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Alpina - bad news / good news

M

Mucksmear

Very Strong User
Last weekend I succeeded in doing precisely what I’ve been trying not to do. I botched the landing at Tick pt. Totally misjudged the approach speed and the bottom fell out as I descended into the slower air while slowing down too much. The nose dug into the hard pack in the LZ and the Alpina came to a complete stop in about 2”. Looks like the anti-crush brace that sits in the fuse between the wing’s LE popped free which allowed the wings to pinch forward. In the video you can clearly see the point where she stalls and pitches forward.

Good news is that it doesn’t look so bad now that I’ve gotten things back into alignment so at this point it’s just a matter fiberglass repair across the fractures

 
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Some of the bigger fractures along the back of the canopy opening were displaced on impact and their jagged edges intermeshed to make it impossible to realign without sawing through the jammed areas. Once they were freed up I was able to push some of the fuselage back into position. The biggest point of crushing was the port side LE with the wing root from the wing joiner to the LE folded inwards a few degrees. I used a 1/4-20 bolt with threaded couplers to make a spreader bar to push the port side back out.
 

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Alpina was my dream plane when I started out in the early '70's.

Is it an original Alpina or one of the 2000, 3000 etc derivatives?

The orginal is truly a classic and flies as well as it looks.

Doc.
 
Mucksmear said:
“Original” Alpina CS. I agree, I prefer the classic lines of the original over the more modern versions.
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I hope you can repair it, Mucky.

I make no bones about it, my Alpenbrise is ewhere I hoped the Alpina (MKII) would have gone before they were taken over by Hitek. But alas it was not to be.

Its a beautiful model.

Cheers

Doc.
 
First off, very sorry to see the carnage. But great to see some video of her doing her thing (start of the video).

The landing all looked good until the big nose pitch down. Both landing approaches looked textbook perfect for this slope, so trying to understand why this happened. You had the nose down the entire approach as what looks like enough angle to negate any stall concerns. I did notice some gusting on the final approach and think the wings had dropped low enough where they avoided a gust, but the tail was lifted by the gust?? You would know best, can this plane actually stall on approach? It does have a lot of flap, but seemed like you had enough energy in the airframe.

Anyhow, thank you for sharing.. And I know you will get her looking great again! Sure is nice to have those flaps on the Alpina! Nigel's was always tough to land without them.
 
Wayne said:
First off, very sorry to see the carnage. But great to see some video of her doing her thing (start of the video).

The landing all looked good until the big nose pitch down. Both landing approaches looked textbook perfect for this slope, so trying to understand why this happened. You had the nose down the entire approach as what looks like enough angle to negate any stall concerns. I did notice some gusting on the final approach and think the wings had dropped low enough where they avoided a gust, but the tail was lifted by the gust?? You would know best, can this plane actually stall on approach? It does have a lot of flap, but seemed like you had enough energy in the airframe.

Anyhow, thank you for sharing.. And I know you will get her looking great again! Sure is nice to have those flaps on the Alpina! Nigel's was always tough to land without them.
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With the Ritz 3 aerofoil the wing can be a bit prone to stalling at low speeds if its not 100% smooth.

Doc.
 
I’m pretty sure I simply flew her right down to the stall. The nose down attitude may have been less “sufficient” than it appears, given the descent rate and the 70-80 degrees or so flap angle. Afterwards, I debated sending up the Coyote (quit while I’m ahead?) but I went up anyways and had a most perfect of soft landings, about 2 or 3 meters closer to the edge of the cliff.
 
Sorry to have seen that. Honestly, whenever I have a really good landing there it feels like there was some luck involved. It's not the easiest place I've ever landed. Glad it's repairable, that's a beautiful plane.
 
Gorgeous model. Sorry to see it collapse.

Question as i am not familiar with CS build the newer models have a piece of wood dedicated to prevent fuselage collapse encouraged by wings inertia. Was that not implemented in this classic or insufficient? The landing looked innocent on the video.
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Hope you fly again soon!
 
Aloyz said:
Gorgeous model. Sorry to see it collapse.

Question as i am not familiar with CS build the newer models have a piece of wood dedicated to prevent fuselage collapse encouraged by wings inertia. Was that not implemented in this classic or insufficient? The landing looked innocent on the video.View attachment 20638

Hope you fly again soon!
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Some tips from me - previous owner of three Alpina's.

I put a piece of Birch ply at the front and another the rear of the wing on mine (3) many years ago. As I remember it extended about one inch in front of the wing LE position and the same at the back but about one inch behind. Loads of room to do it and I had seen many crushed in that position. It worked well.

Actually, this an inherent problem with a front/rear-flexible blade joiner. Great in vertical stress, but very poor in horizonal

Also, on an Alpina its a good idea to make a pretty sturdy and long radio tray to bolster up that boat of a fuselage. Mine was two laminated layers of 3/16" Birch ply and extended from the very front to way past the leading edge of the wings. That also provides some more support in the event of a sudden forward moving wing.

Heavy? Yep, but thats great - better to have strength-adding payoad than useless lead up front.

Added to that we used to glass the wings - I had already begun to use vac bagging in the mid '70's. In our club (ISA) we called it "wind bagging" which makes a fait bit of difefrence to the rigidity. I have forgotten how many Alpinas I have seen - unglassed - with lovely bowed wings in a hard loop or turn. Trouble was - too hard and you lost aileron control as they stick.

The last thing I did was to add a bit of balsa stiffening to the fin area during the build as the back on some could be a bit waggly.

As a testament, all of my Alpina's were sold to make way for other things, mainly life, as I was still a grad student. None were broken, even with my somewhat famous 'arrivals' from time to time. I can still hear "Hammond landing!" every time I went around the back.

Great models. Pity they did them in with the 2000, 3000, etc etc

Cheers,

Doc.
 
Yes, the CS calls for an anti-crush brace between the LE in a separate addendum to the instruction booklet. The design also has a plywood brace spanning the fuselage near the TE.

In this instance, looks like my anti-crush brace popped out on the hard landing. Probably insufficient roughening of the inside of the fuselage where the failed brace anchor was epoxied, so this will have to be addressed during the repair.

If I didn’t have a brace at all, the damage may have been more severe.
 
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Repairs have finally resumed! With the fuselage cracks aligned and stabilized with epoxy/cabosil earlier, I’ve now marked the cracks and outlined a region to sand/scuff that I can actually reach from the inside. Shining a light on the outside of the fuselage backlights the cracks as seen from the inside. A small mirror on the floor of the fuselage helped me see the areas on the underside of the top of the fuselage immediately behind the canopy. A Dremel right angle attachment with permanent grinding wheel just fits through the canopy opening and into the repair area.

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Mirror - Great Idea!

Dremel 90 degree?? Never seen one before. Very handy on challenging jobs like this.
 
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