Thursday, January 23, 2014

Match Drilling Of Longerons Completed

Once again braving the 2 degree morning temperatures, a trek was made out to the shop and Mike’s two burner propane heater received another good workout. The day’s goal was to wear three jackets, ignore the inhospitable elements and finish match drilling the very aft end of the left longeron then move on and complete the right longeron before getting too chilled.

The F-1255-R longeron was match drilled to the F-1205B roll bar attach plate during a previous work session so all that was left to do was complete the match drilling of the outside edge of the longeron using the F-1270-R fuselage side skin as the template.
As with the left longeron, the match drilling of the outer edge of the F-1255-R longeron began from the center section forward.
Match drilling the forward most rivet hole in the F-1255-R longeron.

The match drilling of the right longeron was, for the most part, uneventful. There was a small gap between the side skin and a small portion of the bottom of the canopy deck … however, with the aid of a clamp, the small gap was closed and the longeron was drilled. Once the center section forward was match drilled, the aft portion of the longeron was match drilled next.
  Almost done, just a few more holes remain to match drill into the F-1255-R longeron.
Match drilling of the F-1255-R longeron completed.

Now that both F-1255 longerons are finally match drilled, the F-1270 fuselage side skins need to be removed so the aft tab mentioned in the previous post can be trimmed off and all the freshly drilled holes can be deburred. Also there are nutplates to install on the F-1270 skins along with the air vents.

Normally, the longerons would be finished at this point ... but in order to accommodate the flush rivets being used on the DOG Aviation RV-12 project, all of the rivet holes on the sides of both longerons now need to be machine countersunk for the flush rivets being used.