Some wing progress

[Mark Julicher]

Re: Some wing progress

Flying without cocktail service and flush toilets is barbaric.

[Hank Jarrett]

Re: Some wing progress

The problem was that the FAA senior Execs would not ALLOW the red tag to be removed. None of them would take the responsibility for over-riding the guy who put it there and he couldn't be found. It was a perfect example of administrative executives with NO experience in real maintenance or engineering holding those who actually knew what they were talking about hostage.

Most Federal Government posts are now filled with people with degrees in management or government and not degrees or experience with the subjects of their organizations. I see it ALL THE TIME working with the FAA. When I worked with AGATE we worked with the Small Aircraft Certification Directorate and the FAA Tech Center in NJ. Both were staffed with some of the best people around. The SACD in Kansas City was filled with small GA aircraft lovers who actually FLEW GA aircraft and LOVED airplanes. The Tech Center was slightly less GA oriented, but still aviation crazy people who mostly LOVED aviation (at least at the levels we worked with.....we stayed away from "Mahogany Row" where the Senior Executive Service folks camped out).

The real problem with almost ANY Government organization is with senior leadership who have NO IDEA about the details of their organization. That describes senior management at NASA to a "T" and the FAA has hired an ARMY of people who are managers with no knowledge of aviation. The last meeting I had with the FAA on a contract there were only two people in the room who had ever flown an airplane. My partner and I! There were also two guys who were ex Boeing engineers who really knew their stuff but were not pilots. The guys from the FAA didn't know squat about the technical side of the world. The only experience with flying they had was from the back of an airliner.

Management PhD's are taking the world over.

Hank

[astjp2]

Re: Some wing progress

Its easy, have the FAA prove you are wrong, the air venture thing would have had the red tag removed and a log book entry stating that the propeller was airworthy and I would have flown it out....

[Hank Jarrett]

Re: Some wing progress

Tim, I am not saying you are wrong. I agree with your (OUR) interpretation of the regs, but that doesn't mean someone from the FAA can't (and WON'T) disagree. It doesn't matter if we are right and the guy tagging your plane as down is wrong. It only matters what HE thinks.

Remember the guy at AirVenture who had one of the new (at that time) swept tip props on his plane. An FAA inspector walking the line saw it and in total ignorance put a tag on the plane saying it could not be flown! He later said he thought the swept tips were the result of a prop strike!!!! The FAA guy then LEFT the airshow and the owner of the plane was stuck there. The reps from the manufacturer of the props were still there as were many FAA heavies, but NONE were willing to listen to the manufacturer or owner and remove the grounding of the plane. NO ONE was willing to take responsibility for the guy who had NO IDEA what he was doing! They finally tracked him down and HE had to remove it.

I was AT AirVenture when this happened (as I remember....lots of risk there) and I am pretty sure the company was one of the members of the NASA GA Consortium. It was a MESS because MANY don't seem to understand it the way you are saying it and WE understand it. They don't know enough about our planes to understand what is and isn't safe, so they default to what was done by the factory when the plane was built. All I am saying is if you are going to build new ribs, make them the same as the factory. It shouldn't cost any more to make them just like the drawing than to redesign them, and if they are identical to the originals there would be no way for anyone inspecting to even know if they were new parts or old. As for the rivets, I would bet very few have ever SEEN the original rivets, but if I could get them, personally I would use them instead of the new ones.

I just don't like inviting trouble, and I see the regulation bureaucrats being able to make a real mess of our planes if they go all Draconian on us. Just remember what happened when a past factory owner convinced a bunch of bureaucrats that there was a problem with our struts. The truth counted for NOTHING. The bureaucrats will make the decision that results in the least perceived risk to THEM.

Hank

[astjp2]

Re: Some wing progress

Plan on $2-15K for raw material to build the ribs, minimum quantities apply. Plus the time to build and the time to make fixtures that meet your idea of FAA requirements..... The roll formed J tubing to make the metal doors was going to cost me $8k minimum. I had to buy 1500' per order before they would even tool up to make it and I had to pay the tool up fee on top of the material. If your wings are covered, who is ever going to see the rib material?

I agree with Hank, it needs to legal. Conceptually it shouldn't be that hard. Dakota Cub must have already proven their extrusion is as good as the Cub T-stock. Someone would have to get it blessed that it's as good or better than the Taylorcraft T-stock. Then you get it blessed as a replacement. It would probably take a DER like Terry and, of course, some $$$.

I've got a worse problem with my YO-57 which has metal wings. The truss ribs are similar to the SBS but the attachment at the metal spar is totally different. I don't want to go down the extrusion route because I want to maintain the authenticity. I don't really want to modify SBS ribs either, which is approved but again not authentic. I also want to minimize splice repairs. I really want new T-stock so I can remanufacture the ribs like new. It doesn't appear hard to find someone who can roll-form the "T", even in small quantities. My problem has been finding the .012 aluminum. So far I have not found any thinner than .016 thru normal sources. I'm not plugged into specialty sources. I think it takes about a 1"x.012" strip to form the "T", probably 2024 or 6062. I'll have to check the drawing. If anyone knows a source for the aluminum, I'll pursue getting some formed to the L-2 drawing.

[astjp2]

Re: Some wing progress

Show me anywhere in the tcds where it says that the rib material is a type design issue. The type design is based on the TCDS! which is right out of the IA handbook. The FAA has no idea nor drawing to show them what was original and they dont want the drawings. Not everything in the airplane must conform to original. The PA22 has listed an "automotive type" generator, that means that the FORD, Chrysler and GM aviation generators are approved. If it came with a Motorcraft, and its not available, then you are LEGAL to put in a Chrysler as long as it has the corresponding and associated equipment swapped out (over current/voltage Regulator, wiring etc). There is an AC in the tech part of the forum that talks about substitution of materials.

