated craft are from a bygone era is encouragingly forward looking and I applaud your grasp of the future of aircraft. When Boeing launch a full fibreglass passenger jet, I'm right behind them. So other than bag the aircraft options, challenge decades of solid fabrication, and throw 'vague' challenges to my reasoning by claiming them as illogical in return, what is it exactly you bring to advance this conversation in a meaningful way? Best Regards, Ramjet Thanks for the invitation Ramjet but I think I have pretty comprehensive stated my position. You might like to read my last few replies particularly to bexrbetter (needs to be opened up to get the whole message) Therein find some real life performance figures (without embroidery) for my little baby, plus a reference Robin Austins astonishing Rotax 912 ULS powered Soneri (metal wings). Can't resist just a making a small comment in the spirit of your Hilux canopy "longbow" - I am the proud owner of a Daihatsu Rocky 2.8 turbo diesel (520,000kms). I purchased it new in 1985. It has a small opening composit "sunroof" & a rear large fixed composite roof section. Other than a small chip, and multiple scratches they appears structurally sound and fully functional - now that's 33 years old but I would not compare it to my 2000 commissioned composite fuselage. In my mind completely different operating environment, design & engineering even if the materials used are (distantly ?) related.
skippydiesel Posted February 6, 2018 Posted February 6, 2018 Have a look at Pipistrel virus short wing, high cruse speed low stall and air brakes.... Yes very nice - If you have the SSSS ATEC Fayeta NG - similar performance but at a lower acquisition cost.
rrogerramjet Posted February 12, 2018 Author Posted February 12, 2018 Aluminium alloy sheet is subject to corrosion in the laps and fatigue. That type of construction isn't everlasting. No plane should be left out all the time.If there's an easier flying object to look after than a Jabiru airframe I don't know of it.. I'd like better feel in the controls., perhaps but it wouldn't be bad enough to stop me enjoying the good side of it's durability and toughness. Nev. Now flying heavy GA with noticeable difference in response and weight to throw it around and the noticeable authority all the way to the ground I (think I) know what you mean about light controls. I have also come to like the 'steering wheel' in front of me and now wonder how I ever learnt to fly with that faux PC joystick in the middle ! Ramjet
rrogerramjet Posted February 12, 2018 Author Posted February 12, 2018 Thanks for the invitation Ramjet but I think I have pretty comprehensive stated my position. You might like to read my last few replies particularly to bexrbetter (needs to be opened up to get the whole message) Therein find some real life performance figures (without embroidery) for my little baby, plus a reference Robin Austins astonishing Rotax 912 ULS powered Soneri (metal wings).Can't resist just a making a small comment in the spirit of your Hilux canopy "longbow" - I am the proud owner of a Daihatsu Rocky 2.8 turbo diesel (520,000kms). I purchased it new in 1985. It has a small opening composit "sunroof" & a rear large fixed composite roof section. Other than a small chip, and multiple scratches they appears structurally sound and fully functional - now that's 33 years old but I would not compare it to my 2000 commissioned composite fuselage. In my mind completely different operating environment, design & engineering even if the materials used are (distantly ?) related. Hi No I haven't read all your replies and it is comments about boats and canopies on 4wd's (yes Im guilty too) that don't provide any useful information for any of us to make a reliably informed decision about aircraft, and was clearly excluded in the set of requirements to drive this thread. To that point, noone has yet (or have I missed it?) clearly stated they have a glass plane they leave out in all weathers and 20 yrs later it is good to fly.. Maybe those owners are too busy running station ops to be mucking about on this forum..? There is a J170 I see parked outside at YMER with the ubiquitous 2ft grass underneath and to my surprise it was gone the other day, I presume for a fly, so I must go speak to them. (and have a look at their plane) Check if the fuel consumption at a given airspeed makes sense. Are the stall figures at max permissible take of weight (same for take off role, take off distance to 50 ft, max climb and max level cruise speed). Indicated air speeds should also include engine rpm (& if IFA prop, manifold pressure) Be very careful of claims where a range of engines & hp are permissible (which engine was used for each performance claim). Totally agree - and not just book figures, from real flying demos. cheers Ramjet
KRviator Posted February 12, 2018 Posted February 12, 2018 An RV-9 will be good for 150kts on a 160hp motor with a fixed pitch prop, burning 32l/h. You can bring the fuel burn down further if you have fuel injection and run lean of peak on long trips, but the saving in fuel is often not worth the complexity. FP Sensenich G/A prop, 145KTAS at 24.2LH in my -9A, and I could probably have pushed that out towards 150KTAS if I had paid more attention to drag reduction during the build. EFII would also make a significant-enough-to-warrant improvement next time too!
