Bridlington & Wolds Scale Model Club Forum
Models => Modelling Projects => Topic started by: Pen-Pusher on November 27, 2016, 11:37:14 AM
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Reichsmarschall Hermann Göring instructed the German aircraft machine industry with what is called the ‘3-1000’ objective. Goring needed a plane that could transport 1000kg of bombs (2,200 lb), with a scope of 1000 km (620 miles) and speed of 1000 km/h (620 mph).
The Horten Brothers had been experimenting with flying wing designs in lightweight gliders since the 1930’s. They believed the low-drag of the gliders could be the base for work that would meet Goring’s requests. The wings of the prototype H.IX plane were produced using two carbon infused plywood boards, stuck to each other with a sawdust, resin and charcoal blend.
In 1943, 500,000 Reich Marks was awarded to Horten to assemble and fly a few models of the all-wing and jet-propelled Horten H IX. Subsequently, Horten flew a glider version in March of 1944 but these flying machine did not resemble any current plane being used in the Second World War.
Though Goring was very much inspired with the plane, due to production difficulties and problems mating the engines to the airframe, he transferred the design and build from the Hortens to the German aviation organization Gothaer Waggonfabrik. This later (and remains) the main source of confusion between the Ho 229 and Go 229 designations.
At Goth, the plan experienced a few noteworthy upgrades and modifications but the outcome was the H.IX V2, which was first flown on 2nd February, 1945. The H.IX V2 reportedly displayed very good handling qualities, with only moderate lateral instability (a typical deficiency of tailless aircraft). While the second flight was equally successful, the undercarriage was damaged by a heavy landing caused by Ziller deploying the brake parachute too early during his landing approach. There are reports that during one of these test flights, the H.IX V2 undertook a simulated dog-fight with a Me 262 where the H.IX V2 outperformed the Me 262.
Two weeks later, on 18 February 1945, disaster struck during the third test flight. Ziller took off without any problems to perform a series of flight tests. After about 45 minutes, at an altitude of around 800 m, one of the Jumo 004 turbojet engines developed a problem, caught fire and stopped. Ziller was seen to put the aircraft into a dive and pull up several times in an attempt to restart the engine and save the precious prototype. Ziller undertook a series of four complete turns at 20° angle of bank. Ziller did not use his radio or eject from the aircraft. He may already have been unconscious as a result of the fumes from the burning engine. The aircraft crashed just outside the boundary of the airfield. Ziller was thrown from the aircraft on impact and died from his injuries two weeks later. The prototype aircraft was completely destroyed.
Despite this setback, the project continued with sustained energy. On 12 March 1945, nearly a week after the U.S. Army had launched Operation Lumberjack to cross the Rhine River, the Ho 229 was included in the ‘Jäger-Notprogramm’ (Emergency Fighter Program) for accelerated production of inexpensive ‘wonder weapons’. The prototype workshop was moved to the Gothaer Waggonfabrik (Gotha) in Friedrichroda, western Thuringia where, In the same month, work commenced on the third prototype, the Ho 229 V3.
The V3 was larger than previous prototypes, the shape being modified in various areas, and it was meant to be a template for the pre-production series Ho 229 A-0 day fighters, of which 20 machines had been ordered. The V3 was meant to be powered by two Jumo 004C engines, with 10% greater thrust each than the earlier Jumo 004B production engine used for the Me 262A and Ar 234B, and could carry two MK 108 30 mm cannons in the wing roots. Work had also started on the two-seat Ho 229 V4 and Ho 229 V5 night-fighter prototypes, the Ho 229 V6 armament test prototype, and the Ho 229 V7 two-seat trainer.
During the final stages of the war, the U.S. military initiated Operation Paperclip, an effort to capture advanced German weapons research, and keep it out of the hands of advancing Soviet troops. A Horten glider and the Ho 229 V3, which was undergoing final assembly, were secured for sending to the United States for evaluation. On the way, the Ho 229 spent a brief time at RAE Farnborough in the UK during which it was considered whether British jet engines could be fitted, but the mountings were found to be incompatible with the early British turbojets, which used larger-diameter centrifugal compressors as opposed to the slimmer axial-flow turbojets the Germans had developed. The Americans were just starting to create their own axial-compressor turbojets before the war's end, such as the Westinghouse J30, with a thrust level only approaching the BMW 003's full output.
