The De Havilland DH.101 Mosquito Hawk

[kitnut617]

I think I'd better start a thread on this now.  I've started to get items for this build but for the most part it will be scratch built as there is just no  correct size donor kit to use.  Various suggestions have been made in the Mosquito thread of what to use but none seem to match anywhere close to the shapes I need for the bulkheads.

Anyway, for those who haven't followed the Mosquito thread, the DH.101 was a proposed 'scaled-up' Mosquito with the intent for it to carry at the minimum, 8000 lbs of bombs inside the bomb bay.  Initially I have found references to the DH.101 in the Putman De Havilland book and then the Sharp/Bowyer book on the Mosquito.  The only dimensional information I could find was in the Putman book which stated that the prop diameter was to be a 15 foot diameter contra-prop powered by a Sabre Mk.20SIM (I've not been able to find any other information on this type of Sabre though).  What the Putman book says about it is it had a three speed, two stage supercharger and the only other Sabres which had this configuration were the Mk.VII and Mk.VIII, both of which were 3000+ hp engines, so we can see the DH.101 was to have some serious horsepower.  This was so it could fly at high altitude and at 400+ mph at height carrying 8000 lbs of bombs.

When I first got interested in this aircraft there wasn't very much to go on, but that changed about 5 years ago.  That's because a 3-View drawing was discovered by Bill Taylor of De Havilland Support Ltd quite by chance, when he was going through some DH manuals he has.  The company supplies new and spare parts for real De Havilland aircraft that are still flying today but not for Mosquitos though.

[kitnut617]

Bill Taylor passed the drawing on to Tony Buttler who then published a side profile of it in Air-Britain's Spring 2005 Aeromilitaria along with some dimensions, 65 foot span by 47'-6" long.  The various books that reference the DH.101 all insinuate it was just a direct scaled-up DH.98 Mosquito, so this gave me a starting point for figuring out what size I needed to build a 1/72 model of it.  65 feet divided by 72 equals 10.83333" and as the DH.98 is 54'-2" in wingspan it wasn't hard to figure out how much bigger it was to be, 1.2 times bigger in fact which would be the same as a 1/60 scale DH.98.  54'-2" divided by 60 also equals 10.83333" so that's how I arrived at the size to build.

As there's no kit at 1/60 of the Mosquito, I had to find a good drawing of the DH.98, which proved a lot harder than what I thought it would.  I couldn't even get one from the Mosquito Museum.  Anyway, I did find one which when I got it was supposed to be a 1/32 scale copy, but it doesn't work out at that scale, actually 1/30.68 scale.  I just recently found out that not only could I get the drawing copied, I could get it scaled to 1/60 at the same time, I was at last able to get a 'visual' of what the DH.101 would look like compared to a DH.98.  But then things didn't work out very well after that, the wing span was ok but the length was out,  a DH.98 is 41'-2" in length and that divided by 60 equals 8.2333", then multiplied by 72, equals 49'-4 13/16".  The length that the article said it was is about two feet too short and the side profile looks like it might be longer.  This below is the published side view of the DH.101

[kitnut617]

The next problem I found was when I scaled and printed the side view using the dimension of 15 feet for the prop as stated in the Putman book, it ended up a bit bigger all over than the side profile of the DH.98 in the 1/60th drawing.  I wasn't sure what to do because it looked like the stated wing span of 65 feet might be wrong but then I started running my 1/72 scale ruler over the 1/60th drawing I found that the prop diameter measured out at about 14 feet.  This just happens to match a Hawker Tempest prop diameter so I then scaled and printed the DH.101 side view so that I got 14 feet across the prop tips with my 1/72 scale.  Then I was amazed to find that this side view fitted almost perfectly the 1/60th DH.98 side view.

[kitnut617]

It was suggested that as I was in contact with Tony Buttler through my Air-Britain membership, I should ask him about the length discrepancy, which I did.  Tony's reply was that when he had the side view copied and reduced in size, the guy who did the printing had marked in the length with a ballpoint pen (Biro actually) and that he wasn't sure what the correct length was.  He said he would send me a few scans he had done of the original drawing which he did.  I was able to determine from those that the length is very close to 49'-6" which is only a couple of inches longer than what the 1/60 scale drawing measures out when I use the 1/72 scale on it.

The elongated side view though is a bit of an optical illusion, mainly because of three things.  First one is a bit obvious, although the airframe has been scaled up 1.2 times, the canopy hasn't, it's virtually the same in size as the DH.98 canopy.  The second one isn't quite as obvious though, for some reason the fin and rudder have been set closer to the tailplanes.  When I look at the Mosquito and Hornet, the very end of the fin/rudder chord lines up with the elevator hinge line on the tailplane, on the DH.101 it's about half way down the actual elevator part.  Third one is the size of the nacelles, even though they are bigger than the DH.98 nacelles, they're not as big as the DH.98 nacelles which have been scaled to 1/60 scale.

[kitnut617]

Tony Buttler sent me enough scans to show the front view and the top view.  Top view reveals the wings are just the same as the DH.98 wings in profile, tailplane span though it a bit wider.  In the front view I was able to confirm that the prop diameter was 14 feet although it doesn't show how many blades there are to each prop.  The most interesting part of the front view is the undercarriage arrangement, these are not like the DH.98 u/c at all, they're similar to the DH.103 Hornet but bigger.  Single leg towards the center of the fuselage with the wheel offset of the nacelle centerline towards the wing tip.  Wheels measure out at 48" diameter and rumaging through the spares box I found some True Detail Catalina wheels which are about right in size.  The nice thing about this set is the nose wheel of the Catalina just happens to match the tail wheel size of the DH.101 too.  I thought about making the u/c legs (which I still might do) but I've ordered a set of B-25 u/c legs from Scale Aircraft Conversions, mainly because they seem to be about the right size.  For propellers I'm going to go with a Tempest prop from Aeroclub I think, but then make my own rear spinner and use blades from a B-29 or something like that for the opposite turning prop.  The fronts of the nacelles I'm going to go with the Ventura Tempest Mk.I conversion and for the canopy, probably a Squadron/Falcon item.  Cockpit detail I will probably go with a Pavla Mosquito bomber set.

