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xblueh2o

Well Known Member
Had a rare free day today so I beat feet to the airport to get some work done.
Looking for a sanity check here.

Reading the last instruction in the build manual on page 6-4. Which says in part, "Mark the location and orientation of VS-803PP, VS-411PP and VS-412PP. Disassemble , de-burr, dimple, machine countersink etc etc etc."

What is giving me pause is that there is no dimpling or countersinking involved with VS-411PP or VS-412PP. The sanity check I am hoping for is that this is in fact two different sets of instructions.
1. Mark the orientation of the VS-411PP and VS-412PP so they can be reassembled in the same place because you match drilled them to the VS-803PP. Stop.
2. Disassemble, de-burr, dimple and machine countersink the VS-803PP and VS-808PP as necessary.

Also wondering what people are doing regarding direction of rivets. Aside from the lower AN426 rivets which the plans call for to be assembled with the shop head forward, is there a standard on the rest of the rivets regarding which side of the spar the shop head should be on?
 
You are correct that there are no flush rivets for -411 or -412. I took the instruction as you did, as "mark these parts, disassemble, and deburr/dimple/countersink the entire spar assembly as needed."

As for direction of rivets, it really doesn't make a huge difference. If there are no other factors, good practice is to put the shop head on the thicker material. But if, say, one orientation is more favorable for setting the rivet, by all means use that criteria; setting a good rivet is more important than orientation.
 
Rivet direction

Yep. It came to me in a dream so to speak. I woke up last night about 03:00 and I thought I remembered a long ago tidbit passed on to me by an experienced A&P. When riveting two different thickness materials together it is preferable to have the manufactured head on the side with the thinner of the two materials. I re-read the instructions in section 5 while eating breakfast but didn't see anything like that. Got to work and asked one of our tech's and he said yes, without other extenuating circumstances it is preferred to have the manufactured head on the thinner material.
 
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Rivet direction

A reference a builder should have is the bible of aircraft maintenence, FAA Publicaton AC43-13. It has saved me lots of time trying to find someone who has the answer to my problem.
 
Funny you should mention that. I have been searching for my copy but it was packed away three moves ago and has probably vanished. Time to order a new one.
 
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