The only surviving Ho 229 airframe, the V3 and indeed, the only surviving World War II-era German jet prototype still in existence was, until very recently, at the Smithsonian National Air and Space Museum's restoration facility in Suitland, Maryland, USA. In December 2011, the National Air and Space Museum moved the Ho 229 into the active restoration area of the Garber Restoration Facility and it is now almost fully restoration and on public display.
Models of the Horten ‘flying wing’ started with the PM 1/72 version (Single and twin seat) manufactured in Turkey. This very simple kit kit has subsequently appeared in IPC, Pioneer2, MPC, Matchbox and Revell packaging. The first Revell issue was extremely short lived and now almost impossible to find outside the collector’s market as Revell then decided to introduce their own, more complex kit - but initially labelled it as the Goth Go 229 before realising their error, changing it to the Horten IX/Go 229. A third change a few years ago labelled the kit simply as the Horton Go 229 and so it goes?
There are kits in 1/48th, 1/32nd and several flying models from 1/20 up to 1/6th if you have a mortgage agreed with your model shop. For the purposes of this article I will deal with the original PM and final Revell issues and make what comparisons and build options I can....
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PM issued the A1 (IX) and V7 (Twin-seat) versions in a very basic kit format having 17 and 18 parts (incl canopy) respectively. The mouldings however are crisp with little flash evident but detail is sparse. (Curiously the Matchbox offering was in a very brittle plastic and was often found to be broken I'm told) If you choose this model you will have work cut out to add detail to the cockpit and wheel wells. The large fron wheel and struts are moulded as one which is never satisfactory and really needs replacing with a scratch built assembly. Fit overall is good and the dimensions scale up well with the published details although I am suspicious on the buried-depth of the engine exhausts on the rear fuselage. I have not measured up the Revell offering yet but the photo below shows the differing approach to construction and detail...
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Looking at both the 1/72 PM and Revell kits it is obvious neither has captured the peculiar curvatures of the single seat canopy (Photo#1). The PM kit in particular will require a new canopy if this option is chosen. Curiously, the 'proposed' twin seat would have had a more bulbous canopy - presumably to aid visibility in the training and nightfighter roles and that is better represented in the kit. Both kits 'appear' to have the engine exhaust funnel slightly accentuated both in depth and length though the PM issue (Photo #3) is more akin to the photo (#2) of the actual prototype upon which it was based? (Time and build will no doubt prove me wrong) Ah well, back to the plastic....
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With the decision made to go with the basic PM kit first, I looked again at the kit parts (Photo #1) Mmmmm, not much to shout about there? What does become obvious, if (and it's a big IF) it is possible to overcome the canopy contour problems there's 'B' all to see through it. (This reminds me of my early building days when kits only had at best a separate seat as opposed to those with a moulded headrest and pilot's head all in one? - but I digress). No matter what detail will eventually fill this space, it needs to be boxed in first - so out comes the trusty plasticard (Photos #2-4). Note to self There are a couple of other orifices that need some backing where the ejector chutes are located for the guns...
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The undercarriage - especially the nose wheel/strut arrangement - will require some remedial, if not complete rebuilding work. Obviously in tooling the kit the manufacturers (PM) worked only from a side view and assumed the forward oleo was supported by two retracting struts positioned one above the other. Alas, this was not the case. A study of the photos below will show the difference between the kit and the 1/1 model under renovation? One issue I do have is the inclusion of a mudguard as various photographs of the 1/1 show this both fitted and absent? Of interest, the Revell kit (Photo #3) would appear from this photo (not mine) to have designed their's a bit better!
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Returning to the cockpit. The curse of the PM single seat is certainly the cross-section of the cockpit. i'm no good with vac-forms or making my own from acetate sheeting despite many tries, so I resort to the mystic art of heating the kit canopy gently (with the 'present' Mrs D's hairdryer) over a clay master mould. There is the hint of a flared edge now so just hope it fits?
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Oooooh,
You are a brave man, using the 'bosses' hairdryer most likely without consent.
Think to get a good 'flared' cockpit canopy you would need a male and female mould system. Though I have to admit, with the hairdryer, it is a novel approach to correcting the problem.
I'm watching this project with interest.
