What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Drilled Head AN bolts

D

DeltaHotel

Member
I have been thinking about changing out some of the AN bolts for drilled head bolts. Such as AN3H-4A for AN3-4A. This would allow the use of safety wire. I'm not suggesting replacing all of the bolts, but just one example would be the bolts that attach WD-1207 and WD-1208 to the stabalator spar. It looks like it would be difficult to inspect these bolts with the aircraft assembled. I know we are using locking nut plates, but the safety wire would be visable and easy to inspect. Is this too much like belt and suspenders? What do you guys think? If you say "built it like the plans" because it is an ELSA, I would be willing to ask Van for a letter of authorization to substitute the drilled heads.
 
This is one case where...

DeltaHotel said:
I have been thinking about changing out some of the AN bolts for drilled head bolts. Such as AN3H-4A for AN3-4A. This would allow the use of safety wire. I'm not suggesting replacing all of the bolts, but just one example would be the bolts that attach WD-1207 and WD-1208 to the stabalator spar. It looks like it would be difficult to inspect these bolts with the aircraft assembled. I know we are using locking nut plates, but the safety wire would be visable and easy to inspect. Is this too much like belt and suspenders? What do you guys think? If you say "built it like the plans" because it is an ELSA, I would be willing to ask Van for a letter of authorization to substitute the drilled heads.
Click to expand...

...there is 50 plus years of actual experience on just about every aircraft in the US fleet...:)

Correctly used, self locking hardware works - the suspenders are not really needed on top of the belt.

AC 43.13 defines the minimum prevailing torque for re-use of self locking hardware, making these bolted connections meet FAA specifications.

No need to deviate from standard aircraft practices here.
 
DeltaHotel,

Just put some torque seal on the bolt heads where you can see it during your preflight. If the seal is broken, inspect it further.
 
Suspenders not always needed

As usual, Gil is right. GOD knows he's the toughest, most thorough builder I have ever met and I attribute 122 glorious hours to the many suggestions and ideas he made.

Now, if he can only shed that British accent I will stop teasing him. Hahahaha
 
You must log in or register to reply here.
Back
Top