Rainbow Inspection Plate Pics

Bartman

Administrator
Staff member
Location
New Jersey, USA
#1
Not sure what exactly the question was but this was being discussed so I thought I'd post pics since my parts were removed and sitting on the garage floor.

Rainbow sells an STC for installation of inspection plates that mount above the tops of the front spars, in two places on each wing, I believe it's just outboard and just inboard of the front lift strut attach points. I'm not sure, the parts are already off my wings and I didn't take pics since I knew they weren't going back in after the spars were swapped out.

More info here;
https://champcitabriadecathlonforums.com/threads/rainbow-spar-inspection-plates.32/

So here's what I do have, hope it helps. The last one is Hannah, she's always got to have her butt on my pillow, always.

IMG_20190225_200137765.jpg IMG_20190225_200151812.jpg IMG_20190225_200201557.jpg IMG_20190225_200206813.jpg IMG_20190225_200217860.jpg IMG_20190225_200222878.jpg IMG_20190225_200422167.jpg IMG_20190225_200859396.jpg
 
Last edited:

Bob Turner

Well-known member
#4
My understanding of the AD is that every square inch of the spar gets equal attention. Rainbow is correct in that the place you want to watch is near those doubler plates. The compression cracks occur when the wing hits something (the ground, a fence post, a hangar . . .) so if others use your airplane, having that window into the critical area is a great idea. If all you are doing is the AD, the window is little help, since you have to do the entire spar. I don't have the window, but if I hit something, fabric will come off for a serious inspection.
 

Bartman

Administrator
Staff member
Location
New Jersey, USA
#5
That is my understanding also Bob, all four surfaces of each spar along the entire span. The Rainbow plates make looking at the most critical spots a little easier, probably not a bad idea.
 

Bruce

Well-known member
Location
Knoxville TN
#6
Thanks for the pics, I am leaning towards not putting them in as you stated the entire spare is to be inspected, and I don't like the looks of these as installed. I sent these pictures to rainbow and asked if they have a better looking instillation pictures, that was yesterday and they have not responded as of yet. I started cleaning the glue off last night and am trying to learn as much as possible before I start to re assemble which will happen after Sun and Fun. inspplate.jpg plate2.jpg inspplate.jpg plate2.jpg
 

Bob Turner

Well-known member
#7
My point was - if you do the initial inspection before cover (the only realistic way) and after that you are the only person who operates and stores your aircraft, you don't need it. Extra scrutiny in that area beyond what the AD mandates is appropriate after you hit something. Then you may want to take a really good look! And sometimes the compression fracture can be under the plywood, and really hard to spot.
 

aftCG

Well-known member
Location
Tacoma, WA
#8
Ron's viewpoint is that without them you have a high likelihood of not seeing compression fractures. I think they're ugly and a place for water to get in.

He has several spar chunks to back up his theory.
 

Bruce

Well-known member
Location
Knoxville TN
#9
Please clarify some things, Ron is he from Rainbow, second you say chunks is this from spar failure or from water getting into the spar? Other than looking poor I also was concerned with water getting inside the wing if you are not able to keep it in a hanger.
 

Bob Turner

Well-known member
#10
Ron is correct - if you suspect a compression crack, you need to take a look.

He - and the FAA - seem to agree that compression cracks do not spontaneously appear - you have to hit something.

If you do hit something, Ron's little window is the least you should do. The AD is no help at all, since it talks of mirrors, Bendalights, and wedges. Anybody who has done a semi-honest spar AD will tell you it is nonsense on several levels.

My recommendation - your wingtip hits something, take about three square feet of fabric off, top and bottom, from just inboard of the lift strut outward, on both spars, top and bottom, and go in there with a high intensity light and magnification. You will miss a compression crack easily by using inspection ports, although Ron's is way better than the ones allowed by the AD.

If you do not hit anything, or own a Decathlon, the AD is good enough. You won't have compression cracks.

Edit: opinion.
 

aftCG

Well-known member
Location
Tacoma, WA
#11
Please clarify some things, Ron is he from Rainbow, second you say chunks is this from spar failure or from water getting into the spar? Other than looking poor I also was concerned with water getting inside the wing if you are not able to keep it in a hanger.
Yes, Ron=Rainbow Ron. The chunks I refer to are several less than full length samples which have compression cracks. He even had one that Ray Charles would declare as junk - and it had been flying around for some time like that.

The AD is no help at all, since it talks of mirrors, Bendalights, and wedges. Anybody who has done a semi-honest spar AD will tell you it is nonsense on several levels.
Also exactly what Ron says
 

Bartman

Administrator
Staff member
Location
New Jersey, USA
#12
Please clarify some things, Ron is he from Rainbow, second you say chunks is this from spar failure or from water getting into the spar? Other than looking poor I also was concerned with water getting inside the wing if you are not able to keep it in a hanger.
for what it's worth, my rainbow plates were sealed with silicone caulk when i got the plane.
 
#13
Bob:
Elaborate on : "If you do not hit anything, or own a Decathlon, the AD is good enough. You won't have compression cracks. "

What relevance does owning a Decathlon have. Are they treated differently in regards to the AD..????
 

Bob Turner

Well-known member
#14
I own a Decathlon. I promise you, if I hit something with the wingtip, its owner will know. A serious inspection will follow.

If a Citabria is in, say, a club, you have no idea whether it has hit something, and the AD inspection, even with Rainbow kit, is inadequate if there has been a hit.

I am sure I did not hit anything this year, and the Bendalite and mirror will suffice. I am in a hangar, so no fuel truck hit me when I wasn't looking.