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1:32 scale - Port Victoria P.V.7 'Grain Kitten'


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Hi all,
The last few models I've built, including the Macchi M.5 I'm currently working on, have all proved to be a challenge in one way or another.
So while I'm waiting for decals to arrive, I thought I'd start on what will effectively be an 'out of the box' (OOB) build, mainly due to there being no information available on this one-off prototype.

The aircraft is the very small Port Victoria P.V.7 'Grain Kitten', a resin kit from 'Planet Models'.

In an attempt to break the stalemate on the Western Front, the German Imperial Navy commenced air raids on England, first against military then later civilian targets.
The first attack came on the night of 19th January 1915 when the German Zeppelin L3 attacked and bombed Great Yarmouth on the Norfolk coast, resulting in the death of two civilians.
That same night another Zeppelin attacked Kings Lynn and two more people died.
Public outrage provoked the government to introduce measures to counter the Zeppelin air raids, however anti-aircraft guns proved ineffective, as the airships flew too high and were able to shut down their engines and glide, making detection from the ground extremely difficult.
The Admiralty put forward the idea that aircraft, launched from decks on ships or from floating and towed pontoons, could intercept and destroy the airships over the sea, preventing the wreckage falling over land and causing more damage and casualties.
This prompted designs for lightweight fighters that were capable of being ‘sea’ launched.
The Port Victoria P.V.7 ‘Grain Kitten’ was a prototype fighter designed and built by the Port Victoria Marine Experimental Aircraft Depot on the Isle of Grain.
The aircraft was a very small and light weight tractor biplane, intended to fulfil the Admiralty requirements and was designed by W.H. Sayers.
The wings were of the ‘sesquiplane’ configuration, the lower wing being much smaller than the upper wing.
The wings featured the same high-lift section as used in previous Port Victoria aircraft and were fitted with ailerons only on the upper wing.
It was intended to use a 45 hp (34 kW) geared ABC Gnat two-cylinder air-cooled engine and the armament was a single Lewis gun mounted above the upper wing.
The P.V.7 first flew on 22 June 1917, powered by a 35 hp (26 kW) ABC Gnat engine, as the intended engine was not available.
The official trials took place on the 6th of October 1917 but the P.V.7 proved to be tail heavy in the air and difficult to handle on the ground and the sesquiplane layout and high lift wings were c onsidered not to be suitable for such a small aircraft.
In addition, the Gnat engine proved to be extremely unreliable, with test flights being forced to remain within gliding distance of an airfield, in case of engine failure.
The P.V.7 was rebuilt with new wings of conventional aerofoil section, a modified tail and a new undercarriage to eliminate some of the problems found in testing.
However, the low power and unreliability of the Gnat engine prevented the P.V.7 being suitable for its intended use and the P.V.7 was never flown again after it was rebuilt.

In June 1917 the German military stopped using Zeppelins for bombing raids over Britain. 
Although a tremendous psychological weapon, they had actually caused little damage to the war effort.
Of  115 Zeppelins built, 77 had either been shot down or otherwise totally disabled.
Instead, air raids continued but using aircraft, such as the Gotha.

Crew: One
Length: 14 ft 11 in (4.55 m)
Upper wingspan: 18 ft 0 in (5.49 m)
Lower wingspan: 12 ft 7 in (3.84 m)
Height: 5 ft 3 in (1.60 m)
Wing area: 85 sq ft (7.9 m2)
Empty weight: 284 lb (129 kg)
Gross weight: 491 lb (223 kg)
Engine:  ABC ‘Gnat’ air cooled two-cylinder horizontally-opposed piston engine, 35 hp (26 kW)
Performance:
Maximum speed: 85 mph (137 km/h, 74 kn) at 6,500 ft (2,000 m)
Service ceiling: 11,900 ft (3,600 m)
Time to altitude: 22 min to 10,000 ft (3,000 m)
Armament:
A  single .303 inch Lewis machine gun, located above upper wing.

