kasper

2 hours ago, Bosi72 said:

Keep the ball in the centre and nose below horizon. Check stall speeds for various Angle of Banks from your POH. Don't assume instructor see everything.

 

 

You assume that every aircraft has or could have a ball - they do not and a whole group recreational aircraft cannot have them.

Your homework is to work out the two general types of aircraft that RAAus have on their register that cannot have a ball ever.

Hint - Both groups cannot spin

Hint - Neither groups fly by reference to the nose and horizon 😛

Well the original lightning bug stalled at a claimed 54knts.  You are never going really slow in one so who needs a big rudder 😛

They fly very slowly and with the mccoulogh engines it it tough to mishandled at the speeds.  As a twin operating from The Oaks in the heat and with my cream bun fed physical size I was flying around trees a couple of miles south of the strip taking off on 18. Took an age to get to circuit height then came back.  Never tried taking off on 36 because it would not have climbed enough to get out of the rising ground to the north.

Lovely fun plane to fly and with such low speed it would not worry me single engine as it would just have been extending the glide. 

Walking through the issues of Climb at power with full forward stick means the tail group is probably providing a positive lift moment in cruise.  Assuming this is not a canard I'm not happy to fly. Where do I look and why

In a  tractor aircraft where the net negative moment from the tail to balance everything is not required I'm looking for two or three areas that cause it 

a. CofG at the rear of limitations plus something else

b. Misrigged control surfaces or runs ... Or even cables that are stretching. 

C. Ridiculously overpowered airframe -prop blast over centre section providing too much lift the tail can't hold down.

d. Flaps misrigged to be deployed when in retracted position

any of these can provide parts of what you report. 

3 hours ago, skippydiesel said:

Modern composite aircraft do not lend themselves to plans or very basic kit build.  I think I will be close to the mark when I say all are very advanced kits.  The components's are often kiln cured, in a mold - so not a practical kit build in the same sense as a metal/wood aircraft.

 

This does mean they are navigating a vert thin line between factory built & kit built.

 

The up side is that there is little room for aerodynamic or structural variations, that can occur in older style or plans built kits that depend on the skill of the builder.  This should mean more consistent safety and performance between projects.

What has this got to do with

1. registration classifications or

2. the numbers on the side of the plane or

3. answering the actual question asked?

If it was built/assembled by anyone other than a factory where they have the ability to issues the aircraft as a complete aircraft with a factory registration under an agreed/accepted design and manufacture process is makes not a jot if it was a set of plans, a dream of the builder or a super fast kit built at the factory by the owner (owner assist).

The question was how can 19- reg be a factory aircraft - the short and complete answer is it cannot and it is home built regardless of what degree of kit was used to make it. 

If it’s got one of the following numbers on the side it’s factory built:

25-  55-  24-  23- 26- 

plus most 32-

if it’s got 19- then it’s not “factory” built … except it might have been/‘ish

19- reg are either built from scratch by a builder or from a kit by a builder. 
 

that builder can be a factory and it’s one path a factory can use to design and develop an aircraft - build 1 or 2 and register them 19- which is very flexible and then base the factory build on the prototypes that were 19- reg. 
 

so there are 19- reg airframes that were built at a factory by the factory but were effectively pre-production or prototypes that were registered as home built. 
 

other than these few airframes floating around nothing that came out if a factory ad a factory airframe to the accepted certification standard will have 19- on the side.  
 

Sellers may misdescribe a home built that has an equivalent factory build or an importer may historically have been inadvertently given 19- reg on an actual factory airframe.

If the first applies it’s just misdescribed but if it was in error registered 19- and should never have been be very cautious- raaus or casa could at any time audit your airframe and ground it until it’s converted to the correct rego and that may be impossible or just expensive. 

