Dafydd Llewellyn Posted January 29, 2014 Posted January 29, 2014 So, where does that put the idea (my idea) of wanting to build something because I want to build it?I want to build a flyin' machine out of metal (I like to work with metal), that looks very 1930's, a sort of roughly scaled F4U. I don't want to make it because it's a practical economical aircraft, I don't want to mass produce or market it, I want to make one because I've always wanted one. You can register it under CAO 95.55 as a .19 registered aircraft. Or you can do it under CASR 21.191 as a private amateur-built, VH registered. Go read CASA AC 21.4 and 21.10. Or read the RAA airworthiness manual. I was talking about factory-built aircraft - i.e. aircraft built for commercial sale. You cannot do THAT under the .19 registration class in CAO 95,55, nor under CASR 21.191. You got eyes; use 'em. 1
Bob Llewellyn Posted January 29, 2014 Posted January 29, 2014 Yes, I understand the current categories, I was meaning in regard to repeating things that have been done before, and design durability. Keyword alert! Keyword alert! look, the good old Aus CAA / CASA folk who created the ultralight categories wanted no truck with durability, OR crashworthiness; the sooner pesky ultralighters eliminate themselves from this mortal coil, the better. This is not a joke; the low stall speed / low wing loading perversion that regulators have, is anti-safety. Firstly, the vast majority of ground gusts in calm old North America are under 15 kts; so a takeoff safety speed / approach speed of 1.3 times 50kts almost eliminates wind shear / convective turbulence type accidents. Anything with a lower stall speed needs a greater margin - say, 1.4 times 40 kts or 1.5 times 35 kts - and a larger margin again in an Aussie summer. Secondly, the material used in those seven-acre wings uses up the available (category) weight limit, leaving stuff all structural reserve in random structural members like, say, wingspars. Thirdly, the ludicrously low weight limits mean that a high power to weight is practicable, and so you get aircraft like the wire-braced Drifter, with a rough air penetration speed of ~54kts, a manouvring speed of ~65 kts, and a Vc of 70 (from memory; the ratios are about right, even if the numbers are a little high); or the 912 engined Sabre, with a cruise speed of ~125kts and a maximum rough air speed of ~65 knots. The industry proponents of CAO 101:55 wanted a 45 kt stall speed and 544 kg MTOW; they got 40 knots, fudged up to 42 when the Skyfox couldn't make it, and 450kg - which is why earlier Skyfoxes, Lightwings etc have such miserable official disposable loads, and th e'fox has short fatigue lives on certain components.. It's regulation in the interests of danger. Note that, after the rest of the world had watched 101:55 for a few years, the Europeans came up with JAR VLA (45 kt stall, 750 kg MTOW), and the Yanks came up with LSA (40 kt Vs0, 45 kt Vs1, 600kg MTOW, 650 if webfooted). So - I suggest you focus on 95:55.1.5; 544 kg, 45 kt Vs0, RAAus ops so owner maintenance.
Roundsounds Posted February 4, 2014 Posted February 4, 2014 I am a relative new comer to RAAus, however have a reasonable amount of experience in GA. The assumption you can jump from one GA single engined aircraft type into another without some form of instruction is not always correct. It will depend upon your previous experience as to how you transition between aircraft types, I would think a similar approach could be used in the RAAus world. CAO 40.1.0, para 4 - "Authority Given by class endorsements" (a GA PPL holder will generally be issued a class endorsement to operate piston engine aircraft with a max takeoff weight below 5700kg, to which you can add design features such as retractable undercarriage, tailwheel, etc) Para 4 reads: 4.4 The holder of a class endorsement must not fly as pilot in command or co‑pilot of any aeroplane included in the class unless he or she: (a) is familiar with the systems, the normal and emergency flight manoeuvres and aircraft performance, the flight planning procedures, the weight and balance requirements and the practical application of take-off and landing charts of the aeroplane to be flown; and (b) has sufficient recent experience or training in the aeroplane type, or in a comparable type, to safely complete the proposed flight; and © if an aeroplane in that class has a special design feature, holds a special design feature endorsement referred to in paragraph 5.1 for that design feature. Note The owner and operator of an aeroplane included in a class of aeroplane should: (a) ensure that a person who proposes to fly as pilot in command or co-pilot of the aeroplane complies with subparagraph 4.4 (a); and (b) where necessary, require the person to provide evidence of recent experience or training in the aeroplane type or in a comparable aeroplane type; and © if the aeroplane has a special design feature, ensure that the person holds a special design feature endorsement for that design feature. Once you have experience on several types the "comparable type" clause may cover you. Becoming familiar with handling, systems etc may be a matter of reading a manual or talking to someone with experience on type. I've flown several single seat GA types and that's the method I used.
Guest Nobody Posted February 4, 2014 Posted February 4, 2014 And this is a reasonably good way to approach things... It basically says before you fly anything, make sure that you have experience in something similar or get some training. … Hopefully the RA-Aus Ops manual could adopt this approach…. I am a relative new comer to RAAus, however have a reasonable amount of experience in GA. The assumption you can jump from one GA single engined aircraft type into another without some form of instruction is not always correct. It will depend upon your previous experience as to how you transition between aircraft types, I would think a similar approach could be used in the RAAus world.CAO 40.1.0, para 4 - "Authority Given by class endorsements" (a GA PPL holder will generally be issued a class endorsement to operate piston engine aircraft with a max takeoff weight below 5700kg, to which you can add design features such as retractable undercarriage, tailwheel, etc) Para 4 reads: 4.4 The holder of a class endorsement must not fly as pilot in command or co‑pilot of any aeroplane included in the class unless he or she: (a) is familiar with the systems, the normal and emergency flight manoeuvres and aircraft performance, the flight planning procedures, the weight and balance requirements and the practical application of take-off and landing charts of the aeroplane to be flown; and (b) has sufficient recent experience or training in the aeroplane type, or in a comparable type, to safely complete the proposed flight; and © if an aeroplane in that class has a special design feature, holds a special design feature endorsement referred to in paragraph 5.1 for that design feature. Note The owner and operator of an aeroplane included in a class of aeroplane should: (a) ensure that a person who proposes to fly as pilot in command or co-pilot of the aeroplane complies with subparagraph 4.4 (a); and (b) where necessary, require the person to provide evidence of recent experience or training in the aeroplane type or in a comparable aeroplane type; and © if the aeroplane has a special design feature, ensure that the person holds a special design feature endorsement for that design feature. Once you have experience on several types the "comparable type" clause may cover you. Becoming familiar with handling, systems etc may be a matter of reading a manual or talking to someone with experience on type. I've flown several single seat GA types and that's the method I used.
