more data- PULP98 and AVGAS and det and vapour lock

[Jabiru7252]

A link to the flipped plane...

 

https://www.airhistory.net/photo/27966/VH-ASV

 

 

[kgwilson]

I was wrong. The wing spar AD affects quite a few PA28 models (some 5400 aircraft) that have more than 5,000 airframe hours. It was prompted by an inflight failure of the wingspar of an Arrow that killed the Instructor & student.

 

https://www.avweb.com/aviation-news/new-piper-wing-spar-ad-affects-5400-aircraft/

[facthunter]

They were a feasible basic trainer BUT what do they do for someone a bit more advanced?  Do you want to put it on line?  Nev

[Garfly]

 

 

[RFguy]

there are quite a few ADs on various corrosion events for PA28s.  But inspecting is not a big deal. 'worst case' is that  a couple of (flush) inspection ports get installed under the wing near the root.  there are others that can be accessed through floor panels etc.  there are corrosion ADs all over the place as you migth expect from a 50 yo aircraft. 
On every aircraft I have looked at (the books), ADs are all up to date. That's what they are of course, ADs.... 

 

The AD system can be a right pain in the arse, but it is also there to save your arse.    It's why I am getting out of 24-...... A manufacturer knowlingly aware of faults, or contesting their existance , or in denial etc, and doing nothing about it.  So many items should have been ADs for one vendor in particular. 
It's not that I dont like LSA, or I am a GA stob, it is that with 24-, you cant touch it- you are not allowed to.....even if it is deadly.   That is a flaw IMO with the current setup.

With 19- owner builder, you can do something about it and dont have to go for the ride with the vendor's opinion. 

 

Edited February 6, 2023 by RFguy

[facthunter]

You can't do anything not AD'd or approved with normal GA either. You have to go EXP-GA.  Not even fit a throttle friction nut.  Nev

[RFguy]

that's right ! but planes are usually well sorted...... even if one bolt breaks somewhere on some aircraft in the world, it gets thoroughly checked out.

The AD system works. 

It's not that I dont like the vendor, the engines are OK --- it's just the rules I have to work under with a 24- plane mean I have to accept a vendor's decisions and judgement and in this case this is wanting WRT engines in my opinion. In this case, the LSA rules prevent me taking  the situation into my own hands.  There is an option which is E24- Experimental 24- but E24 is NOT carte-blanch like 19- (although still must of course be within acceptable engineering standards for 19- )   ... E24 is very specific on the change. the E bit is for a specific change- IE say- ROTAX conversion.  ... For selling-  I am in two minds whether continue refurbing the 3300 engine with original heads+pistons  etc and sell that way  , or (complete the ) rotax conversion  it and go E24..     Filling it with Mahle pistons (there is a good track record people using those)  and LCH (fixed the evils of recession, MOGAS detonation , valve swallowing in one go)  is certainly a sure way to get reliability but you cant get it signed off easily. Then you have an insurance issue.   Certainly domain of the 19- which is a bit of wild west.  I really want a 19- J230. 

 

 

Edited February 6, 2023 by RFguy

[facthunter]

There's a lLAG in the AD system. It's a response to a risk that emerges as a result of experience in the field over time. If you are in the vanguard of the "high hours on a type brigade" maybe what happens to you will help others but maybe NOT you.  A mechanical fuel injected old clunker is probably the best engine to deal with but NEW or near  new.. Fuel injection will stop dangerous backfiring which is a cause of much engine damage. Lean mixtures cause a reduction of effective Octane rating also. Hot and lean equals  a crispy engine with a lot of friction.  Nev

[Bosi72]

9 hours ago, facthunter said:

Had a look at a Decathlon?

Do you have a Decathlon for sale ?  

[kgwilson]

4 hours ago, RFguy said:

that's right ! but planes are usually well sorted...... even if one bolt breaks somewhere on some aircraft in the world, it gets thoroughly checked out.

The AD system works. 

It's not that I dont like the vendor, the engines are OK --- it's just the rules I have to work under with a 24- plane mean I have to accept a vendor's decisions and judgement and in this case this is wanting WRT engines in my opinion. In this case, the LSA rules prevent me taking  the situation into my own hands.  There is an option which is E24- Experimental 24- but E24 is NOT carte-blanch like 19- (although still must of course be within acceptable engineering standards for 19- )   ... E24 is very specific on the change. the E bit is for a specific change- IE say- ROTAX conversion.  ... For selling-  I am in two minds whether continue refurbing the 3300 engine with original heads+pistons  etc and sell that way  , or (complete the ) rotax conversion  it and go E24..     Filling it with Mahle pistons (there is a good track record people using those)  and LCH (fixed the evils of recession, MOGAS detonation , valve swallowing in one go)  is certainly a sure way to get reliability but you cant get it signed off easily. Then you have an insurance issue.   Certainly domain of the 19- which is a bit of wild west.  I really want a 19- J230. 