I would throw in location and the training of the instructor as well

... my instructors were all long in the tooth ultralight pilots not GA

... all my training was at a non-tower non-GA airfield

B2F errors were always allowed to develop in early training with focus on balanced turn as the core.  The fact we were still a relatively long time from touchdown allowed the instructor to highlight the runway alignment error and either allow correction or go around.

B2F errors were just part of the fun of flying and as you progressed in training it was just a focus change on deciding earlier on in the B2F turn if you can correct it with continued turn past 90 and then realign or just throw away that approach and go around early.

I found that mindset has "set" in me and I am pretty good at focusing on balance first and if I end up off alignment by a small margin so be it  ... and if its too much off alignment I go around.

On average I probably go around more than the average pilot but I am happy ... its just that much more flying I get to do 😉 

One track wins on designer/builder.  But not all tandem wings are modified mignet designs - these are mignet formula but not modified mignet. 

Only correct answer - not a generic answer for this type 😛

Yes shedding is what we are hoping for ... but given the industry my day job is in we get direct NSW public health updates on numbers in the LGA that are positive or post infection positive - currently 1 and with 1 known local (Adam Marshall our 'beloved' local member) we can only hope that the sewerage testing is bloody sensitive and its picking up 1 persons shedding only.

But not looking forward to the next few days.  'Drive through' testing at the airport here was running at an 8-10 hour wait from 8am last week and that was triggered when the positive guy headed to Lismore on the flight and there was a spurt on testing anyone with a cough or headache as we had contact traced people to Armidale from there ... 

Hmmm

Sitting here behind a mask in the office here in Armidale today I find that COVID virus fragments have been detected in the Armidale sewerage ... damn!

Agree with RossK - the virus does not move to spread its people that do.  I am not looking forward to what might happen if a positive case turns up here in town.

Hopefully its just Adam Marshall (MP) shedding crap virus - literal crapping out virus particles - as he is a known recent recovery positive COVID delta case who is in town.  fingers crossed  

First jab down for me and second to come next month, but if we go into lockdown up here I am staying on the farm till its over.

Butt ugly??

Northrup YC-125 Raider might be another name for it but I think Butt Ugly is closer to the mark

48 minutes ago, rgmwa said:

It’s not the ‘design by eye’ part that would would worry me. It’s the ‘confirm by test’ bit that would make me think twice about buzzing around at 1,000 feet to find out which part of my design needed improving. 

 Then for you I  would suggest either factory build or home build from a design you trust.  Your profile lists vans rv-12 so you appear to accept something that's not certified but  but from a designer you trust. 

For me I have 1 airframe from a factory that is stock. I have another from a factory that's very not stock. The other three airframes are my design and build. One of those incorporates parts from factory the others are completely mine.  

For me it's a mix of maths and test. And as I'm the only person who will EVER fly my airframes I'm ok with accepting my design and the risks. 

That's experimental 😃

37 minutes ago, APenNameAndThatA said:

I’m confused about this. Aren’t you supposed to use maths when you design aircraft? 

If you want. But there are alternates. Take an existing know element from another aircraft and incorporate into yours is perfectly legitimate. As is design by eye and confirm by test. 

If you are designing a one off self build then you are free to do what you like. That's the point of experimental 😃

My co-owner of a Pou many years ago whacked the flea into a raised bank next to the runway at near takeoff speed … the undercarriage took much of the loads as it came to a stop. The front wing twisted when it struck and the main spar snapped into match stocked at every pickup point. 
 

one new undercarriage.  One new centre section. One repaired engine cowl and it was up and flying again. 

11 minutes ago, duncan_rtfm said:

I've just checked my HM293 plans, and it seems that they specify 25mm OD, 22mm ID.  Am I reading this correctly?

Yes, that is how he specs the tubes - OD and ID in your pic = 1.5mm wall 25OD mild steel and thats what works nicely in a gently failure mode when you whack the ground at speed ...

