skippydiesel

2 hours ago, onetrack said:

I would never use anything from Supercheap on an aircraft, because Supercheap focus 100% on the cheapest products they can find, to produce the maximum profit.

There's a lot of rubbishy rubber products that come out of Malaysia, Indonesia and China, that Supercheap mostly specialise in. If you want quality in rubber components, you use Gates products, and Gates Green Stripe where possible.

Anything designed for Marine use normally has superior quality in construction style and materials.

 

Rubber components are the weak link in every engine system. Anything you can do to reduce the amount of rubber in an aircraft is going to appreciably increase that aircrafts safety level.

If it was my choice, and my aircraft (and I don't own an aircraft), I'd be choosing to eliminate as many rubber/rubberised hoses, as I possibly could. 

 

Any hose that is red or yellow coloured has a short life, due to more rapid and more intense UV absorption. Green-coloured hose has the longest life, due to minimal UV absorption.

Careful there One Track - metal lines (the most likely alternative), are not without problems. Vibration/resonance has been known to fatigue metal tubes, resultant leak over a hot engine may be a bit uncomfortable (me old mate F10 will bee alarmed ).

The conservative 5 year Rotax recommendation for the replacement of rubber components, related to the engine, PROVIDED quality products are used (quality does not necessarily = cost) almost guarantees safety in this context.

I am 110% with you on the SCA parts - I am am happy to use all sorts of" stuff",  from any source (including Bunnings Aero Space) but draw the line on using anything that may adversely effect the continuance of safe flight.

The cheery colouring of hoses, is unlikely to indicate anything about the hoses performance - its a marketing tool. Want to get some idea if a hose will "do the job" for you ? - look up its specifications. No/limited specs - dont purchase.

11 hours ago, F10 said:

No, the Gazelle has coolant rad setup unique to it, as do Kitfox, Eurofox, all slightly different rad positioning. So we had to rummage through the hose bends bin at "Supercheap Aerospace" to get the right bend size and then cut the pipe length as required. Some say, SCA fuel pipe is dodgy, well its pretty thick fuel pipe with a good grippy softish feel, I have used it before, it's tough, simple, handles Mogas just fine. Lasts forever in most old Holden of Falcon wagons...Like I said, I plan to inspect the engine on a regular basis, the Gazelle is good in that the cowling is just two pieces, top and bottom, easy to remove. Take them off and the whole engine is exposed. Good advice I was given is to choose a fuel line or coolant line and carefully follow it over the engine beginning to end. Then choose and follow another. Don't try look over the whole engine as such, its too much information to take in one hit, so you may miss something. 

So you are able to get the same level of specification information for a SCA supplied hose as you are for a Gates (from Repco) ?????

I confess, I misused the loose float bowl (focused in on the hose) so well done F10 - this is definitely the sort of avoidable error that may cause a fire -  far more so than correctly fitted fuel hoses.

3 hours ago, John Robert said:

This link will resolve any disagreement about Rotax approval of Teflon hoses.<https://legacy.rotaxowner.com/si_tb_info/serviceinfo/si-912-022.pdf>

As in rubber hoses there are different qualities in Teflon. I have read that non conductive hoses are the best. I would spend some time researching specifications before I fitted them. They cannot be fitted to the standard barbed fittings used for rubber hoses. So that requires replacement of all fittings. The kit cost is about Au $2000  + shipping for all oil & fuel hoses with fire sleeves. The supplier for Vans Aircraft tests each hose after assembly. Seems like a lot of $ but it would reduce the labour on the  first install with no other costs after that. The value of the  additional safety with the fire sleeves would depend on the individual.  Personally I would not want to fly without the fire sleeve especially as the CT does not have a steel firewall.

Everyone assess risk differently - use good quality hose every 5 years, look after your electrical security and it is most unlikely you will experience a fire as a result of a spit hose or an arcing wire. I have never heard of this in a well maintained aircraft, & I suggest its rare across  all sport aircraft. If it improves your feeling of security - go with it but doubt the cost effectiveness of the (Teflon).

