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Spliced repair on the outboard end of spar?

Radioflyer

Well Known Member
I came across an interesting bit of damage history on an RV6. What would you think about a wing spar that had 1.5 feet of damage removed from the outboard end and repaired with an equivalent spliced section? Various wing skins were replaced per plans. The plane has been flying for 1400hrs since the incident caused the wing damage and repairs.
Should this plane be limited to non-acrobatic flight modes only?
 
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If spiced properly, I would think you’re fine. You’re best bet is to take pictures from the front and back of the repair, and email Vans tech support for a real answer. Try to get measurements of doubler thickness and rivet spacing..
 
Per the two answers above, the only entity who can approve a spar repair is the Manufacturer. Even though the “Manufacturer” technically is the builder in EAB, I believe the intent is the “Design Engineer”, is the only authority, which would be Vans.
So, unless you have the skills to analyze the repair structurally, go back to Vans.
 
The repairs were done by "Cinncinati Hangar 6" twenty years ago and signed off by the holder of the repairmans certificate. It seems a new 1.5 foot section of spar was obtained from Vans, butt spliced and reinforced with "box doublers" of .041 2024T3 and "flat doublers" of 2024T3. I doubt that I can get in there and take pictures.
My guess is that the repairs were done by a reputable shop and should be fine.
The plane otherwise appears in great shape.
However, in general, I wonder if a main spar repair of this nature is a reasonable exercise. My guess is that in any case, this would greatly decrease resale value and that most would just walk away.
 
Dig Deeper

I doubt that I can get in there and take pictures.

You should be able to easily access and photograph the repair work by removing the wingtip, then getting Van’s to evaluate it.

My guess is that the repairs were done by a reputable shop and should be fine.

A guess is a dangerous thing when talking about critical structure. This is what can happen to incorrectly repaired spars, even when performed by seemingly reputable shops:


https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/90047/pdf

With that said, it is possible to safely repair structures if the engineering is done correctly.

Skylor
 
Some of the later RV-6's had jig built spars. *IF SO* then the wing can be replaced by another jig built wing, However the aft spar attachment may need to be r&r from the fuselage.

Or, likely there are wing kits still floating around that haven't been built. Again, you'd want a late kit if this is a late RV6.

If it isn't a jig built RV6 spar, and you determine the wing should be replaced (for your own comfort, per advice, or...) my advice would be don't bother with this one. It's a big hard job to make it all line up, or alternatively, to remove & replace the center section of the fuselage.

I probably have my notes somewhere on how to identify the jig built spars (or contact Phlostogen).
 
By "jig-built", do you mean built by the Phlogiston factory? As far as I know, the characteristic of Phlogiston spars is that they are gold anodized. If the spar is silver colored, I guess it likely was handbuilt, not jig-built. I have not seen this spar, only logbook entries. Except for the final condition inspection after the repairs, no specific 43.13b references were made, which may be a red flag by itself.
At any rate, that link to a failed spar repair, though different materials were used in that case, at least suggests that while spars may be repaired to some utility, the full strength may not be recovered.
 
By "jig-built", do you mean built by the Phlogiston factory? As far as I know, the characteristic of Phlogiston spars is that they are gold anodized. If the spar is silver colored, I guess it likely was handbuilt, not jig-built. I have not seen this spar, only logbook entries. Except for the final condition inspection after the repairs, no specific 43.13b references were made, which may be a red flag by itself.
At any rate, that link to a failed spar repair, though different materials were used in that case, at least suggests that while spars may be repaired to some utility, the full strength may not be recovered.

What he is referring to as "jig-built" is the later spars that are interchangeable between aircraft.

The early Phlogiston spars were match-drilled to the individual center section carry-through and not interchangeable between aircraft.
 
Personally I wouldn’t count on any vintage RV-6 wing being able to just swap in a different wing by unbolting and bolting on a new one.
It is just about a certainty that some holes will have to be adjusted for oversized bolts.
Should be no need for it though. Spars are repaired all the time. Even on certificated aircraft, and not necessarily with a repair designed and approved by the manufacturer. AC43.13 has a lot of guidance and is often the only reference used. I would have no issue flying an RV with an 18” long repair splice at the outboard end if it was done per 43.13 and with good workmanship.
 
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I would splice mine before replacing, but..