10 minutes ago, duncan_rtfm said:

Hi,

See post above/below.  Various lengths.  My only concern is whether I need to go with 25mm tube vs 20mm OD

 

Duncan

On the wing struts your OD of 20mm seems fine as they are primarily loaded in tension and it will all come down to wall thickness and how you do the ends

on the legs it’s a difficult question to answer as it depends on how you are springing the leg - rubber in compression - rubber in tension - shock springs in compression and then it’s also an issue of which leg component you add the spring to because at least one of the leg members will primarily be in compression and that element greatly benefits from greater OD to reduce the risk of compression failure of a hollow tube.

do some comparison design shopping. Read over the original hm290 or hm293 leg designs and consider how yours stacks up to them on design.  I can report that the original main hm290 leg and struts can take a whack sufficient to destroy the wings and collapse safely to the ground with the pilot stepping out of the aftermath unscathed. The tubes failed gently absorbing a lot before failure and that is what you want in a design. 

11 hours ago, duncan_rtfm said:

Hi guys,

Thanks for your suggestions, but I've given this some more thought, and because I don't have any of the kit needed to hotwire foam, this is what I've decided to do.

Materials required:

 

1. 2x 25mm steel (or aluminium) tubes
2. 1x sheet XPS foam (local hardware store, $12.50)
3. 2x steel/aluminium/brass/carbon fibre rods (4mm diameter)

Method:

1. Chop the foam sheet (1200mm x 600mm x 30mm) into a zillion 100mm chord "riblets"
2. Grease up the tube and the big hole in the riblets with West epoxy
3. Thread required number of the riblets onto the steel pole, bonding each new one to the preceding with some West
4. Thread the two brass/aluminium/ carbon fibre rods through the 4mm diam alignment holes
5. Wait for it all to set
6. Rinse and repeat

All that's left to do is to affix the attachment hardware to the ends of the steel/aluminium tubes, and to coat the foam with a layer or two of epoxy and possibly a layer of glass fibre.

 

There are enough little riblets in a single sheet of XPS from from Bunnings to make several struts for several planes.  Just sit back and watch the router do its magic.  Of course, hotwiring things would be easier, but as I say, I don't have the kit.

Carbon fibre rods are overkill - dead weight and $$

Just the foam formers west epoxy to the tube + a fiberglass skin (definitely very light woven fabric and not CSM) will be entirely enough.

I've done similar on a set of lift struts for the sapphire (replacing a wrapped fiberglass hollow section streamline) and I did not have CNC so rough cut the sections, drilled the tube hole, assembled the stack with epoxy (glue to tube, flox filler between layers) and then used masonite templates on the ends and a sanding stick to bring to final shape before glassing and finishing. 

1.5m struts gained 400g which was acceptable to me as that was pretty much exactly the weight of the hollow skin forms I removed. 

1 hour ago, skippydiesel said:

certain professionalism in aviation

Why do you expect it? 

For safety or for process?

If for safety whose - Pilot/pax or general public?

AUF/RAAus knocked on the head decades ago the link between airframe design/maintenance and risk to general public.

CASA/RAAus - despite your opinion on the effectiveness of it - decry all liability for pilots/pax for the operations of the airframes - those yellow stickers are their notice of this 

So if it is process why expect the same process in RAAus as applies in GA when there is a stated and designed difference?

I would ask - do you expect the same professionalism of all motor vehicles? 

Given that they are demonstrably of higher risk to the general public than RAAus aircraft the risk would demand that ... yet several states have very different compliance regimes - annual inspection after 3 yrs old, inspection only on sale of vehicle and after being tagged by police etc.  and any/all maintenance and repairs on them is at the owners discretion without any documentation required ...

Aviation is in my experience not really different from many aspects of mechanical repair and maintenance but comes from a history of fanatical documentation in the name of 'safety' which is actually not required for safety but may help reduce risk of failure and/or identify failure/unsafe events after the event.

Simple really. If it didn’t come out of a factory as a fully build and registered aircraft it’s an experimental airframe and engine and you really need to work from that point and not expect anything to be exactly what you might expect from a factory airframe and engine.  
 