Mike 

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Hi all,
Well, when I said a basic 'out of the box (OOB)' build, what I really meant was -------------------------

The upper wing ailerons are moulded as part of the wing.
The kit has no resin or photo-etch control horns.
So I've removed the two ailerons and sanded the leading edges to a more rounded profile.
I created a slit indent on both sides of the ailerons, then drilled through a 0.3 mm diameter hole.
Into the holes and indent I fitted photo-etch control horns from the 1:48th scale PART set.
Three holes of 0.3 mm diameter were drilled through the wing (x1) and ailerons (x2) for the control wires.

Now onto the tail plane/elevators and the fin/rudder,

Mike

prep3.jpg

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Never heard about that little plane before and have to shake my head, when I see the concept and the HP of the engine. On the other hand strange concepts always attract my wandering mind and it's great to see you, putting your magic on this one. The pic of the real thing looks like a slightly overscaled RC-plane.

Cheers Rob

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Hi all,
Thanks.
In fact there were two aircraft built by Port Victoria for the Admiralty design.
The P.V.7 'Grain Kitten', but also the P.V.8 'Eastchurch Kitten'.
The P.V.8 was partially built at the RNAS Experimental Flight at Eastchurch and was design by the Chief Technical Officer, G.H. Millar.
Later it was moved to the Isle of Grain to be completed.
It was similar to the P.V.7 in size and performance and like the P.V.7 carried a single Lewis machine gun above the upper wing.
The engine was intended to be the 45 hp (34kW) ABC Gnat engine, however like the 'P.V.7 it was first fitted with the less powerful 35 hp (26 kW) ABD Gnat engine.
It first flew in September 1917 but found to be unstable in flight so was modified with a revised tail plane and elevators.
It proved to be superior to the P.V.7 but also suffered similar engine reliability problems.
Like the P.V.7 it was considered to be unsuitable for its intended roll.
However it was packed ready to be shipped to the USA for evaluation in March 1918, although whether it was actually sent is uncertain.  

Mike

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Hi all,
The elevators are supplied as separate parts,but are intended to be just glued directly to the tail plane.
The parts have been moulded very thin so that would be way to weak a joint.
Also, again, the kit has no resin or photo-etch control horns.
So I've modified the elevators in a similar way as I did for the ailerons.
The exception being the holes for the control horns are 0.5 mm diameter and the holes and rods for attaching the elevators to the tail plane are 0.3 mm diameter.

Now onto the fin/rudder,

Mike

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  • Administrators
On 3/23/2020 at 4:37 AM, DocRob said:

Never heard about that little plane before and have to shake my head, when I see the concept and the HP of the engine. On the other hand strange concepts always attract my wandering mind and it's great to see you, putting your magic on this one. The pic of the real thing looks like a slightly overscaled RC-plane.

Cheers Rob

I won't post a pic because it'll sabotage a WIP thread, but remember the USA explored a very similar concept with the cute little Sperry Messenger, a similar sized airplane with a three cylinder radial..  The US Army had an idea they could use a lightweight disposable aircraft as a substitute for a mounted courier or "messenger".  The designer, if I recall the article I read, to demonstarte his new aircraft, actually landed it on the steps of the US Capitol building, and then, after showing it off, took off again..

It was a tad bit more successful, and also sold on the civilian market as a pocket sized personal aircraft.   I think the designer disappeared over the Channel in one while on an air race??

Lukgraph makes a model of the Messenger, BTW.

 

 

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Hi all,
The lower wings are intended to just 'butt' joint against the fuselage sides.
Not good, so I've added 0.8 mm diameter rod into the lower wing halves.
The longer rod passes through the fuselage and into the lower wing on the opposite side.

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Also the cockpit has been completed as far as possible as there is no information available.
The seat has been replaced with a 'Barracuda' wicker seat and cushion.
'HGW Models' seat belts fitted and instrument decal from 'Airscale' used.
Rudder control lines from 0.2 mm Nickel-Silver tube and 0.4 mm Aluminium tube.
Switch wire added from 'PlusModel' 0.2 mm diameter wire.

