Replies to This Discussion

Permalink Reply by Phill Barnes on November 13, 2009 at 5:49am

Mathieu
Anothr question for you.
What glue is proposed for the centre spar mods and is it for structural purposses or is it to stop any rubbing or chafing of surfaces in that region?

Phill

Permalink Reply by Matt Heintz on November 13, 2009 at 6:11am

We used PARTITE 7350. We are using the glue for gap filling as the primary reason. However, it is an excelling bonding agent and since we did the static load tests with this glue, we are strongly recommending it. It will be added to the upgrade drawings and kit.

APPLICATION INSTRUCTIONS

• All surfaces must be clean, dry, dust and grease free. Best result will be achieved with surfaces that have been lightly abraded immediately prior to bonding.
• Proper mixing is required for the curing and adhesive strength development.
• Excess adhesive can be wiped away with organic solvent. Adhesive bond should be allowed to develop full strength before subjecting to any service loads.

Permalink Reply by Alan Uhr on November 14, 2009 at 7:11am

Mathieu,
On many vehicles made in this country, the structors are bonded together with a special tape. I have also seen rotorblades bonded this way on their trailing edges. That said, instead of drilling out the solid rivets on tha main spar, could the angle be match drilled where the rivets are so the angle just fits flush with the spar and then bonded with this special bonding tape. It would eliminate the drilling out of all solid rivets.
Alan Uhr

Permalink Reply by Jeff Garrett on November 20, 2009 at 10:31pm

Mathieu

As you are now aware the older 601's had -5 rivets in the spar and the newer 601's have -6 rivets so I am not sure that method will work but I will be removing the rivets in the other wing this weekend and will be sure and let you know exactly what size drill bit is the smallest that will allow you to use a rivet gun to "push" out the stem. Also the -6's can be bucked with a 3x gun but I am not sure the rivet is expanding in the hole enough. We tested both and the 4x does a much better job.

Keep up the great work
Jeff

Permalink Reply by Gabriel Kremer on November 16, 2009 at 12:13am

If you reference the Advisory Circular AC43.13 you will find information on proper removal or the solid rivets. The biggest thing in drilling out the solid rivets is to drill in the center with the next size smaller drill bit. If you see chips coming out as you drill stop immediately cause you are not centered and only go deep enough to facilitate removal of the head with a twist of the drill bit to the side or stick a punch in the hole and tip it to the side. This advice comes from a few years of doing structural mods on large corporate jets that require much more attention to detail seeing there presurrized. Still must be very careful in this situation also.You can also more than likely find a Licensed Airframe Mechanic with experience to help you remove them. Its an easy process cause of the type of rivets Zenith uses and if i was personally in your area I would be glad to help you with the remove and install. Another option is to find an Vans Aircraft builder and ask them for help seeing they use the same type of rivet to build the entire aircraft.

Permalink Reply by Mike Armstead on November 12, 2009 at 7:47pm

Several people people are considering adding wing lockers while doing the wing upgrade. I would like to also, but am a little concerned about cutting a large hole in this area of the wing. There are already a couple of nose ribs missing in this area because of the fuel tank and now I'm adding a large hole in this same area. I noticed the zenith factory plane did not have them and I'm guessing the plane that was stress tested in Canada did not have them. Is there any reason to believe that adding a wing locker could reduce the stregth or torsional stiffness of the wing?

Thanks,
Mike

Permalink Reply by Matt Heintz on November 13, 2009 at 5:21am

Good point. It is my suggestion at this time that you should not add the wing lockers. However, the new "L" extrusion that we are adding to the upper spar caps adds a huge amount of strengthening in that area. There is no objective evidence that there has been more accidents with or without wing lockers, same as hinged or hingeless ailerons. However, I am waiting for an answer from Chris Heintz on this.

Permalink Reply by Mike Armstead on November 13, 2009 at 9:54am

Thanks, I would very much like to hear Chris's opinion on this. I had originally considered adding them out closer to the end of the wing (past the fuel tank) where there is less stress, but I realize that would have implications also if the plane was ever spun, but 95 percent of the time they would be empty anyway.

Permalink Reply by Matt Heintz on November 14, 2009 at 4:10pm

Chris has no objection to the wing lockers.

Permalink Reply by Terry Phillips on November 19, 2009 at 11:44pm

You raise an interesting point regarding the correlation between accidents and wing lockers and aileron hinge design (Piano or Flex). For the record, could you provide us the data to complete this table? I haven't seen this information anywhere. I've filled in the hinge where I'm pretty sure the airplanes were CZAW built.

Accident ..............Aileron Hinge(P/F) Locker (Y/N)
--------------- ............-------------------------- ------------------
Oakdale
Yuba City
Saint Fulgent
Polk City ......................P
Capao do Leao
Barcelona
Markermeer ..................P
Antelope Island
Agnos

Permalink Reply by Matt Heintz on November 20, 2009 at 7:18am

Terry,
I cannot get into the details of the accidents as I am unclear as to when I can discuss this with the public based on the signed agreements I have with the NTSB.

It would be great if there was a pattern in the accidents such as all accident aircraft had hinged ailerons or wing lockers. But that is not the case. This is why the NTSB and the FAA have not pinpointed the accidents to anything specific other than the NTSB stating flutter.

So with all due respect to all, I do not want to discuss accident details. Let us focus on the upgrade, and making sure that all aircraft are tougher and less prone to vibrations etc.
Thanks you.

Permalink Reply by Terry Pender on November 13, 2009 at 9:49am

Mathieu
Can I substitute one .062"x3/4"x3/4"x144" 6061-T6 angle for the two 6-ZU-1-3 Top Rear Spar Angle's in each rear spar?
Also, can I use AN470AD-5 rivets?
Thanks
Terry
650 plans build

• ‹ Previous
• 1
• …
• 3
• 4
• 5
• 6
• 7
• …
• 19
• Next ›
• Page