Rollers And Axles

+1 on that, Wrat. I was biting my tongue to keep from posting the same response. At the next annual inspection, any IA inspector worth his shingle will ground the aircraft until the approved parts are reinstalled. It is his job to find "improvements" like this. A seat sliding back to the rear stop on takeoff is not a trivial matter...

I have watched IA's carefully inspect seat rails and parts, and they take seat reliability seriously.

If your street rod fails on the way to the swap meet, you call a tow truck. With an aircraft it is often the coroner who is called...
I completely agree with your point about a seat sliding rearward on takeoff and being an issue. I have had a Cessna do that to me once and I will never forget it either.

This plane uses a pin through both seat rails that positively lock the seats into position relegating that issue to Cessna's and others with an inferior design from the factory. When you lock the seat into position the pin goes thru both sides of the square tubing and the seat rail is trapped in the middle. Only way a seat could slide is if both pins were to fail which is damn near impossible.

This is only for the rolling portion and that is all. This plane does not use seat stops to prevent it from moving too far rearward as it has never been an issue with it at all.

Sent from my LGLS991 using Tapatalk
 
Maybe I came across wrong. Often i do.

I'm not critiquing the design. I have every confidence that it is a 'better' design. Too many times, the exigencies of regulation and approval have forced the hand of engineers to compromise on an inferior design. Been there many times, myself. This is not a question of your design. I'm sure the seat is better for it. No question. No doubt some poor sap at the factory has been fighting this fight for years and years to a deaf FAA.

(They very closely resemble the IRS, you know...)

This is just a question of ever-expanding government regulation. One of my little bits of life I do are 8110-3 forms for a favorite customer of mine in China. It doesn't matter if chinamen are good aircraft mechanics or good designers or even good pilots. What matters to the FAA is the *paperwork*. That's it. And it's getting harder and harder because what with our bizjet industry getting personally trashed by the Oval Office, the FAA has less and less to do and so they're out for more points to score wherever they can get them. Be warned.

As Bob said:
I have watched IA's carefully inspect seat rails and parts, and they take seat reliability seriously.

+1. This is real. If you've not experienced it, good for you! Happy day. If you can get away with it. Good for you. It's like going 70 in a 65. You're right, they got bigger fish to fry. Right up until they don't. Then it's a very bad day.

Good luck.

Wrat
 
I completely agree with your point about a seat sliding rearward on takeoff and being an issue. I have had a Cessna do that to me once and I will never forget it either.

I've had that happen also, that instant CG change makes things interesting :eek:
 
I also have no issue with the part itself, which is probably just fine. I have owned half a dozen aircraft, under both standard and experimental (exhibition and racing) registrations, and have several friends who are A&P's and IA's, so I have a pretty good idea how the system works. There is not too much wiggle room, and what there is can be quite variable from day to day and by who you are dealing with at the time.
 
Maybe I came across wrong. Often i do.

I'm not critiquing the design. I have every confidence that it is a 'better' design. Too many times, the exigencies of regulation and approval have forced the hand of engineers to compromise on an inferior design. Been there many times, myself. This is not a question of your design. I'm sure the seat is better for it. No question. No doubt some poor sap at the factory has been fighting this fight for years and years to a deaf FAA.

(They very closely resemble the IRS, you know...)

This is just a question of ever-expanding government regulation. One of my little bits of life I do are 8110-3 forms for a favorite customer of mine in China. It doesn't matter if chinamen are good aircraft mechanics or good designers or even good pilots. What matters to the FAA is the *paperwork*. That's it. And it's getting harder and harder because what with our bizjet industry getting personally trashed by the Oval Office, the FAA has less and less to do and so they're out for more points to score wherever they can get them. Be warned.

As Bob said:


+1. This is real. If you've not experienced it, good for you! Happy day. If you can get away with it. Good for you. It's like going 70 in a 65. You're right, they got bigger fish to fry. Right up until they don't. Then it's a very bad day.

Good luck.

Wrat
I agree that they usually do have bigger fish to fry.

My ap ia is a very good friend of mine and is okay with the design that I made. So are several other I/A's that actually specialize in this airframe. I say if they are good with it then why shouldn't the faa? Of course they want the paperwork but for the small price I am charging I would have to triple that amount to pay for the paperwork and it would not be cost effective to switch to this design. If at any time a mechanic or someone else say the faa sees these and doesn't like it then it is a simple change to go back to original. I have instructed everyone that has bought a set to keep them and not throw away the originals.

Have you seen the recent trend with the faa allowing non certified avionics in certified aircraft? I think it is an awesome deal and really opens up some new doors for the aviation world regarding private pilots with their own aircraft.

Sent from my LGLS991 using Tapatalk
 
I've had that happen also, that instant CG change makes things interesting :eek:
Yes, and when the seat goes back, your first instinct is to pull yourself back forward by the yoke, which you quickly figure out gives you an even better view of the sky, and then try to sort things out before you hit the ground nose first. It all happens quite quickly...
 
My thoughts exactly Bob! It is a scary ride for few intense seconds but I also had a really good instructor who purposely pulled my seat handle one day in a c-172 to demonstrate what it is like on takeoff to have a seat slide rearward. I was really glad that he had done that so that when it did indeed happen to me on my own I knew what to do and not panic or put the plane in the ground by trying to pull myself forward with the yoke.

Thankfully I am taller at 6ft and so even at the rearward most limit of the seat I still am able to manipulate all of the controls with very little trouble so that helped quite a bit as well.

Sent from my LGLS991 using Tapatalk
 
My thoughts exactly Bob! It is a scary ride for few intense seconds but I also had a really good instructor who purposely pulled my seat handle one day in a c-172 to demonstrate what it is like on takeoff to have a seat slide rearward. I was really glad that he had done that so that when it did indeed happen to me on my own I knew what to do and not panic or put the plane in the ground by trying to pull myself forward with the yoke.

Thankfully I am taller at 6ft and so even at the rearward most limit of the seat I still am able to manipulate all of the controls with very little trouble so that helped quite a bit as well.

Sent from my LGLS991 using Tapatalk
I was in the RH seat when it happened to the PIC, so I was able to help sort it out without much issue, but the experience was definitely eye opening. We did not need any coffee that morning after that experience.
 
Last edited:
Hi Kevin,
First let me welcome you to the Forum. This is an awesome site and hope you will continue to share.

Just so I am clear, what you have improved is really an assembly aid. A method that holds the parts together while they are being assembled, and once installed the cir-clip could disappear and all would be good.

My friend is a pilot and when I met him he was flying a Lake amphibious certified aircraft. He is also an AME. I know at work he was forever bringing in some of the hydraulics for the landing gear to install new seals etc. Also I remember rebuilding the controllable pitch prop, and vaguely remember him having to get some sort of oversite.

Since then he has sold the Lake, and is currently flying experimental RV-7, which I helped him build. Next we built A waiex Y tail with the VW modified engine. And are currently building a Panther with a Lycomming (don't recall the model...narrow something??).

I am only mentioning all this because I can now relate to what you have done compared with all the decisions one has to make when building a plane from "almost clear" plans.

And yes I know there is a world of difference between experimental and certified.

Looking forward to your future posts.

David
 
Back
Top