fairey swordfish Fairey Swordfish

[Martin Fraser]

Hi folks,

Following on from my last two scale Fleet Air Arm aircraft, Wessex MK1 and Westland Wasp, I’m now planning on a fixed wing subject. I’m using the Cliff McIlwee 72’’ plan that comes out at 7.5:1 so very near to the 1/8 helicopters. Suggested power is listed as 60 2st or 90 4st so I’m hoping my recently acquired Saito FA–120 R3 radial will be provide enough scale oomph.

 

This will be my first balsa and ply model since the mid seventies so I’ll be asking a load of newbie questions from you experienced builders.

Cheers, Marty

[Dale Bradly]

Nice! One of my favorites since reading To War in a Stringbag. 

[Paul De Tourtoulon]

Nice plane and engine choice,,

[Martin Fraser]

Hi Folks,

 

I’ve finally got going on the project and started with cutting out the fuz frames. I’ve located F1 20mm further back to accommodate the Saito R3 length so that the prop driver flange is in the correct place.

There’s not much detail on the plan regarding servo location so I’m thinking that the throttle will live under a removable observer / gunner’s floor, connected by a snake along with the other servos for the tail and RX etc.

The target weight is stated at 8.5 lbs / 3.8kg. I’m assuming this is without the engine etc? I don’t want to add any unnecessary weight and there’s no mentioned of balsa grades. So what should I use for the many 3/32” stringers aft of the cockpit area?

 

TIA, Marty

[Manish Chandrayan]

Signed up for the ride ? 

[alan p]

Depends if you are looking for strength or lightness, Bass wood strip is a combination of both so a  comprimise.

Though if cost enters the equation ?.

[Martin Fraser]

7 hours ago, alan p said:

Depends if you are looking for strength or lightness, Bass wood strip is a combination of both so a  comprimise.

Though if cost enters the equation ?.

Hi Alan,

The 3/32" sq balsa I have feels more suited to a little rubber powered model. Bass sounds like a good idea. It's a right pain to break a stringer and have to cut the covering to repair it. The Saito weighs 890g so I'm hoping a few extra grams on the tail shouldn't be a problem.

 

Cheers, Marty    

[Martin Fraser]

Hi all,

Not much of a flying weekend so pottering on with the ‘String-bag’ in the man cave. As you can see it’s not a flat truss type of construction and I’ve had to do a bit of jigging up to check my woodwork.

I’ve found a few typos on the plan such as the keel longeron 5/8”x7/8”! That should read 5/8”x1/8” and a missing frame section. However, it’s taking on a 3D shape now and I’m having to think ahead of where servos etc are going to fit, providing apertures in the bulkheads for control runs and wiring. There’s a white tail light in the trailing edge of the rudder!

I do like to build with total servicing in mind so that will require some thought with the fuel tank access. Saito state the engine at full throttle will burn 24cc of juice per minute so I’m planning on using a Slec 9oz/270cc tank.

 

All for now, Marty

[Martin Fraser]

Hello all,

 

I’ve lost a bit of traction on the build of late due to various things but have done most of the stringers on the fuselage in bass wood (lime) thanks for the suggestion AlanP. They feel much stronger than balsa and will only add a few grams.

 

I’m at that stage where I need to plan and possibly install the hardware in the fuselage such as fuel tank, servos and control runs before I do any planking and sheeting. The plans on first inspection seemed pretty comprehensive but as well as omissions there are some inaccuracies i.e. 3mm out in the spar cut-outs in the wing ribs, they don’t correspond to the wing plan view!

 

The full size aircraft’s tail control cables exit the fuselage aft of the gunner’s position so I would like to emulate this detail if only for the rudder. Having never installed a closed loop control run before, are there any good examples I should look at? Also, the tail wheel shown is fixed, should I think about a castoring unit or connected to the rudder?

 

One great feature of the Swordfish is the amazing wing fold system whereby the mainplanes are unlocked from the flight position and folded back to be secured parallel with the fuselage. This was carried out by the deck crew – probably quicker than it’s taken me to type it. It would be great to embody this detail on the model for scale authenticity and transport but would need to be robust and fail-safe for obvious reasons.

 

I’m about to place an order for more material for the wings. Spruce is listed for the spars and balsa for the ribs, which are capped and I’ll cover with Oratex or similar but what grade do folks recommend?. All suggestion appreciated.

 

Cheers, Marty

[kc]

If you haven't built for a long time there could be some newer materials available now which might help.   Liteply in 2mm or 3mm is available from SLEC and Balsa Cabin etc.   Some people use foamboard instead of balsa in some areas.  Worth looking at SLEC website.   Also check out Mick Reeves website for thin epoxy glass sheet ( Pro Skin ) and lots of useful fittings.