Very little "wrong" with a properly completed splice, and on the RV-4/6, the outboard sections are relatively simple. I would not try to splice anywhere mid-inboard due to the layered build up. I have personally been involved in splicing a Boeing 727 airliner out board wing spar segment. Replacing the spar/wing would be a potential problem at the center section, but can be done with making new splice plates (4130 steel, heat treated after drill) to get the precision fit required. The Phlogiston spars (anodized gold) where the same spars you would get in a kit order, but sent to and assembled by Phlogiston techs, then sent back to Vans to go in your kit. As far is I know, all -4's and -6's have hand drilled spar components that are close, but not exactly the same, and the wing kits included the fuselage spar carry through frame and splice plates. My spar kit (I built mine) actually came from Vans with 2 oversize bolts for a couple locations they had to correct common to the splice plates. In your case, for comfort level, have a structurally adept A&P or Vans engineers look at what has been accomplished. Like most MFG's, Vans may be very conservative because they have to be.
 
Like most MFG's, Vans may be very conservative because they have to be.

Was hoping you'd reply. 43.13 (application/guidance) has probably affected most everything in the air. Guessing you have a staff DAR where you work?

Will bet you a beer there will be no "approval" from the OEM. Like all the others, they'll probably agilely deflect. Why issue a position and potentially accept liability when there's no benefit for them?
 
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Other factors:
- that repair is in the lowest-loaded section of the wing out at the tip.
- a spar repair could be weaker, as strong as, or stronger than the original spar, depending on the details.
- 1400 hours since it was repaired sounds pretty well proven in practise. Did the owner do any aerobatics in 1400 hours? Seems unlikely it could fly that long without doing any.

Could be a great opportunity to talk the price down due to the unknown and get a great deal on an otherwise fine RV.
 
As far is I know, all -4's and -6's have hand drilled spar components that are close, but not exactly the same, and the wing kits included the fuselage spar carry through frame and splice plates.

I disagree based on personal experience.
My RV-6A kit (via estate sale), was missing the spar splice plates. Van's tech support gave me the bad news that I was probably screwed (i.e. facing a really difficult job), but to contact Phlogiston. I contacted them and found out that they engrave a serial number onto the spar, told me where to look, and if the SN was xxxx or larger then my spars had been jig drilled and they would be able to use their jig to make up new splice plates.

My SN was in the newer range, and the delivered splice plates matched right up, on my RV-6A.

Looking back in my emails, I find my wings were from 1996, and that phlogiston changed to using a jig in around 1993.

If this had not been the case it would have been a really horrid job... trying to accurately match drill steel, based on the locations of holes in a completed wing spar. Picture jigging up two wings under a Bridgeport Mill.... and most likely needing to yank the center section back out of the fuselage besides, in order to connect the wings.
 
I disagree based on personal experience.
My RV-6A kit (via estate sale), was missing the spar splice plates. Van's tech support gave me the bad news that I was probably screwed (i.e. facing a really difficult job), but to contact Phlogiston. I contacted them and found out that they engrave a serial number onto the spar, told me where to look, and if the SN was xxxx or larger then my spars had been jig drilled and they would be able to use their jig to make up new splice plates.

My SN was in the newer range, and the delivered splice plates matched right up, on my RV-6A.

Looking back in my emails, I find my wings were from 1996, and that phlogiston changed to using a jig in around 1993.

If this had not been the case it would have been a really horrid job... trying to accurately match drill steel, based on the locations of holes in a completed wing spar. Picture jigging up two wings under a Bridgeport Mill.... and most likely needing to yank the center section back out of the fuselage besides, in order to connect the wings.

Glad it worked out well for you but in the interest of providing useful valid info for people that use the forums as for technical info, I standby my previous statement to not count on all holes aligning when alternate wings are fitted to an RV-6 or 4.
At Van’s we didn’t even consider wings to be a universal fit on the later models that only have 10 bolt holes in each spar, until some time in the mid 2000’
 
Without seeing the repair its hard to judge however on the face of it I wouldn't be too concerned. Clearly somebody has put their name to it and signed it off as an acceptable repair and as mentioned above, its proven itself by virtue of having survived 1,400 hours of operation. Not that this is necessarily a good thing of course. Plenty of production aircraft are out there flying around with similar repairs and the last 1.5 feet are not exactly overburdened structurally.

Typically this kind of damage is a result of either a birdstrike or a ground handling/taxi incident and especially in the case of the latter what people often overlook is the damage which can occur around the inboard rear spar area. At this point in the history of that aircraft I would be more interested in closely inspecting the inboard rear spar area and the rear spar carry-through in the fuselage for working rivets and buckling or bulging. Damage in this area would concern me significantly more than a splice in the outboard main spar.
 
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