The reality is that the value of an experimental airframe will vary wildly depending on how experimental it is be that an odd design or components not maintained in the same way and to the same life  certified aircraft are.  
 

unless buyers and pilots entering RAAus aircraft start working form that point a lot of people are likely to try and MaKe experimental the same as factory.  It’s not.  It’s not supposed to be.  And if you push to make it so you are killing off experimental as a group and returning to the 1960-1997 period where you had home built that were SO restricted that in 35 years fewer designs were allowed than my husband and I have in fingers and toes.  

Given the thread drift I'll make the distinction between acts/inactions and underlying beliefs.

The belief that difference based on race or nation exists is racism or xenophobia.

Choosing to act or not act towards someone based on those beliefs is discrimination.

If that discrimination is in the provision of goods and services in Australia then you are in the realm of unlawful discrimination. 

If your discrimination is not unlawful then it falls to individuals assessing your actions and expressed views that are racist or xenophobic to decide their reactions to you. 

On this forum one option is the ignore user function. 

Cheers. 

Yep.  The only vehicle in our fleet that was replaced early was a Ford ranger … simply because it was always our for repair/maintenance. The rest - all Japanese and Korean - have happily just run in with Std service and get to life and just keep going. 

2 hours ago, kgwilson said:

That 50 gigawatts is equal to the all of the current production of electricity from all existing power stations in Australia at this point in time. It is a very ambitious project but an example of what can be done. It won't stop the fossil fuel protagonists from criticising it though.

And that's the point - a single very large proposed WA zero carbon could cover all current Australian consumption and would have the ability to location and time shift the electricity to where it is currently used/consumed.  There is already wind/solar as a distributed generation capacity attached directly to the existing copper network that can't store ... but there are stand alone storages being proposed to deal with parts of that.  That distributed copper network connected generations/storage is growing - companies are already investing in it even without significant Govt. incentives. 

Everyone bags out EVs on the grounds they will "kill the network" and claim solar/non-fossil cannot provide the additional electricity to cover above the existing.

Sorry but spend admittedly large numbers on major remote solar/wind generation and think about a mix of storage/time/locations shift options (water/battery/gas/chemical) and add to that smarter grid connections at houses/EV charge points and as a large system the electricity system has a good possibility to provide existing use cover + EV car conversion demand + expansion.

Well all that infrastructure out to Roma in Qld could be useful in 10 to 15 years ...

In WA they are looking at mixed solar/wind covering 15,000 square kilometres and could produce up to 50 gigawatts of energy ... but putting that energy into hydrogen and ammonia to move not via wires but pipelines/trucks/trains/ships to be used as electrical generation at point of use:

https://www.abc.net.au/news/2021-07-13/green-energy-hub-planned-for-south-coast-of-wa/100288734

If they did something on a smaller scale out in Roma but stored the hydrogen/ammonia to time shift generation to consumption they could recycle the wires infrastructure to feed it back into the SE Qld grid. 

Strangely planning to reuse infrastructure is what they want to do at Liddel in NSW - stop generating from burning coal and use the water storage to store excess generated energy from grid and time shift it back to consumption when needed - a hydro battery.   

The only thing I can see for certain is that electricity is going to be the major energy use form for the rest of my life and it will move to carbon neutral generation over that time.

Fossil fuels are literally the dinosaur in the electricity market and the major fossil fuel companies know it and are moving to replace their fossil fuel carbon businesses.

But Turbo urea injection whilst reducing nox and co does nothing for pm10 or pm5 or co2 and can’t address the fundamental issue of using/releasing carbon from crude oil. 
 

agreed that for 99% of this forum audience their involvement in anything developmental in the wider area of alternate energy to transport will be only as a consumer of what’s being offered.

but a fair fraction of this forum are very interested in the areas that are possible because they recognise that things will change and they want to know possible changes are considered.