Mike Sun showed a simple way of making folding wings for his DH 60 Moth in an old RC Scale Quarterly - if you haven't seen that I might find my copy and scan it if you ask. 

Edited November 24, 2021 by kc

[kc]

On 02/11/2021 at 11:30, Martin Fraser said:

The target weight is stated at 8.5 lbs / 3.8kg. I’m assuming this is without the engine etc?

I don't ever recall seeing a target weight quoted without engine!   I would expect that would be including  engine but not fuel.    But of course I don't know that plan.....

Nowadays I think the CAA definitions of weight ( 7.5 kilos etc ) includes fuel.

 

The Mike Sun article on folding wings is still on my computer from scanning it for someone else, so it's no problem to send it to you.   Send me a Personal Message if you want it.

Edited November 24, 2021 by kc

[Martin Fraser]

Hi KC,

Is this Mike Sun's moth?  As you say, simple and safe I would think. Yeah, I am a bit out of touch with traditional building as my last two models were moulded GRP and carbon but I've got an account with Slec and have looked at Mick Reeves's site and the Pro skin - interesting material. Hold fire on the Moth article for now as I don't want to get ahead of myself.? 

As far as AUW is concerned I'm still in heli mode, my Wessex is about the same size as this Swordfish (6'.0") long but it tips the scales at 12kg. 

 

Many thanks for the info, Marty

[kc]

That may well be Mike Sun's model or one built to his plan RC135,  but one of his models was in 'Jason' livery.

The details of the wing folding are in the article about building light models which has very clear drawings of the pivots and locking mechanism.   The locking parts and pivots are made from hacksaw blade!  I presume a midget hacksaw blade for his 60 inch span Moth.

[J D 8]

   One of the first things I remember as a little one is being lifted up by a kind sailor to have look in the cockpit of Swordfish I was interested in at Fleet Air Arm station HMS Goldcrest RNAS Brawdy open day. Had a soft spot for the Stringbag since.

[Martin Fraser]

Hello folks,

 

You maybe forgiven for thinking that I and this project was dead but I’m still above the grass and now that the flying season is drawing to a close I am picking up the build where I left off.

 

Just to recap, I’m using the Cliff McIlwee 72’’ plan and I’ve chosen to complicate things somewhat with a wing fold. I’ve come up against quite a few anomalies and the latest is the amount of dihedral shown on the plan. The lower plane at the wing tip is 2 degrees and the upper is detailed at 6 degrees.

I’ve studied loads of photos and I’ve downloaded a CAD drawing to take accurate measurements from it. The full size seems to have no dihedral at all on the lower and the upper only 2 degrees which looks correct.

 

I would prefer to have this looking as scale as possible and I can adjust it easily at this stage but will the scale dihedral give me some stability problems in flight?

 

Many thanks, Marty

[Martin Fraser]

Hello Folks,

 

Well it sure is shed weather and I've run out of excuses for not progressing the Swordfish.  I've got to the stage where I have to think about a lot of things all at the same time. I'm fairly happy with my sprung main U/C and the wing fold hinging but now need to think about servo placement in the lower main planes and in the fuse for the closed loop runs to the empennage. Also, wiring for the landing and nav lights. At the moment I'm dithering over the choice of hinges for the control surfaces. I've got some of the pinned nylon type but not sure if they are up to the job. Any recommends?

 

Many thanks, Marty

[Jon H]

Looks ace, and i wouldnt be worried about the hinge type. Control surface loads will be very low and more or less anything will work fine

[Martin Fraser]

Ah OK John, I'll probably put 3 on each surface. 

 

Many thanks, Marty

[kenair18]

Hi Martin, how is the Swordfish build moving along, what stage are you at and what weight is the model at now. Cheers - ken 

[Martin Fraser]

Hi Ken,

The Swordfish is inching along and is pretty much as you see it above. As far as the plans go they are fine if all you want is a stand-off scale model. It’s drawn with built up main planes i.e. upper and lower to be rigged at the field. Having watched people spend an hour or two rigging biplanes I didn’t fancy going this route so I embarked on redesigning the wings to fold as per the full size aircraft, thereby enabling me to transport it in a normal estate car. So that’s where the fun begins!

 

The more I considered this redesign the more issues became apparent and different stresses would have to be accommodated. The hinging geometry is quite 'interesting' in that the upper centre panel is narrower than the lower and a good bit further forward. The full size lower wings have no dihedral and the upper wings have about 3 degs and are swept back. I wish I had thought to angle its ribs so that they are parallel with the air flow On the plan these are drawn as 7 degs for the upper and about 3degs for the lower. I’m sure it’s this way to give easier handling but compared to the full size it looked daft. So I’ve followed the full size and will fit leading edge slats to the uppers and may even install a gyro!

