A new service bulletin came out today for cracks in the HS forward spar:
http://www.vansaircraft.com/pdf/sb014-01-31.pdf
http://www.vansaircraft.com/pdf/sb014-01-31.pdf
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Does anybody know of occurrences of this cracking i.e. who / what / why / when triggered this SB? I have one possible suspicion...
From reading the SB, inspecting before further flight and then every annual seems fine. So if you don't have cracks and don't think you'll get them just doing that until a crack (possibly) shows up some year seems like a fine way to go...
On page 2, Method of Compliance says:
If no cracks are found, no immediate action is necessary. Repeat this inspection at each subsequent annual condition inspection until such time that this service bulletin has been complied with in its entirety.
I read this as you can inspect as long as there are no cracks, but they do expect us to make the changes that are detailed regardless of whether cracks do form. I wouldn't assume that we aren't going to get cracks if we don't see them, though.
Since I am a couple of months from bolting my HS on for the final time (and first flight), maybe I will wait until there are reports from the flying fleet before deciding to rip into it.
It doesn't say for the 9 models, but I am reading this pretty close and will see if it is looks like it may apply.
So what are other builders going to do with a HS built but hanging in the garage? This SB is some serious work. I don't mind but I don't want to damage a perfectly good HS.
Interesting! Would explain why the RV-8 manual does not call for the notches, but the plans show them since it is a common part to the RV-7.These notches were one of the questions on my builders support list of questions due to the fact that the drawings show them and the actual parts don't have them.
I was told that the notches were a "-7 thing" and the -8's don't need them.
I would like to read the SB as saying to inpect the area at regular intervals for cracks. If a crack is found a repair kit is availble from vansaircraft. But the way it is written it seems they want you to do the mod regardless if cracks are found or not. This to me is like fixing something that are not broken. I had a good look at mine today and some of the rivets I dont have a clue how I am supposed to drill out ,never mind trying to buck those afterwards.I feel sorry for the guys that has just completed their Horizontal stabs.
A quick look with the inspection mirror and camera shows that the Valkyrie doesn?t have the relief notches ?.and no cracks either!
I have a -4 so this doesn't apply, but since I didn't build it will inspect just to learn more about it.
I do have one question concerning the SB:
Method of Compliance:
Inspection: Remove the Empennage fairing. Carefully inspect for cracks emanating from the stress relief notch at the inboard end of the forward horizontal stabilizer spar flanges. (see Figure 1 and figure 3). Clean the area and remove any paint, overspray or primer that could hide a crack. Cracks may be very small and hard to detect.
Doesn't this mean if no cracks are found and it has primer or paint, then you have to remove said primer or paint and inspect again? If you find the crack before removing the primer/ paint you obviously have the work to do. Or possibly when one purchases a plane in the future, if there is a notch, and no doubler, and primer/paint is there the SB has never been complied with?
I don't know, just one way of interpreting it.
Mark
Heading over to the hangar now to have a look. I went over this area pretty closely when the discussions about the vertical stab were going on.
Hi Scott
Thanks for the insight you have provided. Within the limitations of what you can say:
It can be read a number of ways - the RV-8 design is most at risk since the notches were (unintentionally?) omitted? Or the RV-8 has just been lumped in since it is a "similar" design?
- Has this been observed in any RV-8s?
- How can one inspect 'Carefully inspect for cracks emanating from the stress relief notch at the inboard end of the forward horizontal stabilizer spar flanges' when the RV-8 does not have such notches?
Thanks in advance...
With the weather making it a no fly day?
Just finished complying with the SB, no defects noted.
A/C TT: 356.7 hrs
Annual inspection was completed, SB was was not complied with. Unless you manufactured the parts and installed them. Just a clarification.