This is a debate that has no right/ wrong, very similar to the ballistic parachute 

56 minutes ago, John Robert said:

Skippy, you misquoted me. I hope you understand technical instructions better than your understanding of what I wrote. I said "I hung the piece of hose on my hangar wall & left it until the next rubber change at which time I was able to break pieces off it." I have always changed my rubber hoses  at the 5 years recommended time. "My friend was considering" but has not done the Rubber change yet.  Rotax actually use some teflon hoses, cost is maybe what prevents them from having all teflon. If I consider the fact that often the fire sleeve is  damaged  after the removal of the old hose, & it is much more expensive than the hose. Add the cost of 4 new clamps for the hose & sleeve per length, I dont use Jubilee clips just single ear stepless  SS. hose clips. There is a good argument for the teflon kit which is recommended by Van's for the RV 12. If you check on the specs of Teflon hose you may find that there will be zero fuel vaporisation through the hose. Often if something looks fantastic it usually is. I have almost justified the cost of the kit to myself for the next change.

Maaaate! - I may have misunderstood a little (my apologizes) but at the end of the day, when it concerns the engine,  Rotax is the authority you should be listening to, not the airframe manufacturer. Remember Rotax 91 engines, motivate a very wide range of aircraft (certified, LSA  & experimental) - the engine does not change and neither should your source of information.

On the clamps/clips - use whatever you prefer ,the main thing is that the clamps are the right size for the job, provide a 360 even pressure, do not damage the hose and are not done up to tight - clamps are primarily for security, not for preventing leaks. Personally I use fuel injection clamps.

2 hours ago, John Robert said:

I thought that it was compulsory to use a fire sleeve with all fuel & oil lines inside the cowls. Compulsory or not I would not have a naked fuel or oil line around a hot engine without a fire sleeve. My first rubber change from new in 2011 had me tugging & twisting to remove a Gates hose fitted as an original. It still felt soft & pliable & I was wondering if it was really necessary. Changed my opinion when the hose broke & I examined the cords. A fuel line should not break, I hung it on the hangar wall as a reminder & when I did the next rubber change looked at it again. At 10 years old the hose had surface cracks & it was possible to break pieces off . Maybe it was a faulty batch, its still on the hangar wall ready to show anyone who is reluctant to do the 5 year rubber change. Some Flight Design owners in the US had problems with rubber sharves in the Bing float chambers. This was found to be only when they had fitted fuel injection hoses. The reasoning was that the injection hose is much harder & quite difficult to fit . Twisting & pushing was deemed to be the cause of the slivers of rubber finding its way into the carb & causing engine problems often intermittent & difficult to diagnose. It is not necessary to use a high pressure hose designed for fuel injection on a Bing carb that cannot handle  above 5PSI. There could also be an argument that the low pressure hose will compress more easily to give a better seal with lower tension on the fitting. The Rotax fuel pump at one time was not included in the rubber change. It is now & if you have noticed how flimsy the diaphram is for the Bing carbs there is also a similar one in the fuel pump. A shame they do not fit a serviceable pump so the diaphragm can be replaced.

A friend was considering fitting the Teflon hoses which do not have a timed life. They look fantastic,I was given this link but have no experience with this company  <http://aircraftspecialty.com/RV12Fuelkit.html>.

It is  good to have these discussions about critical maintenance there is so much to learn on some of the websites.

 

I have always used Gates fuel injection hose - never even had a hint of a problem (see above post to F10). I think it more likely that:

1.  People fail to blow out (HP air) the hoses befor fitting, thus removing any "swarf" from the cutting to length process
2. Do not use proper hose cutters (cheap as), leading to a lot of swarf generation
3. If fitting is the problem, you have described, they are trying to fit the wrong ID hose - no problemo IF  you get the right hose for the job
4.  Like you, have kept the hose in service, well past the Rotax recommended 5 year change interval.

Picky, I apologise, but the Max fuel  pressure is closer to 6 psi

"A friend was considering fitting the Teflon hoses which do not have a timed life."

I dont get it. Rotax make a recommendation based on their experience & rigorously conducted trials. Your mate goes out and pays "an arm and a leg" for a product, not recognised by Rotax, when he could probably do 50/5 years of Gates fuel hose for a similar price  and stay within Rotax recommendations - Oh I forget "They look fantastic" 

12 hours ago, F10 said:

Also did a 5 year rubber and annual on our Gazelle. 5 year kit from Floods Imports. Came with coolant oil pipes, new fuel pump, old one was fine I think, but it has rubber in it so....out went what was probably a perfectly good pump. Maybe I can give it ti a car crazy mate. Also, kit had new Bing carb rubber diaphragms. Easy to fit, just line up the little tangs on the edges of the diaphragms with carb body and chamber lid. Sounds complicated but it's not. No fuel hose as such or fire protection sheathing, so you have to supply. I don't think its specified, but fire sheathing a good thing on fuel pump hoses.

