[Fearless]

Seat backs - are lightening holes common?

I didn't get any responses when I previously posted this question so I'm trying again. Maybe the mispelling of lightening in the title had something to do with it or maybe I've been voted off the island and no one has bothered to let me know. Here goes.

I was watching the videos that Jerry took of the RV-12 at Sun-N-Fun and saw where they had cut lightening holes into the actual seat backs on the plane. Has anyone else taken this approach on the other RV's. The plans I have on my 9A has the option of cutting them in the seat back brace but I haven't recognized anything in the plans or drawings for having them for the actual seat back. Good idea or bad? What have you previous or current builders done?

Thanks,

 

[Fearless]

Sent an email to Vans for input

I haven't gotten any replies which is strange for this site. I emailed Mel and he suggested I contact Vans so thats what I did. I sent an email to the support group to try to get some feedback. I re-read the RV-12 posting and saw where a couple of RV9/9A drivers are thinking of putting holes in their seats. I'm thinking maybe those ounces will offset the other ounces that I'm adding.

 

[Fearless]

Answer from Van's

They haven't done this before in the higher G load two seaters before. The weigh savings would be ounces and not very useful. Recommend finding weight savings in other areas. This would be one of those areas where the builder finds the term experimental comes into play. Your discretion.

 

[ccarter]

Place witty title here...

Have not heard that before regarding other RV's. Perhaps Van's was close to max weight for an LSA and didn't want to take any chances...

 

[Harold Lanfear]

I did!

I talked to Van's re. holes in the angle brace in the seat back of my -8. They said at the time (a couple of years ago) it 'sounded like a good idea' and to put smaller holes in the center where the weight is concentrated. That's what I did.

I'm not fly it yet, but I've certainly dropping my 180 lb. on it during construction.

By the way, it took out 3 Oz and took about 3 hours.

 

[Norman CYYJ]

A huge weight savings can be had by keeping the instruments and avionics to a minimum and using no primer on the interior and just polished AL for the exterior. Probably about 40 to 50 pounds on paint in these things. Putting lightening holes where ever you can might save a pound maybe 1.5 at the most.

 

[N941WR]

A huge weight savings can be had by keeping the instruments and avionics to a minimum and using no primer on the interior and just polished AL for the exterior. Probably about 40 to 50 pounds on paint in these things. Putting lightening holes where ever you can might save a pound maybe 1.5 at the most.

So...

I wonder how light my -9 would have been w/o the primer? Say 970 lbs, figuring the pimer was 20lbs?

According to Van's, paint should add about 30-40 lbs.

After seeing those holes in the -12 I was seriously thinking about putting them in my seats. Every ounce matters, regardless of where it comes from. If you take an ounce out here and there, you can put it back in with the things you want.

 

[Phil]

Not for me...

It may sound crazy, but I like having more metal underneath my body.

There's nothing really wrong with lightening holes in general. But in the event of an accident, I want all that energy traveling into my seat to be absorbed by the seat. Not me.

The more metal in the seat, the more energy it can absorb. Bending metal doesn't hurt as much as breaking bones .

 

[RickWoodall]

Just a suggestion

Kind of a smart aZZ but....save the three hours cutting the holes, go for a jog. It will do ya better, heck one could dump a couple pounds easily and keep the plane as vans intented.
An ounce here or there really isnt going to get you in the reno races is it.

 

[N941WR]

There's nothing really wrong with lightening holes in general. But in the event of an accident, I want all that energy traveling into my seat to be absorbed by the seat. Not me...

In most aircraft accidents the energy is directed forward, thus the lightening holes drilled in the seat back will have no "impact" on the survivability.

Kind of a smart aZZ but....save the three hours cutting the holes, go for a jog. It will do ya better, heck one could dump a couple pounds easily and keep the plane as vans intented.
An ounce here or there really isnt going to get you in the reno races is it.

So true!

 

[Phil]

Still if I had to put a value on my life, it is worth more than a couple of ounces of Aluminum.

In my opinion, it's worth more than a couple of ounces of gold too.

 

[Bevan]

More metal is beter...

In most aircraft accidents the energy is directed forward, thus the lightening holes drilled in the seat back will have no "impact" on the survivability.QUOTE]

UNLESS something from the baggage compartment (like a screw driver) or some other piece of debris from the aft part of the plane itself, just so happens to go clean through that lightening hole in the seat back and gets you in the kidney. I would think the seatback would not be the best place to save a few ounces.

Bevan
RV7a wiring

 

[Fearless]

I'm not changing yet

I think I'll leave mine alone for now. You can also take the seat backs out and drill holes later like Bill is thinking of doing. I just found it interesting that Van's decided to do this now on the RV-12.