Carbon Canary

The red and black clips off the pump look like alligator clips……not an Anderson plug ??

AOPA CEO - Ben Morgan

Executive Director
Mr Benjamin Morgan
Mobile:  0415 577 724
Email:  [email protected]

Sub orbital spaceflights are now being marketed, but recent research indicates "ill-effects such as breathlessness, loss of vision, a wildly beating heart and a surge of blood pressure.......which may require tensing your lower legs and clenching your buttocks."  Expect 3-4 g on departure and up to 6 g on arrival.

......and that's just in business class 🙂 ! 

To any interested parties, I found this site useful................

Aircraft Engine and Propeller Sizing | AeroToolbox

To seek high public office demands a particular kind of personality regardless of the political persuasion.

Now, about that fuel tax……….

2 hours ago, Garfly said:

That'd be Mark Kyle.  ("Kyle Communications" on the forum.)

 

Ooops, yes thanks, I should have searched the forum rather than relying on my dodgy memory.

i guess the other question is do you really need a CO monitor in a Rotax powered aircraft ?  The cabin heater on a Rotax engine comes off the water radiator, so less risk of CO entering the cabin by that pathway at least.

I thought Windy was the bees knees, but I can see that this app is specifically targeting aviation and makes the information of interest to pilots readily available.  

Yeah, when you think about it, there would be a lot of lawnmowers and speedboats out there that suddenly had very high fuel consumption !

I think you need to be a registered primary producer (farmer) or a mining company to be able to get the rebate.

Back to the original risk of bird strike........I did some of my early training at Warnervale, over the Tuggerah Lakes.  This area has an abundance of pelicans, and the CFI at the time, routinely warned all students about the risk of hitting a pelican, and not trying to out-dive a pelican in the air.  I certainly would not like to hit one - they are big birds !!  I have hit a wedge-tailed eagle with the strut on a C172 though.

I am aware of an LSA (ELA) in Germany where a student had an engine failure in the circuit and elected to pull the chute (!!).  The aircraft was repaired and back flying within 6 weeks.  Of course this is most likely an exception, with the usual outcome that the aircraft is a write-off, but at least the pilot walks away and lives to fly another day.

I have two cars, one with air bags, ABS, etc, etc, and the other over 25 years old with no airbags, no ABS - I don't believe my driving style is any more riskier in the 'safer' car because of its safety features.

40 minutes ago, kasper said:

Well yes the bigger the better is a core rule spoken of ... BUT you are setting a limit of the same number of blades which makes it less different and smaller changes are expected.

 

Overall:

 

The lower the number of blades the fewer leading edges and tips involved and as as result the lower the drag from blades.  On this basis the best prop is a single bladed prop as it has only 1 leading edge and tip producing drag and all thrust (lift) coming from the blade area/pitch that is set to absorb the power applied.

 

When you have a compare of two 3-blade props on the same power engine on an airframe of equal drag you are looking at small changes.

 

A three bladed fixed pitch prop of greater diameter MUST have a lower pitch as it has a greater blade area available without more power so at any rev it has to 'bite' less air as there is more blade absorbing the same power.

A lower pitch blade can be spun up from lower speed more quickly as the excess power allows for that - the increased 'bite' from each increased rpm is less for the same increase in power

 

That is the reason the lower pitch prop will accelerate and climb better than the higher pitch lower span prop.

 

The reason the general spoken rule of bigger is better is that GENERALLY when people want to maximise lower speed performance you add prop blades and reduce span ... if you want to go as fast as possible reduce your number of blades and increase the pitch - in all cases subject to the power requirements ... you may be forced to have more blades to absorb all the power because you run into airframe clearance limits and/or speed of sound issues where at transonic speeds the 'normal' drag laws get screwed up.

 

end of lunch break - Over the hive mind

OK - Thankyou !

So to wrap this up......if I want to go fast, save fuel and don't care about STOL performance, I should choose the shorter of the 3 blade options available.

CC

"Reduction drives on high RPM engines like the 912 allow for slower prop speed at full power and therefore a larger diameter, good for STOL aircraft but less efficient in cruise which is slower than if a smaller diameter prop was installed."

Yes, this is for a 912 ULS. 

OK, I'm a bit slow.  I still can't get my head around the physics involved of why a longer prop blade (all other things being equal, including pitch) is less efficient in the cruise.

Particularly with Nev stating "Small dia props will have less thrust all other things being equal."  

Are you able to provide a 'Prop Design for Dummies' lesson here ?

The (draft) single runway flight paths for WSI airport should be known next month. This may also provide a preliminary idea for the airspace design surrounding the airport.

This will be of critical importance to GA operators at Bankstown.