 

Location of fuel pump on reduction gearbox (Rotax 912) will mean any leak will go all over the top of a hot engine....You will hear a "whoof" and it won't be a dog. So we replaced all our fuel hosing with new, bought from "Supercheap Aerospace". I plan to carry out regular inspections of all hoses, on those weather days, when it's no point getting her out the hangar. The Gazelles had this weird transparent sheathing over all the fuel hoses in the cabin, a sort of double layer, to capture leaking fuel it seems. It was all old and cracked in places, so we got rid of it. Probably a carry over from it's VH-IOP rego days.

 

Ordered new plugs with the 5 year kit, they came with heat paste already put on the threads, nice touch but we did pay for it.           

Maaate! Buying, unknown quality, hoses from SCA is a completely unnecessary risk and no saving in $$$

I have used Gates fuel & coolant hoses, purchased through Repco, for 12  years or so. You can look up (Google) the specifications on all Gates products - try thet with SCA

I personally use fuel injected rated hose, as it gives lower permiability, higher heat/fire resistance and has a working pressure that a Rotax fuel system will never even come close too. Cost per m is only slightly more than carburetor hose (remember Repco sales people can negotiate on the price so do so)

 After 5 years, my hoses are in such good condition, they get re used on my land based machinery.

I used automotive insulating sleeve on my over engine fuel lines - mainly to reduce (sadly not eliminate) fuel vaporisation.

Don't know what fuel pump you have fitted but if its the latest generation (which it should be), it has a fuel/oil bleed point, that you are supposed to fit a hose to, to exit any leaks overboard, well away from the hot engine/exhaust.

OMG!!!! - You guys are soooo negative -Ref rebuilds:  a conscientious owner has already obtain a full engine inspection and "sign off" from Bert Flood Rotax, applied the recommended "storage" regime to prevent all of the possible problems, of which you mention. 

Further, you make such sweeping statements, without any consideration to the obvious huge variation, in the degree of damage sustained. This could be anything from a minor ground incident to an unrecoverable airframe, with every "shade of grey" between.

2 hours ago, waraton said:

This is an old thread but relevant to a hangar chat I had today where we wondering how many projects get delivered and never opened or started and never completed. Do you know of any examples at your airfield?

Waraton; My ATEC Zephyr (originally a kit) is in need of a partial rebuild (a very cheap way to enter the world of RAA aircraft ownership). This is/was an exceptional aircraft with an astonishingly wide flight envelope. beautifully intuitive to fly and economical to operate. As Walrus (above) alluded, time starts to run out and rebuilding  is not something I wish to do at this stage in my life. Happy to supply all the details including photos to anyone who may be interested.

22 hours ago, Thruster88 said:

We need a pic of your new machine 

Europa Classic 

3 hours ago, RFguy said:

what cable is it fed with ?

does it have feedline chokes ?

you'll find that the fibreglass will tend to length the antenna , so it may appear a bit low in frequency.

Best VSWR you will get will be 1.5:1 with that setup, so if its it between 1.5  and 1.8 in the middle of the band, and less than 2:1 at the ends, that will be fine

 

bandwidth of the dipole is proportional to the width of the elements.

A dipole built with flat strip 1/2" wide will have superior bandwidth to an antenna made from 1mm wire.

glen

 

 

From visual inspection, I think the "wire" is about 5mm 

9 hours ago, Jabiru7252 said:

If your SWR is below 2 to1 it's not worth dicking about with, unless that dicking about is easily done. Believe me, I have spent a lot of time playing with antennas, from 1.8Mhz through to 470Mhz. 

Thank you both - GREAT INFORMATION ! Have just signed the sales agreement. Will let you know (the fine detail) what I find when I actually have the aircraft in my possession.

Dipole antenna  has been "glassed" into a composite airframe. It runs to the tail and then rises almost vertically (tail fin slightly swept).

Should my SWR meter suggest modification (long/short) might be appropriate, there does not appear to be any facility for changing anything on the existing set up.

The only alternative would be to fit a conventional antenna  or another dipole.

Conventional antenna would spoil the look of this very "clean" aircraft but clear comms is more important.