Yenn Posted February 6, 2014 Posted February 6, 2014 Are you saying that GA is safer than RAAus? If so what are you comparing. There are a lot of GA pilots who do less flying than RAAus pilots. Is this taken into consideration? Are you saying that GA maintenance is better than RAAus? The most likely time for a GA plane to have a maintenance defect is immediately after it has come out of maintenance. Are all the mechanical defects in RAAus accidents really mechanical or design or even poor airmanship. From what I have seen of RAAus planes and GA there is very little to choose between them. 1 1
Bob Llewellyn Posted February 7, 2014 Posted February 7, 2014 Are you saying that GA is safer than RAAus? If so what are you comparing. There are a lot of GA pilots who do less flying than RAAus pilots. Is this taken into consideration? Are you saying that GA maintenance is better than RAAus? The most likely time for a GA plane to have a maintenance defect is immediately after it has come out of maintenance. Are all the mechanical defects in RAAus accidents really mechanical or design or even poor airmanship.From what I have seen of RAAus planes and GA there is very little to choose between them. By fatality rate, GA in Aus should be a tad ahead of RAAus at the present time. Where is the evidence that GA maintenance defects are mainly caused by maintenance? Where is ANY requirement that RAAus aeroplanes possess physical endurance? 1
Dafydd Llewellyn Posted February 7, 2014 Posted February 7, 2014 Are you saying that GA is safer than RAAus? If so what are you comparing. There are a lot of GA pilots who do less flying than RAAus pilots. Is this taken into consideration? Are you saying that GA maintenance is better than RAAus? The most likely time for a GA plane to have a maintenance defect is immediately after it has come out of maintenance. Are all the mechanical defects in RAAus accidents really mechanical or design or even poor airmanship.From what I have seen of RAAus planes and GA there is very little to choose between them. Well, I've been looking at defects in GA aeroplanes and RAA flying machines as a professional engineer who had to sign for the design of over 3000 repairs under CAR 35, for 40 years, and from what I have seen there IS quite a bit to choose between them - and whilst I have had occasional maintenance defects in my own GA 'plane too, they in no way balance the faults that were discovered and fixed by maintenance. The strength of the GA maintenance system is that it is dealing with mostly aircraft types whose idiosyncracies are well known, so people know where to look for trouble. However, I've also seen it perform excellently with amateur-built aircraft, which are in my experience vastly more prone to have serious design defects. However, the GA aeroplanes are themselves mostly at least twice as old as the RAA types - a lot of them are around 40 years old now - and so they need a better class of maintenance than do most RAA aircraft, for that reason alone. As a result, the skill levels in GA maintenance should be very high - but the current persecution of GA maintenance orgs by CASA - I can only describe it as such - is rapidly destroying the skill base. I doubt the real situation in regard to maintenance has as yet really shown up in the statistics; the only reliable statistic is the fatality rate, and accident investigation as she is currently practiced is not good at providing valid statistical answers that go more deeply into the subject; however look at the defect reports data - there's quite a bit of it in the public domain. GA statistics are likely to get worse, due to both the product liability litigation issues of the 1980s, which shut off the supply of replacement GA aircraft, so we have had to soldier on with the ones that were built before the lawyers went into a feeding frenzy; and due to CASA's counter-productive efforts on the GA maintenance industry. RAA statistics are likely to get worse, because the aircraft were built to such ridiculously tight maximum weight limits, and the design standards failed to address structural fatigue, and the lack of training in regard to maintenance issues such as structural fatigue. Also, the design of powerplant installations in many of the non-certificated RAA aircraft that I have seen, place far too much reliance on luck. It often seems that although the builder is ignorant of the fact that his design is defective, fortune favours fools - for a while. Overall, the entire picture is one of collective insanity, really. So, the various factors that bear on the overall statistics differ considerably between GA and RAA - and both are changing, not for the better. But as an individual, you can do a lot by (a) Learning more about proven maintenance practices - and a starting point is FAA AC 43.13-1 - and (b) Understanding the inherent limitations designed into your aircraft. GA aircraft are mainly built of high-strength materials that are more corrosion-prone that the better lower-strength materials - and so are a lot of RAA aircraft, because that was the only way to get any useful load capacity because of the restrictive limitations. Lower-strength materials in thicker gauges have a lot going for them - but to use that approach, the category limits need to allow for a higher percentage ot the MTOW being structure. That hasn't happened yet; it's high time it did. Also, as Bob has been pointing out, people need to understand the difference between the "commercial" strength of materials, and the "guaranteed minimum" strength. Aircraft materials cost more because of their quality control. Do you want to know that the average strength of the bolts holding your wings on is good enough - or do you want to know that THE bolt holding YOUR wing on is as good as it's supposed to be? 1 1 2
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