danny_galaga

This kinda thing in case there's any confusion. Is it called mode C? (And yes that pic is of a pretty old model, but you get the idea)

Can someone change the poll options to multiple choice for me?

Thanks in advance 🙂

1 hour ago, Thruster88 said:

Is the SkyEcho2 considered to be a transponder for this survey? 

I think for this purpose I mean that thing with the four digit code you can squawk for air traffic control to identity you with

7 hours ago, APenNameAndThatA said:

I voted "yes". I believe that you include all aircraft up to MTOW 600 kg as ultralights? 

I say it is a "yes and no". Maybe we should require people to have a different login for each of their aircraft. 

Yes, up to mtow 600. I used the term ultralight to keep the heading simple. Also I didn't think of the fact some people would have more tha one aircraft. Unfortunately you have about two seconds to edit posts here but I'll see if I can get the pool changed to multiple votes

55 minutes ago, Kiwi said:

I have two Raaus registered aircraft,  one has a transponder one doesn't. 

I would count that as a yes then 🙂

Poll

Good outcome. What I'm most impressed about is that he was wearing a Fedora 🥰

Say what you will about the French, they have a lot of style!

On 04/02/2021 at 8:54 PM, old man emu said:

 

I think I scared people off with the algebra again! But let's press on, ever hopeful of igniting a discussion.

 

First of all, you have to recognise that the propeller is a complex wing, so the design of the blade is an application of the same Lift formula that is used in wing design.

What we have to consider is the velocity of the blade at various positions along the blade.

This equation tells us that the velocity of a point circling a central hub is dependant on the distance from the hub. Therefore, at each point along the blade the value of TAS in the lift formula is different from all the other points along the blade.

 

We would like the velocity (TAS) of each point, when applied to the Lift formula, to be the same, so, leaving air density as a constant for calculation purposes, and assigning it the numerical value of "1", the things that can be played with are Coefficient of Lift and the surface area of the blade at each point.  

 

In simplest terms the area of a wing is given by (Span x Chord). That's for a rectangular wing as on a PA-28. For a trapezoidal wing, we need to know the semi-span (s), which is the distance from the root to the wing tip, and the chord length at the root (cr) and at the tip (ct). Then from the equation for a trapezoid, the area is one half the sum of the tip and root chords times the semi-span, A = .5 * [ ct + cr ] * s.

 

The hard part is working out the Coefficient of Lift of the aerofoil at each station along the length of the blade. 

http://www.thaitechnics.com/propeller/tg8/prop_element.jpg

 

 

What Skippy is asking though is that if it's so scientific, why do you get seemingly different results? Propeller design seems almost like Feng Shui- the result seems to depend on however the individual designer feels at the time 😄 

Loved the first Gal Gadot Wonder woman movie, but yes the second was pretty disappointing

3 hours ago, Old Koreelah said:

 But wait, there’s more! 
There is a persistent rumour that Darwin airport was selected as a possible Space Shuttle landing strip, there being room for 5km without crossing a road.

I think it was plausible. It's as simple as it being at the time the longest runway in the southern hemisphere and the us military were on friendly terms with Australia. Also it is RAAF property so if a shuttle did have to land at Darwin it would have been readily secured.

Dunno about 5km. Maybe if you count every metre of grass either end. Also there wasn't much civilian infrastructure either end. A few houses and then the sea at one end and some bushland at the other. 

I learnt to fly at Darwin international. Can't get much more military then that! Sometimes you be in a circuit and Todd see two FA 18s take off together. Or your have to do orbits while a 747 landed. Certainly an experience but you don't get many touch n goes in an hour on a 3300 metre runway 😄

On 01/10/2021 at 8:29 AM, kgwilson said:

The trim on the warrior and Archer is electric via a button on the yoke but there is also a manual wheel between the seats. The electric was always unreliable and on a number of occasions I would apply trim and note the wheel not moving at all. Then I'd adjust it manually. Then the next time the electric would work. I reported the defect & the LAMEs would check it out, not find any fault and nothing changed.

If the planes I was flying had electric, the instructors did not make us aware of them. Only ever was aware of the wheel. Maybe earlier models didn't have them? Or it was an option?

1 hour ago, Marty_d said:

The answer to this may be completely obvious, but why isn't trim automatic - ie mechanically linked so that when the control surface goes one way, the trim goes the other?

I think it did on the Piper Warrior?

1 hour ago, sfGnome said:

I’m not sure about all Tecnams, but my old one had a fully moving stabilator. I expect that a mechanical trim on it would involve a fairly complicated mechanism, so a small motor and a couple of electrical wires seems somewhat simpler. Having said that, we did have a problem where the pot that sensed the trim position got corroded so the indicator became flakey and we had to replace the whole subassembly, so nothing’s perfect. 🤨

Yes, the Golf I hire has the stabilator. But so did the Piper Warrior I learnt to fly with, and its trim was mechanical. Facthunter is right about the control column switch being handier (I said toggle before but I misremembered it with the flap switch- old age I guess 😄 ) . Even so I really don't like the feel of it.