[kitnut617]

I've been trying to think what other British built aircraft had a single u/c leg but I've drawn a blank, there's plenty of US built ones which the RAF used, and I've no idea what the wheels would have looked like but I'm going to go with the Catalina wheels ---- 'cause I like them   

[Jeffry Fontaine]

I've been trying to think what other British built aircraft had a single u/c leg but I've drawn a blank, there's plenty of US built ones which the RAF used, and I've no idea what the wheels would have looked like but I'm going to go with the Catalina wheels ---- 'cause I like them   

That sounds like a good enough reason if I have ever heard one ;^)

Would the canopy/windscreen component from an Airfix Vulcan be appropriate for this project?

[kitnut617]

Would the canopy/windscreen component from an Airfix Vulcan be appropriate for this project?

The drawing shows that the canopy is a regular Mosquito canopy Jeffry,  the Vulcan canopy is a little bit too modern I think.  The pic below is a Vulcan canopy I'm working on for my Canberra STOVL project.

But I've decided I'm going to build two of these, one will be a prototype with green/grey uppers with yellow lower camouflage, but the second one I'm going to go with a developed version, maybe a B.3 or B.4.  I'll have to get my Sharp/Bowyer book back from my bro' because IIRC, it says it was to carry 8000 lbs internally, but also a 1000 lb under each wing.  That's not far off 12000 lbs so I'm thinking of a high altitude Tallboy carrier ------ so with uprated engines I think this would have been possible.  I was reading somewhere on the 'net, that a Sabre Mk.VII was bench-tested to 5500 hp using +45 boost, so a 4000 hp version wouldn't have been a problem.

So maybe a better canopy for pressurization might be called for.

[kitnut617]

Collecting of parts is progressing, as I knew High Planes Models in Oz stocks Jay's Models items (new owner and/or name for Ventura), with the Tempest Mk.I being one of them, and High Planes having helped me in the past with various items they produce (whole kits and parts of kits), I wrote them an email asking for either a contact to Jay's or to act as an intermediate for me.  The upshot was Steve at HPM, forwarded my email to Jay's and John there has already got in touch with me.  I had asked if they had some short-shot fuselages where the forward fuselage was ok and I've been told he has a number of 'old' stock which were formed in brown plastic that he could let me have.  So in the New Year these will be arriving.

I've figured out how I'm going to produce all the bulkheads that I'll need to do the fuselage, the drawing I have shows only half sections but I've found out I can mirror an image once I've inserted it into my AutoCad program.  The program will allow me to copy, rotate, scale the image but I can't actually pick certain items off the drawing, I have to trace the part to do that.  But when I had my drawing scaled down to 1/60th I got three more copies made so I can mess around with a couple of them but now that I can mirror the image, I'll print off a few pages and then cutout the sections and then join the various sections together.  Then I'll copy that onto a clear sticky-back sheet I have which I'll paste onto a sheet of styrene.

[sequoiaranger]

I guess you are trying to replicate a real-world whiff, so MIGHT not be interested in my idea, but....I have always like the LOOK of the B-42 with the twin bubble canopies and glass nose (below). Maybe use TWO Vulcan canopies??

[kitnut617]

Unless the two go in tandem Ron, there's not enough space to go side by side.  I like the XB-42 too, and the XB-43.  I've got one of each in the stash, Anigrand ones.  But I think for the very high altitude DH.101, one Vulcan canopy will be quite radical all by itself.

[The Wooksta!]

Wheels - 48th Tempest would be better and probably more accurate, given that the Hornet appears to have used Tempest wheels.

Did you look at the Jet Mosquito as I suggested?

[kitnut617]

Wheels - 48th Tempest would be better and probably more accurate, given that the Hornet appears to have used Tempest wheels.

I think you're right, so maybe I do the prototype with the larger Tempest wheels and the other one with the Catalina wheels.

Did you look at the Jet Mosquito as I suggested?

The Jet Mosquito is too small for what I want to do, it's barely bigger than a regular DH.98, wingspan 56'-6", length 46'-6".  the difference in the wingspan appears to be between the fuselage and nacelles. But at this moment, I'm not interested in doing a jet Mosquito but I might do one sometime in the future, I've got to see how this DH.101 will turn out first.

[kitnut617]

Instead of Tempest wheels, I've ordered a set of 1/48 Sea Fury ones.  These have the knobbled tread pattern and when they arrive I'll decide if this is where I want to go with it.  The wheels on the drawing measure out to 18" wide by 48" diameter, Tempest, Sea Fury, Firefly, Hornet all appear to be equipped with the same wheel (which was understandable) and they were 32" diameter in RW which works out exactly 48" once you do the calculation (32 divided by 48 times 72 = 48).  I'm not sure on the width yet.

[kitnut617]

I spent a good part of yesterday and today, tracing the DH.98 drawing and developing wing chords.  As I've built balsa gliders before, I'll probably use the same method to build this one.

I can't make my mind up whether to build the wing all-in-one, or build the fuselage and stick the wings on afterwards.  Either way will need a bit of ingenuity I think, considering how I intend to do the fuselage.