T.21 Restoration

Lovely job Eric (+ team ?) – many cogratulations 🙂

She looks really great. Hope the TestFlight will be a great succes!

Went solo on T21  18th July 1964 at Weston on the Green. Had a cable break at 350 ft

Start of my aviation career as ended up A340 Captain.

Excellent work! She looks beautiful 🙂

Fantastic! Congratulations to you all. Here’s hoping the final paperwork doesn’t take too long.

It’s taken a bit more time than expected – almost ten years and 2700 hours of work – but here she is, restoration complete. We’ll await the paperwork and give her some air under her wings for the first time in 24 years…

And so it begins! Time to put the fabric back on, and cover all those nice repairs and new bits up so no-one can appraciate them anymore. We have started with the aft fuselage, a job in itself.

Well the wings are ready for recover now. We are still looking for some minor parts:
– Oddie fastener for fin fairing
– Two Oddie fasteners for the chute backrest cases
– Top interwing fairing, complete
– Complete set of strut and wing bolts

If there’s anybody who can point us in the right direction, it would save us a lot of time making them…

Nearly forgot how big these things are!

Yes they are big !

Looking gorgeous Eric – lovely workmanship- love the machine gun fitted where the ‘Bomb’ normally fits : )

Thought I’d drop a line or two on where we’re at now. The D-nose ply has been replaced. A fair bit of trailing edge has been renewed. Then all moving bits put back in, and new cables drawn. This finally enabled us to rig it again this Saturday in beautiful weather to rig the control cables correctly. It is starting to look like an aircraft again! There a few minor jobs to do before she goes off to have new main bolts and strut bolts made. After that, we should be ready to start putting fabric on it. But we’ll probably do up some trailer fittings first to have a safe place to store the Beast. For that she is. Nearly forgot how big these things are!

Thank you for the update, always interesting and best wishes with the work.

Remember that 1.5 metre bit of ply that had to go? That takes a lot of elbow grease to get off the ribs and spar. A lot of sanding, dust everywhere.
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All sanded down to bare spruce, the innards of the D-nose are amazingly bare after all this work.
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After all the loose ribs were reunited with the leading edge stringer, and all were freshly cleaned and liberally doused in conservative laquer, it was time to teach the new plywood plate how to swim. Next time we need a bigger tub.
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Then the wet plate was draped over the D-nose. Some clamps were needed to persuade it to bend it into shape.
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Some days later it was dry, and utterly convinced of its new shape. So we then glued it into place.
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The only thing left to do now is to grind away excess and the supporting stringers, the redo all the gussets that attach the aft ribs to the spar face. Oh yeah, and then do it all over again on three more 1.5 metre sections that also need re-plying.

Finished new bit after reworking it down to correct dimensions. Compare to picture 3 of the last post and spot the differences.
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Well, that T30 trailer has been built now too, so the Prefect has a new snug home to live in and travel in style. Which is a good thing. An even better thing is we can now finally get back to work on the port wing of the Sedbergh project. Wasting no time, it was squuezed into the busy shop (winter maintenance has also started on all the fancy white modern ships).

To properly assess the very obvious severe water ingress damage in the D-nose, we opened up some inspection holes for easy access. The term Swiss cheese springs to mind.
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Now, the D-nose of a Sedbergh is a properly robust thing. Thick plywood, lots of strength there. The ribs however are amazingly flimsy.
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A surprise was hiding behind a small suspect patch plywood repair on the nose stringer of the D-nose, somewhere around the strut attachment. Somebody had obviously hit this Sedbergh wing head on against something even more solid than a Sedbergh wing somewhere in time. The repair that was done was, as they say, highly entertaining.
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Yes, that is the wrong type of wood. And yes, it has been glued in end-to-end against the rib and not spliced in 1:15 as it should be. And no, the glue joint is not of the correct thickness. And no, the nose of it does not follow the curve of the D-nose. In fact: the bit of wood looks alarmingly like a section of decorative ceiling liner that was conventiently laying around the shop at the time. Which it probably is, too. O, and the guys doing the repair had also missed the very obvious split that ran from their botched repair along the stringer into the next section of D-nose.
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So, out it came, and a proper bit of wood that was conveniently laying around in our shop was spliced in properly to factory specs and drawings. Looking much better now.
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This gave the D-nose its structural integrity back, so one of the next jobs is to strip back a 1.5 metre section of plywood from the whole D of the D-nose and get that replaced with some proper plywood since the old stuff was beyond saving… Most ribs look to be fine and can be re-used. Which is what we expected, since we have some 30 extra ribs in stock for this section, and the things you tend to need to replace and rebuild usually only are the ones you don’t have in stock anyway.