1 hour ago, skippydiesel said:

My point exactly - an unnecessarily complicated system for an aircraft of this class.

If your argument is that electric trim is unnecessary, I don't disagree. I hate it on the Tecnam. It feels more like a timing thing than a trim thing when you use them

10 hours ago, skippydiesel said:

Yeah! Pre-flight, I just look at or feel for the position of the trim lever - not much to go wrong. As for in flight - all adjustments done on control "feel" (nothing visual).

Yes but on the electric trim like in a Tecnam, it's just a two way spring toggle. The switch always looks the same. Same with the flaps. Although you can see the flaps visually. 

I would imagine there's a potentiometer at the motor end to feed back the position. But I'm just guessing. Is it a tecnam?

15 minutes ago, Marty_d said:

Try about 12 years to get where I am now... mind you I did have to fabricate everything myself.  I was hoping to finish by the time I hit 50 which leaves me about 7 months - don't think I'm going to make it!

You can do it!

11 hours ago, Bruce Tuncks said:

For about 4 years now Danny. I did ruin a LiFe by leaving to master on while parked for a week. The cells gassed and the battery burst open. The terminal voltage was zero and it would not take a charge. So 2 years from an individual battery is my best. I hope the current one lasts longer though than the 2 years so far.

Those LiFe batteries are more fragile in some ways , you need to keep the terminal voltage between certain limits, more than the lead acid types. ( the old Odyssey was left to go to zero volts too, but it came good again on charging and served for another 4 years on a farm buggy)

But as you say, the weight saving with the LiFe  batteries is great. I am surprised that anybody who understands about weight and aircraft has not changed away from lead-acid.

For my kit build im using the lead acid battery supplied. I don't want to change anything because it's taking long enough as it is too build 😄

1 hour ago, Bruce Tuncks said:

Thanks Danny. The batteries are a bit different in that the LiFe is 13.2 volts, charging should cease at 14.2 volts.

It sure doesn't feel like it is struggling, and the motor starts immediately.

You sure know more electrical stuff than I do though.

Actually, that Jabiru was yesterday replaced with a Jab 230 D. This Jab has a big Odyssey battery in it as well as a Camit engine.

One of the things I will do one day will be to replace the Odyssey with a LiFe, but there are other things to do first, like the CHT's.

I have put my worry about this on another thread...

Yeah, sounds like its ok. I didn't know the exact voltage. Seeing as it's about .8V higher than a lead acid to start with, what I imagine was a 'struggle' was still spinning faster than the lead acid battery! How long have you had this setup? That is a great weight savings!

On 14/09/2021 at 8:41 AM, Bruce Tuncks said:

I started with 2 hobbyking LiFe batteries in parallel. They are 8.4 amp-hour 30C, which apparently means that they can provide 252 amps. They weighed just under a kg each, so the 2 were 2kg.

Well I thought I was going to damage the starter motor, so fast did it spin over, so I took one out and it is more normal, with the 6kg down to 1kg.

The old 6kg Odyssey went for another ten years on a farm buggy, but alas  it has had it now.

 

If the voltage of your battery pack is about the same as the original battery (I guess 12V) I wouldn't worry about it. The faster the starter spins, the better. It's normally when they are spinning slowly they get damaged. Eg trying to start with a half dead battery. That's because the slower it is spinning, the more current it draws. It's why we could convert old 6V car systems to 12V without changing the starter or wipers. 

Zero rpm being almost a dead short and The faster it spins, the more back EMF it produces, the less current it draws. infinite RPM would be zero current draw.

In fact if your starter is spinning slower with just that one battery, I would say the battery is struggling

13 hours ago, Kyle Communications said:

Well the above story for me is quite ok.great the coppers are solving crimes using any tool necessary...its only a issue if you are doing something wrong. I believe in cameras everywhere to help stop crime..all these people going on its a invasion of privacy then they must have something to hide. I could not care less if someone in a control room somewhere saw me walking down the footparth scratching my arse or picking my nose.

 

I am not doing anything wrong or illegal who gives a sh#t ?

 

I dont have any issue of the coppers trying to solve crimes...ASIO listen into all of your ph calls and have AI listening looking for keywords. The GSM network was delayed when they put it up because ASIO didnt have all the gear in so they could listen to all the phone traffic. Crooks get by this now of course by encrypting their voice

 

It all goes to whether you are being a criminal or not...I am not so I dont ahve to worry

 

It doesn't matter. This is bad news, it will only further discourage people from using it. 

A not dissimilar, but more serious thing happened in Pakistan where a NGO was administering polio vaccines. The CIA got involved however, trying to find Taliban. So now regular folks who aren't criminals associate polio vaccines with the CIA.

