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The Last Skyhawk


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Tonight I finally got around to clearing the bench and starting my A4. I knew I wanted to produce a Skyhawk with the avionics "hump" so the search began for an appealing colour scheme to go with it.

A search of the internet brought up this Skyhawk, s/n 160264 which was the 2,960th and last manufactured Skyhawk and was delivered on 27th February 1979.

Along with some airframe modifications to Phil and Matts plan I will have to figure out a way to produce the graphics down each side, maybe water slides, but I will have lots of time to think about that before I have to do it.

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So first up was the fuselage. The sides were jointed and glued using the tape method, lines on the plan were extended and the dry sides marked and cut. The former positions were marked and the cut outs formed for the jet intakes. I then added the triangular stock to the sides and the wing seat doublers before cutting the wing seat in the sides using the doublers as a template.

Whilst the sides were pinned to the bench to dry I assembled the battery box, cut the nose floor and assembled the box/nose assembly. By the time I had that together the sides were dry enough to start gluing in formers and wing bolt plate to one side.

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Before I knew it, it was 3am and time to get some sleep so that's as far as I have got today. Hopefully by Saturday night the fuselage will be together and I can start planning the extended nose and hump!

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Thanks Lorenz, yes I'll be changing the fin and nose but not yet decided what to do about the canopy. I have been tempted to build a vac forming box for a while and this model might just be the reason to do it. I might just paint slightly outside the supplied canopy lines and get it halfway there!

Thinking about the colour scheme I could cut a set of masks with my vinyl cutter and airbrush all the insignia on the sides, indeed I could cut masks and airbrush all of it. Just another idea.

This afternoon I assembled the fuselage in the jig ready for gluing up. The cockpit sides were very reluctant to take on the new shape so had to be sprayed with ammonia for encouragement. Whilst I was at it I also sprayed the rear sides at F7 to ease the bending for the tail. The center line of the fuselage was lined up with one of the grid lines on the jig to ensure a straight build.

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F6 was also raised up 1/8" to ensure the nose floor sat flat on the jig base board.

After leaving it to soak for a while I removed the clamps and glued up the tail first including the 1/4" top deck between F5 and F7. I then glued the cockpit sides with aliphatic leaving the top 1/4" clear for some thin cyano. The sides were then pulled in with finger pressure and cyano used to glue and clamp the top corners. The sides fell nicely onto F2 but were bowing off F3 so I used a couple of clothes pegs in reverse to push the sides onto the former.

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Excellent start Chris. Will be watching with interest.

Canopy solution - get one from Traplet.

Decal solution - get Tim at Model Markings to do them for you. Not worth all the hassle for £10.

I am doing the same hump on my Israeli Air Force version. I am going to do it out of blue foam.

I am also going to add some padding at the rear around the fin to make it more blended than as per the design. Might do that out of foam also.

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Good progress Chris - going together very nicely!

I do hope you decide to take part and join in the fun Lindsay! A great excuse for another weekend out with us on the Orme in September!

Pete - the canopy concern is that the Traplet one made from my plug is modelled on the earlier variants B to F. For the A-4M model, as being modelled here by Chris, the pilots visibility was improved via a modified canopy - slightly more 'bulbous' and with revised canopy framing - more glass/less metal basically. Of course you could just fit the standard Traplet moulding, but the 'Gods of Slope Scale' wouldn't be at all happy and they would surely send us light South Easterly winds during our September weekend wink

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  • 3 weeks later...

A slight delay in proceedings due to some better weather and some nice powered flying at last!

I now have 2 building benches! One outside for repairs and servicing and my bench in the shed for full builds so should be getting back to it this week! Better get my finger out! laugh

Linds, the PSS builds are interesting as I've come across some design and building methods I've not seen in i.c builds before. I suspect it's because the PSS models have to be strong for landings (diching) but still light. It's definitely expanded my building techniques. yes

As for the flying, well I'm still learning that! It helps to have a mate ? nagging you to throw your new models off a cliff over the sea claiming "It'll be fine" (Peter) surprise

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LOL - wish I could help you take the plunge and throw them off for you with my hands on the sticks but you fly Mode 2 and me Mode 1 - there are lots of others however who will do that for you. You just have to have faith that models will stay up in the air on slope lift and not crash and burn into the sea below!

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  • 1 month later...

Thanks Peter! It would help if I didn't have to maiden them by throwing them out over the sea each time too! A maiden over land would be nicer!

