Spar Scarf Joint

[VaporGlobalAviation]

Opinions welcome... I am looking at buying a 78 Decathlon that had wing/aileron damage in 1980. Repairs were noted in the logs as "repaired with factory new parts". Upon my inspection I found a Scarf Joint in the spar (see pictures). I am thinking this is a "pass" as the intended mission of the aircraft is aerobatics. Inputs welcome.

The picture is of the right forward wing spar, from the strut attach point towards the wingtip.

 

[Hiperbiper]

Just from the pictures I'd say whoever did that joint was really good.
Nothing wrong with a properly done splice in a wood spar. Probably half the 1946 onwards Aeroncas had spar splices from the factory. I know Bellanca used factory-spliced front spars while they owned the TC.
Properly done a spar splice is as strong or slightly stronger than a one piece spar blank...

Chris

 

[Bob Turner]

Agree. If it is just a scarf joint without the thicker side plates it is most likely a factory splice.

 

[Big Ed]

If that aircraft has been doing aerobatics since 1980 without problem, then that is a pretty well tested repair. I would not hesitate to fly acro in it, and I fly my '78 Super D fairly aggressively these days.

Having said that, 40+ years is approaching the upper lifespan limit of the airframe without a restoration of some kind. If that aircraft has original fabric, there are pretty high odds that you or someone else is going to be recovering it in the next 5 to 10 years.

That will create a decision point where you have the opportunity to replace the spar or swap for metal wings, should you be so inclined. Although that spar looks in such great shape, you might just varnish it and put it back together!