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A Fierce Storm is Brewing

(An extract form the CMFC news letter)

For those who are unaware, I have been building a fairly large Hawker Typhoon for more years than I really care to own up to. It's just been one of those projects that has been revisited, off and on, as my motivation takes me. It was seeing a superb model at the Hastings show this year that has spurred me on to complete it.

General Design

One of my earliest R/C models, on getting back into modelling in the early eighties, was a Dennis Bryant Typhoon. At 63" and powered by a Super Tigre G60, she was a great sight in the air and I vowed to build a bigger version one day. I roughly scaled up the Dennis Bryant plan by 40% and ended up with a projected span of 88". The original design had a built up wing and the layout would not cater for retracts. I therefore decided to build a foam wing and use thick glass cloth to give a semi-stressed skin structure. As it turned out, this was not really strong enough after the cutouts for the retracts, flaps and servo boxes had been made. I ended up inserting an 1/8th ply spar to strengthen the centre section.

Wings and associated mechanicals

The retracts used are the biggest Spring Air types, which take Robart sprung oleos directly into the pivot blocks. The wheels are Sullivan 5” lightweights which, whilst not really big enough, are much easier to cater for in the already large ‘wells’. The flaps are cut into the underside of the wing and are made from 1/16th ply re-inforced with a hardwood dowel leading edge spar and small ply riblets. The two sections of flap on each side are linked together and operated by an individual servo per wing. Hinging is provided by the large Robart hinge points. These are used on all hinged surfaces.

The leading edge of each wing was recessed to take cables for the lights. There are both navigation lights and high power landing lights (both Sullivan products). These took quite a time to install but were well worth the effort.
The Nav. lights required the clear covers to be moulded over a balsa plug and were actually quite easy to do.

Fuselage

The fuselage was re-designed to cater for both a single cylinder engine, but with the option of upgrading to the inline twin cylinder Super Tigre G6000 if required. The current intended powerplant is an O.S. BGX-1, which at 35cc, should be enough power for the likely weight of 20lbs.

The actual structure of the fuselage was only upgraded as far as the formers and longerons were concerned. The skin was left at 3/32nd balsa to save weight. The heavier glass cloth adds additional strength anyway! Although the Typhoon had a retracting tailwheel, I felt the additional rear end weight was not worth the massive counterbalance required at the short nose. Every Typhoon I have built (3 so far) has needed alot of nose weight, and I really didn't want to add any to this one!

Cowling and Canopy

The cowling was made for me by Terry (Pink) from a blue foam plug that I carved myself. It's a superb piece of work and really looks the part.

The exhausts were made by Ian (Poisden-Watts) and were cast in resin after a mould had been made from a hardwood plug. He even painted them in an authentic rust colour!

The canopy has been a bit of disaster so far and I might yet scrap it if I can get a better shape one. I've seen a Tempest kit in the USA, which is about the right size, so I'll probably investigate this soon. The canopy sliders were built using a method advised by Mark (Fricker). It's too difficult to explain in words but works well and is not that hard to do.

Painting

Ian (Poisden-Watts) kindly offered to paint the beast for me and we spent a whole weekend at it!! We used Flair paint., the light grey had to be darkened slightly and the green needed some red in it to look authentic. It was surprising how little we actually used and I have enough to do at least one more decent sized fighter in the future.

I'm currently working on the painting of the 'Markings'. The roundels are compass drawn and ‘freehand’ filled. The letters were cut from masking film and painted on using it as a stencil. Everything else was masked with tape (D-Day stripes and fuselage band etc).

The Future

It is intended to equip the model with bomb drop capability and even rockets! The hard points are already in the wings and the conduits for the cables are installed and ready. If she last a few flights then I will work out what to do first. With only 8 channels on my radio, I will need to think about how to operate them!

This is about the state of play so far. Next come the panel lines drawn with water-soluble pencils and shaded with airbrushed ink. Mark Fricker is going to help here and those of you who have seen his models and my Sea Fury will know the effect it creates.

First Flight

The first flight day dawned in May 2002. The weather was ok with light wind and some cloud cover. The word had spread, and the entire club seemed to be there!

I put her together and checked over the systems/controls to check for transit damage. All was ok. I filled the air retract system and fuel tank (160 turns of my hand pump!).

Starting was relatively simple and I performed a ‘nose up’ test to check the mixture. She had been run in my garden so it was pretty close.

Alan carried her to the take off point and I tried to steady my nerves. I have never been so nervous about a first flight!

No excuses now, so I told Alan to let her go. Acceleration was ok and she responded well to rudder. I backed off the full up elevator quickly and ‘balanced’ her level. Just a slight back pressure and she was off!!!

Climb out was smooth and the controls both responsive and progressive. I decided not to put the gear up on the first flight in case of an emergency. A good decision as it happens. After two or three circuits trailing quite a lot of smoke from what appeared to be a ‘screaming’ engine, suddenly the engine went very loud. The silencer had come off! A stroke of good luck meant that she was in an ideal place to come straight in and land. Having not tested the flaps I decided to leave them up. The approach was very smooth with good control and she settled in for a fairly good (if slightly one wing down) landing. Amazingly (based on my 60” version), she did not nose over. I collapsed in a heap with immense relief!!

Post flight inspection showed the header coupling had disconnected and would need a better securing system. I was also convinced that I had the wrong prop on (18 x 8) as the engine screemed a lot without performance to match. Next time would see an 18 x 10 fitted.

Mike took some photos to record the flight and has kindly enlarged them for me.

Further Flights

She has flown again with much better performance (18 x 10 prop). The third flight saw the shedding of the spinner and some damage as I tried to get her into the field after the engine stopped at the wrong end after a low pass.

Further flights have shown up a cooling problem that I’m trying to resolve and a hole dug by a dog/rabbit tripped her up and smashed the canopy. Nothing too major and she will fly again soon.

Rockets/Bombs

Hope to get these fitted for the summer!!