In case you were wondering: no, we haven’t forgotten about you all. We’ve just been a bit busy to get the Prefect finished in time to fly it this year. Yesterday saw it finally finished after six months of on and off work on it. Here it is sitting outside looking very smart in the evening sun. The wing issue has been addressed with lots of new bits going in. The new vertical tail looks just like the old one. While we were at it the control cables were renewed too, and lots of other small jobs added up to a lot of hours (manufacturing a new inspection hatch hinge will take up three hours any day, for instance!). Yesterday’s weight & balance saw it some kilograms lighter than last weighing, which is great. Time to fly is coming up soon…

Time to get back to work on the T21, soon. But first we’ll have to finish building the new trailer for the Prefect, so it has a place to live again. It is now taking up the workshop space of the T21…

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Damn! That pilot got lucky!

It wasn’t that much of a drama. The wing still has its structural integrity intact, but it will require a fair bit of work to get it up to (our) standard again. The tail issue is a known one with several of the Slingsby types, but this has been one of the worst cases I have seen, developing in a rather short timespan. There’s a reason for annual inspections, I always say.

Damn! That pilot got lucky!

Well, the Sedbergh project is still going strong, with work slowing down a bit with the usual amount of other commitments in the workshop during winter.

One of these ‘other commitments’ is a Slingsby Prefect that has been brought in for its annual. The annual turned out to be a fair load of work. First of all there was the vertical tail. It is not by all means a big vertical tail on this aircraft, but it seems to be very useful for flying, so we are somewhat attached to it. Unfortunately, the fuselage turned out to no longer be attached to it properly. What started out as a minor crack, turned out to be Pandora’s box.

This is what we started with.
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And then we discovered that Rib 1’s gluejoint to the top fuselage ply had partially failed. This is what helps hold the tail to the rest of the aircraft. So we opened a little inspection hole.
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We then noticed that the D-nose longeron had disbonded from its position on the fuselage cross rib. So it too had to come out.
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And then we took off the top of the fuselage skin to have proper access. By now very little of actual tail section was left. But we finally had a basis to work with.
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After a bit of work the top fuselage skin was in again, and the framework of the vertical stabilizer started to resemble, well, a vertical stabilizer again.
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So we decided we might as well put some new skin on it. Note that this picture is not 24 hours after the first in this post…
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Shortly after that we started off with the wing inspection. And then stopped and drank beer, because we found a large mouse nest, which has done some damage to the interspar area near the wing strut attachment – of course the most complex wing bit to repair. Still working on a solution, but I am confident it’ll buff out with some days/weeks of work…

PS: the tail damage turned out to be because the rudder cable stops had not been refitted after its last overhaul in 1988 by a previous owner, leading to overstress damage of the tail. If you have a Prefect: check if these are fitted. It’ll save you a lot of work!

Eric,

Good to see you are getting there. Look forward to seeing the T21. This is the last time I will be using G-ASEA as I have sold my Luton Minor. So Will be changing name.

Dave

Eric,

Good to see you are getting there. Look forward to seeing the T21. This is the last time I will be using G-ASEA as I have sold my Luton Minor. So Will be changing name.

Dave