HS attach bolt hole drilled wrong

CPSONE · #1 11-24-2011, 10:48 PM

Going over the 7A QB I just acquired and the prev. owner drilled the horizontal stab front spar attach holes at the wrong place. The outside one on one side bisects the edge of the longeron putting a notch in it like a half moon. the other side just grazed the edge of the longeron not even going though it.
I know where these holes are supposed to be and am about to order a new aft deck and all associated parts to "rebuild" the aft deck and will even replace the attach bars for the rear HS spar...but...

Any other ideas that would be a quicker and just as sound a fix?
(I have a new horizontal stab that will be used so will not use the one that came with the QB.)
Has anyone else had this problem with notched out longerons? Howd' ya fix it?
Thanks. (at least I saved a bunch of money buying this thing??).
Sorry no pics yet.

Ralph Inkster · #2 11-25-2011, 12:11 AM

Hi again Mike- sorry to have raised the point on the spar attach bolts, or maybe good that I did (for you).
Drop by my hangar next time you are in Calgary & I can show you the fix I tried to describe over the phone.
Basically replace the lost strength of the longeron by riveting .063 plates on top & below the longeron. Make the plates wide enough to also tie the longeron & bulkhead making a strong pad to attach the hoiz spar. The upper plate would replace the .063 spacer that normally would be between the rr deck & spar anyway.

Ralph Inkster · #3 11-25-2011, 12:16 AM

Also, no problem either Horiz assy with the empenage deal. I can deal with the spar with the misdrilled spar.
Cheers

CPSONE · #4 11-25-2011, 09:46 AM

Thanks Ralph!
Glad you brought it up.
I'll take some pics and send them to Van's to see what they say also but your fix sounds good.

JonJay · #5 01-18-2012, 07:56 AM

One suggestion made to me for repairs on an experimental aircraft is to look at the certified world for documentation. Many certified aircraft have documented repairs in their manuals that show acceptable repair methods. The trick is finding a repair that is similar to what you need to accomplish.
Cessna 210, Beech T34, Grumman Goose, are manuals recommended to me that have documented longeron and spar repairs.
These could be used as a guide line when repairing our RV's, or at least give us some ideas that where proven in other aircraft.
I am waiting for my copies of these to review for some repairs I need to make on the Fiat and I will post what I find if appropriate to this kind of issue.