Back early(ish) from Greenacres and with several models still in the caravan there's a bit more space in the shed so the Corsair was relegated to the fuselage rack whilst waiting for a new cowl and the bench cleared ready for a dedicated re-start on the last Skyhawk! smiley

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OK almost all of the Corsair cleared off the bench! There's a scuff I still need to polish off the canopy! blush

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Managed a bit of time on the A4 this week but not many photographs! The decking is complete with the nose built up and shaped. The intake pods are also complete. I made an electronics hump from 1/8 balsa and 1/4 triangle stock. I've also made the rearmost part of the canopy structure from laminations of 1/2" balsa since it will be connected to the hump.

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Still need some more accurate shaping but it's getting there. I'm using a 1/72 plastic model and 3 view drawings to help with the shapes and proportions.

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This is the inside of the electronics hump. Started off like a canoe!

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I've also modified the fin and rudder to an A-4M

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and added the tail plane and supports.

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Got a little help from this fella who sat quietly on the rudder whilst I jigged and checked the tailplane was square!

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I have yet to make a start on the canopy though. I have an understanding of the different shape from Phils origional and will either vac form my own or shrink a pop bottle over a wooden plug. I've not decided yet!

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Sorry it's a very brief update but between servicing and repairing airframes, work, family life and flying time is quite short! smiley

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Posted by Steve Houghton on 19/07/2016 23:36:27:

A good looking build, Chris. Keep us informed of your approach to canopy moulding - it's always useful to see how builders tackle this.

Will do Steve. I suspect it's going to be a pop bottle shrunk over a plug due to time constraints!

Time for another quick update. Due to a developing tight schedule I have decided to cover the A4 with film. I was going to go with glass cloth and epoxy resin with a sprayed finish but that can get quite heavy and knowing me I get way too involved in it and it'll take a lot of time. So whilst at Cosford I picked up a couple of rolls of OraCover.

Using film presents it's own problem though. As I've made the ribbed rudder covering it isn't going to be easy so I wanted to have a go at it to see if I was going to have to glass and spray the whole fin instead! Now I don't mean to teaching anyone how to suck eggs but for any body out there who wants a ribbed rudder and also wants to cover with film but doesn't think they can do it, you can!

I started with a 1" wide strip of covering and tacked one edge to the bottom of the lowest rib

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then turning the iron over 90 degrees I I fixed the film to the top edge of the rib

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I then put a tiny cut in the bottom corner where the fin meets the body of the rudder and ironed the recessed flat between the ribs

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Another tiny cut where the underside of the next rib meets the rudder body and then I ironed the remaining two edges inside the recess

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The leading edge was then lightly tacked down

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With a very sharp blade I cut the leading edge of the covering 1/8 " from the recess

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The covering was then ironed onto the raised flat of the rib above

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which was then trimmed flush with a sharp blade and the trailing edge ironed around the back of the rudder

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and trimmed flush

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Then I started again with another strip, starting by tacking to the last rib covered

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and so on until all the ribs and recessed were covered. I then went over the film with the iron slightly hotter and ironed out all the wrinkles I could. It's not 100% perfect (nothing is ever perfect) but at 50' and 40 mph you'll not see the blemishes!

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And the other side

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That took around 2 hours for each side! Whilst the iron was still hot I covered the rest of the tail assembly too

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Now I just need to fine sand the fuselage and get that covered then I can build the wing!

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Wow, that is impressive Chris. I was thinking about a poly-c finish and paint for mine but I would rather use film so now I will give it a go but I don't think it will turn out as neat as yours. I have built the Fuz and now about to make the fin and rudder so this is good timing. Also, what adhesive did you use on your modified rudder, by the way?

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  • 2 weeks later...

A bit more progress this week, Might be in with a good chance of finishing on time yet!

Piers, I pinned the ribs in place to line them up and used super phatic with a fine nozzel to wick into the balsa and glue them.

Steve, good excuse for new toys tools there, treat yourself! yes

Peter, that just about sums up my biggest problem when building. I can stick the wood together quite quickly but often get too involved in the detail and finishing which drags it out a lot. Hopefully I won't get too carried away with this one!

I have now stuck the wing together and have gone for dual servos with torque rods. I would like to have a centre line drop tank and had to give some thought on how to release it before landing. As it's on the centre line it's now so easy to use a push rod through a guide so I have come up with a simple alternative. I have made a notched cutout in each of the centre ribs which when joined will make a 1/8" slot. I then made a servo mount on one side of the rib which will simply rotate the servo horn through a slot in the ribs and engage in a slot cut into the pylon for the drop tank. I hope the pictures make more sense?

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I used the useless ply spar which was too short in height as a doubler for the centre ribs to strengthen them. If for any reason the tank doesn't drop at least it'll stand a chance of landing on the tank without ripping out the ribs from the wing!

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