skippydiesel Posted February 12, 2018 Posted February 12, 2018 FP Sensenich G/A prop, 145KTAS at 24.2LH in my -9A, and I could probably have pushed that out towards 150KTAS if I had paid more attention to drag reduction during the build. EFII would also make a significant-enough-to-warrant improvement next time too! WOW!!!! - so it costs Chris SS 7.8 LPH to go an extra 5 Knots and your fuel flow is somewhere in the region of 4 - 6 LPH higher than a Rotax powered high performance RAA registerable aircraft achieving about the same air speed - is all this adding up??
spacesailor Posted February 12, 2018 Posted February 12, 2018 "To that point, noone has yet (or have I missed it?) clearly stated they have a glass plane they leave out in all weathers" Someone DID, A brand new Jab left at YBUD, for a couple of years, And it was Not flyable I was lead to believe. VH-ILL. spacesailor 1
turboplanner Posted February 12, 2018 Posted February 12, 2018 There’s no point leaving a glass aircraft out in the open when the door surrounds etc have gaping gaps that let in the rain.
Mick Posted February 12, 2018 Posted February 12, 2018 "To that point, noone has yet (or have I missed it?) clearly stated they have a glass plane they leave out in all weathers"Someone DID, A brand new Jab left at YBUD, for a couple of years, And it was Not flyable I was lead to believe. VH-ILL. spacesailor It is still there and no way I would get in it.
KRviator Posted February 12, 2018 Posted February 12, 2018 WOW!!!! - so it costs Chris SS 7.8 LPH to go an extra 5 Knots and your fuel flow is somewhere in the region of 4 - 6 LPH higher than a Rotax powered high performance RAA registerable aircraft achieving about the same air speed - is all this adding up?? Pretty much, yep. The 24.2 is accurate based on flight time tests, not just indicated fuel flow, though it does vary slightly up to 24.5 sometimes. This is for flight at 8,500', and it takes 10.5L to climb to and descend from that altitude. With the engine in my -9A, you can run MoGas too, so there is not a significant difference in operating costs between a Rotax-powered Lightning, (for example) and an RV-9A. And depending on your mission, the -9A can be registered RAAus too - mine is one of two on the register.
spacesailor Posted February 12, 2018 Posted February 12, 2018 Mick I spoke the son of the owner who said they have plans for the aircraft. His Mum & Dad are both very well known doctors in Perth. I hope they know about the aircraft. spacesailor 1
facthunter Posted February 12, 2018 Posted February 12, 2018 Roger, Best control feel is with rods, done well. A DHC-1 Chipmunk is a good example.. Heavier aircraft with hydraulics lack feel but have a lot of effect when spoilers come into the equation as well as ailerons. Nev
M61A1 Posted February 13, 2018 Posted February 13, 2018 Amazing things can be done with composites, and they can have good longevity if properly built and cared for, but it is difficult to work with in the homebuilder environment. To do it properly there needs to be good environmental control of temps and humidity and have a good vacuum bagging or autoclave system. Metal is popular and long lasting because it's easy to work with and tolerant of extremes of environment. Yes, it can corrode, but if properly treated at manufacture it can last a very long time. I have seen images of WWII airframes recovered in New Guinea that still have the QA markings on the metal.It can fatigue, but if conservatively designed it will outlast the builder. Both have certain advantages, but both need proper care or neither will survive. I work with both composites and sheetmetal, composites are great, but for home building, I like metal. I would like to see homebuilder put more effort into preventative treatments at the construction stage though. Most of them just seem to like to rivet it all together then paint the outside, not a good recipe. 1 1 1
spacesailor Posted February 13, 2018 Posted February 13, 2018 "Most of them just seem to like to rivet it all together then paint the outside", This is what most kit & plan designer's tell us to do. (maybe not expected to last very long,(new pilot+new aircraft)). "and they can have good longevity if properly built and cared for, but it is difficult to work with in the homebuilder environment." The aircraft left to Rot at Ybud, Is factory made, and has not lasted as long as expected. spacesailor
poteroo Posted February 13, 2018 Posted February 13, 2018 There are many considerations with purchase or building. Probably most important, (IMHO), is how experienced you are, and what is your proposed mission with the purchased aircraft. Low time pilots need the extra hours flying that a lower speed aircraft brings with it = experience in dodging wx, with flight planning and with wringing the best performance out of oneself and the aircraft. A fast aircraft tends to make a pilot complacent...even lazy. In a final analysis, it can be a case of hare v tortoise. I've flown a number of slow, (90-100KTAS), aircraft over a 30 year timeframe in the WA wheatbelt, (averaging 300 hrs pa), and found my absolute best value aircraft was not a C180 or 182 - but a humble C170 which flew beautifully at 95 kts and 27 LPH of avgas or Super/PULP. I could have done pretty much the same job with a modern day Brumby, Tecnam, Sling, etc - but they have only recently arrived on scene. happy days, 4
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