14 hours ago, kasper said:

Larger prop = lower blade pitch = better acceleration and climb at the expense of high end speed

 

smaller prop = coarser pitch = slower acceleration and take off and climb but higher top end speed and efficiency at higher speed. 
 

up to you which flight performance end of the envelop you wish to preference . 

Thanks Kasper for your insights. 

I have very little understanding of prop design vs objective, but the fundamental effect of a change in prop pitch is clear.

Just to clarify, and I should have included this in my original post - this is for e-props ground adjustable propeller(s).  As you may know, these props are 'skinny'.

Are you able to provide a deeper explanation for why blade length (as opposed to pitch) has an effect on climb performance, etc ?.........or is it related to where the greater amount of pitch (AoA) occurs along the length of the blade ? That is, a longer blade has the centre of AoA 'thrust influence' further along the blade, which is spinning faster, etc  or, is it related to a longer prop requiring a lower adjusted pitch angle to achieve the desired WOT rpm ?.....Or something completely different ??

I'm expecting the aircraft will spend most of its life in cross country cruise rather than circuit work, so will err toward a prop that delivers best cruise performance.

I believe RFGuy is the local agent for e-props, so I may pester him with this question too.

Thanks again.

CC

The manufacturer of an aircraft offers the option of either a 165cm or a 170cm  3 blade prop……of the same prop type, from the same prop manufacturer.

What are the pros and cons of the longer prop vs the shorter one ?

Bunnings carry it, but I’m not sure about the ‘reputable’ bit.

Noticed this in the latest issue of Sport Pilot.

The inbuilt CO senser is a smart idea assuming it works better than the paper sticker on the dash. I also am assuming they have resolved the noise during charging issue.

It ain’t cheap, but you get what you pay for.  Interested in any comments or real world experience if anyone has used one yet.
 

https://www.design4pilots.com/categories/useful/products/pilot-co-charger

Easy decision for me to support the cause.

I have visited various aviation related museums and always enjoyed the experience and they have always exceeded my expectations for what can be achieved by usually a small bunch of motivated volunteers.

I wish the ABAM every success !

I dug a bit deeper, and pulled up a new application for insurance on my Super fund website.  It contained the following questions :

Do you regularly engage in, or intend to engage in, any of the following hazardous sports or activities? Please tick all boxes that apply.

Water sports or activities e.g. snorkelling, scuba diving, free diving

Motor sports or activities e.g. motorcycle, motorcar, motor boat

Snow/winter sports or activities e.g. skiing, snowboarding, ice skating, ice hockey

Aerial sports or activities or aviation e.g. skydiving, hang gliding, parachuting, ballooning

Combat sports or martial arts e.g. taekwondo, boxing, fencing

Field sports or team sports e.g. hockey, football including touch or soccer, roller derby

Horse riding or equestrian activities e.g. polo, rodeo , dressage, jumping

Rock climbing, abseiling or other adventure sports or activities e.g. mountain biking, parkour

Any other hazardous sport or activity not mentioned

Now the problem for me is that I have held the insurance policy through the super fund for so long, I have no idea how I answered the questions, but I fully expect I did tick the box for aerial sports as I have been committing aviation for a long time.  I think the super fund also have changed insurance providers over that time as well, but imagine the policies were simply novated across to the new provider.

So I guess I will need to phone the super fund and ask some hypothetical questions regarding my cover and to see if my premium needs to change.

Thank you !

I always wondered why they were mentioned together.

CC

Is there a difference between a Rod, Pole and Perch ?  If not, why does all three require being quoted for imperial measurement.

Hmmm, you motivated me to check the PDS of my policy through Super.

The only specific cover exclusion for death, terminal illness or TPD is from an act of war, or service in the armed forces or if a payment would expose the insurer to sanctions under UN resolutions.

That's it.

8 hours ago, Old Koreelah said:

Every time I top up my tyres I have to reset the servo’s unit from PSI to kpa.

Australia metricated thirty-odd years ago and we STILL can’t use the simplest, most sensible system ever conceived. 

Every vehicle has a recommended tyre pressure placard, usually next to the driver’ door. They are all in kPa, a very simple system, used EVERYWHERE, except backward countries.
What the hell is a PSI? What’s a pound? A square inch? 

 

One Pascal is the pressure exerted by 10grams (two teaspoons of water) sitting on one square centimetre (a fingernail). Standard air pressure is 1 Atmosphere, almost exactly 100 kPa, so if you put two Atm in your tyre, it’s about 200 kPa.

 

Can we please throw out those ancient, inefficient measurements?

Two teaspoons - now there is standard measure 😎

Teaspoon, Tablespoon, half a cup, SydHarb.

Wasn't that the problem that made the space shuttle Challenger explode ?  The fuel 'O' ring was metric rather than imperial or something ??