Avro 707A

The Avro type 707A was an experimental tailless delta-winged aircraft, developed and test flown to better understand the aerodynamics of what eventually led to the Avro Vulcan bomber. One could think of the 707 as a "Baby Vulcan", as it obviously shares the same overall look despite being much smaller. Several prototypes were built, the 707A representing the third design generation of the type (oddly enough, the designations were, in order, 707, 707B, 707A, and 707C). A total of five prototypes were built.

Construction Notes

This project should be considered an experiment, since I had not built a vacform kit for a very long time. I used the Maintrack "Projext-X" kit of the Avro 707C which dates back to the 1980s. This kit represents the two-seater, final version of the type. It differs externally from its immediate predecessor (the 707A) only by the shape of the canopy. Note that there are now other (I assume better) kits of the 707 available, in several scales [7, 9], but like I said, this was an experiment...

Main components; note the fuselage bulkheads and the weight added to the nose.

Fuselage halves closed. The spine and the vertical fin are a separate part.

Styrene tube was used to make sure the wings were positioned correctly (wrt. one another). For assembly, the tube was cut and a rod was inserted inside.

Airframe complete.

The kit is relatively simple to construct as far as the vacform technique goes. Care had to be taken not to "over-sand" some parts that needed more attention than others (for example, to sharpen the edges of the wheel wells I managed to make the wing plastic too thin and had to reinforce it with some Evergreen stock and Tamiya putty). The kit comes with resin parts for the wing root jet intakes, the correct placement of which was difficult. I also added intake fences (separators?) on the inside at the wing root, from 10 thou styrene sheet cut to shape with a Cricut cutter. Fair amount of putty had to be used to close the seams between the fuselage and the wings. Furthermore, some of the grooves on the wings to represent the flaps and ailerons were rather fictitious, so I had to fill those and scribe new ones afterwards.

The wing/fuselage seam needed a lot of putty.

Canopy masked and sprayed with the cockpit interior color.

The kit comes with some white metal parts, most of which are rather useless mainly because the metal was very soft (this was the case with the nose probe which I replaced with one made of steel wire, aluminum tubing, and styrene tubing). At the end, I only used the main landing gear legs (which were some of the best-cast white metal I have seen), the "fork" of the nose gear, and the nosewheel. The main wheels came from Hasegawa's Hurricane, with new wheel hubs cut from 10 thou styrene. I also cut all the gear doors from the 10 thou sheet. To furnish the cockpit, I used the instrument panel from the Revell Mistral left over from my Vampire project (I had no interior pictures of the 707, but honestly you cannot really see it) and a Pavla resin Martin Baker Mk.1 ejection seat. For the engine tailpipe I used a leftover part from the Mistral (this falls in the "close enough" -category).

Canopy

To back-date the kit, I needed to replace the canopy with one I made myself using the "crash molding" technique. The Squadron clear sheets I bought nearly 30 years ago had yellowed a bit, but I used them anyway since the actual transparent openings are very small and the cockpit inside is very dark. I used a Cricut cutter to cut masks from regular Tamiya masking tape; the artwork for the masks is here if anyone needs it.

Canopy master fashioned from the KP 1/72nd scale MiG-19 canopy.

First attempt at crash molding.

Successful result, cut out from the sheet

Canopy installed and masked. Tell me this aircraft does not look like a Vulcan!

Painting and Markings

I painted the model overall first with Alclad white micro-filler primer, several coats, with some sanding in between. I then used Mr.Color #58 "orange yellow". I was really struggling to get a decent, smooth orange surface (much more so than with my all-yellow Northrop N-9M). The orange paint does not cover at all, so several coats (5+) were needed.

The kit comes with strange "dry" decals which, in my case, had somehow deteriorated and were unusable. And I was making a different aircraft anyway, so the tail numbers could not be used regardless. I prepared artwork for both the national markings as well as the tail numbers. They are available here; note that the PDF document has several layers:

• "decals": actual artwork to be printed on a decal sheet
• "masks": artwork you can cut from masking tape to paint white areas on top of which the decals are placed
• "background": light blue background, not to be printed

I printed the decals with a color laser printer (HP M255dw) on new decal paper I just discovered: SunnyScopa makes paper that does not need to be coated after printing. The decals went on well, although some very minor silvering did occur (I don't think this was the fault of the paper, though). You can buy the paper on Amazon.

A test shot of the new decals.

Primer coat(s) applied.

Orange coats applied, and masks removed.

I finished the model with first a few coats of Alclad clear gloss followed by a mixture of Testors Dullcote and Glosscote.

References Used

There is a reasonable amount of reference material one can find about the different variants of the Avro 707, but going through these I realized that it tends to be just the same pictures, over and over. Nevertheless, I felt I had enough to build the model. These are the principal sources I used:

1. Aeroplane Monthly May 1974
2. Aeroplane Monthly March 1988
3. Aeroplane Monthly October 1992
4. Aeroplane Monthly February 1994
5. Aeroplane Monthly April 2007
6. Air Enthusiast Nineteen (August-November 1982)
7. Airfix Model World May 2020
8. British Experimental Turbojet Aircraft (Jones); Crowood Aviation Series; Crowood Press 2006
9. Scale Aircraft Modelling June 2007
10. Vulcan - RAF's Atomic Avenger; Aeroplane Icons 13; 2013
11. Wings of Fame volume 3
12. X-Planes of Europe - Secret Research Aircraft from the Golden Age 1946-1974 (Buttler & Delezenne); Hikoki Publications 2012

The Avro 707 is quite often covered in reference sources about the Avro Vulcan [5, 6, 10, 11]. Also, references [7, 9] above are only included because they have articles about other Avro 707 kits.

The model won the 3rd prize in the well-attended category "Aircraft: Scratch-built, vacu-forms and conversions" at DowneastCon 2023 (IPMS Southern Maine Scale Modelers; Sanford, ME) on 2023-04-16.

Picture of the model was the group header picture for the Facbook group "Vacuform/Resin Kit Builders" during the first week of April 2023.