I have read several posts, in the "fuel plane" forum that H9 warbirds horiz. stabs have been known to fly off?

I picked up a Spit 60 in very good condition. I have not flown the plane yet, and I am now concerned about this issue.

Anyone here have any info?

What engine are you using?

I've got a Spit, Corsair, Hellcat, Thunderbolt, and had a Warhawk. All H9s.

The Corsair and Hellcat have both clocked over 100mph on radar. Long shallow dive to the runway into the radar. One of 'em, I forget which, actually did 113mph.

I've had the covering off the stabs of the Spit and the Hellcat. The wood and glue on both looked as good as I hoped it would. The Hellcat wood looked very good. Hard and straight grained.

Never seen in the other two, but have felt their resistance by hand... after shrinking the covering while assembling them. Do that with every ARF. They both felt solid. The TBolt has shown me speed equal to the Hellcat. The P40 was sold some years back.

Speed is what kills 'em. Got OS91 two strokes on 'em all. I'd put money on mine they'll be around until I do something stupid, and not because the tails fluttered.

Keep the covering tight. That's important. And feel 'em to insure they're not weak. Then go for it. They're warbirds after all.

BTW, I've seen a couple of them that blew up in the air. The guys who owned 'em weren't too concerned with wrinkles in their covering. I'm guessing that might have contributed, but got not a clue if it did.

I do know it's worthwhile to keep your skin tight and loose covering on poor wood is bad.

The Spit has a Saito 100 FS, which is a common engine used on that plane.

Hopefully the stab issues are isolated incedences.

Originally Posted by tacx

The Spit has a Saito 100 FS, which is a common engine used on that plane.

Hopefully the stab issues are isolated incedences.

I'd say the stab issues are present for every ARF we get from China. The more popular the ARF, the more apt we are to know about any failures it has. Warbird guys have a lot of fly-ins so word gets around easier.

All we can do with any ARF is keep the covering tight, check to see if any part can be flexed by hand, and if we're worried still, then peel off some covering.

I had a Kyosho P40 that showed a crease in the stab after the 2nd flight. It was right where one would be if the structure was failing. Peeling off the underside covering showed a soft LE, insufficient structure near the fuselage, and lousy glue. The factory worker obviously didn't fly model airplanes who slapped that part together.

I put in some wood. Glued it good. Soaked the punk wood with CA. Recovered with Ultracote tightly. And just about wore the sucker out the next year or so, until I sold it.

We might not be building kits in this new modern ARF world, but we still have the need to learn some craftsmanship.

A club member is flying the H9 Corsair with a saito 100 and has wrung it out pretty good. I have the F6F, P-40, and P-51, all with .91 4-strokes. Not barn burners but the P-40 was clocked at 90mph, and its 7 years old. I fly fairly scale.
Edwin

In our club we have them all, Spitfire, P47,P51, Corsair (I fly the Spit 60 with a 4 stroke OS 91)
The all get up to "MACH Plenty" and have not seen any problems.

I have heard the same over on the electric side too. I have the 50 size Corsair and had the P-40, also have the 40 sport P-51 and haven't had any problems or signs of problems with the el on any of them.
I think those who have may have just been a bit heavy handed when cutting away the covering to glue in the horizontal stab and actually cut into the wood.

Originally Posted by V2rider

I have heard the same over on the electric side too. I have the 50 size Corsair and had the P-40, also have the 40 sport P-51 and haven't had any problems or signs of problems with the el on any of them.
I think those who have may have just been a bit heavy handed when cutting away the covering to glue in the horizontal stab and actually cut into the wood.

Yes, from what I read a slight score line on each side made while cutting the covering may have been the root of the problem. I lifted the covering and cut it in the air & then laid it back down to avoid scoring the wood.

Originally Posted by V2rider

I have heard the same over on the electric side too. I have the 50 size Corsair and had the P-40, also have the 40 sport P-51 and haven't had any problems or signs of problems with the el on any of them.
I think those who have may have just been a bit heavy handed when cutting away the covering to glue in the horizontal stab and actually cut into the wood.

That's certainly possible, but if they use epoxy and make sure to get some on the cuts, there won't be any weakening.

If you use slow enough epoxy and apply it so it'll soak into any cuts, those areas wind up stronger than before. Same thing with carpenters glue and any solid, penetrating glue. Even gap filling CA reinforces and will even penetrate deeper.

You've got to hack away wood for that sloppy cutting to weaken significantly if you're using good, penetrating glue and enough of it. Especially epoxy actually will strengthen.

Some guys at my field had this problem with the spitfire and the mustang. They all seem to be flutter induced. Here is a disturbing but educational video on the Hangar 9 Spitfire 60 H-Stab Failure. There is a slow motion shot also which shows what happened.

Hangar 9 Spitfire H-stab failure (0 min 46 sec)

It looked like the left side of the Horizontal stabilizer came off?

After looking at both the Spitfire and P-51, and finding poor centering of the hinge cutins for the CA type hinge, and glue problems that stress the joints and cause disruptive air flow, it is easy to understand why they FAIL.
I start by putting in nylon 3/4" hinges or 3/16" Robart hinge points. This allows me to redrill or recut the slot for the hinge. I use rotary tool setup as a mill to cut the slot, or Robart Centering Drill Tool. Horizontal and Vertical stabs can both be fixed the same way. The gap where the H-stab fits in the Spitfire was a bit big, so CA or thin layer of epoxy will not work well to fill the gap. I used Polyurethane glue and a spray of windex with ammonia to foam fill the gap.
The extra stress of a CA hinge will cause uneven movement, and is worse with all the propwash pushing on it.

I just bought myself a H9 P-47 Thunderbolt 60. Are there any build threads? I have been trying to find some but haven't.