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Engine Provenance


skippydiesel

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Just wondered what the consensus of opinion might be:

 

Recently became interested in a, potentially high performance, LS class aircraft, kit built, Rotax 912 ULS powered but very little additional info by way of description or photos.

 

Vendor - (extremely honest)  informed me that he did not know where the engine had come from (speculated from a school) or what hours it had run up. He himself had had considerable work done on engine & gearbox and stated it runs well.

 

This information fairly knocked the fantasy out of me - I apologised for wasting his timer and withdrew my interest.

 

I appreciate that as a kit built aircraft, there are many things that may not be legally required, regarding its provenance (& component parts), accident history, etc however I am dreaming when I suggest that most owners would have fairly good records ?

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Pete, I think Skippy probably meant to write, "Am I dreaming when I suggest that most owners would have fairly good records?"

 

And I would reply, that if you find someone selling any type of aircraft, and they can't provide detailed records, I would consider that persons attitude towards flying and aircraft maintenance, falls well short of what is required by any interested reasonable aviator.

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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.  

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My suggestion would be to apply proof-loads before flying. Just make sure the proof-loads are not so high as to cause damage which was not there to begin with.

Of course a big inspection before and after the loading.

There seems little interest in proof-loading in Australia and I think the reason for this is due to the risk of damage during the test.

As for the engine, surely its condition is not too hard to determine?

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Interesting!

 

I think my Q was more to do with the expectation of a certain professionalism in aviation. I was very surprised to have the owner of the aircraft tell me he had no knowledge of the engines origin/provenance - seems a little like winding back the odometer on a car.

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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.

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12 minutes ago, kasper said:

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.

Unfortunately and to my profound disappointment, I guess you are correct - aircraft owners/pilots are no more professional than car owner /drivers.

 

As for cars/vehicles of which I have bought and sold quite a few in my life - Yes I do expect a certain level of traceability (provenance), service history, etc - I have along list of graduated check points, when purchasing a vehicle. At the highest level - one failure = walk away. Lowest (can be a few) =  reduction in bid.

 

Cars like aircraft can/do have replacement engines from time to time - not a problem if legitimately acquired, known mileage/hrs, etc

 

For me it is much the same for a aircraft - I have only ever purchased one but over the last 18 months have looked at perhaps 12 - actually made contact with vendor on 8 or so, inspected 3. I still dont have an aircraft. Over this time I have developed a very detailed check list. One of the most significant points is engine provenance  - no history = walk away.

 

Safety is only one factor - anticipated maintenance/repairs, expected service life, etc all come into a pre purchase/decision making inspection.

 

For sure ! Ii a RAA 19 aircraft there is much left to the owners discretion. Come sale time, if you dont have the documentation (build record, accident/repair record, airframe/engine log book, etc) you are unlikely to get a good price and may have a long wait before that buyer at a knockdown price comes along.

 

 

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If you have a homebuilt aircraft, as I have, you need to have kept meticulous records for the full life of the aircraft. If not you will have trouble proving it is what you are representing it to be. So if you are offered an aircraft with poor records be very careful. It may be an egg, but is probably well on the way to being an omelette.

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The L4 I contact says RAAus aircraft should have separate airframe, engine and propeller log books. That way if you sell or buy a second hand engine for instance the log book goes with the engine.  When ever I buy an aircraft I want the log books and I retain a photo copy of my sold aircraft log books that were up to date on sale.

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  • 3 weeks later...

Please explain more Red. No disrespect here.  Personally, I would prefer an unknown airframe to fail in the workshop in preference to on the first flight. But I have to say that I have never seen a proof-loading take place for real, unless you count the Melbourne Janus wing fatigue test.  I don't think the Schneiders did proof loading, but they sure did a lot of flight testing. I can remember Harry Schneider rigging up a bag of sand near the tail-end of a new glider design. He had to demonstrate spin recovery at aft c   of g ( an inch behind the rear "limit"). He had a string to pull on to spill out the sand as a safety measure. 

 

Edited by Bruce Tuncks
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