 

 

There are no 19 230s. But you could buy a 430 which is GA experimental & you get a couple of kids seats in the back if you want them.

[Methusala]

23 hours ago, facthunter said:

There's a lLAG in the AD system.

Here we go again. Can the cognicenti please not make it difficult for us dumb c...s by avoiding opaque acronyms. I could not get a workable expansion of this from Google. Thanks in advance, Don

[facthunter]

Sorry it's a fat thumb problem. It's meant to be LAG. I have nerve damage in one hand. Nev

[pmccarthy]

Are you an old lag?

[old man emu]

13 hours ago, Methusala said:

Can the cognicenti

Non sum unus de cognicenti, but I did find that LAG is an acronym for "lowest adjacent grade". But don't try to find an answer by Googling. You'll only come up with stuff about slope on footpaths beside buildings.

 

For CASA's opinion on "petrol" types of fuels look up AWB28-003 Issue 1, dated 2007

[facthunter]

LAG in this context means delay in  response. You have to establish an issue BEFORE you can  respond to it and the manner of response be decided.also.  Hysteresis in instrument readings is another example  Nev

[pmccarthy]

And parallax is why something looks bigger when you look at it on an angle, rather than straight down, as noticed in public urinals.

[Garfly]

 

 

 

 

On YT:

 

"Now that GAMI's G100UL is fully approved and awaiting distribution, owners are hearing questions about how unleaded fuel might cause valve damage in aircraft engines. It was once a thing in car engines, but in this video, AVweb's Paul Bertorelli examines the issues and finds valve seat recession an unlikely consequence of using unleaded aviation fuel"

 

https://www.youtube.com/watch?v=ovJBJjZTjsk

 

[skippydiesel]

 

https://www.youtube.com/watch?v=ovJBJjZTjsk

 

Interesting particularly that some manufacturers did not start using hardened seats & valve stems (?) until 2019.

 

Have a friend with a RR (Continental) forget the actual engine,  think 100hp. He has an STC for ULP  - persisted with mo gas for a while - had the engine  reconditioned twice in that time, due to damaged valves/seats - now exclusively AvGas & no further problems - all a bit unscientific, to be sure but makes you stop & think.

[RFguy]

it's a good video....

Looks bad for Continental, good for Lycoming. and less than ideal for continental company behaviour.

 

[facthunter]

It's not just simply a question of hardness with valve stems. The guide material has to be compatible with the valve material and IF you mismatch them all bets are off.  If the valve stem surface galls it resembles a file and the life will be very short.. There's been stuff out stressing this for AGES. At least 30 years.   Tetra ethyl lead helps valve SEATS  by melting like a flux. It doesn't promise anything for the guides. and doesn't work in liquid cooled Heads Like Rotax 912's  because they don't get hot enough and it just builds up on the seat unevenly and you lose compression. Nev

Edited March 6, 2023 by facthunter

[aro]

The theory that he describe as the "pixie dust theory" is basically saying that lead compounds on the surfaces stop them from sticking together (micro welding).

 

I'm not a welder, but if you told me that contaminants on the surfaces could stop a weld from sticking I'd say it sounds quite likely.

[facthunter]

It's like using sand as flux when welding on the forge.  In that instance it melts and flows  and It stops oxidation. Lead is BAD for bronze seats as it alloys with the bronze on the exhaust seat.  Nev

[skippydiesel]

I do wonder at all those AvGas guzzling GA aircraft, flying around, with just the pilot and the occasional Pax (usually one).

 

They could be in a ULP powered two seater (I prefer 2 seats to one, as need somewhere to put all my flying junk/nav stuff etc) with all/most of the attributes (if not more) at a fraction of the purchase/running cost, no STC and worries about long term engine damage.

[kgwilson]

A lot of them don't have to use Avgas. During the debate in the US there was a study done & they found over 80% of the US fleet of piston powered aircraft could run on unleaded fuel. Most don't because of ignorance or availability. Now with the Gami approval hopefully that will change. It needs to here as well

[spacesailor]

AND, what ' servo ' will sell '' aviation '' unleaded ethanol infused fuel . Knowing it could fall on their own head .

When filling your can of super petrol . for ' aviation ' , do you tell the servo were it will be used .

spacesailor

Edited March 6, 2023 by spacesailor