You just need people to do what's best for the general population, don't give them any reason to not participate.  Clearly even criminals have been participating, which is good because the virus doesn't discriminate.

15 hours ago, Markdun said:

This is not what I read earlier but nevertheless it says much the same.

https://theconversation.com/most-covid-deaths-in-england-now-are-in-the-vaccinated-heres-why-that-shouldnt-alarm-you-163671

I’m not sure where they get the twenty fold reduction in hospitalisation (of vaccinated people) as the tested efficacy of the AZ vaccine is a tad over 90% and this correlates pretty well with the ten fold reduction in deaths that countries like the UK are experiencing (& which is a compelling individual benefit from vaccinating).  But it becomes very muddy and complicated once you start breaking the data down by age cohorts.

 

Regarding Israel and lesser extent the UK, keep in mind the testing and measurement of vaccine efficacy is NOT immunity to Covid infection but avoiding hospitalisation or death as a consequence of infection. Infection (& transmission) of Covid by vaccinated people is still very much a thing.  Earlier research indicated infection and transmission was reduced by 50%, but this has effectively been wiped out by the increased R0 of the Delta variant AND the behaviour of vaccinated people....ie. ‘I’m vaccinated so I can go to the nightclub, travel and shop’.  I don’t think it’s the waning effect of the vaccine yet....but I could be wrong on that....lots of vested commercial interests wanting booster shots for rich developed countries!

Oh. Ha. Yes I see. I misunderstood your sentiment. We have an anti vaxxer conspiracy theorist at work, and so much spurious 'Alan Jones' logic spews out of his mouth I geta little wary. Yes of course the more people are vaccinated, the closer to one hundred per cent of COVID deaths will have been vaccinated. Simple maths 🙂

8 hours ago, Markdun said:

Here is some data....might help when comparing proposed policies for Australia like get population vaccinated and let it rip, or as ScuMo said in Parliament last week, ‘yes, people may die but you can go to their funeral and to church’.  
UK daily death rate is now tracking around 1.6 deaths per million per day and many of these deaths are of vaccinated people (last I read on this it was just over 50% vaccinated).  And this is after they have had Covid kill the most vulnerable. That means if we follow this approach....vaccinate, ‘freedoms’ and open up borders sans quarantine etc we can expect 40 deaths per day or around 15,000 deaths per year.  This is still roughly in accord to my previous ‘back of the envelope’ estimate and is consistent or less than estimates of some expert epidemiologists.  It is of-course much more than annual flu deaths, road deaths, or estimates by experts like Doherty which were based on low incidence of infection with ongoing TTIQ (track, trace, isolate, quarantine) and lockdowns.  
Second graph is vaccination rates.  

I haven’t included a graph of daily infections...but that graph does show infection rates doing the usual up and down waves, including in vaccinated populations.  The big difference in vaccinated populations is that the death rates and hospitalisations are greatly reduced, but death rates and hospitalisations remain significant nevertheless.

I agree fully with previous comments about us having to change our behaviour, like fly-ins to private airstrips, avoiding mass transportation (trains, large passenger planes, quarantine and negative Covid tests for international travel...as many European countries now do) ongoing into the future....ie. no back to the way it used to be.

Covid with climate change is making it all very depressing....it feels very much like Neville Shute’s ‘On the beach’, with us here in Oz just waiting for the inevitable environmental disaster to roll on down from the north.  And we also appear saddled with a completely incompetent government which is becoming less democratic by the second. I feel for my children and grandchildren.

 

sorry to be lazy but where is the info on the deaths of vaccinated people? The last data i was reading about (The Economist I think) was from the US where virtually no one who was vaccinated was being hospitalised. In Israel it may be on the rise again but that may be due to the fact they were way early on vaccinations and really are the first to be due a booster.

17 minutes ago, onetrack said:

One has to remember, the Americans are extremely distrusting of their Govts, and have been for 200+ years. Many American Govts have been quite untrustworthy.

 

To add to that, there was the dreadful testing and manufacturing error of the first polio vaccine in 1954 (the Cutter Incident), that killed 5 American children, paralysed another 50, and made 40,000 children very ill.

 

This led to a lot of distrust of vaccines amongst Americans, which still carries on to this day. Add in the regular number of conspiracists, right wing "freedom lovers" and gun nuts, plus a fair dose of national paranoia, and the stage is set for much dissent.

 

https://www.washingtonpost.com/history/2020/04/14/cutter-polio-vaccine-paralyzed-children-coronavirus/

 

 

And yet even the most recalcitrant states in the US have better vaccination rates than here. I'm sure we will over take them soon, but it shows how much Australia has dragged it's feet when even Georgia has a higher rate of vaccination.

I think the lottery idea has merit. I cant remember the exact figures, but one state in the US introduced it and gave away say $6 million and saved say $60 in medical expenses.

Give people a chance to win a million bucks and let's see how many people remain sitting on the fence 😄