TN Retro Jet 75

[Djay]

tanks installed

[Djay]

the flap come airbrake.

[Major]

Looks very good. Is it that easy model to build, or you just don't sleep or do anything else?? It appeared so quickly.

Tom

[Djay]

Hi Tom, it actually went together really quick untill it came to shaping the wing T/E and L/E's, there was so much wood to remove it took forever, planing and sanding outside, looked like it had been snowing here.

Covering took just over half a day, hardest part was working out the scheme to use up the scraps I had, as there was not enough material to do 1 colour anywhere as the model is so large.

Well after a couple of frustrating nights it is all finished.

Tuesday night I hooked evrything up and plugged in the hand held terminal to program the ECU and radio nd the starter would not engage.

I had the turbine in and out about a dozen times before sorting it out . The starter motor and housing were new and there must have been a small bur or something inside the housing stopping the motor from going forward the last couple of millimeters into the housing. After about 2 hours I gave up and went to bed.

Last night I discovered the burr, got it all sorted and the turbine spun up, so everything was thrown back in, rushed outside , squirted some fuel into the tanks and fired up the motor.it started and ran first time so was well please.

I then installed the elevator pushrods, rudder and nose steering pull pull cables and set them up ok. Ailerons were installed and flap and aileron pushrods made and fitted. Travels were then set up on the t/x. went to fit the two aileron horns and found that out of the pack of 8 heavy duty horns I brough, 1 base was missing and 1 set of mounting bolts were missing, so into the scrap box for replacement horns.

Wing was fitted and a large lump of lead, about 1 1/2 lbs was fitted in the nose for balance..

Battery power is 2 LiPo's, one for the pump/ecu and the other for the r/x via a magnetic switch and regulator.

so now bar a few trim details and tidying up of the servo wiring it is ready for its test flight tomorrow morning, all going well with the turbine.

Will post some pics of the completed model once I get it to the field tomorrow morning.

Heres hoping all goes well.

Darryl

[Djay]

Well it flew.

engine started first time, and I set it up to learn the rpm curve for the ecu and t/x. When I returned it to the pits after the ground run, all the solartex on the bottom of the tail boom was burnt to a crisp and come away from the exhaust heat.

After refuelling the plane was handed over to our chief pilot and the turbine was started again and the plane taxied out to the runway, when the nose wheel locked up solid. The axle had screwed itself in as the wheel rotated and seized up, so a little use of a screwdriver and a drop of fuel for lubrication saw it freed enough to taxi. Full power was applied and after about 3 foot the plane tried to lift off, but it was kept down to allow speed to build up.After rotation it flew with just a little up trim required.

Turns were a bit funny as it required opposite aileron to level off each time after the wings were brought back level, stalls were non existant and it flew very slow without the flaps, and was flown on just under half throttle most of the flight.

after a 5 min flight it was brought in to land with no incidents, though without flaps the approach is fast. we did not use flaps because the wrong switch was flicked and we thought they were down, when in fact they were not. it arrived back in the pits and we noticed the right hand aileron pushrod had broken, which is why it turned funny. So need to send off for some heavy duty pushrods.

Plane weighs about 20 lb, 6 lb of which is the wing alone, and has 1.5 lb lump of lead in the nose. after a 5 min flight and 5 mins on runway idling whilst wheel was repaired it used 1/3 rd of the main 50 oz tank, the 24 oz and UAT were still full.

with my boomerang sprint.

rear of tail boom is now sheeted with litho plate , wheel has been adjust to remove the burrs on the axle and wheel hub and pushrods will be ordered later today. this will give me time to finish of the trim and tidy up the insides, paint the nose cone and I may even remove the second tank, but will decide after the next flights.

Now waiting for TN to release his 1/4 scale Hurricane so I can order one, and then maybe make his Vampire to replace the ageing boomerang I have.

[Major]

Good to hear that maiden was uneventful - congratulations!

[Andy Green]

I've just updated the photos of the build on my website. All in all a simple and enjoyable build.

This is the first TN design I have built but would reccommend them, everything just fits.

Andy

[Lee Smalley]

its just so god damn ugly!! sorry !!

[Djay]

had a couple more flights with the retro jet, and have had a few problems.

I replaced the aileron and flap pushrods with heavy duty carbon rods and flew again.

The model kept wanting to turn hard left and needed a lot of opposite aileron to level off still, tried the flaps and the model rocketed 90 degrees upwards.

managed a flapless landing and does it come in fast. I cut the engine just before touchdown and it rolled at least 150 meters down the runway before slowing enough to turn.

I checked the servos at home and one aileron servo must have a tooth missing as it occasionally would jump to a new neutral position, so replaed both aileron servos with new ones.