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I'll be moving back onto the Macchi M.5 build now, so this build will be on hold for now,

Mike

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Hi all,
If you think the cockpit is small and somewhat cramped, here's a shot of the replica Port Victoria P.V.8 'Eastchurch Kitten'.
This is being ground run at the Yorkshire Air Museum at Elvington, near York in the UK.
This is similar in size and concept to the P.V.7 'Grain Kitten'.

pv8replica.jpg

Mike

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  • 1 month later...

Hi all,
Now the Macchi M.5 model is finished I'm going back to continue working on the Port Victoria PV.7 'Grain Kitten'.
It'll be a totally different mindset as the Macchi was one of the largest models I've built to date and the 'Kitten' will probably be the smallest model I'll ever build in this scale.
It's another resin model and will doubtless have the usual challenges of a 'limited run' kit.
The main areas that take the time are usually the cockpit and engine.
However, as I've already finished the cockpit and there is no visible engine to speak of, the build shouldn't take that long to complete - we'll see,

Mike   

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Hi all,
The four wing support struts supplied in the kit do not have internal support rods, as the upper wing, although solid resin, is small and therefore light weight.
Normally I would use the kit supplied struts. However one of the struts was missing the locating pin at one end.
Possibly it could have been drilled and pinned, but I decided to replace all four struts with micro-tube and internal support rods.
As before, I used the 'Strutter' tool to create aerofoil sections from 1.2 mm diameter micro-tube with internal 0.5 mm rod supports.
The rods were soft soldered in the aerofoils sections,

Mike

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Hi all,
The four fuselage to upper wing cabane struts have now been created, using the same method as for the four inter plane struts.
Being resin and small, the upper wing tends to flex slightly in the centre section, which is why it is slightly clear of the cabane struts.
When finally fitted it will seat fully onto the struts, 

Mike

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wingstruts12.jpg

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Hi all,
The only weapon intended to be fitted to this aircraft was a Lewis machine gun, fitted over the centre cut-out of the upper wing.
However there are no photographs or details of this weapon fitted to the PV.7 and the kit does not supply any weapons for this model.
The only comparison I could find were photographs of a Lewis machine gun fitted on the Port Victoria PV.8, the  ‘Eastchurch Kitten’. 
The Lewis machine gun fitted to the PV.8 was offset to the right, presumably to allow easier access to the cockpit for the pilot.
As can be seen on the following photographs of the PV.7, there is what appears to be the front mounting for a Lewis machine gun, located on the forward centre line of the wing.
Therefore I decided to fit an aftermarket gun.  In this instance it was the Lewis Mk.II (13-32056) from ‘Gaspatch’.

I drilled through the pivot mounting point of the Lewis, then modified a swivel mount from my spares box.
That was also drilled through and a 0.4 mm diameter tube was inserted through both to allow the gun to pivot on the mounting.
The front support for the gun is 0.5 mm diameter tube, secured into the upper wing then flattened with pliers.

Mike

Port Victoria PV.8 'Eastchurch Kitten' (Ser No.540).

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Port Victoria PV.7 'Grain Kitten' (Ser No.539).

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Hi all,
The undercarriage strut assembly has been fitted.
I had to shorten the span of the axle fairing as it was too long, causing the two undercarriage struts to spread too far apart at the bottom.
This meany cutting off the pre-moulded stub axles, so those were added afterwards using 0.5 mm diameter rod.
Another problem is that the material used to mould the undercarriage parts seems to be neither styrene or normal resin.
Whatever it is the finish is moulded smooth and hard and the parts will not join using CA adhesive.
In the end I resorted to using two part epoxy adhesive, which did the trick,
Locating holes needed to be drilled into the underside of the fuselage as they're were none,

Mike


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  • 2 weeks later...

Hi all,
Thought it was about time for an update.
The model has now been primed and painted, using 'AK Interactive' white primer and filler, 'Hataka' lacquers and 'Tamiya' acrylic paints.
Once painted it was sealed with 'Alclad' Light Sheen lacquer, then given a coat of 'Flory Models' Dark Dirt fine clay wash.
This was removed as desired to leave a weathered effect then re-sealed with the 'Alclad' lacquer.

Now it's onto pre-rigging before fitting the upper wing.
Then I'll be final rigging,

Mike

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