 

Anyway back to the plan. I had thought of getting the ribs and bulkheads laser cut but glad I didn’t as many of the cut-outs don’t correspond to the plan view. Also, some of the ribs on the tail plane are not a mirror image of one another i.e. the left side spacing is exactly 1/8th out from the right side. No big deal but something that is there to catch you out when installing some hard points for bracing struts and rigging wires.

 

The U/C is drawn as bent piano wire but I’ve gone for a wishbone with a sprung oleo as per full size. There isn’t much detail where to put servos and access to the fuel tank is worrying me at the moment – I do like to be able to service everything.

 

I hope this doesn’t sound too negative about the plan as it’s quite old I guess and drawn in the traditional way without the help of CAD and some of my problems are due to inexperience in balsa bashing and the others are with going off piste design wise. If you keep it simple and watch out for a few googlies then I would go for it.

Cheers, Marty.

P.S. As far as engines go it might have the Saito radial installed but it sounds a bit sporty or a single 90 or 120 up front. I’m guessing AUW is going to be 5Kg ish.

 

[kenair18]

Hi Martin, thank-you for your latest post, it was very helpful so I've ordered the plans, mine will be for sport flying with a sport scale appearance and use a small gas engine.

 

I second your thoughts about biplane assembly, my late RCAF flying pal used to quip that it took 3 men and a small boy to assemble a truly scale biplane though this photo from our field only had two men and a large boy doing the assembly on a Tiger Moth.

 

I'm unsure of which colour scheme I will use, either a Bismarck attack Swordfish or a Royal Canadian Navy scheme, maybe I'll decide when the model is covered.

I'll start cutting out the parts this spring, make a kit so to speak and start the Swordfish build in the winter of 2024-2025. I don't rush a building anymore so it may be a 2 winter build.

[kenair18]

Hi Martin,

I got the Clifford McIlwee  Swordfish plans today and I'm trying to figure out if there is a template or outline for the fuselage "plywood" sides. I've looked and looked but cannot seem to see a line on the fuselage plan that indicates the outline of the plywood side.  I've put an arrow on the photo to  show what part I'm talking about. How did you figure this part out?

Cheers - ken kalynuk

[Martin Fraser]

Good morning Ken,

Well done on getting the plan.

I know what you mean, a template wound have been most helpful. However, there is a straight line showing its top edge and I identified it by measuring the slots for it in the fire wall and F8. Similarly, its bottom edge can be checked by cross referencing with the other frames. 

 

As plans go, it does need a bit of deciphering and there is some confusing labelling of things.  The side view of the fuselage shows the frame numbers logically but the top view has them going from F5 to F10 and F11 then back to F8 ???  Knowing what I know now, I would cut out the frame bulkheads 1 to 8 and dry fit them onto the two plywood sides. Once happy notch F1 and F8 to accept the upper and lower square longerons and then notch the other frames to suit. Same with the stringers as the cut outs for them on the plans are a bit out of whack.  Also, there's very little detail on where to place servos so think about their locations and their control runs now and make provision for them in the frames.  I'm going a bit scale and using closed loops for the elevator and rudder - yes it's a right fiddle! 

 

Please fire away with any queries and I'll do my best to shed a light.

 

Regards, Martin

 

 

 

 

[kenair18]

Thanks Martin for the pics, that is what I figured. I'm transferring the plan templates to stiff poster type paper to make templates then I'll cut a kit of parts for next winters build. 

BTW I found this pic of Cliff McIlwee on Facebook with his Swordfish from way back when? I've messaged Cliff M but have not heard back.

 

I'm in the middle of a Hawker Tempest build from Sepp Uiberlacher plans - 83" wingspan - I'm running out of steam as I want to be out flying but it's still

winter for at least a month.

cheers - ken

[Martin Fraser]

Hi Ken,

Yeah, that's what I did as it saves the plans a bit.  Cliff's model looks great - nice scheme!  I wonder how many Swordfish have been built from his plans?  I was down at the Navy Wings hangar at Yeovilton a few years ago to look at the full size and spotted a model of one up on top of a container but I could get to it unfortunately. 

 

I served there as a young air mechanic in the early 70s and the historic flight's hangar was just a 100mts from ours and I didn't pay that much attention to the old 'String Bag' but when they wheeled the Sea Fury out everyone downed tools for the start up and subsequent flying display. Now 50 years on I can appreciate what an amazing aircraft the Swordfish is and what it achieved in the hands of true heroes.

 

Enjoy the Tempest build but save some balsa for the Swordfish.

 

The sun is out so I'm off flying now.

 

Cheer. Martin.