The rib material was "key word WAS" a standard material which is no longer manufactured therefor eligible for substitution. AC43.13 also talks about repairs and specifications of truss type ribs, it does not differentiate between brands, there is nothing about Piper vs. Taylorcraft in AC43, just a general material spec. They also call out using AN470-AD rivets in AC43 but the originals were AN450 series steel tublar rivets...The FAA has to prove that it is not in compliance, if you do a 337 for the repairs IAW ac43, you are covered because it can be used as APPROVED data or acceptable data depending on application, which is the IA's responsibility to determine.

It is the same old "Does it work and is it safe" vs "Is it legal" problem. The ribs made from Cub stock do not meet the "Conforms to the original design" sniff test. Not that there are 3 IAs in the nation who would spot the difference. My point isn't that it won't work (it WILL and the Cub stock looks like it might even be BETTER than the Taylorcraft stock) but that if we are going to go to all the trouble to make material to build ribs, lets conform to the specifications. It will be less expensive to conform than to get an STC to use the better stuff.
I don't like it either, but when we start to cheat on the specification in the TC we loose our credibility with the FAA and they have every chance they will come down on us.....HARD. I don't want a FISDO guy looking inside my wing who has NO IDEA what he is looking at and deciding if I am out of conformance (or just MAY be). We already have dealt with unqualified FAA people getting into our wing struts and causing all sorts of chaos for us. I don't want it on wing ribs where someone may demand I tear covering off to prove my ribs are in conformance.
NOT a good idea to be making unauthorized design changes. They DO NOT CARE if you improved the design or your repair is "just as good", they are bureaucrats who will simply ground your plane to be on the "safe side".

Hank

Lots of good FAA folks, but I am not willing to roll the dice.

[stearman3]

Re: Some wing progress

I've got multiple sheets of.012 if any one is interested...............

[Bigdog]

Re: Some wing progress

I agree with Hank, it needs to legal. Conceptually it shouldn't be that hard. Dakota Cub must have already proven their extrusion is as good as the Cub T-stock. Someone would have to get it blessed that it's as good or better than the Taylorcraft T-stock. Then you get it blessed as a replacement. It would probably take a DER like Terry and, of course, some $$$.

I've got a worse problem with my YO-57 which has metal wings. The truss ribs are similar to the SBS but the attachment at the metal spar is totally different. I don't want to go down the extrusion route because I want to maintain the authenticity. I don't really want to modify SBS ribs either, which is approved but again not authentic. I also want to minimize splice repairs. I really want new T-stock so I can remanufacture the ribs like new. It doesn't appear hard to find someone who can roll-form the "T", even in small quantities. My problem has been finding the .012 aluminum. So far I have not found any thinner than .016 thru normal sources. I'm not plugged into specialty sources. I think it takes about a 1"x.012" strip to form the "T", probably 2024 or 6062. I'll have to check the drawing. If anyone knows a source for the aluminum, I'll pursue getting some formed to the L-2 drawing.

[Hank Jarrett]

Re: Some wing progress

It is the same old "Does it work and is it safe" vs "Is it legal" problem. The ribs made from Cub stock do not meet the "Conforms to the original design" sniff test. Not that there are 3 IAs in the nation who would spot the difference. My point isn't that it won't work (it WILL and the Cub stock looks like it might even be BETTER than the Taylorcraft stock) but that if we are going to go to all the trouble to make material to build ribs, lets conform to the specifications. It will be less expensive to conform than to get an STC to use the better stuff.
I don't like it either, but when we start to cheat on the specification in the TC we loose our credibility with the FAA and they have every chance they will come down on us.....HARD. I don't want a FISDO guy looking inside my wing who has NO IDEA what he is looking at and deciding if I am out of conformance (or just MAY be). We already have dealt with unqualified FAA people getting into our wing struts and causing all sorts of chaos for us. I don't want it on wing ribs where someone may demand I tear covering off to prove my ribs are in conformance.
NOT a good idea to be making unauthorized design changes. They DO NOT CARE if you improved the design or your repair is "just as good", they are bureaucrats who will simply ground your plane to be on the "safe side".

Hank

Lots of good FAA folks, but I am not willing to roll the dice.

[astjp2]

Re: Some wing progress

Hank, WHY? if it works, it really does not matter...original just costs more and is so low of volume that it is not cost effective for something that is not value added.

[Hank Jarrett]

Re: Some wing progress

The shape and size of the "T" section on an original Taylorcraft rib is different than the Cub as well as the airfoil section. I have seen pre war ribs repaired with Cub "T" section but what is really needed is a repair cross section customized for the Taylorcraft size as well as "T" stock that matches the original.

[astjp2]

Re: Some wing progress

Original piper/Taylorcraft on top, Dakota cub in the middle, stamped rib on bottom....

[astjp2]

Re: Some wing progress

I have a wall of cub ones that I rob for repair material....I was planning on making a jig to build them from extruded aluminum. The extruded ones are much stronger and they would be built like a Dakota cub rib. That is why I bought the CP-450 riveter. 28,000 pounds of squeeze. Foot controlled and it takes both the .250 and .187 sets. I also have been working on coming up with the tooling to mill the extrusion. The riveter pictured below was rebuilt by me at work before they auctioned it off. Tim

[Hank Jarrett]

Re: Some wing progress

We need to get all of us together who need them (or will) and build a fixture to make them and the "T" sections they are made from. They are just not available in the numbers that are needed for all the planes being restored. We WILL run out, and soon.

Hank

[danglandt]

Re: Some wing progress

I am interested in buying some stick ribs. How do I get in touch?

Dan Glandt