Aircraft Notes


 

The FMS (Freewing) T28

 

This is a reasonably big chunk of foam aircraft which has been well planned and executed. The assembly is a pleasure and it flies like a dream. As a regular choice to fly, it has replaced my PZ T28 (which is now permanently on floats). Both are great flyers, and even the micro T28, although is a bit more lively. Fly it outdoors in calm conditions to get the feel of it before attempting indoor flying. Back to the FMS T28....the parts fit is very snug, so do not think that you can apply glue and assemble the parts, and move them to get a good alignment....the glue grabs, so get it right the first time. It has no vices and your maiden flight will be incident-free.
Things to note:

The wings contain lights, retracts, flaps, and ailerons, so there are too many servo cables to allow the wings to be removed conveniently. I leave mine assembled for day to day flying. Speaking of the wings, I recently had an accident that broke a wing and badly bent the outer panel so I looked like it had polyhedral. Gorilla glue was sufficient to butt join the break, and hot water treatment solved the bent problem. I was impressed with the process, and satified with the resulting corrected appearance! Just search for "hot water treatment + foam models" for more info. Adds life to models!!!

 

My main concerns have been related to the nosewheel/retract method. No matter how well you land, the nosewheel starts to appear to bend back. The prop clearance is OK under normal conditions, but becomes vulnerable as the nosewheel gets bent further back. Slight imperfections while landing start costing you prop blades. (They are individually fitted into the hub) Then, one day when trying to lower the wheels to land, you find that the nose wheel will not deploy.

What has happened is that the nose leg has now bent too far back, and the retract mechaism has enough grunt to retract but jams the wheel hard against the top of the wheel well. You now find out that it does NOT have enough grunt to overcome the force holding it! You can only belly land and hope for minimal damage. Remove the battery asap and undo the screws that hold the nose gear in the plane. My gear doors broke off in the landing and that's when I found out how hard it is to spares for FMS aircraft. The nose gear can be completely dis-assembled to bend it straight, and I cut the plastic dummy suspension link off, as that was the first part to hit the wheel top surface.

While I was working on the nose gear I smelt burning so pulled the battery. The electronics was fried & it still stinks! The wheels were deployed and I was not doing anything stressful to them, so I do not the reason it burnt. It had that way for 10 mins while I was working an something else. Beats me. So I put a bolt though the rotating bit and fixed the nosewheel till a replacement arrives. Order a spare (as well as a spare prop) when you buy one of these, you will need it. And check the operation after every landing to catch any jamming early.

Speaking of wheels, I noticed that one of the main wheels was twisting laterally, and got progressively worse. Eventually, I really needed to fix it, so bit the bullet and removed the wheel assembly from the wing. The wheel leg was turning, and I could not find a clamping screw to tighten. Until I poked around inside the axle in the retract....there are allen screws inside the hollow axle that hold the leg firm!

 

The last weak point that I found was the rudder. All the hinges are just the same foam pinched in. But the rudder has the habit of often touching the ground before the main wheels. And my mate Gil said that it can touch on take-off too. So I must watch that tendency as I had to re-hinge the rudder conventionally recently. With only the first stage of flap, the T28 lifts off after a few metres without any elev input, which saves the rudder!

 

As I now only have one complete prop until the spares arrive, I have tried an alternative prop arrangement for day to day flying. I have cut 25mm off each blade of a 14x10 electric prop, and it flies about the same as the 3 blade prop. The battery stays cool, so it is not stressing the speedie. And there is more ground clearance. The inside of the hub needs reaming to allow it to fit the hex drive though.

 

Nevertheless, if you buy one you won't regret it. Just order those spares!

 

Escale P47 Last Flight

This model is at its best in low winds, up to 7Km/hr, and is er, was, a delight to fly in spite of its light weight. It had to be actually flown through the takeoff and landing. And it had the advantage of keeping my mind active so I was aware of what was needed at those times. I will miss it.

It had made about 30 flights, maybe more, over the couple of years that I had it It used a servo for the retracts, and gave very little trouble. I was always able to retract without any jamming. It looked great with the servo-slower installed.

Anyway, it is too much to expect to repair a foamy that has come in contact with the ground vertically. Although I cut the throttle, the loss of one wing caused too much loss of control!

The other wing is about 30m away

It was pretty disconcerting to start to pull out of a mild loop, and see a wing break away!!! Here I have placed the wing halves against the belly pan as a background so you can see the mainspar. You wouldn't think that it was a mainspar tho!!! Flat carbon about 1mm x 4mm!!!! And those spars seem to overlap when I join the wing, I suspect that they were simply joined by overlapping and glueing the carbon pieces together! I am not impressed with knowing that I was flying with such a weak join. I hasten to assure you that this plane had led a gentle life, flown without abnormal stresses, especially as it was too light to do much with except fly in a scale manner. And it had never been crashed.

So, the warning to Escale model owners is to watch for any warning that a wing failure is imminent (cracks may form in the foam), and preferably add your own centre reinforcing of ply, carbon tube or whatever and do not rely on the factory build. This aircraft could be downright dangerous, especially if flying in a public area with spectators.

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