Took it out again today and flew it. It does a wheelie on take off and you have to push down elevator to get the nosewheel back down, and then it lifts off by itself.

It still flew funny, a lot of aileron input needed and if slowed down a little bit from full throttle, it just seemed to almost fall out of the sky during a turn, even though it had loads of forward speed , dragging its tail a bit and almost stopping, so it had to be full throttle in the turns.If you made a turn it required full opposite aileron to bring back level, and then it seemed like it would not go but then would, almost like there was a delay in the signal or the plane was going to be unrecoverable.

It still flew to the left, though I managed to sort the flap to elevator mix ok, and brought it in for a full flap landing in about 20 meters of runway.

Done a few mods this afternoon to it.

Added a couple of multi boxes on the ailerons and elevator. I am sure the elevator servos, though the same and Y leaded together are moving at different rates and travel, causing some of the problem, so they were set up through the multibox to match them both up.

The ailerons were set up with differential to help with the turning and a small amount of rudder mixed in.

On the top of the wing, a very small strip of wood was glued in front of the spoilers as I am sure they are lifting up slightly in flight and causing the turn to the left and trouble levelling the plane back, the wood will stop the airflow under the airbrake part of the spoiler which sits on top of the wing.

wiring was tidied up as there was now less off it due to the multi boxes.

Will try again next week hopefully, and try and cure the tail dragging in the turns, even though it is slightly nose heavy.

Lee here is a picture of my ugly plane for you.

Darryl

[Alex McEwan]

Just got mine flying been waiting for decent weather.

now got four flights on her and she is close to been fully setup. Needing some weight off the front !

Turbine New Jets-Munt VT80

Did some changes from plans.

Added wing tube to allow splitting the wings due to space in wing this required me to reduce the dihedral

I heard the original model had problems with tail, so skinned the tail in glass and made the surfaces flush fitting using dubro hinges.

Flaps/airbrake I ditched the thin ply airbrake and used G10 very rigid also hinged on bottom edge to allow air to flow under flap, works very well.

That’s about It, very easy to build and fly just wished it had been designed with longer nose so less weight (Hint Hint Tony)

[Lee Smalley]

nice job with the buil Djay and the colour scheme is pretty good, certainly the nicest one i have seen ... but that still is not saying a lot... sorry mate, i understand the reasoning behind the design, but to be honest mate, any one of the boomerangs models fly like a trainer anyway and look a million times better, so i can not understand why anyone would go for one of these, thats all, i initially was concerned that the boomer i got would be tough to fly, but i was assured they are stupidly easy to fly and land, and to just get one.. so i did and it was the best thing i ever did.

[Djay]

Hi Lee.

I agree with the Boomer , I had an Intro years ago and now have the Sprint for the last few years.

It flies like a vintage model, stable dependable, you know it will not stall, drop out of the sky or have any issues on take offs and landings.

But, you have to look at it from another perspective.

I had the Jet Joe 1800 engine sitting around for years doing nothing,and despite what people say this is over 8 years old and still reliable and going strong.

I love building, to me I prefer this to flying, even though I can fly nearly all year round. So when this plan came up it was natural to build this purely for the fact I could, ., and it was such a quick and easy build. The engine now has a home and I get to build something different, cheap and easy. It also allows me to let people have a go at our club with no issues if it gets damaged.

Now it is built and flow, I am onto the next building projects and this will probably gather dust, along with my other 50+ models, most of which are kit/plan built.

I am particularley fond of building TN's models as they look good, fly well and are so easy to build and I am looking at building his Vampire to replace the Sprint soon.

Darryl

[Dwain Dibley.]

I really like it, it's proper retro and I love that kind of thing. Well done for having a go at summat different Djay.

D.D.

[Wez]

Hi Djay ,

Did you sort the flight problems out with the retro jet ?

just covering mine ,not my favourite job.

Wez

[Djay]

Hi Wez.

yes, I flew it again this morning and apart from requiring full up elevator trim and still requiring more it flew well. Had to do the flight holding up elevator in, which was not to much of a problem.

It was responsive to the ailerons niceley and turned well without dropping the tail.

I moved the C of G forward and also mixed in a small amount of down trim with the throttle and it flies nice and level at all settings instead of climbing at full throttle.

At half and full flaps there is no pitch change or rolling, full flap is 90 degrees.

Unfortunatly I broke the nose gear on landing, since new the axle and tyre keep binding and on touchdown the wheel seized causing the leg to snatch backwards, bending the upper portion and breaking off the plastic leg retaining cuff bolted to the front frame, then the cast yoke snapped .

But all in all I have declared the plane flyable, so new nose gear ordered from TN.

Post a pic of yours when done.

Darryl