Cheers,
Bigkev
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I did both of these kits a while ago and like you I found the Revell kit far superior, although I went no where near the level of scratch building you have added, both just OOB builds for me. Zouke Mura have taken it to another level though.
Regards Bridlufc
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I'll pick up the medal for gallantry on the 14th BigKev...? Yes, a male/female mould would have been the ideal way to make a new cockpit but with my limited skills that would have resulted in failure. No, with gentle heating and rolling the outer engines with the shaft of my modelling knife I've managed to improve the cross section a bit - but just a wee bit!
Thanks Bridlufc. The Revell kit is really the best option though the overall dimensions and profiles are almost identical. I will review the build of the Revell one in due course... maybe after the headaches have subsided....? Zouke Mura? Well you know what they say, 'Tomorrow is another country!'
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Just came across the little gem and continuing my Horten theme - this neat little resin kit produced by UMM in the USA is of the V1 glider. It has fine recessed panel lines, vacuform canopy, white metal, photo-etch and decals for one aircraft. (Wonder if the 'present' Mrs D is amenable to Christmas gifting?)
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The Horten was fitted with the first German 'ejector seat' but I have to wonder of this would have been effective?
Because of the low profile and angular cockpit, the angle between the seat and seat back was 120 degrees (almost the same as that on the F.16A). It would appear the twin-seat trainer/nightfighter would have had a more bulbous cockpit affair but to allow for this in the single seat PM kit, you have to remove the 2 mm 'shelf' at the rear of the cockpit housing (Compare Photo #1 and #2) on the upper section. Having built the 'box' for the cockpit it now needs to be removed and lengthened too - but at least this will give me an opportunity to add some sparse detail... (he says optimistically!!)
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Okay, having removed the cockpit box to increase its length, I've added some rudder pedals, joystick and bracing struts (if you can make them out on sides forward of the seat) I'll tidy lines and add seat straps before replacing in bottom fuselage/wing...
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Before mating the upper and lower halves it is necessary to give the engine exhaust housings some attention (See photo #1). These are too thick and need careful filing and sanding. A small curve need to be added to the outer edge where the engine and wing surface meet. The intakes (Photo#2) are not quite so bad but will also need some 'pruning'. Remember, this aircraft was mostly constructed of wood and resin fibre and there were no 'sharp' edges.
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Some ways back I mentioned the problem with the main (nose wheel) undercarriage assembly. Remedial action means removing the oversimplified struts moulded as part of the one piece wheel and oleo. Rummaging the spares box to find two likely candidates for the main box-strut which, with a little shaping, trimming and more shaping, finally adopts something akin to the correct shape. A triangular brace cut to size and assembly begins!!
It might look a bit rough and ready at the moment but some careful filing may well see this end up as a reasonable copy of the real thing.... Be still my beating heart I hear you say!
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The redundant portion from the original wheel moulding can be used to provide two struts and support bar required to complete the new assembly...
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Dummkopf!
I've just realised I need to open up the wheel wells (See marked sections) but have already joined the upper and lower sections....! Ah well, it may not be such a disaster as there were no actual 'wells' just open space in the airframe! Now where's that drill?
'Donner und Blitzen!' as they say in all the best comics. (Donner kebab for the non-vegetarians)
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Having cut out the front wheel well (Nearly exhausting my range of Celtic expletives!!) I am continuing with the building of the complex strut assembly, taking this from the published diagrams rather than the surviving aircraft in the US as the undercarriage there was modified to provide more support on public display. The wheel well itself will incorporate some framework that was fitted between the upper and lower wing/fuselage surfaces but that will be all. Two additional struts will form the final attachment of the undercarriage oleo to the bay but this 'dry-fit' will give some idea of what it might look like
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Tubular framing adds some depth and detail to wheel well for nose undercarriage - much will be barely visible after painting. Also added split linking strut to nose wheel door to fix against link on strut. Note: All U/C doors need to be sanded down to about 1 mm thickness as in the kit they are moulded between 3 and 4 mm. Finally, I have left just enough of a ledge to add door links and 'plumbing' before painting.
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Good progress, coming along nicely.