Not my aircraft (no commissions involved) however you might just be interested:

 EUROPA XS MONOWHEEL FOR SALE!

Located Serpentine

(Currently registered VH-IHV but can be RAAus)

First flown in 2005, this plane has only flown 115 hours
Fitted with Jabiru 3300 engine and Airmaster AP 420 constant speed prop
MLG Extreme mini EFIS
Microair VHF radio and transponder
ARIA GPS and IPad mini mount
Angle of attack indicator
Long range fuel tank included
Custom made transport trailer
Various spare parts including fixed pitch Jabiru propeller.

Performance as offered
Cruise 145kts TAS at 19 litres per hour
Range 450 NM or 670NM with long range tank on board

With fixed pitch prop fitted (approx 10 kg weight saving)
Cruise 125kts TAS at 16 litres per hour

Price $45,000

Jim McAvoy
[email protected]
0412227411

Attention Radio Guru's - Is a dipole antenna inherently "tuned" and suitable for any transceiver?  or does it need the attention of a SWR meter like a conventional antenna?

In my limited (mainly NSW) experiencing every "security controlled" airfield I have landed at had, no one checking who I was, if I even had an ASIC, or had any interest in my movements in/out the "security" gate to get fuel - total waste of tax payer & pilots dollars. This ridiculous system must not be promoted in any way and should be vigorously apposed at every opportunity.

There is a way round it - you can phone/call ahead and request a security escort to &  from your aircraft - Can you imagine how that would go down??

2 hours ago, K5054 said:

I think I will sell it and install this

 

https://www.scintex.com.au/products/engine-fuel-consumption-gauge-supply-return?_pos=30&_sid=a33b01d08&_ss=r

Get the single sensor + gauge for $900

9 hours ago, pmccarthy said:

It is not optional for GA pilots, must have ASIC or Avid.

You sure? - If not flying in/out "security controlled" airfield there would not be anyone to take any interest in an ASIC /Avid.

1 hour ago, APenNameAndThatA said:

I did not find the article supportive of the card. It provided me with information that I thought was helpful: it’s not an access card, watch where you walk, and people are obliged to dob on you, and you have to renew every two years. I didn’t know any of that.

 

It seemed to imply that you could not or should not apply for one for fun, but if you fly into security-controlled airports for fun, you will need one. 

Maaaaaaaaaaaate! - there is nothing positive about the ASIC, not one redeeming feature,  as applied to  small regional airfields - its a DUD.  The positive  "spin" as used in this Red Card article, is just not worth the fee payed to the author for the first sentence.

That Sport Pilot - the public face of RAA -should publish this dross, is an insult to the membership. RAA must hear, from us, laud and clear that ASIC is to be vigorously apposed at every opportunity.

I stand to be corrected; Something is not right about your fuel delivery/return system. The fuel return is more about minimising vapour "lock" than maintain a set pressure. As Scott said your return should be a comparative "trickle". The mechanical pump has the capacity to deliver way more fuel than the 2 carburettors will ever need.

My system predates the use of a T fitting, with fixed aperture, having an adjustable/heavy pressure relief system. I had very good results from my fuel computer, using a hall effect turbine sensor, on the main fuel supply line (nothing on the return or boost/alternate supply).

You dont actually need a second "sender". Perhaps you just want one for the heck of it.

Most Rotax 91 range engines have a fixed aperture return line, the dribble of fuel that goes back to the tank can be easily accommodated in your set up menu, under total fuel used.(no need for a return line sender)

7 hours ago, pmccarthy said:

The review of this aircraft in the latest Sport Pilot is interesting, the plane sounds great. Am I right in thinking that a 17:1 glide ratio will make it quite sensitive to turbulence due low wing loading?

Very nicely presented, looks to have a good fit & finish but what I cant understand is why its low/high speed performance is so underwhelming.

Sport Pilots most recent issue (No 99) page 51, "Getting Red Carded "by a Mr Ed Jones - This article reads (to me) as a promotional/supportive statement for the ASIC program, as it is applied to sport/recreational pilots flying in/out of minor  ("security controlled") regional airfields.

Don't know about you but I am appalled that Sport Pilot would be taking this supportive position, of what can only be seen as a political "knee jerk" gross overreaction to the 9/11 terrorist attacks in the USA. Its not so much the complete waste of our tax payers dollars, as the ridiculous imposition on us as pilots FOR NO DECERNABLR SECURITY BENEFIT.

ASIC, as applied to small regional airfields, is not a program that should be getting any support from the aviation media or sport  pilots in general.

Sport Pilot should immediately distance itself from this article and make a statement affirming its opposition to ASIC.

44 minutes ago, Yenn said:

GA aircraft usually have the oil pressure sender mounted on a manifold away from engine vibration purely because they know the vibration caused sender problems. To do that you have to have a flexible connection between manifold and engine something else to go wrong.

Pleasure explain how mounting on a manifold (usually connected solidly to the engine) will reduce vibration ?

11 minutes ago, PommyRick said:

They sent an email looking for offers a few weeks ago for these last three Bristell. But with 1700/1800 hours,

they are pretty high.

 

Max $20K each and you might have some change left over to repair/replace all those little  & not so little parts as they "give up the ghost"

1 hour ago, turboplanner said:

 

 

1 hour ago, turboplanner said:

1 hour ago, turboplanner said:

The Power stroke starts with the gas mixture confined to a tiny space above the piston.

 

The fuel air mixture is certainly "confined" however this is a result of being inside a rigid cylinder with one end (piston) reducing the volume (pressurising the air fuel mixture. The ignition of the air fuel mixture initiates a burn (expanding gas) which drives down the piston delivering the power stroke.

 

As the piston travels down, the gas expands and the byproduct of expansion is cooling.   

 

Noooo ! - the gas expands because its burning (hot hot) any cooling, is completely overcome by the fuel/air mixture burning at high speed 

 

 Intercoolers and aftercoolers are two different products. The Intercooler cools the air before it reaches the turbo pump section and the Aftercooler cools the air after it comes out of the turbo blower.

 

The air coolers in a boosted engine, will always operate after the  air "pump"  (usually an exhaust powered turbine but could also be a belt /gear/chain powered screw pump). The combination of pressurising the air and in a turbo charger the heat from the exhaust side of the system, raises the air temperature & reduces density . Lower density = less O2/M3. To recover some of the lost efficiency, an air cooler (usually air to air but can be an air to liquid) i s used between the turbo and the inlet of the engine.

 

I was just explaining the principle that by cooling the air you can stuff more in during the compression stroke.

 

In a 4 stroke the air enters the combustion chamber during the inlet stroke not during the compression stroke. In a 2 stroke the air enters during the later stages of the power/erly stages of the compression stroke.

 

The principles I discussed work for all ICE engines at all rpm. You can tell an engine builder knows what he is doing by listening to the engine ticking over at 500 rpm.    Although I did mention power increase due to better breathing, the aspect of what I was discussing here relates to combustion process and it's various temperatures, but high and low which overlay the other piston temperatures discussed in earlier post; it's a bigger moving target and you can change the piston temperatures by allowing and engine to breath in better and breath out better (non-technical terms I know), and it makes a lot of difference if through using a plenum intake chamber, one cylinder breathes better than another, and the same with a common exhaust manifold.

 

You have lost me here - Yes engines will be able to burn more fuel, delivering more power, for a given capacity, if they can "breath" better. Your plenum chamber idea ?? - In my limited experience the plenum chamber is a "box/large duct" that contains filtered air (colud be cooled &  pressurised), that then "feeds" into the carburetors/inlet manifold (injected fuel system). The plenum does not in itself do anything much.

1 hour ago, turboplanner said:

 

                                                 

1 hour ago, turboplanner said:

 

                                                           

Turbo me old  mate - Bit hard to follow -Lot of non engineering words to confuse matters - However I get your gist.

The "expansion" stroke usually referred to as the power/combustion stroke, does not reduce pressure in the chamber - if it did you wouldn't get much in the way of power being delivered. 

Intercoolers, sometimes called after coolers, pretty much only apply to exhaust turbo (possibly super) charged engines.

Forced air (turbo/super charged) engines do not "give a smaller volume" of intake air - they cool the air, allowing for a higher density/oxygen content. This  allows for more fuel to be burnt. Can also assist with scavenging and cleaner/less polluting combustion.

As for inlet/exhaust optimisation on aero engines - in general these "tuning" techniques work better on high rpm engines. eg Rotax 2 & 4 strokes (land based vehicles). Slow revving LyCons will get some benefit but it will be minimal.

The whole consent is known as Volumetric Efficiency - describing the ability of an engine to process the fuel air mixture.