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As previously mentioned, construction of the 1/1 scale HO 229 followed normal Horten practice. The entire centre section was composed of welded tube construction and the wings (single spar) wood construction with ply covering. The undercarriage was a completely retractable three-wheel, tricycle layout with the front wheel taking about 50% of the total weight when resting on level ground. One noticeable difference in trying to replicate the undercarriage is that whilst the much mentioned front wheel assembly simply retracts in to the void of the fuselage, the main u/c seems to have a more defined wheel well. Studying the available photographs and plans released by the Smithsonian, neither the PM nor Revell kits provide a correct assembly here. The PM is over simplified (photo) and the Revell seems more conjectural than practical. The PM kit gives us a shallow impression (photo) whereas the Revell offering (previous photos) proffers a deep trench-like affair for the main strut. I can find no evidence of this?
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Unfortunately with the PM kit (building) the u/c doors are about minus 1 mm all round. (How I wish I had checked all this before starting!) The ‘cut’ lines leave you with a 1 mm strip that requires removing on the main u/c door (Photo) which is okay if you’re placing the machine on it’s very basic legs (photo) so to speak; but leaves us with the problem of scratch building the inner doors which (as they would have to be!!!) having a curious cross-section and profile….
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The complex nose wheel linkage between the main oleo and door is finally fitted...
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I've ordered a book from Germany which includes detailed plans for the main undercarriage so meantime I've attached these by PVA to allow for removal and alteration later. Now I have to return to the cockpit details and decide on a colour scheme...
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Christmas Eve and the first 'hairy-stick' application of Vallejo is encouraging. I've chose a North African 'Desert' scheme which, of course is speculative - but as the scheme on the only surviving aircraft is obscure and different on both wings - it'll have to suffice!
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Undersides...
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More research reveals the Ho-229 (Go-229) IX was of mixed construction, with the centre pod made from welded steel tubing and wing spars built from wood (Photo #1). The wings were made from a series of two thin, carbon-impregnated plywood panels (3 mm and 4 mm) pressure-glued with a resin, charcoal and sawdust mixture (See diagram on Photo #2) Production models would have seen this covering glued by a heating process using resin alone and two special furnaces had been built for this process. (These were recovered by British and US Army engineers, dismantled and flown back to their respective countries. In the UK, De Havilland used these extensively). The production models would most likely incorporate several flex-strips of rubber which had been tried on other experimental aircraft.
The wing had a single main spar, penetrated by two jet engine inlets, and a secondary spar was used for attaching the moving surfaces. It was designed with a 7g load factor and a 1.8× safety rating; therefore, the aircraft had a 12.6g ultimate load rating. The wing's chord/thickness ratio ranged from 15% at the root to 12% then 8% at the wingtips. The aircraft was fitted initially with retractable tricycle landing gear, with the nose gear assembly on the first two prototypes sourced from a He 177's tail-wheel system (wish I’d known this earlier!!!) with the third prototype using an He 177A main gear wheel rim and tire on its custom-designed nose-gear strut work and wheel fork.
A drogue parachute housing would have been fitted on the underside of the tail to slow the aircraft on landing. The pilot sat on what was the German’s ejection seat. A special pressure suit was also developed by Dräger for the prototypes which would not be pressurised. The aircraft was originally designed for the BMW 003 jet engine, but as that engine was not quite ready, the Junkers Jumo 004 engine was substituted.
Lateral and vertical control was achieved with elevons and spoilers. The control system included both long-span (inboard) and short-span (outboard) spoilers, with the smaller outboard spoilers activated first. This system gave a smoother and more graceful control of yaw than would a single-spoiler system.
Weapon loads must be pure speculation at this point. One drawing of the twin-seat version produced at the Gotha factory in 1945 shows provision for two under wing pods (canon/rocket ?) outboard of the centre-section. Whatever the intended role for this aircraft was, its legacy must also include an ongoing fascination by many modellers today.
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Anyway, the colour scheme finally chosen for this offering is based on an experimental scheme tried out on two Me 110's in North Africa c.1942. The sand base colour will be covered with two shades of disruptive 'blotches' following a standard camo-pattern.... (I hope?)
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More progress...
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Hi Pen-Pusher,
Like the 'what if scheme' for this Ho229 something I've not seen tried before. Keep it up chum, looks good so far.
Cheers,
Bigkev
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The aforementioned cockpit seems to have 'splayed' well enough with the hair dryer treatment so with a little touching up of the paintwork round the intakes and a coat of varnish, this will be finished...
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??